MultimediaWiki - User contributions [en]

Dialogic IMA ADPCM

2025-10-22T23:11:00Z

Lord Nightmare: further clarification

* Microsoft Audio ID: 0x0010
* Extension: vox, oki
* Company: [[Dialogic]], Oki Electric Industry
* Official Specification: http://multimedia.cx/mirror/dialogic-adpcm.pdf

Dialogic ADPCM is a variation of the standard [[IMA ADPCM]] algorithm that is optimized for monaural voice data. The encoder operates on 12-bit input samples and outputs 4-bit encoding for each sample. This yields a 3:1 compression ratio.

Dialogic ADPCM data is transported in raw files bearing the extension VOX. For each byte in the file, the high nibble (bits 7-4) is decoded first, then the low nibble.

The decoding algorithm is the same as the standard IMA ADPCM algorithm with the following modifications:

* A different, smaller step table is used (refer to Appendix A for the table). The table contains 49 values ranging from indices 0..48.
* The predictor is always initialized to 0 at the start of decoding.
* The step table index is always initialized to index 0 at the start of decoding.
* When the index is modified by the ADPCM delta, it should be clamped within the 0..48 range, rather than 0..88.
* When the diff is applied to the predictor, it should be clamped within a signed 12-bit range (-2048..2047) rather than a signed 16-bit range.
* The output samples are 12 bits in resolution and should be scaled as necessary.

== Modified Step Table ==

int dialogic_ima_step[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449,
494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

== Hardware Implementations ==
The following ICs can decode this codec:
* OKI MSM5205 [dec] (Note that this particular chip, unlike any of the other OKI ADPCM decoder/codec chips, does not saturate the accumulator at its limits)
* OKI MSM5218 [codec]
* OKI MSM6295 [dec]
* OKI MSM6585

[[https://console5.com/techwiki/images/f/f8/MSM5205.pdf MSM5205/MSM5218 Datasheet]]

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

Dialogic IMA ADPCM

2025-10-22T23:10:02Z

Lord Nightmare: fix an incorrect piece of information about the initial index value

* Microsoft Audio ID: 0x0010
* Extension: vox, oki
* Company: [[Dialogic]], Oki Electric Industry
* Official Specification: http://multimedia.cx/mirror/dialogic-adpcm.pdf

Dialogic ADPCM is a variation of the standard [[IMA ADPCM]] algorithm that is optimized for monaural voice data. The encoder operates on 12-bit input samples and outputs 4-bit encoding for each sample. This yields a 3:1 compression ratio.

Dialogic ADPCM data is transported in raw files bearing the extension VOX. For each byte in the file, the high nibble (bits 7-4) is decoded first, then the low nibble.

The decoding algorithm is the same as the standard IMA ADPCM algorithm with the following modifications:

* A different, smaller step table is used (refer to Appendix A for the table). The table contains 49 values ranging from indices 0..48.
* The predictor is always initialized to 0 at the start of decoding.
* The index is always initialized to index 0 (value of 16) at the start of decoding.
* When the index is modified by the ADPCM delta, it should be clamped within the 0..48 range, rather than 0..88.
* When the diff is applied to the predictor, it should be clamped within a signed 12-bit range (-2048..2047) rather than a signed 16-bit range.
* The output samples are 12 bits in resolution and should be scaled as necessary.

== Modified Step Table ==

int dialogic_ima_step[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449,
494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

== Hardware Implementations ==
The following ICs can decode this codec:
* OKI MSM5205 [dec] (Note that this particular chip, unlike any of the other OKI ADPCM decoder/codec chips, does not saturate the accumulator at its limits)
* OKI MSM5218 [codec]
* OKI MSM6295 [dec]
* OKI MSM6585

[[https://console5.com/techwiki/images/f/f8/MSM5205.pdf MSM5205/MSM5218 Datasheet]]

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

TwoCC

2020-01-03T00:52:39Z

Lord Nightmare: add more wikilinks for yamaha adpcm and oki/dialogic adpcm

The TwoCC is the audio counterpart to the [[:Category:Video FourCCs|video FourCC]]. It is the audio format identifier used in the [[RIFF]] based multimedia formats by [[Microsoft]] ([[WAV]] and [[AVI]]). The TwoCC is 2 bytes long and stored in little endian format on disk. You can register your TwoCC with Microsoft but it seems that only some companies perform this process.

If you need help finding any codec mail me compn@ffmpeg.org

* 0x0000 Microsoft Unknown Wave Format
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0001 Microsoft PCM Format]]
* [[Microsoft_ADPCM|0x0002 Microsoft ADPCM CODEC for MSACM msacm.msadpcm msadp32.acm]]
* 0x0003 IEEE FLOAT Microsoft IEEE754
* 0x0004 Compaq Computer VSELP (codec for Windows CE 2.0 devices)
* 0x0005 IBM CVSD IBM Corporation
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0006 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0007 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* 0x0008 Microsoft DTS
* 0x0009 Microsoft DRM
* 0x000A WMSpeech Microsoft
* 0x000B Windows Media RT Voice Microsoft
* [[Dialogic_IMA_ADPCM|0x0010 OKI ADPCM]]
* [[Microsoft_IMA_ADPCM|0x0011 IMA ADPCM CODEC for MSACM msacm.imaadpcm imaadp32.acm]]
* 0x0012 Videologic MediaSpace ADPCM
* 0x0013 Sierra ADPCM Sierra Semiconductor Corp
* 0x0014 G723 ADPCM Antex Electronics Corporation
* 0x0015 DIGISTD DSP Solutions, Inc.
* 0x0016 DIGIFIX DSP Solutions, Inc.
* [[Dialogic_IMA_ADPCM|0x0017 Dialogic OKI ADPCM]]
* 0x0018 MediaVision ADPCM
* 0x0019 CU CODEC Mobile Voice Hewlett-Packard Company
* 0x001A Hewlett-Packard HP DYNAMIC VOICE
* [[Yamaha_ADPCM|0x0020 Yamaha ADPCM]]
* 0x0021 Sonarc Speech Compression
* 0x0022 DSP Group TrueSpeech(TM) Audio Codec for MSACM V3.50 msacm.trspch tssoft32.acm
* 0x0023 ECHOSC1 Echo Speech Corporation
* 0x0024 Audiofile AF36 Virtual Music, Inc.
* 0x0025 APTX Audio Processing Technology
* 0x0026 Audiofile AF10 Virtual Music, Inc.
* 0x0027 Prosody 1612 codec for CTI Speech Card Aculab plc
* 0x0028 LRC Merging Technologies S.A.
* 0x0030 Dolby Labs AC2
* 0x0031 Microsoft GSM 6.10 Audio CODEC for MSACM msacm.msgsm610 msgsm32.acm
* 0x0032 MSNAudio Microsoft
* 0x0033 Antex ADPCME Antex Electronics Corporation
* 0x0034 Control Res. VQLPC Control Resources Limited
* 0x0035 DigiReal DSP Solutions, Inc.
* 0x0036 DigiADPCM DSP Solutions, Inc.
* 0x0037 Control Res. CR10 Control Resources Limited
* 0x0038 NMS VBXADPCM Natural MicroSystems
* 0x0039 CS IMAADPCM Roland RDAC Crystal Semiconductor IMA ADPCM
* 0x003A ECHOSC3 Echo Speech Corporation
* 0x003B Rockwell ADPCM Rockwell International
* 0x003C Rockwell DIGITALK Rockwell International
* 0x003D XEBEC Xebec Multimedia Solutions Limited
* 0x0040 G721 ADPCM Antex Electronics Corporation
* 0x0041 G728 CELP Antex Electronics Corporation
* 0x0042 Microsoft G.723.1 CODEC MSACM msacm.msg723 msg723.acm
* 0x0043 IBM AVC ADPCM
* 0x0044 MSG729 Microsoft
* 0x0045 ITU-T G.726 ADPCM
* 0x0050 MPEG (MP1/MP2) ISO/IEC
* 0x0050 QDesign MPEG QDesign Corporation qmpeg.acm
* 0x0052 InSoft RT24 (ACM codec is an alternative codec)
* 0x0053 PAC InSoft, Inc.
* 0x0055 MPEG Layer-3 Audio Codec for MSACM msacm.l3ACM l3codeca.acm
* 0x0057 AMR-NB
* 0x0058 AMR-WB
* 0x0059 Lucent G.723
* 0x0060 Cirrus Cirrus Logic
* 0x0061 ESS Technology ESPCM / Duck DK4 ADPCM
* 0x0062 msacm.voxacm160 vct3216.acm Voxware v1.1.6/1.1.8 File-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0062 Voxware file-mode codec / Duck DK3 ADPCM
* 0x0063 Canopus ATRAC Canopus, co., Ltd.
* 0x0064 G726 ADPCM APICOM
* 0x0065 G722 ADPCM APICOM
* 0x0066 DSAT Microsoft
* 0x0067 DSAT DISPLAY Microsoft
* 0x0069 msacm.voxacm160 Voxware v1.1.8 Bitstream-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0070 Voxware AC8 (Lernout & Hauspie CELP 4.8 kbps) lhacm.acm
* 0x0071 Voxware AC10 (Lernout & Hauspie CBS 8kbps) lhacm.acm
* 0x0072 Voxware AC16 (Lernout & Hauspie CBS 12kbps) lhacm.acm
