mirror of
https://github.com/xenia-project/FFmpeg.git
synced 2025-01-23 04:16:07 +00:00
80e103d04c
this patch enhances the jpeg header writer. It can be asked to omit quantisation and huffman tables and it can write different horizontal and vertical sampling factors. (the last thing is useless for libavcodec itself (because libavcodec only handles YUV420P at ecoder level), but the values are initialized so that operation of libavcodec is not impaired) Originally committed as revision 290 to svn://svn.ffmpeg.org/ffmpeg/trunk
FFmpeg - (c) 2000,2001 Gerard Lantau. 1) Introduction --------------- ffmpeg is a hyper fast realtime audio/video encoder, a streaming server and a generic audio and video file converter. It can grab from a standard Video4Linux video source and convert it into several file formats based on DCT/motion compensation encoding. Sound is compressed in MPEG audio layer 2 or using an AC3 compatible stream. What makes ffmpeg interesting ? - Innovative streaming technology : multiformat, real time encoding, simple configuration. - Simple and efficient video encoder: outputs MPEG1, H263, Real Video(tm), MPEG4, DIVX and MJPEG compatible bitstreams using the same encoder core. - Real time encoding (25 fps in 352x288 on a K6 500) using the video4linux API. - Generates I and P frames, which means it is far better than a MJPEG encoder. - Hyper fast MPEG audio layer 2 compression (50 times faster than realtime on a K6 500). - Hyper fast AC3 compatible encoder. - simple and very small portable C source code, easy to understand and to modify. It be may the smallest decent MPEG encoder :-) - optional non real time higher quality encoding (different motion estimators available). - Audio and Video decoders are in development. ffmpeg is made of two programs: * ffmpeg: soft VCR which encodes in real time to several formats. It can also encode from any supported input file format to any input supported format. * ffserver: high performance live broadcast streaming server based on the ffmpeg core encoders. 2) Documentation ---------------- * Read doc/ffmpeg.txt and doc/ffserver.txt to learn the basic features. * Read doc/TODO to know what are the know bugs and missing features. * Read doc/README.dev if you want to contribute or use the codec or format libraries. 3) Licensing: ------------ * See the file COPYING. ffmpeg and the associated library are licensed under the GNU General Public License. I may change the license of libavcodec and libav to LGPL if many people ask it (and if they submit good patches!). * This code should be patent free since it is very simple. I took care to use the same video encoder/decoder core for all formats to show that they really ARE THE SAME except for the encoding huffman codes. Gerard Lantau (glantau@yahoo.fr).