On Tue, May 10, 2016 at 2:10 PM, Michael Niedermayer <mich...@niedermayer.cc> wrote: > > libavformat gathers information about streams in av_find_stream_info() > and that is all information completely unneeded by decoders > no decoder needs the width and height from the parser run by > av_find_stream_info() or other fields. These are only needed when they > come from format headers. > The only reason to go to the troubble to set these fields (and thats > quite some troubble) is to provide this information to the user > application and thus user > >
Technically the decoders wouldn't need this information, that is correct. However, many applications do on a technical level. ffmpeg.c for example would die a horrible death if it wouldn't know the resolution of the video beforehand, because its setup requires this crucial information before initializing filters and output encoders. One could write an application to respond to such data on the fly, but alas many apps at least want an initial value, or can't even respond to dynamic changes at all. Having this information available to the user to choose streams from is nice, but not the only reason. - Hendrik _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