* 0x0073 Voxware AC20 (Lernout & Hauspie CBS 16kbps) lhacm.acm
* 0x0074 Voxware MetaVoice Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0075 Voxware RT29 Metasound Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0076 Voxware RT29HW
* 0x0077 Voxware VR12
* 0x0078 Voxware VR18
* 0x0079 Voxware TQ40
* 0x007A Voxware SC3
* 0x007B Voxware SC3
* 0x0080 Softsound Softsound, Ltd.
* 0x0081 Voxware TQ60
* 0x0082 Microsoft MSRT24 (ACM codec is an alternative codec)
* 0x0083 G729A AT&T Labs, Inc.
* 0x0084 MVI MVI2 Motion Pixels
* 0x0085 DataFusion Systems G.726
* 0x0086 DataFusion Systems GSM610
* 0x0088 ISIAUDIO Iterated Systems, Inc.
* 0x0089 ONLIVE OnLive! Technologies, Inc.
* 0x008A MULTITUDE FT SX20 Multitude, Inc.
* 0x008B G.721 ADPCM Infocom ITS A/S
* 0x008C CONVEDIA G729 Convedia Corporation
* 0x008D Not specified congruency, Inc.
* 0x0091 SBC24 Siemens Business Communications Sys
* 0x0092 Dolby AC3 SPDIF Sonic Foundry
* 0x0093 MediaSonic G.723
* 0x0094 Prosody 8KBPS Aculab plc
* 0x0097 Zyxel ADPCM ZyXEL Communications, Inc.
* 0x0098 Philips LPCBB smlpcbb.acm
* 0x0099 PACKED Studer Professional Audio AG
* 0x00A0 Malden PhonyTalk Malden Electronics Ltd.
* 0x00A1 Racal Recorder GSM Racal Recorders
* 0x00A2 Racal Recorder G720.a Racal Recorders
* 0x00A3 Racal G723.1 Racal Recorders
* 0x00A4 Racal Tetra ACELP Racal Recorders
* 0x00B0 NEC AAC NEC Corporation
* 0x00E1 Microsoft ADPCM
* 0x00f4 WRPR codec
* 0x00FF AAC
* 0x0100 Rhetorex ADPCM
* 0x0101 IBM mu-law / BeCubed Software IRAT
* 0x0102 ALAW IBM a-law format
* 0x0103 ADPCM IBM AVC Adaptive Differential Pulse Code Modulation
* 0x0111 Vivo G.723
* 0x0112 Vivo Siren
* 0x0120 PHILIPS CELP Philips Speech Processing
* 0x0121 PHILIPS GRUNDIG Philips Speech Processing
* 0x0123 DEC G723 Digital Equipment Corporation Digital G.723
* 0x0125 Sanyo LD ADPCM
* 0x0130 Sipro Lab Telecom ACELP.net audio codec Sipro Lab TelecomInc. sl_anet.acm
* 0x0131 Sipro Lab Telecom ACELP.4800
* 0x0132 Sipro Lab Telecom ACELP.8V3
* 0x0133 Sipro Lab Telecom ACELP.G.729
* 0x0134 Sipro Lab Telecom ACELP.G.729A
* 0x0135 Sipro Lab Telecom ACELP.KELVIN
* 0x0136 VOICEAGE AMR VoiceAge Corporation
* 0x0140 G726ADPCM Dictaphone Corporation
* 0x0141 CELP68 Dictaphone Corporation
* 0x0142 CELP54 Dictaphone Corporation
* 0x0150 Qualcomm PureVoice
* 0x0151 Qualcomm HalfRate
* 0x0155 TUBGSM Ring Zero Systems, Inc.
* 0x0160 Windows Media Audio msacm.msaudio1 msaud32.acm
* 0x0161 Windows Media Audio V2 V7 V8 V9 / DivX audio (WMA) / Alex AC3 Audio msaud32.acm
* 0x0162 Windows Media Audio 9 Professional Microsoft, Inc.
* 0x0163 Windows Media Audio 9 Lossless Microsoft, Inc.
* 0x0164 WMA Pro over S/PDIF
* 0x0170 UNISYS NAP ADPCM Unisys Corporation
* 0x0171 UNISYS NAP ULAW Unisys Corporation
* 0x0172 UNISYS NAP ALAW Unisys Corporation
* 0x0173 UNISYS NAP 16K Unisys Corporation
* 0x0174 MM SYCOM ACM SYC008 SyCom Technologies
* 0x0175 MM SYCOM ACM SYC701 G726L SyCom Technologies
* 0x0176 MM SYCOM ACM SYC701 CELP54 SyCom Technologies
* 0x0177 MM SYCOM ACM SYC701 CELP68 SyCom Technologies
* 0x0178 Knowledge Adventure ADPCM
* 0x0180 MPEG2AAC Fraunhofer IIS
* 0x0190 DTS DS Digital Theater Systems, Inc.
* 0x0200 Creative Labs ADPCM
* 0x0202 Creative Labs FastSpeech8
* 0x0203 Creative Labs FastSpeech10
* 0x0210 UHER ADPCM UHER informatic GmbH
* 0x0215 Ulead DV AudioACM Driver msacm.dvACM dvacm.acm
* 0x0216 Ulead DV Audio Codec Ulead Systems, Inc. Dvacm.acm
* 0x0217 Ulead MP3 codec engine msacm.ulmp3acm Warning: Codec is disabled
* 0x0220 Quarterdeck Quarterdeck Corporation
* 0x0230 I-Link VC I-link Worldwide
* 0x0240 RAW SPORT Aureal Semiconductor
* 0x0241 ESST AC3 ESS Technology
* 0x0250 IPI HSX Interactive Products, Inc.
* 0x0251 IPI RPELP Interactive Products, Inc.
* 0x0260 CS2 Consistent Software
* 0x0270 Sony ATRAC3 (SCX, same as MiniDisk LP2)
* 0x0271 Sony SCY
* 0x0272 Sony ATRAC3
* 0x0273 Sony SPC
* 0x0280 TELUM Telum Inc.
* 0x0281 TELUMIA Telum Inc.
* 0x0285 Norcom Voice Systems ADPCM Norcom Electronics Corporation
* 0x028e MSN Messenger Audio Codec msacm.siren sirenacm.dll
* 0x0300 Fujitsu FM TOWNS SND
* 0x0301 Not specified Fujitsu Corporation
* 0x0302 Not specified Fujitsu Corporation
* 0x0303 Not specified Fujitsu Corporation
* 0x0304 Not specified Fujitsu Corporation
* 0x0305 Not specified Fujitsu Corporation
* 0x0306 Not specified Fujitsu Corporation
* 0x0307 Not specified Fujitsu Corporation
* 0x0308 Not specified Fujitsu Corporation
* 0x0350 DEVELOPMENT Micronas Semiconductors, Inc.
* 0x0351 CELP833 Micronas Semiconductors, Inc.
* 0x03eb DVMPEG Audio Darim Vision Co., Ltd. dvacmau.dll
* 0x0400 BTV Digital (Brooktree digital audio format)
* 0x0401 Intel Music Coder for MSACM msacm.imc imc32.acm
* 0x0402 Indeo® audio software msacm.iac2 iac25_32.ax
* 0x0450 QDesign Music
* 0x0500 On2 VP7 On2 Technologies AVC Audio
* 0x0501 On2 VP6 On2 Technologies
* 0x0680 AT&T Labs VME VMPCM
* 0x0681 AT&T Labs TPC
* 0x0700 YMPEG Alpha (dummy for MPEG-2 compressor)
* 0x08AE ClearJump Lightwave Lossless http://www.clearjump.com
* 0x0AAC HDX4 AAC Jomigo GmbH
* 0x1000 Olivetti GSM
* 0x1001 Olivetti ADPCM
* 0x1002 Olivetti CELP
* 0x1003 Olivetti SBC
* 0x1004 Olivetti OPR
* 0x1100 Lernout & Hauspie codec
* 0x1101 Lernout & Hauspie CELP codec
* 0x1102 Lernout & Hauspie SBC codec
* 0x1103 Lernout & Hauspie SBC codec
* 0x1104 Lernout & Hauspie SBC codec
* 0x1400 Norris Communication
* 0x1401 AT&T Labs ISIAudio
* 0x1500 Soundspace Musicompress Soundspace Music Compression Netspeak GSM - nsgsm32.acm
* 0x1501 Netspeak Truespeech - nstsp32.acm
* 0x181C VoxWare RT24 speech codec Voxware Inc.
* 0x181E Lucent elemedia AX24000P Music codec
* 0x1971 Sonic Foundry LOSSLESS
* 0x1979 Innings Telecom Inc. ADPCM
* 0x1C07 Lucent SX8300P speech codec
* 0x1C0C Lucent SX5363S G.723 compliant codec
* 0x1F03 CUseeMe DigiTalk (ex-Rocwell)
* 0x1FC4 NCT ALF2CD codec http://www.nctsoft.com
* 0x2000 AC-3ACM Codec msacm.ac3acm ac3acm.acm
* 0x2001 Dolby DTS Dolby Labs
* 0x2002 RealAudio 1 / 2 14.4
* 0x2003 RealAudio 1 / 2 28.8
* 0x2004 RealAudio G2 / 8 Cook (low bitrate)
* 0x2005 RealAudio 3 / 4 / 5 Music (DNET)
* 0x2006 RealAudio 10 AAC (RAAC)
* 0x2007 RealAudio 10 AAC+ (RACP)
* 0x2500 Reserved range to * 0x2600 Microsoft
* 0x3313 makeAVIS (ffvfw fake AVI sound from AviSynth scripts) ff_acm.acm
* 0x4143 Divio MPEG-4 AAC audio
* 0x4180 fortherecord MPEG AAC celp?
* 0x4201 Nokia adaptive multirate Nokia Mobile Phones
* 0x4243 Divio's G726 Divio, Inc.
* 0x434C LEAD Speech
* 0x564C LEAD Vorbis
* 0x5756 WavPack Audio xiph.org [open source]
* 0x6665 Litewave audio compressor (lw.zip from http://www.clearjump.com)
* 0x674f Ogg Vorbis mode 1 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6750 Ogg Vorbis mode 2 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6751 Ogg Vorbis mode 3 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x676f Ogg Vorbis mode 1+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6770 Ogg Vorbis mode 2+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6771 Ogg Vorbis mode 3+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x7000 3COM NBX 3Com Corporation
* 0x706D FAAD AAC (open source)
* 0x77A1 The True Audio
* 0x7A21 GSM-AMR (CBR, no SID) EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x7A22 GSM-AMR (VBR, including SID) GSMA/3GPP EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x8180 (unverified) For the Record - http://www.fortherecord.com
* 0xA100 COMVERSEINFOSYS G723 1 Comverse Infosys Ltd.
* 0xA101 COMVERSEINFOSYS AVQSBC Comverse Infosys Ltd.
* 0xA102 COMVERSEINFOSYS OLDSBC Comverse Infosys Ltd.
* 0xA103 Symbol Technology's G729A Symbol Technologies Canada
* 0xA104 VoiceAge AMR WB VoiceAge Corporation
* 0xA105 Ingenient Technologies Inc. G726
* 0xA106 ISO/MPEG-4 advanced audio Coding AAC.
* 0xA107 Encore Software Ltd's G726 Encore Software Ltd.
* 0xA109 Speex ACM Codec xiph.org (Open Source)
* 0xC0CC GigaLink Audio Codec
* 0xDFAC DebugMode SonicFoundry Vegas FrameServer ACM Codec
* 0xe708 Unknown -
* 0xF1AC Free Lossless Audio Codec FLAC
* 0xFFFC VDOwave Audio
* 0xFFFE Extensible wave format
* 0xFFFF In Development / Unregistered

