lör 2018-02-17 klockan 22:45 +0100 skrev Marton Balint: > The reference point for a KAG is the first byte of the key of a Partition > Pack. > > Fixes ticket #2817. > Fixes ticket #5317. > > > Signed-off-by: Marton Balint <c...@passwd.hu> > --- > libavformat/mxfdec.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c > index fcae863ef4..95767ccba4 100644 > --- a/libavformat/mxfdec.c > +++ b/libavformat/mxfdec.c > @@ -2875,8 +2875,8 @@ static int mxf_read_header(AVFormatContext *s) > * for OPAtom we still need the actual essence_offset > though (the KL's length can vary) > */ > int64_t op1a_essence_offset = > - round_to_kag(mxf->current_partition->this_partition + > - mxf->current_partition->pack_length, > mxf->current_partition->kag_size) + > + mxf->current_partition->this_partition + > + round_to_kag(mxf->current_partition->pack_length, > mxf->current_partition->kag_size) + > round_to_kag(mxf->current_partition->header_byte_count, > mxf->current_partition->kag_size) + > round_to_kag(mxf->current_partition->index_byte_count, > mxf->current_partition->kag_size);
This seems like a rather elemental miscalculation, that I wrote even. I took a look at S377m, it had this to say: > The first gridline in any partition is the first byte of the key of > the partition pack that defines that > partition. Each partition starts at ThisPartition (plus run-in) so this patch should be correct. What's perhaps more suspect is the calculation itself. It should *always* be possible to locate where Op1a essence starts, by scanning to the first essence KLV. MXF is flexible enough that having some sketchy calculation for where it *might* be is probably not correct. One is free to insert any amount of padding Of course this entire patchset would be unnecessary if we just used bmxlib instead. /Tomas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
