DTS: Difference between revisions
(Another link to DTS information) |
(Some notes on bitstream coding) |
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The [[VideoLAN]] project has created [http://developers.videolan.org/libdca.html libdts/libdca] an open source implementation of DTS. Unfortunately libdts was pushed underground through patent scare tactics for a while. | The [[VideoLAN]] project has created [http://developers.videolan.org/libdca.html libdts/libdca] an open source implementation of DTS. Unfortunately libdts was pushed underground through patent scare tactics for a while. | ||
== Bitstream coding == | |||
There are four different bitstream formats -- little- or big-endian and 16 or 14 bits per word. | |||
=== Raw bitstream coding === | |||
Raw bitstream is packed into 16-bit words with possible little- or big-endian. | |||
=== 14-bit words === | |||
This kind of bitstream is packed into 16-bit words where high two bits contain some auxiliary information (parity?). This coding is used in many DTS-in-[[WAV]] files. | |||
=== How to distinguish different versions === | |||
Every frame in DTS starts with 32-bit syncword which can be used to distinguish current bitstream encoding: | |||
{| border="1" | |||
! Sequence !! Bitstream type | |||
|- | |||
| 7F FE 80 01 ||raw big-endian | |||
|- | |||
| FE 7F 01 80 ||raw little-endian | |||
|- | |||
| 1F FF E8 00 07 Fx || 14-bit big-endian | |||
|- | |||
|FF 1F 00 E8 Fx 07 ||14-bit little-endian | |||
|} | |||
[[Category:Audio Codecs]] | [[Category:Audio Codecs]] | ||
Revision as of 10:33, 11 February 2007
- Codec ID: 0x2001
- Company: DTS Inc.
DTS Coherent Acoustics is a perceptual audio codec. The main technique used is a QMF filter together with Huffman, ADPCM and vector quantization.
Specification can be found through the ETSI, search for DTS. Info completeing the incomplete specification can be found here [1], [2] and here [3].
The VideoLAN project has created libdts/libdca an open source implementation of DTS. Unfortunately libdts was pushed underground through patent scare tactics for a while.
Bitstream coding
There are four different bitstream formats -- little- or big-endian and 16 or 14 bits per word.
Raw bitstream coding
Raw bitstream is packed into 16-bit words with possible little- or big-endian.
14-bit words
This kind of bitstream is packed into 16-bit words where high two bits contain some auxiliary information (parity?). This coding is used in many DTS-in-WAV files.
How to distinguish different versions
Every frame in DTS starts with 32-bit syncword which can be used to distinguish current bitstream encoding:
| Sequence | Bitstream type |
|---|---|
| 7F FE 80 01 | raw big-endian |
| FE 7F 01 80 | raw little-endian |
| 1F FF E8 00 07 Fx | 14-bit big-endian |
| FF 1F 00 E8 Fx 07 | 14-bit little-endian |