From: Kieran Kunhya <kier...@obe.tv> Sent: Wednesday, June 1, 2022 9:16 PM To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> Cc: softworkz <softwo...@hotmail.com> Subject: Re: [FFmpeg-devel] [PATCH 0/6] Implement SEI parsing for QSV decoders
On Thu, 26 May 2022 at 09:09, ffmpegagent <ffmpegag...@gmail.com<mailto:ffmpegag...@gmail.com>> wrote: But that doesn't help. Those bugs exist and I'm sharing my workarounds, which are empirically determined by testing a range of files. If someone is interested, I can provide private access to a repository where we have been testing this. Alternatively, I could also leave those workarounds out, and just skip those SEI types. I don't care much for QSV but I would say b-frame reordering heuristics like the one you are using may not necessarily catch all the possible structures in the wild from third-party encoders. I am not using any b-frame reordering heuristics, I just take the payloads in the order in which MSDK(QSV) provides it, and it has turned out that they are reordering the data according to the display order. I did some detailed analysis of files with out-of-order B-frames: https://gist.github.com/softworkz/36c49586a8610813a32270ee3947a932 Did you take a look? VLC had (has?) heuristics for this which would cause captions to not be frame accurate. Captions aren’t exactly “frame accurate” anyway as each frame has just a very small piece of information and only when a certain sequence is complete, it leads to some new letters or line being ready for display. But out-of-order would screw this definitely, but I haven’t seen any such cases. The code I’m submitting has been in testing for quite a while with a bunch of users and many files and TV streams with MP2Video, H264 and HEVC were tested. You could still be right, that there is a case. A while ago I had digged through https://streams.videolan.org/ and downloaded all samples that seemed to have CC, but maybe I missed one for the case you’re talking about. Do you have an idea where/how I could find such stream? Thanks, softworkz _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
