[FFmpeg-devel] [PATCH] lavc/parser: export resolution and format in AVCodecContext if not already set

[Marton Balint]

On Tue, 15 Mar 2016, Rodger Combs wrote:

> This allows avformat_find_stream_info to finish without opening a decoder in
> more cases.

That may be a good thing, but it still removes existing functionality. 
Would it be too much work to introduce avformat_find_stream_info2 with an 
additional flags parameter where the user can set if he wants the code to 
open a decoder to get additional information?

>
> Since decoders still export some information that the corresponding parsers
> don't, this causes some fields to be unset in ffprobe output where the
> decoder would previously have only been called in avformat_find_stream_info.
> If this is a problem, the parsers should be updated to report that information
> as well.

Have you checked how "widespread" is this problem? E.g. how many 
previously known values will not be present in ffprobe -show_streams 
output if you run it to our sample corpus? If it is more than a few 
cases, (so fixing the parses is not a reasonable amount of work) then we 
shouldn't just break the output of ffprobe, but figure out something to 
keep it as full of information as possible.

Regards,
Marton