[[Category: Multimedia Terminology]]

Dialogic IMA ADPCM

2020-01-03T00:50:42Z

Lord Nightmare: note about MSM5205 not saturating its accumulator, add more OKI chips, add link to datasheet

* Microsoft Audio ID: 0x0010
* Extension: vox, oki
* Company: [[Dialogic]], Oki Electric Industry
* Official Specification: http://multimedia.cx/mirror/dialogic-adpcm.pdf

Dialogic ADPCM is a variation of the standard [[IMA ADPCM]] algorithm that is optimized for monaural voice data. The encoder operates on 12-bit input samples and outputs 4-bit encoding for each sample. This yields a 3:1 compression ratio.

Dialogic ADPCM data is transported in raw files bearing the extension VOX. For each byte in the file, the high nibble (bits 7-4) is decoded first, then the low nibble.

The decoding algorithm is the same as the standard IMA ADPCM algorithm with the following modifications:

* A different, smaller step table is used (refer to Appendix A for the table). The table contains 49 values ranging from indices 0..48.
* The predictor is always initialized to 0 at the start of decoding.
* The index is always initialized to 16 at the start of decoding.
* When the index is modified by the ADPCM delta, it should be clamped within the 0..48 range, rather than 0..88.
* When the diff is applied to the predictor, it should be clamped within a signed 12-bit range (-2048..2047) rather than a signed 16-bit range.
* The output samples are 12 bits in resolution and should be scaled as necessary.

== Modified Step Table ==

int dialogic_ima_step[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449,
494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

== Hardware Implementations ==
The following ICs can decode this codec:
* OKI MSM5205 [dec] (Note that this particular chip, unlike any of the other OKI ADPCM decoder/codec chips, does not saturate the accumulator at its limits)
* OKI MSM5218 [codec]
* OKI MSM6295 [dec]
* OKI MSM6585

[[https://console5.com/techwiki/images/f/f8/MSM5205.pdf MSM5205/MSM5218 Datasheet]]

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

TwoCC

2020-01-03T00:40:58Z

Lord Nightmare: add wikilink for MSADPCM

The TwoCC is the audio counterpart to the [[:Category:Video FourCCs|video FourCC]]. It is the audio format identifier used in the [[RIFF]] based multimedia formats by [[Microsoft]] ([[WAV]] and [[AVI]]). The TwoCC is 2 bytes long and stored in little endian format on disk. You can register your TwoCC with Microsoft but it seems that only some companies perform this process.

