RealAudio cook: Difference between revisions
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for multichannel data there may be additional four bytes: | for multichannel data there may be additional four bytes: | ||
bytes 16-19 channel mask | bytes 16-19 channel mask | ||
== Frame organisation == | |||
In case of multichannel audio frame data may consist of several subpackets (for 5.1 it's usually 4 subpackets). In this case sizes in 16-bit words for subpackets 1-N are stored as bytes at the end of frame data. | |||
Subpacket data is XORed with <code>0x37 0xC5 0x11 0xF2</code>. | |||
[[Category:Audio Codecs]] | [[Category:Audio Codecs]] | ||
[[Category: MDCT Audio Codecs]] | [[Category: MDCT Audio Codecs]] | ||
[[Category: Multichannel Audio Codecs]] | [[Category: Multichannel Audio Codecs]] | ||
Revision as of 03:52, 11 July 2012
- FourCC: cook
- Company: Real
- Samples: http://samples.mplayerhq.hu/real/AC-cook/
RealAudio cook (a.k.a. Cooker a.k.a. gecko) is an audio codec created by Real. It features different coding modes.
Cook Flavors
00 8 Kbps Music - RealAudio 01 11 Kbps Music - RealAudio 02 16 Kbps Music - RealAudio 03 20 Kbps Music - RealAudio 04 32 Kbps Music - RealAudio 05 44 Kbps Music - RealAudio 06 64 Kbps Music - RealAudio 07 32 Kbps - RealAudio 08 6 Kbps Music - RealAudio 09 20 Kbps Stereo Music 10 32 Kbps Stereo Music 11 44 Kbps Stereo Music 12 64 Kbps Stereo Music 13 96 Kbps Stereo Music 14 64 Kbps - RealAudio 15 20 Kbps Music High Response - RealAudio 16 32 Kbps Music High Response - RealAudio 17 16 Kbps Stereo Music - RealAudio 18 20 Kbps Stereo Music - RealAudio 19 20 Kbps Stereo Music High Response - RealAudio 20 32 Kbps Stereo Music - RealAudio 21 32 Kbps Stereo Music High Response - RealAudio 22 44 Kbps Stereo Music - RealAudio 23 44 Kbps Stereo Music High Response - RealAudio 24 64 Kbps Stereo Music - RealAudio 25 96 Kbps Stereo Music - RealAudio 26 12 Kbps Stereo Music - RealAudio 27 64 kbps Stereo Surround - RealAudio 28 96 kbps Stereo Surround - RealAudio 29 44 kbps Stereo Surround - RealAudio 30 96 Kbps 5.1 Multichannel - RealAudio 10 31 132 Kbps 5.1 Multichannel - RealAudio 10 32 184 Kbps 5.1 Multichannel - RealAudio 10 33 268 Kbps 5.1 Multichannel - RealAudio 10
Type Specific Data
Cook data is encapsulated in RealMedia files which transport type specific data needed by different codecs. Cook requires 8 bytes of type specific data for monophonic audio and 16 bytes for stereo data. Multi-byte numbers are big-endian:
mono and stereo data:
bytes 0-3 Cook version bytes 4-5 samples per frame per channel bytes 6-7 number of subbands used in the frequency domain
stereo data requires 8 more bytes:
bytes 8-11 unused bytes 12-13 joint stereo subband start bytes 14-15 joint stereo VLC bits
for multichannel data there may be additional four bytes:
bytes 16-19 channel mask
Frame organisation
In case of multichannel audio frame data may consist of several subpackets (for 5.1 it's usually 4 subpackets). In this case sizes in 16-bit words for subpackets 1-N are stored as bytes at the end of frame data.
Subpacket data is XORed with 0x37 0xC5 0x11 0xF2.