[FFmpeg-devel] [PATCH] avformat/fivdec: cached keyframes before video or audio stream was created

[Michael Niedermayer]

On Wed, Jul 27, 2016 at 09:56:02AM +0800, XinZheng Zhang wrote:
> On Wed, Jul 27, 2016 at 7:25 AM, Michael Niedermayer
> <michael at niedermayer.cc> wrote:
> > On Wed, Jul 27, 2016 at 01:31:29AM +0800, XinZheng Zhang wrote:
> >> On Wed, Jul 27, 2016 at 1:12 AM, Michael Niedermayer
> >> <michael at niedermayer.cc> wrote:
> >> > On Tue, Jul 26, 2016 at 08:17:46PM +0800, Xinzheng Zhang wrote:
> > [...]
> >> >> +
> >> >> +    AVStream *streams[2] = {vstream, astream};
> >> >> +    for (i = 0; i < 2; i++) {
> >> >> +        current_stream = streams[i];
> >> >> +        if (current_stream && current_stream->nb_index_entries==0) {
> >> >> +            for (j = 0; j < flv->keyframe_count; j++) {
> >> >> +                av_add_index_entry(current_stream, flv->keyframe_filepositions[j], flv->keyframe_times[j] * 1000,
> >> >> +                                   0, 0, AVINDEX_KEYFRAME);
> >> >> +            }
> >> >> +        }
> >> >> +    }
> >> >> +
> >> >> +    // free keyframe index only if all expected streams have been created
> >> >> +    if (((vstream && vstream->nb_index_entries>0) || !flv->vhead_exists) &&
> >> >> +        ((astream && astream->nb_index_entries>0) || !flv->ahead_exists)) {
> >> >> +        av_freep(&flv->keyframe_times);
> >> >> +        av_freep(&flv->keyframe_filepositions);
> >> >> +        flv->keyframe_count = 0;
> >> >> +    }
> >> >> +}
> >> >
> >> > spliting add_keyframes_index() out must be in a seperate patch
> >> >
> >> > also i would not trust the *head_exists flags, IIRC they can be
> >> > wrong and they are not needed
> >> > the function should just take the table load it with
> >> > av_add_index_entry() and free the table.
> >> > The rest should not be needed
> >> > should be much simpler unless iam missing something
> >> >
> >> >
> >>
> >> If I don't trust the head_exists flags, when should I free the index table?
> >> Should I keep the index util both a\v stream have been loaded or keep
> >> it util the flv_read_close().
> >
> > the table was freed after av_add_index_entry()
> > that should still work fine unless i miss somethig
> >
> 
> [meta]-[v]-[v]..........................[a]
> In this case both video and audio stream share the same index table.
> I am not know whether the audio stream exists until the first audio
> packet parsed.
> I thought that I should keep the index until all the streams have been loaded.

in the example above the video key frame table would be loaded
and added into the video stream once it has been created, and
freed afterwards
nothing is done with audio (currently or after the change)

if the audio table is prior the video one its loaded and freed once
the video table is encountered

do i miss something ?

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct answer.
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