If you need help finding any codec mail me compn@ffmpeg.org

* 0x0000 Microsoft Unknown Wave Format
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0001 Microsoft PCM Format]]
* [[Microsoft_ADPCM|0x0002 Microsoft ADPCM CODEC for MSACM msacm.msadpcm msadp32.acm]]
* 0x0003 IEEE FLOAT Microsoft IEEE754
* 0x0004 Compaq Computer VSELP (codec for Windows CE 2.0 devices)
* 0x0005 IBM CVSD IBM Corporation
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0006 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0007 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* 0x0008 Microsoft DTS
* 0x0009 Microsoft DRM
* 0x000A WMSpeech Microsoft
* 0x000B Windows Media RT Voice Microsoft
* 0x0010 OKI ADPCM
* [[Microsoft_IMA_ADPCM|0x0011 IMA ADPCM CODEC for MSACM msacm.imaadpcm imaadp32.acm]]
* 0x0012 Videologic MediaSpace ADPCM
* 0x0013 Sierra ADPCM Sierra Semiconductor Corp
* 0x0014 G723 ADPCM Antex Electronics Corporation
* 0x0015 DIGISTD DSP Solutions, Inc.
* 0x0016 DIGIFIX DSP Solutions, Inc.
* 0x0017 Dialogic OKI ADPCM
* 0x0018 MediaVision ADPCM
* 0x0019 CU CODEC Mobile Voice Hewlett-Packard Company
* 0x001A Hewlett-Packard HP DYNAMIC VOICE
* 0x0020 Yamaha ADPCM
* 0x0021 Sonarc Speech Compression
* 0x0022 DSP Group TrueSpeech(TM) Audio Codec for MSACM V3.50 msacm.trspch tssoft32.acm
* 0x0023 ECHOSC1 Echo Speech Corporation
* 0x0024 Audiofile AF36 Virtual Music, Inc.
* 0x0025 APTX Audio Processing Technology
* 0x0026 Audiofile AF10 Virtual Music, Inc.
* 0x0027 Prosody 1612 codec for CTI Speech Card Aculab plc
* 0x0028 LRC Merging Technologies S.A.
* 0x0030 Dolby Labs AC2
* 0x0031 Microsoft GSM 6.10 Audio CODEC for MSACM msacm.msgsm610 msgsm32.acm
* 0x0032 MSNAudio Microsoft
* 0x0033 Antex ADPCME Antex Electronics Corporation
* 0x0034 Control Res. VQLPC Control Resources Limited
* 0x0035 DigiReal DSP Solutions, Inc.
* 0x0036 DigiADPCM DSP Solutions, Inc.
* 0x0037 Control Res. CR10 Control Resources Limited
* 0x0038 NMS VBXADPCM Natural MicroSystems
* 0x0039 CS IMAADPCM Roland RDAC Crystal Semiconductor IMA ADPCM
* 0x003A ECHOSC3 Echo Speech Corporation
* 0x003B Rockwell ADPCM Rockwell International
* 0x003C Rockwell DIGITALK Rockwell International
* 0x003D XEBEC Xebec Multimedia Solutions Limited
* 0x0040 G721 ADPCM Antex Electronics Corporation
* 0x0041 G728 CELP Antex Electronics Corporation
* 0x0042 Microsoft G.723.1 CODEC MSACM msacm.msg723 msg723.acm
* 0x0043 IBM AVC ADPCM
* 0x0044 MSG729 Microsoft
* 0x0045 ITU-T G.726 ADPCM
* 0x0050 MPEG (MP1/MP2) ISO/IEC
* 0x0050 QDesign MPEG QDesign Corporation qmpeg.acm
* 0x0052 InSoft RT24 (ACM codec is an alternative codec)
* 0x0053 PAC InSoft, Inc.
* 0x0055 MPEG Layer-3 Audio Codec for MSACM msacm.l3ACM l3codeca.acm
* 0x0057 AMR-NB
* 0x0058 AMR-WB
* 0x0059 Lucent G.723
* 0x0060 Cirrus Cirrus Logic
* 0x0061 ESS Technology ESPCM / Duck DK4 ADPCM
* 0x0062 msacm.voxacm160 vct3216.acm Voxware v1.1.6/1.1.8 File-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0062 Voxware file-mode codec / Duck DK3 ADPCM
* 0x0063 Canopus ATRAC Canopus, co., Ltd.
* 0x0064 G726 ADPCM APICOM
* 0x0065 G722 ADPCM APICOM
* 0x0066 DSAT Microsoft
* 0x0067 DSAT DISPLAY Microsoft
* 0x0069 msacm.voxacm160 Voxware v1.1.8 Bitstream-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0070 Voxware AC8 (Lernout & Hauspie CELP 4.8 kbps) lhacm.acm
* 0x0071 Voxware AC10 (Lernout & Hauspie CBS 8kbps) lhacm.acm
* 0x0072 Voxware AC16 (Lernout & Hauspie CBS 12kbps) lhacm.acm
* 0x0073 Voxware AC20 (Lernout & Hauspie CBS 16kbps) lhacm.acm
* 0x0074 Voxware MetaVoice Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0075 Voxware RT29 Metasound Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0076 Voxware RT29HW
* 0x0077 Voxware VR12
* 0x0078 Voxware VR18
* 0x0079 Voxware TQ40
* 0x007A Voxware SC3
* 0x007B Voxware SC3
* 0x0080 Softsound Softsound, Ltd.
* 0x0081 Voxware TQ60
* 0x0082 Microsoft MSRT24 (ACM codec is an alternative codec)
* 0x0083 G729A AT&T Labs, Inc.
* 0x0084 MVI MVI2 Motion Pixels
* 0x0085 DataFusion Systems G.726
* 0x0086 DataFusion Systems GSM610
* 0x0088 ISIAUDIO Iterated Systems, Inc.
* 0x0089 ONLIVE OnLive! Technologies, Inc.
* 0x008A MULTITUDE FT SX20 Multitude, Inc.
* 0x008B G.721 ADPCM Infocom ITS A/S
* 0x008C CONVEDIA G729 Convedia Corporation
* 0x008D Not specified congruency, Inc.
* 0x0091 SBC24 Siemens Business Communications Sys
* 0x0092 Dolby AC3 SPDIF Sonic Foundry
* 0x0093 MediaSonic G.723
* 0x0094 Prosody 8KBPS Aculab plc
* 0x0097 Zyxel ADPCM ZyXEL Communications, Inc.
* 0x0098 Philips LPCBB smlpcbb.acm
* 0x0099 PACKED Studer Professional Audio AG
* 0x00A0 Malden PhonyTalk Malden Electronics Ltd.
* 0x00A1 Racal Recorder GSM Racal Recorders
* 0x00A2 Racal Recorder G720.a Racal Recorders
* 0x00A3 Racal G723.1 Racal Recorders
* 0x00A4 Racal Tetra ACELP Racal Recorders
* 0x00B0 NEC AAC NEC Corporation
* 0x00E1 Microsoft ADPCM
* 0x00f4 WRPR codec
* 0x00FF AAC
* 0x0100 Rhetorex ADPCM
* 0x0101 IBM mu-law / BeCubed Software IRAT
* 0x0102 ALAW IBM a-law format
* 0x0103 ADPCM IBM AVC Adaptive Differential Pulse Code Modulation
* 0x0111 Vivo G.723
* 0x0112 Vivo Siren
* 0x0120 PHILIPS CELP Philips Speech Processing
* 0x0121 PHILIPS GRUNDIG Philips Speech Processing
* 0x0123 DEC G723 Digital Equipment Corporation Digital G.723
* 0x0125 Sanyo LD ADPCM
* 0x0130 Sipro Lab Telecom ACELP.net audio codec Sipro Lab TelecomInc. sl_anet.acm
* 0x0131 Sipro Lab Telecom ACELP.4800
* 0x0132 Sipro Lab Telecom ACELP.8V3
* 0x0133 Sipro Lab Telecom ACELP.G.729
* 0x0134 Sipro Lab Telecom ACELP.G.729A
* 0x0135 Sipro Lab Telecom ACELP.KELVIN
* 0x0136 VOICEAGE AMR VoiceAge Corporation
* 0x0140 G726ADPCM Dictaphone Corporation
* 0x0141 CELP68 Dictaphone Corporation
* 0x0142 CELP54 Dictaphone Corporation
* 0x0150 Qualcomm PureVoice
* 0x0151 Qualcomm HalfRate
* 0x0155 TUBGSM Ring Zero Systems, Inc.
* 0x0160 Windows Media Audio msacm.msaudio1 msaud32.acm
* 0x0161 Windows Media Audio V2 V7 V8 V9 / DivX audio (WMA) / Alex AC3 Audio msaud32.acm
* 0x0162 Windows Media Audio 9 Professional Microsoft, Inc.
* 0x0163 Windows Media Audio 9 Lossless Microsoft, Inc.
* 0x0164 WMA Pro over S/PDIF
* 0x0170 UNISYS NAP ADPCM Unisys Corporation
* 0x0171 UNISYS NAP ULAW Unisys Corporation
* 0x0172 UNISYS NAP ALAW Unisys Corporation
* 0x0173 UNISYS NAP 16K Unisys Corporation
* 0x0174 MM SYCOM ACM SYC008 SyCom Technologies
* 0x0175 MM SYCOM ACM SYC701 G726L SyCom Technologies
* 0x0176 MM SYCOM ACM SYC701 CELP54 SyCom Technologies
* 0x0177 MM SYCOM ACM SYC701 CELP68 SyCom Technologies
* 0x0178 Knowledge Adventure ADPCM
* 0x0180 MPEG2AAC Fraunhofer IIS
* 0x0190 DTS DS Digital Theater Systems, Inc.
* 0x0200 Creative Labs ADPCM
* 0x0202 Creative Labs FastSpeech8
* 0x0203 Creative Labs FastSpeech10
* 0x0210 UHER ADPCM UHER informatic GmbH
* 0x0215 Ulead DV AudioACM Driver msacm.dvACM dvacm.acm
* 0x0216 Ulead DV Audio Codec Ulead Systems, Inc. Dvacm.acm
* 0x0217 Ulead MP3 codec engine msacm.ulmp3acm Warning: Codec is disabled
* 0x0220 Quarterdeck Quarterdeck Corporation
* 0x0230 I-Link VC I-link Worldwide
* 0x0240 RAW SPORT Aureal Semiconductor
* 0x0241 ESST AC3 ESS Technology
* 0x0250 IPI HSX Interactive Products, Inc.
* 0x0251 IPI RPELP Interactive Products, Inc.
* 0x0260 CS2 Consistent Software
* 0x0270 Sony ATRAC3 (SCX, same as MiniDisk LP2)
* 0x0271 Sony SCY
* 0x0272 Sony ATRAC3
* 0x0273 Sony SPC
* 0x0280 TELUM Telum Inc.
* 0x0281 TELUMIA Telum Inc.
* 0x0285 Norcom Voice Systems ADPCM Norcom Electronics Corporation
* 0x028e MSN Messenger Audio Codec msacm.siren sirenacm.dll
* 0x0300 Fujitsu FM TOWNS SND
* 0x0301 Not specified Fujitsu Corporation
* 0x0302 Not specified Fujitsu Corporation
* 0x0303 Not specified Fujitsu Corporation
* 0x0304 Not specified Fujitsu Corporation
* 0x0305 Not specified Fujitsu Corporation
* 0x0306 Not specified Fujitsu Corporation
* 0x0307 Not specified Fujitsu Corporation
* 0x0308 Not specified Fujitsu Corporation
* 0x0350 DEVELOPMENT Micronas Semiconductors, Inc.
* 0x0351 CELP833 Micronas Semiconductors, Inc.
* 0x03eb DVMPEG Audio Darim Vision Co., Ltd. dvacmau.dll
* 0x0400 BTV Digital (Brooktree digital audio format)
* 0x0401 Intel Music Coder for MSACM msacm.imc imc32.acm
* 0x0402 Indeo® audio software msacm.iac2 iac25_32.ax
* 0x0450 QDesign Music
* 0x0500 On2 VP7 On2 Technologies AVC Audio
* 0x0501 On2 VP6 On2 Technologies
* 0x0680 AT&T Labs VME VMPCM
* 0x0681 AT&T Labs TPC
* 0x0700 YMPEG Alpha (dummy for MPEG-2 compressor)
* 0x08AE ClearJump Lightwave Lossless http://www.clearjump.com
* 0x0AAC HDX4 AAC Jomigo GmbH
* 0x1000 Olivetti GSM
* 0x1001 Olivetti ADPCM
* 0x1002 Olivetti CELP
* 0x1003 Olivetti SBC
* 0x1004 Olivetti OPR
* 0x1100 Lernout & Hauspie codec
* 0x1101 Lernout & Hauspie CELP codec
* 0x1102 Lernout & Hauspie SBC codec
* 0x1103 Lernout & Hauspie SBC codec
* 0x1104 Lernout & Hauspie SBC codec
* 0x1400 Norris Communication
* 0x1401 AT&T Labs ISIAudio
* 0x1500 Soundspace Musicompress Soundspace Music Compression Netspeak GSM - nsgsm32.acm
* 0x1501 Netspeak Truespeech - nstsp32.acm
* 0x181C VoxWare RT24 speech codec Voxware Inc.
* 0x181E Lucent elemedia AX24000P Music codec
* 0x1971 Sonic Foundry LOSSLESS
* 0x1979 Innings Telecom Inc. ADPCM
* 0x1C07 Lucent SX8300P speech codec
* 0x1C0C Lucent SX5363S G.723 compliant codec
* 0x1F03 CUseeMe DigiTalk (ex-Rocwell)
* 0x1FC4 NCT ALF2CD codec http://www.nctsoft.com
* 0x2000 AC-3ACM Codec msacm.ac3acm ac3acm.acm
* 0x2001 Dolby DTS Dolby Labs
* 0x2002 RealAudio 1 / 2 14.4
* 0x2003 RealAudio 1 / 2 28.8
* 0x2004 RealAudio G2 / 8 Cook (low bitrate)
* 0x2005 RealAudio 3 / 4 / 5 Music (DNET)
* 0x2006 RealAudio 10 AAC (RAAC)
* 0x2007 RealAudio 10 AAC+ (RACP)
* 0x2500 Reserved range to * 0x2600 Microsoft
* 0x3313 makeAVIS (ffvfw fake AVI sound from AviSynth scripts) ff_acm.acm
* 0x4143 Divio MPEG-4 AAC audio
* 0x4180 fortherecord MPEG AAC celp?
* 0x4201 Nokia adaptive multirate Nokia Mobile Phones
* 0x4243 Divio's G726 Divio, Inc.
* 0x434C LEAD Speech
* 0x564C LEAD Vorbis
* 0x5756 WavPack Audio xiph.org [open source]
* 0x6665 Litewave audio compressor (lw.zip from http://www.clearjump.com)
* 0x674f Ogg Vorbis mode 1 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6750 Ogg Vorbis mode 2 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6751 Ogg Vorbis mode 3 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x676f Ogg Vorbis mode 1+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6770 Ogg Vorbis mode 2+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6771 Ogg Vorbis mode 3+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x7000 3COM NBX 3Com Corporation
* 0x706D FAAD AAC (open source)
* 0x77A1 The True Audio
* 0x7A21 GSM-AMR (CBR, no SID) EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x7A22 GSM-AMR (VBR, including SID) GSMA/3GPP EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x8180 (unverified) For the Record - http://www.fortherecord.com
* 0xA100 COMVERSEINFOSYS G723 1 Comverse Infosys Ltd.
* 0xA101 COMVERSEINFOSYS AVQSBC Comverse Infosys Ltd.
* 0xA102 COMVERSEINFOSYS OLDSBC Comverse Infosys Ltd.
* 0xA103 Symbol Technology's G729A Symbol Technologies Canada
* 0xA104 VoiceAge AMR WB VoiceAge Corporation
* 0xA105 Ingenient Technologies Inc. G726
* 0xA106 ISO/MPEG-4 advanced audio Coding AAC.
* 0xA107 Encore Software Ltd's G726 Encore Software Ltd.
* 0xA109 Speex ACM Codec xiph.org (Open Source)
* 0xC0CC GigaLink Audio Codec
* 0xDFAC DebugMode SonicFoundry Vegas FrameServer ACM Codec
* 0xe708 Unknown -
* 0xF1AC Free Lossless Audio Codec FLAC
* 0xFFFC VDOwave Audio
* 0xFFFE Extensible wave format
* 0xFFFF In Development / Unregistered

[[Category: Multimedia Terminology]]

TwoCC

2020-01-03T00:40:04Z

Lord Nightmare: add more wikilinks for PCM, u-law and a-law

The TwoCC is the audio counterpart to the [[:Category:Video FourCCs|video FourCC]]. It is the audio format identifier used in the [[RIFF]] based multimedia formats by [[Microsoft]] ([[WAV]] and [[AVI]]). The TwoCC is 2 bytes long and stored in little endian format on disk. You can register your TwoCC with Microsoft but it seems that only some companies perform this process.

