Quoting Scott Theisen (2024-12-14 04:06:45) > On 12/13/24 17:39, Marth64 wrote: > > Hi Scott, > > > > Thanks for sharing this. I had read your original email also > > ([RFC] libavcodec/mpeg12dec.c: CC data from skipped frames) > > and was thinking about the statement. The patch helps > > visualize the issue a bit better. > > > > I need to study this and test it to understand it better. > > Meantime, I will apply locally and play around with it. > > > > If any more seasoned EIA608 experts have any thoughts please share. > > The problem is the use of av_buffer_realloc() instead of av_buffer_alloc(). > > | old_size | > realloc(new_size) > | old_size + (undefined values) | (new_size total bytes) (new_size is > always > old_size) > realloc copies data already in the buffer to the first old_size bytes. > > The SCTE-20 code sets the extra space to 0, but the others leave it > undefined. > > However, the old_size data is then overwritten, potentially partially, while > the size of the array is still new_size when there are only new_size - > old_size > valid bytes. > > I think it is reasonable to concatenate the CC data until a frame can be > exported. > Since I don't know if there is a frame exported when all of the video > frame's data slices > have been skipped (e.g. B frame with open GOP),
what exactly do you mean by 'skipped' here? -- Anton Khirnov _______________________________________________ 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".
