Patch by Cyril Russo, stage D nexvision A laposte net

Originally committed as revision 23285 to svn://svn.ffmpeg.org/ffmpeg/trunk

Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.

Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk

output audio stream.

Originally committed as revision 18621 to svn://svn.ffmpeg.org/ffmpeg/trunk

Otherwise doxygen complains about ambiguous filenames when files exist
under the same name in different subdirectories.

Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 15762 to svn://svn.ffmpeg.org/ffmpeg/trunk

Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.'  to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".

Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk

Modify av_audio_convert() to use AVAudioConvert context struct; add av_audio_convert_alloc() and av_audio_convert_free() support functions.

Originally committed as revision 14496 to svn://svn.ffmpeg.org/ffmpeg/trunk

Add sample format support functions: avcodec_get_sample_fmt_name(), avcodec_get_sample_fmt(), avcodec_sample_fmt_string()

Originally committed as revision 14484 to svn://svn.ffmpeg.org/ffmpeg/trunk