If you need help finding any codec mail me compn@ffmpeg.org

* 0x0000 Microsoft Unknown Wave Format
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0001 Microsoft PCM Format]]
* 0x0002 Microsoft ADPCM CODEC for MSACM msacm.msadpcm msadp32.acm
* 0x0003 IEEE FLOAT Microsoft IEEE754
* 0x0004 Compaq Computer VSELP (codec for Windows CE 2.0 devices)
* 0x0005 IBM CVSD IBM Corporation
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0006 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* [[PCM#Microsoft_WAV.2FAVI.2FASF_Identifiers|0x0007 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm]]
* 0x0008 Microsoft DTS
* 0x0009 Microsoft DRM
* 0x000A WMSpeech Microsoft
* 0x000B Windows Media RT Voice Microsoft
* 0x0010 OKI ADPCM
* [[Microsoft_IMA_ADPCM|0x0011 IMA ADPCM CODEC for MSACM msacm.imaadpcm imaadp32.acm]]
* 0x0012 Videologic MediaSpace ADPCM
* 0x0013 Sierra ADPCM Sierra Semiconductor Corp
* 0x0014 G723 ADPCM Antex Electronics Corporation
* 0x0015 DIGISTD DSP Solutions, Inc.
* 0x0016 DIGIFIX DSP Solutions, Inc.
* 0x0017 Dialogic OKI ADPCM
* 0x0018 MediaVision ADPCM
* 0x0019 CU CODEC Mobile Voice Hewlett-Packard Company
* 0x001A Hewlett-Packard HP DYNAMIC VOICE
* 0x0020 Yamaha ADPCM
* 0x0021 Sonarc Speech Compression
* 0x0022 DSP Group TrueSpeech(TM) Audio Codec for MSACM V3.50 msacm.trspch tssoft32.acm
* 0x0023 ECHOSC1 Echo Speech Corporation
* 0x0024 Audiofile AF36 Virtual Music, Inc.
* 0x0025 APTX Audio Processing Technology
* 0x0026 Audiofile AF10 Virtual Music, Inc.
* 0x0027 Prosody 1612 codec for CTI Speech Card Aculab plc
* 0x0028 LRC Merging Technologies S.A.
* 0x0030 Dolby Labs AC2
* 0x0031 Microsoft GSM 6.10 Audio CODEC for MSACM msacm.msgsm610 msgsm32.acm
* 0x0032 MSNAudio Microsoft
* 0x0033 Antex ADPCME Antex Electronics Corporation
* 0x0034 Control Res. VQLPC Control Resources Limited
* 0x0035 DigiReal DSP Solutions, Inc.
* 0x0036 DigiADPCM DSP Solutions, Inc.
* 0x0037 Control Res. CR10 Control Resources Limited
* 0x0038 NMS VBXADPCM Natural MicroSystems
* 0x0039 CS IMAADPCM Roland RDAC Crystal Semiconductor IMA ADPCM
* 0x003A ECHOSC3 Echo Speech Corporation
* 0x003B Rockwell ADPCM Rockwell International
* 0x003C Rockwell DIGITALK Rockwell International
* 0x003D XEBEC Xebec Multimedia Solutions Limited
* 0x0040 G721 ADPCM Antex Electronics Corporation
* 0x0041 G728 CELP Antex Electronics Corporation
* 0x0042 Microsoft G.723.1 CODEC MSACM msacm.msg723 msg723.acm
* 0x0043 IBM AVC ADPCM
* 0x0044 MSG729 Microsoft
* 0x0045 ITU-T G.726 ADPCM
* 0x0050 MPEG (MP1/MP2) ISO/IEC
* 0x0050 QDesign MPEG QDesign Corporation qmpeg.acm
* 0x0052 InSoft RT24 (ACM codec is an alternative codec)
* 0x0053 PAC InSoft, Inc.
* 0x0055 MPEG Layer-3 Audio Codec for MSACM msacm.l3ACM l3codeca.acm
* 0x0057 AMR-NB
* 0x0058 AMR-WB
* 0x0059 Lucent G.723
* 0x0060 Cirrus Cirrus Logic
* 0x0061 ESS Technology ESPCM / Duck DK4 ADPCM
* 0x0062 msacm.voxacm160 vct3216.acm Voxware v1.1.6/1.1.8 File-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0062 Voxware file-mode codec / Duck DK3 ADPCM
* 0x0063 Canopus ATRAC Canopus, co., Ltd.
* 0x0064 G726 ADPCM APICOM
* 0x0065 G722 ADPCM APICOM
* 0x0066 DSAT Microsoft
* 0x0067 DSAT DISPLAY Microsoft
* 0x0069 msacm.voxacm160 Voxware v1.1.8 Bitstream-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0070 Voxware AC8 (Lernout & Hauspie CELP 4.8 kbps) lhacm.acm
* 0x0071 Voxware AC10 (Lernout & Hauspie CBS 8kbps) lhacm.acm
* 0x0072 Voxware AC16 (Lernout & Hauspie CBS 12kbps) lhacm.acm
* 0x0073 Voxware AC20 (Lernout & Hauspie CBS 16kbps) lhacm.acm
* 0x0074 Voxware MetaVoice Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0075 Voxware RT29 Metasound Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0076 Voxware RT29HW
* 0x0077 Voxware VR12
* 0x0078 Voxware VR18
* 0x0079 Voxware TQ40
* 0x007A Voxware SC3
* 0x007B Voxware SC3
* 0x0080 Softsound Softsound, Ltd.
* 0x0081 Voxware TQ60
* 0x0082 Microsoft MSRT24 (ACM codec is an alternative codec)
* 0x0083 G729A AT&T Labs, Inc.
* 0x0084 MVI MVI2 Motion Pixels
* 0x0085 DataFusion Systems G.726
* 0x0086 DataFusion Systems GSM610
* 0x0088 ISIAUDIO Iterated Systems, Inc.
* 0x0089 ONLIVE OnLive! Technologies, Inc.
* 0x008A MULTITUDE FT SX20 Multitude, Inc.
* 0x008B G.721 ADPCM Infocom ITS A/S
* 0x008C CONVEDIA G729 Convedia Corporation
* 0x008D Not specified congruency, Inc.
* 0x0091 SBC24 Siemens Business Communications Sys
* 0x0092 Dolby AC3 SPDIF Sonic Foundry
* 0x0093 MediaSonic G.723
* 0x0094 Prosody 8KBPS Aculab plc
* 0x0097 Zyxel ADPCM ZyXEL Communications, Inc.
* 0x0098 Philips LPCBB smlpcbb.acm
* 0x0099 PACKED Studer Professional Audio AG
* 0x00A0 Malden PhonyTalk Malden Electronics Ltd.
* 0x00A1 Racal Recorder GSM Racal Recorders
* 0x00A2 Racal Recorder G720.a Racal Recorders
* 0x00A3 Racal G723.1 Racal Recorders
* 0x00A4 Racal Tetra ACELP Racal Recorders
* 0x00B0 NEC AAC NEC Corporation
* 0x00E1 Microsoft ADPCM
* 0x00f4 WRPR codec
* 0x00FF AAC
* 0x0100 Rhetorex ADPCM
* 0x0101 IBM mu-law / BeCubed Software IRAT
* 0x0102 ALAW IBM a-law format
* 0x0103 ADPCM IBM AVC Adaptive Differential Pulse Code Modulation
* 0x0111 Vivo G.723
* 0x0112 Vivo Siren
* 0x0120 PHILIPS CELP Philips Speech Processing
* 0x0121 PHILIPS GRUNDIG Philips Speech Processing
* 0x0123 DEC G723 Digital Equipment Corporation Digital G.723
* 0x0125 Sanyo LD ADPCM
* 0x0130 Sipro Lab Telecom ACELP.net audio codec Sipro Lab TelecomInc. sl_anet.acm
* 0x0131 Sipro Lab Telecom ACELP.4800
* 0x0132 Sipro Lab Telecom ACELP.8V3
* 0x0133 Sipro Lab Telecom ACELP.G.729
* 0x0134 Sipro Lab Telecom ACELP.G.729A
* 0x0135 Sipro Lab Telecom ACELP.KELVIN
* 0x0136 VOICEAGE AMR VoiceAge Corporation
* 0x0140 G726ADPCM Dictaphone Corporation
* 0x0141 CELP68 Dictaphone Corporation
* 0x0142 CELP54 Dictaphone Corporation
* 0x0150 Qualcomm PureVoice
* 0x0151 Qualcomm HalfRate
* 0x0155 TUBGSM Ring Zero Systems, Inc.
* 0x0160 Windows Media Audio msacm.msaudio1 msaud32.acm
* 0x0161 Windows Media Audio V2 V7 V8 V9 / DivX audio (WMA) / Alex AC3 Audio msaud32.acm
* 0x0162 Windows Media Audio 9 Professional Microsoft, Inc.
* 0x0163 Windows Media Audio 9 Lossless Microsoft, Inc.
* 0x0164 WMA Pro over S/PDIF
* 0x0170 UNISYS NAP ADPCM Unisys Corporation
* 0x0171 UNISYS NAP ULAW Unisys Corporation
* 0x0172 UNISYS NAP ALAW Unisys Corporation
* 0x0173 UNISYS NAP 16K Unisys Corporation
* 0x0174 MM SYCOM ACM SYC008 SyCom Technologies
* 0x0175 MM SYCOM ACM SYC701 G726L SyCom Technologies
* 0x0176 MM SYCOM ACM SYC701 CELP54 SyCom Technologies
* 0x0177 MM SYCOM ACM SYC701 CELP68 SyCom Technologies
* 0x0178 Knowledge Adventure ADPCM
* 0x0180 MPEG2AAC Fraunhofer IIS
* 0x0190 DTS DS Digital Theater Systems, Inc.
* 0x0200 Creative Labs ADPCM
* 0x0202 Creative Labs FastSpeech8
* 0x0203 Creative Labs FastSpeech10
* 0x0210 UHER ADPCM UHER informatic GmbH
* 0x0215 Ulead DV AudioACM Driver msacm.dvACM dvacm.acm
* 0x0216 Ulead DV Audio Codec Ulead Systems, Inc. Dvacm.acm
* 0x0217 Ulead MP3 codec engine msacm.ulmp3acm Warning: Codec is disabled
* 0x0220 Quarterdeck Quarterdeck Corporation
* 0x0230 I-Link VC I-link Worldwide
* 0x0240 RAW SPORT Aureal Semiconductor
* 0x0241 ESST AC3 ESS Technology
* 0x0250 IPI HSX Interactive Products, Inc.
* 0x0251 IPI RPELP Interactive Products, Inc.
* 0x0260 CS2 Consistent Software
* 0x0270 Sony ATRAC3 (SCX, same as MiniDisk LP2)
* 0x0271 Sony SCY
* 0x0272 Sony ATRAC3
* 0x0273 Sony SPC
* 0x0280 TELUM Telum Inc.
* 0x0281 TELUMIA Telum Inc.
* 0x0285 Norcom Voice Systems ADPCM Norcom Electronics Corporation
* 0x028e MSN Messenger Audio Codec msacm.siren sirenacm.dll
* 0x0300 Fujitsu FM TOWNS SND
* 0x0301 Not specified Fujitsu Corporation
* 0x0302 Not specified Fujitsu Corporation
* 0x0303 Not specified Fujitsu Corporation
* 0x0304 Not specified Fujitsu Corporation
* 0x0305 Not specified Fujitsu Corporation
* 0x0306 Not specified Fujitsu Corporation
* 0x0307 Not specified Fujitsu Corporation
* 0x0308 Not specified Fujitsu Corporation
* 0x0350 DEVELOPMENT Micronas Semiconductors, Inc.
* 0x0351 CELP833 Micronas Semiconductors, Inc.
* 0x03eb DVMPEG Audio Darim Vision Co., Ltd. dvacmau.dll
* 0x0400 BTV Digital (Brooktree digital audio format)
* 0x0401 Intel Music Coder for MSACM msacm.imc imc32.acm
* 0x0402 Indeo® audio software msacm.iac2 iac25_32.ax
* 0x0450 QDesign Music
* 0x0500 On2 VP7 On2 Technologies AVC Audio
* 0x0501 On2 VP6 On2 Technologies
* 0x0680 AT&T Labs VME VMPCM
* 0x0681 AT&T Labs TPC
* 0x0700 YMPEG Alpha (dummy for MPEG-2 compressor)
* 0x08AE ClearJump Lightwave Lossless http://www.clearjump.com
* 0x0AAC HDX4 AAC Jomigo GmbH
* 0x1000 Olivetti GSM
* 0x1001 Olivetti ADPCM
* 0x1002 Olivetti CELP
* 0x1003 Olivetti SBC
* 0x1004 Olivetti OPR
* 0x1100 Lernout & Hauspie codec
* 0x1101 Lernout & Hauspie CELP codec
* 0x1102 Lernout & Hauspie SBC codec
* 0x1103 Lernout & Hauspie SBC codec
* 0x1104 Lernout & Hauspie SBC codec
* 0x1400 Norris Communication
* 0x1401 AT&T Labs ISIAudio
* 0x1500 Soundspace Musicompress Soundspace Music Compression Netspeak GSM - nsgsm32.acm
* 0x1501 Netspeak Truespeech - nstsp32.acm
* 0x181C VoxWare RT24 speech codec Voxware Inc.
* 0x181E Lucent elemedia AX24000P Music codec
* 0x1971 Sonic Foundry LOSSLESS
* 0x1979 Innings Telecom Inc. ADPCM
* 0x1C07 Lucent SX8300P speech codec
* 0x1C0C Lucent SX5363S G.723 compliant codec
* 0x1F03 CUseeMe DigiTalk (ex-Rocwell)
* 0x1FC4 NCT ALF2CD codec http://www.nctsoft.com
* 0x2000 AC-3ACM Codec msacm.ac3acm ac3acm.acm
* 0x2001 Dolby DTS Dolby Labs
* 0x2002 RealAudio 1 / 2 14.4
* 0x2003 RealAudio 1 / 2 28.8
* 0x2004 RealAudio G2 / 8 Cook (low bitrate)
* 0x2005 RealAudio 3 / 4 / 5 Music (DNET)
* 0x2006 RealAudio 10 AAC (RAAC)
* 0x2007 RealAudio 10 AAC+ (RACP)
* 0x2500 Reserved range to * 0x2600 Microsoft
* 0x3313 makeAVIS (ffvfw fake AVI sound from AviSynth scripts) ff_acm.acm
* 0x4143 Divio MPEG-4 AAC audio
* 0x4180 fortherecord MPEG AAC celp?
* 0x4201 Nokia adaptive multirate Nokia Mobile Phones
* 0x4243 Divio's G726 Divio, Inc.
* 0x434C LEAD Speech
* 0x564C LEAD Vorbis
* 0x5756 WavPack Audio xiph.org [open source]
* 0x6665 Litewave audio compressor (lw.zip from http://www.clearjump.com)
* 0x674f Ogg Vorbis mode 1 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6750 Ogg Vorbis mode 2 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6751 Ogg Vorbis mode 3 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x676f Ogg Vorbis mode 1+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6770 Ogg Vorbis mode 2+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6771 Ogg Vorbis mode 3+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x7000 3COM NBX 3Com Corporation
* 0x706D FAAD AAC (open source)
* 0x77A1 The True Audio
* 0x7A21 GSM-AMR (CBR, no SID) EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x7A22 GSM-AMR (VBR, including SID) GSMA/3GPP EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x8180 (unverified) For the Record - http://www.fortherecord.com
* 0xA100 COMVERSEINFOSYS G723 1 Comverse Infosys Ltd.
* 0xA101 COMVERSEINFOSYS AVQSBC Comverse Infosys Ltd.
* 0xA102 COMVERSEINFOSYS OLDSBC Comverse Infosys Ltd.
* 0xA103 Symbol Technology's G729A Symbol Technologies Canada
* 0xA104 VoiceAge AMR WB VoiceAge Corporation
* 0xA105 Ingenient Technologies Inc. G726
* 0xA106 ISO/MPEG-4 advanced audio Coding AAC.
* 0xA107 Encore Software Ltd's G726 Encore Software Ltd.
* 0xA109 Speex ACM Codec xiph.org (Open Source)
* 0xC0CC GigaLink Audio Codec
* 0xDFAC DebugMode SonicFoundry Vegas FrameServer ACM Codec
* 0xe708 Unknown -
* 0xF1AC Free Lossless Audio Codec FLAC
* 0xFFFC VDOwave Audio
* 0xFFFE Extensible wave format
* 0xFFFF In Development / Unregistered

