Hi, On 3/27/2019 12:18 PM, Andreas Rheinhardt wrote:
This also changed the handling of unknown-sized elements: They are now ended whenever an element not known to be allowed in them is encountered. If we are already on level 1 and encounter an element not known to be allowed in an unknown-sized segment, this is treated as an indication that an error might have occured. I hope this is fine.
I haven't looked at the code yet, but an unknown element doesn't mean it's an upper level element. I think it should be either skipped or considered as bad data. If it's a known element but complitely misplaced it should not be going upper in the hierarchy. Only when a valid upper element it should go up in the hierarchy.
Dale's sample "bear-320x240-live.webm" btw has cues at the end that use unknown-sized elements (wastefully coded on eight bytes) for CuePoints and CueTrackPositions which is spec-incompliant. They are not referenced by a SeekHead and so can't be used for seeking, but if they were, neither current FFmpeg nor FFmpeg with my patches applied would be able to use them. Are such files common (this is the first such file I ever saw)? If so, I could probably make it work.
If CuePoints are not referenced by the SeekHead at the front of the file (or the indirect SeekHead) they are useless anyway.
I have cced Steve for this (I didn't the first time, because I thought that he (as a maintainer) would also be a subscriber to this list).
I am subscribed but not the maintainer. In fact I know little about this code.
Oh, and I did not check with Valgrind that the new lacing code doesn't read uninitialized data. I don't even know how to use Valgrind. I just read the code. If someone more knowledgeable than I could please test it...
You might also use LLVM with ASAN (address sanitizer) it's helpfull for this (or so I have been told).
_______________________________________________ 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".
