mirror of https://git.ffmpeg.org/ffmpeg.git
0147f19856
* Some BeOS fixes:
- errno stuff
- nanosleep() replacement
- added a doc/README.beos
* mov reader still has problems with most videos (skips many chunks),
- It should now read .mov files with zlib-compressed moov headers (aka cmov)
- added SVQ1 support.
- removed mapping 'raw ' and 'yuv2' to h263, was my mistake.
- added IMA4 support. (tested)
- fixed frame rate (it reported 0 fps or something before)
- extended file probing ('wide' and 'free' atoms)
- improved .mov/.mp4 detection (or so I think)
* adpcm
* added zlib support, with header file and lib check
Originally committed as revision 780 to svn://svn.ffmpeg.org/ffmpeg/trunk
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| .. | ||
| FAQ | ||
| HOWTO-STREAM | ||
| README.beos | ||
| README.dev | ||
| README.tech | ||
| TODO | ||
| bench.txt | ||
| ffmpeg.txt | ||
| ffserver.conf | ||
| ffserver.txt | ||
README.tech
Technical notes: --------------- Video: ----- - The decision intra/predicted macroblock is the algorithm suggested by the mpeg 1 specification. - only Huffman based H263 is supported, mainly because of patent issues. - MPEG4 is supported, as an extension of the H263 encoder. MPEG4 DC prediction is used, but not AC prediction. Specific VLC are used for intra pictures. The output format is compatible with Open DIVX version 47. - MJPEG is supported, but in the current version the huffman tables are not optimized. It could be interesting to add this feature for the flash format. - To increase speed, only motion vectors (0,0) are tested for real time compression. NEW: now motion compensation is done with several methods : none, full, log, and phods. The code is mmx/sse optimized. - In high quality mode, full search is used for motion vectors. Currently, only fcode = 1 is used for both H263/MPEG1. Half pel vectors are used. Audio: ----- - The mpeg audio layer 2 compatible encoder was rewritten from scratch. It is one of the simplest encoder you can imagine (800 lines of C code !). It is also one of the fastest because of its simplicity. There are still some problems of overflow. A minimal psycho acoustic model could be added. Currently, stereo is supported, but not joint stereo. - The AC3 audio encoder was rewritten from scratch. It is fairly naive, but the result are quiet interesting at 64 kbit/s. It includes extensions for low sampling rates used in some Internet formats. Differential and coupled stereo is not handled. Stereo channels are simply handled as two mono channels. - The mpeg audio layer 3 decoder was rewritten from scratch. It uses only integers and can be 16 bit precision for the synthesis filter at the expense of a slight precision loss. A slower bit exact mode is available too for compliance testing.