[[Category: Multimedia Terminology]]

TwoCC

2020-01-03T00:37:10Z

Lord Nightmare: add wikilink for MS IMA ADPCM

The TwoCC is the audio counterpart to the [[:Category:Video FourCCs|video FourCC]]. It is the audio format identifier used in the [[RIFF]] based multimedia formats by [[Microsoft]] ([[WAV]] and [[AVI]]). The TwoCC is 2 bytes long and stored in little endian format on disk. You can register your TwoCC with Microsoft but it seems that only some companies perform this process.

If you need help finding any codec mail me compn@ffmpeg.org

* 0x0000 Microsoft Unknown Wave Format
* 0x0001 Microsoft PCM Format
* 0x0002 Microsoft ADPCM CODEC for MSACM msacm.msadpcm msadp32.acm
* 0x0003 IEEE FLOAT Microsoft IEEE754
* 0x0004 Compaq Computer VSELP (codec for Windows CE 2.0 devices)
* 0x0005 IBM CVSD IBM Corporation
* 0x0006 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm
* 0x0007 Microsoft CCITT G.711 (A-Law and u-Law) CODEC for MSACM msacm.msg711 msg711.acm
* 0x0008 Microsoft DTS
* 0x0009 Microsoft DRM
* 0x000A WMSpeech Microsoft
* 0x000B Windows Media RT Voice Microsoft
* 0x0010 OKI ADPCM
* [[Microsoft_IMA_ADPCM|0x0011 IMA ADPCM CODEC for MSACM msacm.imaadpcm imaadp32.acm]]
* 0x0012 Videologic MediaSpace ADPCM
* 0x0013 Sierra ADPCM Sierra Semiconductor Corp
* 0x0014 G723 ADPCM Antex Electronics Corporation
* 0x0015 DIGISTD DSP Solutions, Inc.
* 0x0016 DIGIFIX DSP Solutions, Inc.
* 0x0017 Dialogic OKI ADPCM
* 0x0018 MediaVision ADPCM
* 0x0019 CU CODEC Mobile Voice Hewlett-Packard Company
* 0x001A Hewlett-Packard HP DYNAMIC VOICE
* 0x0020 Yamaha ADPCM
* 0x0021 Sonarc Speech Compression
* 0x0022 DSP Group TrueSpeech(TM) Audio Codec for MSACM V3.50 msacm.trspch tssoft32.acm
* 0x0023 ECHOSC1 Echo Speech Corporation
* 0x0024 Audiofile AF36 Virtual Music, Inc.
* 0x0025 APTX Audio Processing Technology
* 0x0026 Audiofile AF10 Virtual Music, Inc.
* 0x0027 Prosody 1612 codec for CTI Speech Card Aculab plc
* 0x0028 LRC Merging Technologies S.A.
* 0x0030 Dolby Labs AC2
* 0x0031 Microsoft GSM 6.10 Audio CODEC for MSACM msacm.msgsm610 msgsm32.acm
* 0x0032 MSNAudio Microsoft
* 0x0033 Antex ADPCME Antex Electronics Corporation
* 0x0034 Control Res. VQLPC Control Resources Limited
* 0x0035 DigiReal DSP Solutions, Inc.
* 0x0036 DigiADPCM DSP Solutions, Inc.
* 0x0037 Control Res. CR10 Control Resources Limited
* 0x0038 NMS VBXADPCM Natural MicroSystems
* 0x0039 CS IMAADPCM Roland RDAC Crystal Semiconductor IMA ADPCM
* 0x003A ECHOSC3 Echo Speech Corporation
* 0x003B Rockwell ADPCM Rockwell International
* 0x003C Rockwell DIGITALK Rockwell International
* 0x003D XEBEC Xebec Multimedia Solutions Limited
* 0x0040 G721 ADPCM Antex Electronics Corporation
* 0x0041 G728 CELP Antex Electronics Corporation
* 0x0042 Microsoft G.723.1 CODEC MSACM msacm.msg723 msg723.acm
* 0x0043 IBM AVC ADPCM
* 0x0044 MSG729 Microsoft
* 0x0045 ITU-T G.726 ADPCM
* 0x0050 MPEG (MP1/MP2) ISO/IEC
* 0x0050 QDesign MPEG QDesign Corporation qmpeg.acm
* 0x0052 InSoft RT24 (ACM codec is an alternative codec)
* 0x0053 PAC InSoft, Inc.
* 0x0055 MPEG Layer-3 Audio Codec for MSACM msacm.l3ACM l3codeca.acm
* 0x0057 AMR-NB
* 0x0058 AMR-WB
* 0x0059 Lucent G.723
* 0x0060 Cirrus Cirrus Logic
* 0x0061 ESS Technology ESPCM / Duck DK4 ADPCM
* 0x0062 msacm.voxacm160 vct3216.acm Voxware v1.1.6/1.1.8 File-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0062 Voxware file-mode codec / Duck DK3 ADPCM
* 0x0063 Canopus ATRAC Canopus, co., Ltd.
* 0x0064 G726 ADPCM APICOM
* 0x0065 G722 ADPCM APICOM
* 0x0066 DSAT Microsoft
* 0x0067 DSAT DISPLAY Microsoft
* 0x0069 msacm.voxacm160 Voxware v1.1.8 Bitstream-Mode Codecs Voxware, Inc. vct3216.acm
* 0x0070 Voxware AC8 (Lernout & Hauspie CELP 4.8 kbps) lhacm.acm
* 0x0071 Voxware AC10 (Lernout & Hauspie CBS 8kbps) lhacm.acm
* 0x0072 Voxware AC16 (Lernout & Hauspie CBS 12kbps) lhacm.acm
* 0x0073 Voxware AC20 (Lernout & Hauspie CBS 16kbps) lhacm.acm
* 0x0074 Voxware MetaVoice Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0075 Voxware RT29 Metasound Audio Compression Manager Driver msacm.voxacm160 vct3216.acm
* 0x0076 Voxware RT29HW
* 0x0077 Voxware VR12
* 0x0078 Voxware VR18
* 0x0079 Voxware TQ40
* 0x007A Voxware SC3
* 0x007B Voxware SC3
* 0x0080 Softsound Softsound, Ltd.
* 0x0081 Voxware TQ60
* 0x0082 Microsoft MSRT24 (ACM codec is an alternative codec)
* 0x0083 G729A AT&T Labs, Inc.
* 0x0084 MVI MVI2 Motion Pixels
* 0x0085 DataFusion Systems G.726
* 0x0086 DataFusion Systems GSM610
* 0x0088 ISIAUDIO Iterated Systems, Inc.
* 0x0089 ONLIVE OnLive! Technologies, Inc.
* 0x008A MULTITUDE FT SX20 Multitude, Inc.
* 0x008B G.721 ADPCM Infocom ITS A/S
* 0x008C CONVEDIA G729 Convedia Corporation
* 0x008D Not specified congruency, Inc.
* 0x0091 SBC24 Siemens Business Communications Sys
* 0x0092 Dolby AC3 SPDIF Sonic Foundry
* 0x0093 MediaSonic G.723
* 0x0094 Prosody 8KBPS Aculab plc
* 0x0097 Zyxel ADPCM ZyXEL Communications, Inc.
* 0x0098 Philips LPCBB smlpcbb.acm
* 0x0099 PACKED Studer Professional Audio AG
* 0x00A0 Malden PhonyTalk Malden Electronics Ltd.
* 0x00A1 Racal Recorder GSM Racal Recorders
* 0x00A2 Racal Recorder G720.a Racal Recorders
* 0x00A3 Racal G723.1 Racal Recorders
* 0x00A4 Racal Tetra ACELP Racal Recorders
* 0x00B0 NEC AAC NEC Corporation
* 0x00E1 Microsoft ADPCM
* 0x00f4 WRPR codec
* 0x00FF AAC
* 0x0100 Rhetorex ADPCM
* 0x0101 IBM mu-law / BeCubed Software IRAT
* 0x0102 ALAW IBM a-law format
* 0x0103 ADPCM IBM AVC Adaptive Differential Pulse Code Modulation
* 0x0111 Vivo G.723
* 0x0112 Vivo Siren
* 0x0120 PHILIPS CELP Philips Speech Processing
* 0x0121 PHILIPS GRUNDIG Philips Speech Processing
* 0x0123 DEC G723 Digital Equipment Corporation Digital G.723
* 0x0125 Sanyo LD ADPCM
* 0x0130 Sipro Lab Telecom ACELP.net audio codec Sipro Lab TelecomInc. sl_anet.acm
* 0x0131 Sipro Lab Telecom ACELP.4800
* 0x0132 Sipro Lab Telecom ACELP.8V3
* 0x0133 Sipro Lab Telecom ACELP.G.729
* 0x0134 Sipro Lab Telecom ACELP.G.729A
* 0x0135 Sipro Lab Telecom ACELP.KELVIN
* 0x0136 VOICEAGE AMR VoiceAge Corporation
* 0x0140 G726ADPCM Dictaphone Corporation
* 0x0141 CELP68 Dictaphone Corporation
* 0x0142 CELP54 Dictaphone Corporation
* 0x0150 Qualcomm PureVoice
* 0x0151 Qualcomm HalfRate
* 0x0155 TUBGSM Ring Zero Systems, Inc.
* 0x0160 Windows Media Audio msacm.msaudio1 msaud32.acm
* 0x0161 Windows Media Audio V2 V7 V8 V9 / DivX audio (WMA) / Alex AC3 Audio msaud32.acm
* 0x0162 Windows Media Audio 9 Professional Microsoft, Inc.
* 0x0163 Windows Media Audio 9 Lossless Microsoft, Inc.
* 0x0164 WMA Pro over S/PDIF
* 0x0170 UNISYS NAP ADPCM Unisys Corporation
* 0x0171 UNISYS NAP ULAW Unisys Corporation
* 0x0172 UNISYS NAP ALAW Unisys Corporation
* 0x0173 UNISYS NAP 16K Unisys Corporation
* 0x0174 MM SYCOM ACM SYC008 SyCom Technologies
* 0x0175 MM SYCOM ACM SYC701 G726L SyCom Technologies
* 0x0176 MM SYCOM ACM SYC701 CELP54 SyCom Technologies
* 0x0177 MM SYCOM ACM SYC701 CELP68 SyCom Technologies
* 0x0178 Knowledge Adventure ADPCM
* 0x0180 MPEG2AAC Fraunhofer IIS
* 0x0190 DTS DS Digital Theater Systems, Inc.
* 0x0200 Creative Labs ADPCM
* 0x0202 Creative Labs FastSpeech8
* 0x0203 Creative Labs FastSpeech10
* 0x0210 UHER ADPCM UHER informatic GmbH
* 0x0215 Ulead DV AudioACM Driver msacm.dvACM dvacm.acm
* 0x0216 Ulead DV Audio Codec Ulead Systems, Inc. Dvacm.acm
* 0x0217 Ulead MP3 codec engine msacm.ulmp3acm Warning: Codec is disabled
* 0x0220 Quarterdeck Quarterdeck Corporation
* 0x0230 I-Link VC I-link Worldwide
* 0x0240 RAW SPORT Aureal Semiconductor
* 0x0241 ESST AC3 ESS Technology
* 0x0250 IPI HSX Interactive Products, Inc.
* 0x0251 IPI RPELP Interactive Products, Inc.
* 0x0260 CS2 Consistent Software
* 0x0270 Sony ATRAC3 (SCX, same as MiniDisk LP2)
* 0x0271 Sony SCY
* 0x0272 Sony ATRAC3
* 0x0273 Sony SPC
* 0x0280 TELUM Telum Inc.
* 0x0281 TELUMIA Telum Inc.
* 0x0285 Norcom Voice Systems ADPCM Norcom Electronics Corporation
* 0x028e MSN Messenger Audio Codec msacm.siren sirenacm.dll
* 0x0300 Fujitsu FM TOWNS SND
* 0x0301 Not specified Fujitsu Corporation
* 0x0302 Not specified Fujitsu Corporation
* 0x0303 Not specified Fujitsu Corporation
* 0x0304 Not specified Fujitsu Corporation
* 0x0305 Not specified Fujitsu Corporation
* 0x0306 Not specified Fujitsu Corporation
* 0x0307 Not specified Fujitsu Corporation
* 0x0308 Not specified Fujitsu Corporation
* 0x0350 DEVELOPMENT Micronas Semiconductors, Inc.
* 0x0351 CELP833 Micronas Semiconductors, Inc.
* 0x03eb DVMPEG Audio Darim Vision Co., Ltd. dvacmau.dll
* 0x0400 BTV Digital (Brooktree digital audio format)
* 0x0401 Intel Music Coder for MSACM msacm.imc imc32.acm
* 0x0402 Indeo® audio software msacm.iac2 iac25_32.ax
* 0x0450 QDesign Music
* 0x0500 On2 VP7 On2 Technologies AVC Audio
* 0x0501 On2 VP6 On2 Technologies
* 0x0680 AT&T Labs VME VMPCM
* 0x0681 AT&T Labs TPC
* 0x0700 YMPEG Alpha (dummy for MPEG-2 compressor)
* 0x08AE ClearJump Lightwave Lossless http://www.clearjump.com
* 0x0AAC HDX4 AAC Jomigo GmbH
* 0x1000 Olivetti GSM
* 0x1001 Olivetti ADPCM
* 0x1002 Olivetti CELP
* 0x1003 Olivetti SBC
* 0x1004 Olivetti OPR
* 0x1100 Lernout & Hauspie codec
* 0x1101 Lernout & Hauspie CELP codec
* 0x1102 Lernout & Hauspie SBC codec
* 0x1103 Lernout & Hauspie SBC codec
* 0x1104 Lernout & Hauspie SBC codec
* 0x1400 Norris Communication
* 0x1401 AT&T Labs ISIAudio
* 0x1500 Soundspace Musicompress Soundspace Music Compression Netspeak GSM - nsgsm32.acm
* 0x1501 Netspeak Truespeech - nstsp32.acm
* 0x181C VoxWare RT24 speech codec Voxware Inc.
* 0x181E Lucent elemedia AX24000P Music codec
* 0x1971 Sonic Foundry LOSSLESS
* 0x1979 Innings Telecom Inc. ADPCM
* 0x1C07 Lucent SX8300P speech codec
* 0x1C0C Lucent SX5363S G.723 compliant codec
* 0x1F03 CUseeMe DigiTalk (ex-Rocwell)
* 0x1FC4 NCT ALF2CD codec http://www.nctsoft.com
* 0x2000 AC-3ACM Codec msacm.ac3acm ac3acm.acm
* 0x2001 Dolby DTS Dolby Labs
* 0x2002 RealAudio 1 / 2 14.4
* 0x2003 RealAudio 1 / 2 28.8
* 0x2004 RealAudio G2 / 8 Cook (low bitrate)
* 0x2005 RealAudio 3 / 4 / 5 Music (DNET)
* 0x2006 RealAudio 10 AAC (RAAC)
* 0x2007 RealAudio 10 AAC+ (RACP)
* 0x2500 Reserved range to * 0x2600 Microsoft
* 0x3313 makeAVIS (ffvfw fake AVI sound from AviSynth scripts) ff_acm.acm
* 0x4143 Divio MPEG-4 AAC audio
* 0x4180 fortherecord MPEG AAC celp?
* 0x4201 Nokia adaptive multirate Nokia Mobile Phones
* 0x4243 Divio's G726 Divio, Inc.
* 0x434C LEAD Speech
* 0x564C LEAD Vorbis
* 0x5756 WavPack Audio xiph.org [open source]
* 0x6665 Litewave audio compressor (lw.zip from http://www.clearjump.com)
* 0x674f Ogg Vorbis mode 1 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6750 Ogg Vorbis mode 2 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6751 Ogg Vorbis mode 3 CODEC for MSACM msacm.vorbis vorbis.acm
* 0x676f Ogg Vorbis mode 1+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6770 Ogg Vorbis mode 2+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x6771 Ogg Vorbis mode 3+ CODEC for MSACM msacm.vorbis vorbis.acm
* 0x7000 3COM NBX 3Com Corporation
* 0x706D FAAD AAC (open source)
* 0x77A1 The True Audio
* 0x7A21 GSM-AMR (CBR, no SID) EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x7A22 GSM-AMR (VBR, including SID) GSMA/3GPP EmzAMRNBDec.dll (doesnt actually decode properly)
* 0x8180 (unverified) For the Record - http://www.fortherecord.com
* 0xA100 COMVERSEINFOSYS G723 1 Comverse Infosys Ltd.
* 0xA101 COMVERSEINFOSYS AVQSBC Comverse Infosys Ltd.
* 0xA102 COMVERSEINFOSYS OLDSBC Comverse Infosys Ltd.
* 0xA103 Symbol Technology's G729A Symbol Technologies Canada
* 0xA104 VoiceAge AMR WB VoiceAge Corporation
* 0xA105 Ingenient Technologies Inc. G726
* 0xA106 ISO/MPEG-4 advanced audio Coding AAC.
* 0xA107 Encore Software Ltd's G726 Encore Software Ltd.
* 0xA109 Speex ACM Codec xiph.org (Open Source)
* 0xC0CC GigaLink Audio Codec
* 0xDFAC DebugMode SonicFoundry Vegas FrameServer ACM Codec
* 0xe708 Unknown -
* 0xF1AC Free Lossless Audio Codec FLAC
* 0xFFFC VDOwave Audio
* 0xFFFE Extensible wave format
* 0xFFFF In Development / Unregistered

[[Category: Multimedia Terminology]]

Creative ADPCM

2019-04-05T17:12:48Z

Lord Nightmare: This is definitely not a variation on IMA ADPCM, which is an Oki/Dialogic derivative, but is Jayant-based, like Yamaha ADPCM

* Format tag: 0x200
* Company: [[Creative]]

This is a variation of [[Yamaha ADPCM]], which is also used in [[Creative Voice]].

== Decoding Process ==

get new nibble from stream
sign = nibble & 8
delta = nibble & 7
diff = ((2 * delta + 1) * step) / 8
if sign > 0
newval = (oldval * 254 / 256) - diff
else
newval = (oldval * 254 / 256) + diff
step = (ct_table[delta] * step) >> 8
step = clip(step, 511, 32767)
newval = clip(newval, -32769, 32767)
output newval as 16-bit sample

And here is the table used in step modification:

const int ct_table[8] = {
0x00E6, 0x00E6, 0x00E6, 0x00E6,
0x0133, 0x0199, 0x0200, 0x0266
}

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Yamaha ADPCM

2019-04-04T03:13:03Z

Lord Nightmare: add reference to Jayant's paper

* Microsoft Audio ID: 0x0020
* Extension: spb,mmf
* Company: Yamaha
* Sample: http://samples.mplayerhq.hu/A-codecs/format-0x20-laugh.mmf
* ACM Codec: https://web.archive.org/web/20160323215457/http://smaf-yamaha.com/jp/tools/dl/Yamaha-ADPCM-ACM-Driver-100-j.zip

A variant of this codec is used by several Yamaha chips:
* Y8950(MSX-SOUND)
* YM2608（OPNA) [the external ADPCM channel only]
and may also be used on the following chips:
* YM2610(OPNB) [the external ADPCM_B channel only?]
* YMZ263B(MMA)
* YMZ280B(PCMD8)
A (possibly slightly changed) variant is used on the sound chip of Sega Dreamcast and NAOMI:
* Yamaha AICA Super Intelligent Sound Processor
The exact codec was also used by Yamaha [[SMAF]] MA-2 and onward):
* MA-2 (YMU759)
* MA-3 (YMU762)
* MA-5 (YMU765)
* MA-7 (YMU786)

The functionality of this codec is explained fairly extensively in two datasheets:
* Y8950 application manual: http://www.datasheetarchive.com/pdf/download.php?id=212962c2fe1b63fdc5ab320ca05ff3efefc925&type=M&query=y-8950
* YM2608 datasheet (Japanese): http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J.PDF
* Translated version of YM2608 datasheet: http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J%20Translated.PDF

The codec is almost a reference implementation of the codec described in Jayant's 1973 paper [https://archive.org/details/bstj52-7-1119] (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper [https://archive.org/details/bstj52-7-1105] originally coined the term "ADPCM".

