Initial revision
[libav.git] / doc / README.tech
1 Technical notes:
2 ---------------
3
4 - To increase speed, only motion vectors (0,0) are tested
5
6 - The decision intra/predicted macroblock is the algorithm suggested
7 by the mpeg 1 specification.
8
9 - only Huffman based H263 is supported, mainly because of patent
10 issues.
11
12 - Many options can be modified only in the source code.
13
14 - I rewrote the mpeg audio layer 2 compatible encoder from scratch. It
15 is one of the simplest encoder you can imagine (800 lines of C code
16 !). It is also one of the fastest because of its simplicity. They
17 are still some problems of overflow. A minimal psycho acoustic model
18 could be added. Only mono stream can be generated. I may add stereo
19 if needed.
20
21 - I rewrote the AC3 audio encoder from scratch. It is fairly naive,
22 but the result are quiet interesting at 64 kbit/s. It includes
23 extensions for low sampling rates used in some Internet
24 formats. Differential and coupled stereo is not handled. Stereo
25 channels are simply handled as two mono channels.