On Thu, Jul 11, 2024 at 10:28 PM Tomas Härdin <g...@haerdin.se> wrote: > > > + if (s->in_tile_headers == 1 && s->isHT && (!s- > > >Ccap15_b11)) > > + av_log(s->avctx, AV_LOG_WARNING, "COD marker is > > found in HOMOGENEOUS HT set\n"); > > How bad is this and the other markers being present in this case?
At the very least, it means that signaling is inconsistent within the codestream since the standard states that: """ The HOMOGENEOUS set is the set of HTJ2K codestreams where: • none of the functional marker segments, e.g., COD, COC, RGN, QCD, QCC, and POC, are present in any tile-part header; and • no PPT marker segment is present. """ The point of signalling that a codestream is "HOMOGENEOUS" is to allow decoders to configure themselves solely based on information retrieved entirely from the main header. Since, AFAIK, FFMPEG does not rely on the HOMOGENEOUS to short-circuit configuration, incorrect HOMOGENEOUS signalling will likely not impact FFMPEG. This condition may impact downstream decoders and might signal something deeply wrong with the codestream. In any case, maybe the case ought to be clarified to something along the lines of: "Non-conformant codestream: a COD marker is present in a tile-part header even though the codestream is marked as HOMOGENEOUS." > Should we perhaps error out? > > /Tomas > _______________________________________________ > 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". _______________________________________________ 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".