[[Category:Audio Codecs]]

Microsoft ADPCM

2019-04-04T03:10:33Z

Lord Nightmare: fix links

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM
* 'short' ID: MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (builtin predictors are in the range [0..6] but others can be manually defined)
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
// These are the 'built in' set of 7 predictor value pairs; additional values can be added to this table by including them as metadata chunks in the WAVE header
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper [https://archive.org/details/bstj52-7-1119] (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper [https://archive.org/details/bstj52-7-1105] originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the unsigned value of the (signed) nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2019-04-04T03:08:52Z

Lord Nightmare: clean up links to papers, changed to link to archive.org pages for said papers rather than direct to pdfs

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM
* 'short' ID: MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (builtin predictors are in the range [0..6] but others can be manually defined)
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
// These are the 'built in' set of 7 predictor value pairs; additional values can be added to this table by including them as metadata chunks in the WAVE header
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 [[https://archive.org/details/bstj52-7-1119|paper]] (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion [[https://archive.org/details/bstj52-7-1105|paper]] originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the unsigned value of the (signed) nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2019-02-20T20:53:28Z

Lord Nightmare: fix an error in the last sentence

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM
* 'short' ID: MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (builtin predictors are in the range [0..6] but others can be manually defined)
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
// These are the 'built in' set of 7 predictor value pairs; additional values can be added to this table by including them as metadata chunks in the WAVE header
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the unsigned value of the (signed) nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

DVI IMA ADPCM

2018-10-12T02:30:52Z

Lord Nightmare: formatting

According to the [[XAnim]] multimedia application, there are two variants of DVI [[IMA ADPCM]], both of which are encoded and decoded with the IMA ADPCM algorithm. The original variant encodes the top nibble of a byte first, then the bottom nibble. The revised variant has the opposite encoding order.

== DVI4 ==

The [https://www.freesoft.org/CIE/RFC/1890/10.htm DVI4] codec, as defined in [https://www.freesoft.org/CIE/RFC/1890/index.htm RFC1890] is a variant of [[IMA ADPCM]].
In DVI4 the block header stores the initial predictor state, unlike [[IMA ADPCM]] where the block header stores the first sample.
Otherwise, DVI4 is decoded identically to [[IMA ADPCM]].

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

DVI IMA ADPCM

2018-10-12T02:29:08Z

Lord Nightmare: fix heading

According to the [[XAnim]] multimedia application, there are two variants of DVI [[IMA ADPCM]], both of which are encoded and decoded with the IMA ADPCM algorithm. The original variant encodes the top nibble of a byte first, then the bottom nibble. The revised variant has the opposite encoding order.

== DVI4 ==

The [https://www.freesoft.org/CIE/RFC/1890/10.htm DVI4] codec, as defined in [https://www.freesoft.org/CIE/RFC/1890/index.htm RFC1890] is a variant of [[IMA ADPCM]] where, unlike [[IMA ADPCM]] where the header stores the first sample, in DVI4 the header stores the initial predictor state.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

DVI IMA ADPCM

2018-10-12T02:28:39Z

Lord Nightmare: add description of DVI4 codec and links

According to the [[XAnim]] multimedia application, there are two variants of DVI [[IMA ADPCM]], both of which are encoded and decoded with the IMA ADPCM algorithm. The original variant encodes the top nibble of a byte first, then the bottom nibble. The revised variant has the opposite encoding order.

- DVI4 -
The [https://www.freesoft.org/CIE/RFC/1890/10.htm DVI4] codec, as defined in [https://www.freesoft.org/CIE/RFC/1890/index.htm RFC1890] is a variant of [[IMA ADPCM]] where, unlike [[IMA ADPCM]] where the header stores the first sample, in DVI4 the header stores the initial predictor state.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

Yamaha ADPCM

2018-10-12T01:55:53Z

Lord Nightmare: add note about AICA

Microsoft ADPCM

2017-12-28T20:41:32Z

Lord Nightmare: add note about the predictor values, and that others can be added

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM
* 'short' ID: MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (builtin predictors are in the range [0..6] but others can be manually defined)
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
// These are the 'built in' set of 7 predictor value pairs; additional values can be added to this table by including them as metadata chunks in the WAVE header
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft IMA ADPCM

2017-10-30T06:23:41Z

Lord Nightmare: Undo revision 15329 by Lord Nightmare (talk)

* Audio ID: 0x0011
* FOURCC: 'm', 's', 0x00, 0x11
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_DVI_ADPCM
* 'short' ID: DVI_ADPCM
* ACM Codec: 'imaadp32.acm' (included in Windows 95+)

A Microsoft media file (this includes [[Microsoft Wave|WAV]], [[Microsoft Audio/Video Interleaved|AVI]], and [[Microsoft Advanced Streaming Format|ASF]]) that is encoded with [[IMA ADPCM]] data has an audio format number of 0x11. The file will have a [[WAVEFORMATEX]] structure in its header which contains a field named nBlockAlign. This field reveals the size of a block of IMA-encoded data.

Note that Microsoft IMA data can also occur in Apple Quicktime files using the fourcc 'msx0x11'. In this case, a [[WAVEFORMATEX]] header will be attached to the Quicktime file's audio stsd atom.

If the IMA data is monaural, an individual chunk of data begins with the following preamble:

bytes 0-1: initial predictor (in little-endian format)
byte 2: initial index
byte 3: unknown, usually 0 and is probably reserved

The remaining bytes in the chunk are the IMA nibbles. Each byte is decoded bottom nibble first, then top nibble as follows:

byte0 byte1 byte2 byte3 ...
n1n0 n3n2 n5n4 n7n6 ...

If the IMA data is stereo, a chunk begins with two preambles, one for the left audio channel and one for the right channel:

bytes 0-1: initial predictor (in little-endian format) for left channel
byte 2: initial index for left channel
byte 3: unknown, usually 0 and is probably reserved
bytes 4-5: initial predictor (in little-endian format) for right channel
byte 6: initial index (for right channel)
byte 7: unknown, usually 0 and is probably reserved

The remaining bytes in the chunk are the IMA nibbles. The first 4 bytes, or 8 nibbles, belong to the left channel and the next 4 bytes belong to the right channel. This interleaving continues until the end of the chunk:

byte0 byte1 byte2 byte3 ...
n1n0 n3n2 n5n4 n7n6 ...(left channel)
byte4 byte5 byte6 byte7 ...
n1n0 n3n2 n5n4 n7n6 ...(right channel)

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

Microsoft IMA ADPCM

2017-10-30T06:22:40Z

Lord Nightmare: there's no point in storing both the short and long ID, the short ID is just the long id with WAVE_FORMAT removed...

* Audio ID: 0x0011
* FOURCC: 'm', 's', 0x00, 0x11
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_DVI_ADPCM
* ACM Codec: 'imaadp32.acm' (included in Windows 95+)

A Microsoft media file (this includes [[Microsoft Wave|WAV]], [[Microsoft Audio/Video Interleaved|AVI]], and [[Microsoft Advanced Streaming Format|ASF]]) that is encoded with [[IMA ADPCM]] data has an audio format number of 0x11. The file will have a [[WAVEFORMATEX]] structure in its header which contains a field named nBlockAlign. This field reveals the size of a block of IMA-encoded data.

Note that Microsoft IMA data can also occur in Apple Quicktime files using the fourcc 'msx0x11'. In this case, a [[WAVEFORMATEX]] header will be attached to the Quicktime file's audio stsd atom.

If the IMA data is monaural, an individual chunk of data begins with the following preamble:

bytes 0-1: initial predictor (in little-endian format)
byte 2: initial index
byte 3: unknown, usually 0 and is probably reserved

The remaining bytes in the chunk are the IMA nibbles. Each byte is decoded bottom nibble first, then top nibble as follows:

byte0 byte1 byte2 byte3 ...
n1n0 n3n2 n5n4 n7n6 ...

If the IMA data is stereo, a chunk begins with two preambles, one for the left audio channel and one for the right channel:

bytes 0-1: initial predictor (in little-endian format) for left channel
byte 2: initial index for left channel
byte 3: unknown, usually 0 and is probably reserved
bytes 4-5: initial predictor (in little-endian format) for right channel
byte 6: initial index (for right channel)
byte 7: unknown, usually 0 and is probably reserved

The remaining bytes in the chunk are the IMA nibbles. The first 4 bytes, or 8 nibbles, belong to the left channel and the next 4 bytes belong to the right channel. This interleaving continues until the end of the chunk:

byte0 byte1 byte2 byte3 ...
n1n0 n3n2 n5n4 n7n6 ...(left channel)
byte4 byte5 byte6 byte7 ...
n1n0 n3n2 n5n4 n7n6 ...(right channel)

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

Microsoft IMA ADPCM

2017-10-30T06:21:07Z

Lord Nightmare: add acm, wformattag and short id

Microsoft ADPCM

2017-10-30T06:18:01Z

Lord Nightmare: clarify 'short' ID

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM
* 'short' ID: MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Dialogic IMA ADPCM

2017-10-30T06:16:44Z

Lord Nightmare: better format for the hardware implementations

* Microsoft Audio ID: 0x0010
* Extension: vox, oki
* Company: [[Dialogic]], Oki Electric Industry
* Official Specification: http://multimedia.cx/mirror/dialogic-adpcm.pdf

Dialogic ADPCM is a variation of the standard [[IMA ADPCM]] algorithm that is optimized for monaural voice data. The encoder operates on 12-bit input samples and outputs 4-bit encoding for each sample. This yields a 3:1 compression ratio.

Dialogic ADPCM data is transported in raw files bearing the extension VOX. For each byte in the file, the high nibble (bits 7-4) is decoded first, then the low nibble.

The decoding algorithm is the same as the standard IMA ADPCM algorithm with the following modifications:

* A different, smaller step table is used (refer to Appendix A for the table). The table contains 49 values ranging from indices 0..48.
* The predictor is always initialized to 0 at the start of decoding.
* The index is always initialized to 16 at the start of decoding.
* When the index is modified by the ADPCM delta, it should be clamped within the 0..48 range, rather than 0..88.
* When the diff is applied to the predictor, it should be clamped within a signed 12-bit range (-2048..2047) rather than a signed 16-bit range.
* The output samples are 12 bits in resolution and should be scaled as necessary.

== Modified Step Table ==

int dialogic_ima_step[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449,
494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

== Hardware Implementations ==
The following ICs can decode this codec:
* OKI MSM5205
* OKI MSM6295

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

DVI IMA ADPCM

2017-10-30T06:09:41Z

Lord Nightmare: I need to rethink this...

Dialogic IMA ADPCM

2017-10-30T03:42:43Z

Lord Nightmare: add note about hardware decoders for OKI/Dialogic IMA ADPCM

* Microsoft Audio ID: 0x0010
* Extension: vox, oki
* Company: [[Dialogic]], Oki Electric Industry
* Official Specification: http://multimedia.cx/mirror/dialogic-adpcm.pdf

Dialogic ADPCM is a variation of the standard [[IMA ADPCM]] algorithm that is optimized for monaural voice data. The encoder operates on 12-bit input samples and outputs 4-bit encoding for each sample. This yields a 3:1 compression ratio.

Dialogic ADPCM data is transported in raw files bearing the extension VOX. For each byte in the file, the high nibble (bits 7-4) is decoded first, then the low nibble.

The decoding algorithm is the same as the standard IMA ADPCM algorithm with the following modifications:

* A different, smaller step table is used (refer to Appendix A for the table). The table contains 49 values ranging from indices 0..48.
* The predictor is always initialized to 0 at the start of decoding.
* The index is always initialized to 16 at the start of decoding.
* When the index is modified by the ADPCM delta, it should be clamped within the 0..48 range, rather than 0..88.
* When the diff is applied to the predictor, it should be clamped within a signed 12-bit range (-2048..2047) rather than a signed 16-bit range.
* The output samples are 12 bits in resolution and should be scaled as necessary.

== Modified Step Table ==

int dialogic_ima_step[49] = {
16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449,
494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552
};

== Hardware Implementations ==
The OKI MSM5205 and MSM6295 ADPCM player chips can hardware-decode data encoded in this codec. They are commonly found on arcade games.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

DVI IMA ADPCM

2017-10-30T03:07:25Z

Lord Nightmare: add more information

According to the [[XAnim]] multimedia application, there are two variants of DVI [[IMA ADPCM]], both of which are encoded and decoded with the IMA ADPCM algorithm. The original variant encodes the top nibble of a byte first, then the bottom nibble. The revised variant has the opposite encoding order.

[[IMA ADPCM]] and [[Microsoft IMA ADPCM]] are both the same codec, an implementation of the Intel/DVI(R) IMA ADPCM standard, the only difference being encapsulation around (and nybble order of) the ADPCM data. The [[IMA ADPCM]] standard did not specify headers (RIFF/WAV/AU/etc) nor did it specify a nybble order for packing 4-bit ADPCM nybbles to a byte, while the [[Microsoft IMA ADPCM]] implementation does. It is possible that other [[IMA ADPCM]] implementations, such as the one in .AU and .AIFF files, is different in this regard.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

DVI IMA ADPCM

2017-10-30T02:51:56Z

Lord Nightmare: add info about the fact that DVI_IMA_ADPCM, IMA_ADPCM and Microsoft_IMA_ADPCM are all fundamentally the same codec

According to the [[XAnim]] multimedia application, there are two variants of DVI [[IMA ADPCM]], both of which are encoded and decoded with the IMA ADPCM algorithm. The original variant encodes the top nibble of a byte first, then the bottom nibble. The revised variant has the opposite encoding order.

[IMA ADPCM] and [Microsoft IMA ADPCM] are both the same codec, an implementation of the IMA/DVI ADPCM standard, the only difference being encapsulation around the ADPCM data. The [IMA ADPCM] standard did not specify RIFF/WAV file headers, while the [Microsoft IMA ADPCM] implementation does.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

IMA ADPCM

2017-10-30T02:49:15Z

Lord Nightmare: add link to original IMA ADPCM specification document

The [[Interactive Multimedia Association]] (IMA) developed an ADPCM algorithm designed to be used in entertainment multimedia applications. It is particularly fast to encode and decode and does not strictly require any multiplications or floating point operations.

