From 47bbf8a71d22a5e2d5d0152b213b4ed6ec6778c6 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 22 Mar 2007 13:27:11 +0000 Subject: [PATCH] clarify codec_tag Originally committed as revision 8484 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/avcodec.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index e5f246f9a2..db7bbed6dc 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -971,6 +971,13 @@ typedef struct AVCodecContext { /** * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). * this is used to workaround some encoder bugs + * a demuxer should set this to what is stored in the field used to identify the codec + * if there are mutiple such fields in a container then the demuxer should choose the one + * which maximizes the information about the used codec + * if the codec tag field in a container is larger then 32bit then the demxuer should + * remap the longer id to 32bit with a table or other structure alternatively a new + * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated + * first * - encoding: set by user, if not then the default based on codec_id will be used * - decoding: set by user, will be converted to upper case by lavc during init */