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

James Almer jamrial at gmail.com
Fri Apr 20 19:11:42 EEST 2018

On 4/20/2018 1:09 PM, Paul B Mahol wrote:
> On 4/20/18, James Almer <jamrial at gmail.com> wrote:
>> 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.
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> Take real sample from game, if first frame is not marked as keyframe,
> demuxer is wrong.

That's exactly what happens right now with the capcom logo sample in the
FATE suite, as i mentioned earlier.

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