While the encoding and decoding algorithms remain more or less constant across different IMA implementations, the specific on-disk data formats vary. This page describes the common IMA decoding algorithm. See the [[:Category:IMA ADPCM Audio Codecs]] page for various formats used for storing the data on disk.

== Decoding IMA ==
To decode IMA ADPCM, initialize 3 variables:

* predictor: This is either initialized from the data chunk preamble specified in the format or is initialized to 0 at the start of the decoding process.
* step index: Similar to the initial predictor, this variable is initialized from the data chunk preamble or set to 0 at the start of the decoding process.
* step: This variable is initialized to ima_step_table[step_index].

The encoded IMA bitstream is comprised of a series of 4-bit nibbles. This means that each byte represents 2 IMA nibbles. The specific data format will dictate whether the stream is decoded top nibble first or bottom nibble first, and whether there is stereo interleaving within the IMA nibbles. For this discussion, imagine the IMA bitstream as a series of nibbles representing a single audio channel:

n0 n1 n2 n3 n4 n5 ...

Where each nibble represents both a table index and a sign/magnitude number during the decoding process. Transform each nibble in the stream into a signed, 16-bit PCM sample using the following process:

step_index = step_index + ima_index_table[(unsigned)nibble]

diff = ((signed)nibble + 0.5) * step / 4

predictor = predictor + diff

step = ima_step_table[step_index]

Regarding the step index and predictor calculations: Be sure to saturate the computed step index between 0 and 88 (table limits) and the predictor between -32768 and 32767 (signed 16-bit number range). It is possible for these values to outrange which could cause undesirable program behavior if unchecked.

== Optimization ==

A note about the following calculation:

diff = ((sign/mag.)nibble + 0.5) * step / 4

At first glance, it appears that this calculation requires floating point operations and an arbitrary (not power-of-2) multiplication. However, some numerical manipulations reveal some useful simplifications:

diff = ((step * nibble) + (step / 2)) / 4

diff = (step * nibble / 4) + (step / 8)

The step / 8 calculation can be expressed as a bit shift right by 3 (step SHR 3). The first part of the equation can also be simplified. Since a nibble only carries 4 bits, and those 4 bits are a sign/magnitude number, there are only 3 bits of magnitude information. If all 3 magnitude bits are set to 1:

nibble = 4 + 2 + 1

step * nibble / 4 = (4 * step / 4) + (2 * step / 4) + (1 * step / 4) = step + (step / 2) + (step / 4)

Thus, if bit 2 of the nibble is set, add step to diff. If bit 1 is set, add (step / 2 = step SHR 1) to diff. If bit 0 is set, add (step / 4 = step SHR 2) to diff. Finally, if the sign bit is set, subtract the final diff value from the predictor value; otherwise, add the final diff value to the predictor value. The usual algorithm is as follows:

sign = nibble & 8
delta = nibble & 7
diff = step >> 3
if (delta & 4) diff += step
if (delta & 2) diff += (step >> 1)
if (delta & 1) diff += (step >> 2)
if (sign) predictor -= diff
else predictor += diff

This method was particularly useful back when IMA was implemented on commodity CPUs which were relatively slow at multiplication. One multiplication per audio sample had a notable impact on program performance, as opposed to the series of branches, additions and logical bit operations. If multiplication performance is not an issue, it is possible to carry out the diff calculation with only one non-power-of-2 multiplication and no floating point numbers:

diff = ((((signed)nibble+0.5) * step) / 4) * (2 / 2)

diff = (nibble + 0.5) * 2 * step / 8

diff = (2 * nibble + 1) * step / 8

[NOTE: something seems wrong here, e.g. for nibble = 3 and step = 3 we would get with the upper formula
diff = 0 + 1 + 0 = 1
and with the lower one
diff = (2 * 3 + 1) * 3 / 8 = 21 / 8 = 2
Since with ADPCM errors can propagate forever that seems like a really bad thing...
]

== Decoding Tables ==

int ima_index_table[16] = {
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8
};

Note that many programs use slight deviations from the following table, but such deviations are negligible:

int ima_step_table[89] = {
7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
};

== IMA ADPCM Specification ==
A scanned, OCR'ed copy of the original IMA/DVI ADPCM specification document can be found at http://www.cs.columbia.edu/~hgs/audio/dvi/IMA_ADPCM.pdf with original page scans at http://www.cs.columbia.edu/~hgs/audio/dvi/

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]
[[Category:IMA ADPCM Audio Codecs]]

Microsoft ADPCM

2017-10-30T02:41:16Z

Lord Nightmare: add wFormatTag ID

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* wFormatTag ID: WAVE_FORMAT_ADPCM or MS_ADPCM
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2017-10-29T02:07:19Z

Lord Nightmare: fix typo

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* ACM Codec: 'msadp32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2017-10-29T02:06:49Z

Lord Nightmare: add acm codec info

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]
* ACM Codec: 'msadpm32.acm' (included in Windows 95+)

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Yamaha ADPCM

2017-10-29T02:05:04Z

Lord Nightmare: clarify 'codec' link

* Microsoft Audio ID: 0x0020
* Extension: spb,mmf
* Company: Yamaha
* Sample: http://samples.mplayerhq.hu/A-codecs/format-0x20-laugh.mmf
* ACM Codec: https://web.archive.org/web/20160323215457/http://smaf-yamaha.com/jp/tools/dl/Yamaha-ADPCM-ACM-Driver-100-j.zip

A variant of this codec is used by several Yamaha chips:
* Y8950(MSX-SOUND)
* YM2608（OPNA) [the external ADPCM channel only]
and may also be used on the following chips:
* YM2610(OPNB) [the external ADPCM_B channel only?]
* YMZ263B(MMA)
* YMZ280B(PCMD8)
The codec was also used by Yamaha [[SMAF]] MA-2 and onward):
* MA-2 (YMU759)
* MA-3 (YMU762)
* MA-5 (YMU765)
* MA-7 (YMU786)

The functionality of this codec is explained fairly extensively in two datasheets:
* Y8950 application manual: http://www.datasheetarchive.com/pdf/download.php?id=212962c2fe1b63fdc5ab320ca05ff3efefc925&type=M&query=y-8950
* YM2608 datasheet (Japanese): http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J.PDF
* Translated version of YM2608 datasheet: http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J%20Translated.PDF

[[Category:Audio Codecs]]

Yamaha ADPCM

2017-10-29T00:41:39Z

Lord Nightmare: add link to codec, add references to SMAF chips using this codec

* Microsoft Audio ID: 0x0020
* Extension: spb,mmf
* Company: Yamaha
* Sample: http://samples.mplayerhq.hu/A-codecs/format-0x20-laugh.mmf
* Codec: https://web.archive.org/web/20160323215457/http://smaf-yamaha.com/jp/tools/dl/Yamaha-ADPCM-ACM-Driver-100-j.zip

A variant of this codec is used by several Yamaha chips:
* Y8950(MSX-SOUND)
* YM2608（OPNA) [the external ADPCM channel only]
and may also be used on the following chips:
* YM2610(OPNB) [the external ADPCM_B channel only?]
* YMZ263B(MMA)
* YMZ280B(PCMD8)
The codec was also used by Yamaha [[SMAF]] MA-2 and onward):
* MA-2 (YMU759)
* MA-3 (YMU762)
* MA-5 (YMU765)
* MA-7 (YMU786)

The functionality of this codec is explained fairly extensively in two datasheets:
* Y8950 application manual: http://www.datasheetarchive.com/pdf/download.php?id=212962c2fe1b63fdc5ab320ca05ff3efefc925&type=M&query=y-8950
* YM2608 datasheet (Japanese): http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J.PDF
* Translated version of YM2608 datasheet: http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J%20Translated.PDF

[[Category:Audio Codecs]]

Yamaha ADPCM

2017-10-28T23:40:45Z

Lord Nightmare: add notes about other chips which use the Yamaha ADPCM codec, and some sources

* Microsoft Audio ID: 0x0020
* Extension: spb,mmf
* Company: Yamaha
* Sample: http://samples.mplayerhq.hu/A-codecs/format-0x20-laugh.mmf

A variant of this codec is used by several Yamaha chips:
* Y8950(MSX-SOUND)
* YM2608（OPNA) [the external ADPCM channel only]
and may also be used on the following chips:
* YM2610(OPNB) [the external ADPCM_B channel only?]
* YMZ263B(MMA)
* YMZ280B(PCMD8)

The functionality of this codec is explained fairly extensively in two datasheets:
* Y8950 application manual: http://www.datasheetarchive.com/pdf/download.php?id=212962c2fe1b63fdc5ab320ca05ff3efefc925&type=M&query=y-8950
* YM2608 datasheet (Japanese): http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J.PDF
* Translated version of YM2608 datasheet: http://nemesis.hacking-cult.org/MegaDrive/Documentation/YM2608J%20Translated.PDF

[[Category:Audio Codecs]]

Microsoft ADPCM

2017-10-27T09:17:01Z

Lord Nightmare: add another Jayant paper, some clarification

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The adaptation table comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf (Table VIII, 'DPCM' column, B=4).
This paper, along with its companion paper https://ia902601.us.archive.org/13/items/bstj52-7-1105/bstj52-7-1105.pdf originally coined the term "ADPCM".

The relevant values from the paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry, for a final table of:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4, 3.0 }

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2017-10-27T08:39:49Z

Lord Nightmare: formatting

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The AdaptationTable comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf Table VIII, 'DPCM' column, B=4. The values from this paper are:
{ 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }
and Microsoft added an implicit '3.0' value as a 9th entry.

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of
{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }
in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]

Microsoft ADPCM

2017-10-27T08:38:23Z

Lord Nightmare: add note about the origin of the adaptation table from Jayant's 1973 paper, and how it is derived

* Audio ID: 0x0002
* FOURCC: 'm','s',0x00,0x02
* Company: [[Microsoft]]

This format is Microsoft's own custom variation of the ADPCM concept.

MS ADPCM is organized in blocks. Each block has a preamble and a series of coded ADPCM nibbles. The total number of bytes in an individual ADPCM block is obtained through the nBlockAlign field of a media file's [[WAVEFORMATEX]] data structure.

A monaural block begins with the following preamble:

byte 0 block predictor (should be in the range [0..6])
bytes 1-2 initial delta
bytes 3-4 sample 1
bytes 5-6 sample 2

The initial delta and both samples are signed numbers (so take sign extension into account). The block predictor value is used as an index into two adaptation coefficient tables in order to initialize two coefficients, coeff1 and coeff2.

The initial 2 samples from the block preamble are sent directly to the output. Sample 2 is first, then sample 1. The remaining samples are decoded from the ADPCM nibbles, which comprise the rest of the bytes in the block. The bytes are decoded from the upper nibble (bits 7-4) first, then the lower nibble. For each nibble:

* predictor = ((sample1 * coeff1) + (sample2 * coeff2)) / 256
* predictor += (signed)nibble * delta (note that nibble is 2's complement)
* clamp predictor within signed 16-bit range
* PCM sample = predictor
* send PCM sample to the output
* shuffle samples: sample 2 = sample 1, sample 1 = calculated PCM sample
* compute next adaptive scale factor: delta = (AdaptationTable[nibble] * delta) / 256
* saturate delta to lower bound of 16

For stereo data, the block preamble stores interleaved initialization values for the left and right channels:

byte 0 left channel block predictor (should be [0..6])
byte 1 right channel block predictor (should be [0..6])
bytes 2-3 left channel initial idelta
bytes 4-5 right channel initial idelta
bytes 6-7 left channel sample 1
bytes 8-9 right channel sample 1
bytes 10-11 left channel sample 2
bytes 12-13 right channel sample 2

Following the preamble, the left and right ADPCM samples are interleaved within each byte. The upper nibble (bits 7-4) contains the left channel ADPCM code and the lower nibble contains the right channel ADPCM code.

The following tables define the values used to decode MS ADPCM data:

int AdaptationTable [] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
} ;
int AdaptCoeff1 [] = { 256, 512, 0, 192, 240, 460, 392 } ;
int AdaptCoeff2 [] = { 0, -256, 0, 64, 0, -208, -232 } ;

The AdaptationTable comes from Jayant's 1973 paper https://ia902600.us.archive.org/31/items/bstj52-7-1119/bstj52-7-1119.pdf Table VIII, 'DPCM' column, B=4. The values from this paper are { 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 }, and Microsoft added an implicit '3.0' value as a 9th entry.

To obtain the table used by Microsoft ADPCM, multiply the values from Jayant's table by 256 and round down. The adaptation table holds the absolute step size values for signed input nybbles of { 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 } in that order, so take the absolute value of the nybble and use that as an offset into the table.

[[Category:Audio Codecs]]
[[Category:ADPCM Audio Codecs]]