[FFmpeg-devel] [PATCH 1/1] segafilm: fetch duration from the container

[James Almer]

On 4/20/2018 12:34 PM, Gyan Doshi wrote:
> 
> 
> On 4/20/2018 8:35 PM, James Almer wrote:
> 
> 
>> I don't understand the reasoning to invert the logic here. The current
>> behavior is clearly not right. We're marking Inter coded frames as key
>> frames and Intra coded frames as non keyframes.
> 
> This behaviour was how it was originally. See the sample attached to
> #7091. Before inversion, first frame on that file is not marked as KF
> but all remaining frames are.
> 
> If you streamcopy the FATE sample to a new CPK starting at a frame
> currently not marked as KF, with -copyinkf, you should see
> artifact/incorrect decoding in the output.

Wouldn't this hint that the file in question is broken? I see it was
generated with our muxer, which is indeed setting keyframes wrong.

In line 72 from segafilmenc.c I see

        if (pkt->keyframe)
            info1 |= (1 << 31);

So basically, a fifteen years old demuxer got its logic inverted to
match the behavior of an evidently faulty month old muxer.