Changes between Initial Version and Version 1 of Ticket #6418, comment 17


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Timestamp:
Jan 8, 2018, 4:13:27 PM (9 months ago)
Author:
mkver
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  • Ticket #6418, comment 17

    initial v1  
    11I can confirm that this issue affects not only MPEG2, but also H.264 as rycius has said. And it really has something to do with SPS/PPS parsing: It treats recovery point I frames that are not IDR frames as keyframes if they have SPS and PPS inband; if the SPS and PPS is merely available via extradata, it refuses to decode. IDR frames are always treated as keyframes and it works with extradata, too, not only in-band extradata. 
    2 I tested rycius' patch and it really makes qsv not give up if the first frame it finds is not a keyframe; but it does not change which frames qsv treats as keyframes. It should probably be put posted on the developers mailing list to be merged as they see fit. 
     2I tested rycius' patch and it really makes qsv not give up if the first frame it finds is not a keyframe; but it does not change which frames qsv treats as keyframes. It should probably be posted on the developers mailing list to be merged as they see fit. 
    33I'll attach some H.264 samples so that developers have something tangible to work with. 
    44IDR.No.Inband.SPPS.mkv contains two GOPs: First an open GOP with a keyframe (with a recovery message SEI) and then a second GOP with an IDR frame at the beginning. There are no in-band SPS/PPS. With the patch, the first GOP produces some errors, but the second GOP is correctly decoded. Without the patch, nothing is decoded at all.