ACT - Revision history

Ce: Supported since over two years

2014-04-02T10:21:36Z

Supported since over two years

← Older revision		Revision as of 03:21, 2 April 2014
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	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	~~[[Category:Undiscovered Audio Codecs]]~~

Reimar at 17:53, 22 July 2008

2008-07-22T17:53:16Z

← Older revision		Revision as of 10:53, 22 July 2008
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	* Samples: http://samples.mplayerhq.hu/A-codecs/act/		* Samples: http://samples.mplayerhq.hu/A-codecs/act/
	* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip		* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip
			* Unfinished FFmpeg patch: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-February/042714.html

	ACT files are created by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] when recording from the internal microphone.		ACT files are created by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] when recording from the internal microphone.

Voroshil: My previous changes (except bytes order) were wrong

2008-02-27T13:30:31Z

My previous changes (except bytes order) were wrong

← Older revision		Revision as of 06:30, 27 February 2008
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	\|Fine\|\|8000\|\|10\|\|51\|\|510\|\|2		\|Fine\|\|8000\|\|10\|\|51\|\|510\|\|2
	\|-		\|-
	\|Long\|\|4400\|\|11\|\|46\|\|506\|\|6		\|Long\|\|4400\|\|22\|\|23\|\|506\|\|6
	\|}		\|}

Line 126:		Line 126:
	\|}		\|}

	In Long mode one G.729 ~~frame forms 20ms~~ of audio data.		In Long mode one ACT frame forms two G.729 frames and thus 40ms of audio data.

	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	[[Category:Undiscovered Audio Codecs]]		[[Category:Undiscovered Audio Codecs]]

Voroshil: /* G.729A Codec parameters */

2008-02-25T17:31:25Z

G.729A Codec parameters

Voroshil: /* Frame format */

2008-02-25T17:18:03Z

Frame format

← Older revision		Revision as of 10:18, 25 February 2008
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	for(i=0 ; i<frame_size/2; i++)		for(i=0 ; i<frame_size/2; i++)
	{		{
	g729_data[2*i]=act_data[i]		g729_data[2*i+1]=act_data[i]
	g729_data[2*i+1]=act_data[frame_size/2+i]		g729_data[2*i]=act_data[frame_size/2+i]
	}		}


	=== G.729A Codec parameters ===		=== G.729A Codec parameters ===

Voroshil: /* Bitstream */

2008-02-25T17:14:58Z

Bitstream

← Older revision		Revision as of 10:14, 25 February 2008
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	\|Fine\|\|8000\|\|10\|\|51\|\|510\|\|2		\|Fine\|\|8000\|\|10\|\|51\|\|510\|\|2
	\|-		\|-
	\|Long\|\|4400\|\|22\|\|23\|\|506\|\|6		\|Long\|\|4400\|\|11\|\|46\|\|506\|\|6
	\|}		\|}

Alex: G729A wikipedia link

2007-11-20T02:43:57Z

G729A wikipedia link

← Older revision		Revision as of 19:43, 19 November 2007
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	ACT files uses the G729A speech compression codec. There are 3 different ways to record to this format from a player.		ACT files uses the [http://en.wikipedia.org/wiki/G.729a G729A] speech compression codec. There are 3 different ways to record to this format from a player.

	*Fine Rec		*Fine Rec

Merbanan: More ACT data (taken from the amv-codec-tools project)

2007-10-30T17:14:43Z

More ACT data (taken from the amv-codec-tools project)

@@ Line 11: / Line 11: @@
 *Long Vox, in this mode the player will record when voice activated.
-These 3 formats map to 2 bitstream formats, the Fine and Long bitstream formats.
+==ACT File Format==
 {| border="1" cellpadding="5" style="border-collapse: collapse; border-style: dashed; border-color: #2f6fab;"
@@ Line 24: / Line 27: @@
 Files are always aligned to 512 bytes boundary and contains 512 byte header and chunks of the same size. Each chunk consists of fixed number of frames and padding bytes.
 [[Category:Audio Codecs]]
 [[Category:Undiscovered Audio Codecs]]

Merbanan: bitstream format information

2007-10-30T10:39:21Z

bitstream format information

← Older revision		Revision as of 03:39, 30 October 2007
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	* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip		* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip

	ACT ~~is used as codec in is used~~ by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] when recording from the internal microphone.		ACT files are created by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] when recording from the internal microphone.


	ACT ~~is a low complexity~~ speech compression codec. There are 3 different ways to record to this ~~codec~~ from a player.		ACT files uses the G729A speech compression codec. There are 3 different ways to record to this format from a player.

	* Fine Rec		*Fine Rec
	* Long Rec		*Long Rec
	* Long Vox, in this mode the player will ~~just~~ record ~~if there is anything~~ to ~~record~~.		*Long Vox, in this mode the player will record when voice activated.

			These 3 formats map to 2 bitstream formats, the Fine and Long bitstream formats.


			{\| border="1" cellpadding="5" style="border-collapse: collapse; border-style: dashed; border-color: #2f6fab;"
			\|- bgcolor="#f0f0f0" \|
			! Name!! Sample rate!! Frame size!! Frames per chunk !! Chunk size !! Padding bytes
			\|-
			\|Fine\|\|8000\|\|10\|\|51\|\|510\|\|2
			\|-
			\|Long\|\|4400\|\|22\|\|23\|\|506\|\|6
			\|}

	It is unknown if there are several bitstream formats. With the software that are supposed to convert the files to wav audio are 2 or 3 command line programs. When running one the work G729 is mentioned and the bitrate 4,4k. So an initial guess is that the 3 recording formats are 8kbits, 4.4kbits and 4.4kbits with voice activation. And that the codec actually is G729

	==ACT File Format==		==ACT File Format==
			Files are always aligned to 512 bytes boundary and contains 512 byte header and chunks of the same size. Each chunk consists of fixed number of frames and padding bytes.

	~~The first 512 bytes seem to be a regular RIFF header. The function at 0x00401000 is in the call tree when converting act files.~~

	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	[[Category:Undiscovered Audio Codecs]]		[[Category:Undiscovered Audio Codecs]]

Merbanan: Guesses and info

2007-09-29T12:29:14Z

Guesses and info

← Older revision		Revision as of 05:29, 29 September 2007
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	* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip		* Working decoder: http://www.netac.com/Download/C635/C635%20Driver&Tools.zip

	ACT is a low complexity speech compression codec.It ~~might be~~ the G729 ~~speech code~~. ~~There seems to be~~ 3 ~~versions of~~ the ~~format.~~		ACT is used as codec in is used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] when recording from the internal microphone.


			ACT is a low complexity speech compression codec. There are 3 different ways to record to this codec from a player.

			* Fine Rec
			* Long Rec
			* Long Vox, in this mode the player will just record if there is anything to record.

			It is unknown if there are several bitstream formats. With the software that are supposed to convert the files to wav audio are 2 or 3 command line programs. When running one the work G729 is mentioned and the bitrate 4,4k. So an initial guess is that the 3 recording formats are 8kbits, 4.4kbits and 4.4kbits with voice activation. And that the codec actually is G729

	==ACT File Format==		==ACT File Format==

← Older revision		Revision as of 10:31, 25 February 2008
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	\| P0 \|\| Parity bit for Pitch delay \|\| 1 \|\| 1		\| P0 \|\| Parity bit for Pitch delay \|\| 1 \|\| 1
	\|-		\|-
	\| C1 \|\| Fixed codebook first subframe \|\| 13 \|\| 12		\| C1 \|\| Fixed codebook first subframe \|\| 13 \|\| 17
	\|-		\|-
	\| S1 \|\| Signs of fixed-codebook pulses 1st subframe \|\| 4 \|\| 9		\| S1 \|\| Signs of fixed-codebook pulses 1st subframe \|\| 4 \|\| 4
	\|-		\|-
	\| GA1 \|\| Gain codebook (stage 1) 1st subframe \|\| 3 \|\| 3		\| GA1 \|\| Gain codebook (stage 1) 1st subframe \|\| 3 \|\| 3
Line 115:		Line 115:
	\| P2 \|\| Pitch delay second subframe \|\| 5 \|\| 5		\| P2 \|\| Pitch delay second subframe \|\| 5 \|\| 5
	\|-		\|-
	\| C2 \|\| Fixed codebook 2nd subframe \|\| 13 \|\| 12		\| C2 \|\| Fixed codebook 2nd subframe \|\| 13 \|\| 17
	\|-		\|-
	\| S2 \|\| Signs of fixed-codebook pulses 2nd subframe \|\| 4 \|\| 9		\| S2 \|\| Signs of fixed-codebook pulses 2nd subframe \|\| 4 \|\| 4
	\|-		\|-
	\| GA2 \|\| Gain codebook (stage 1) 2nd subframe \|\| 3 \|\| 3		\| GA2 \|\| Gain codebook (stage 1) 2nd subframe \|\| 3 \|\| 3
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	\|}		\|}

	In Long mode ~~2 ACT frames form a~~ G.729 frame.		In Long mode one G.729 frame forms 20ms of audio data.

	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	[[Category:Undiscovered Audio Codecs]]		[[Category:Undiscovered Audio Codecs]]