On 27/10/2020 21:25, James Almer wrote:
Section 6.10.1 of the AV1 spec states:
It is a requirement of bitstream conformance that the value of tg_start is
equal to the value of TileNum at the point that tile_group_obu is invoked.
It is a requirement of bitstream conformance that the value of tg_end is
greater than or equal to tg_start.
Signed-off-by: James Almer <jamr...@gmail.com>
---
Not sure if we should clear priv->tile_num in other places, too.
libavcodec/cbs_av1.h | 1 +
libavcodec/cbs_av1_syntax_template.c | 8 ++++++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/libavcodec/cbs_av1.h b/libavcodec/cbs_av1.h
index a2d78e736f..386774750a 100644
--- a/libavcodec/cbs_av1.h
+++ b/libavcodec/cbs_av1.h
@@ -446,6 +446,7 @@ typedef struct CodedBitstreamAV1Context {
int all_lossless;
int tile_cols;
int tile_rows;
+ int tile_num;
AV1ReferenceFrameState ref[AV1_NUM_REF_FRAMES];
} CodedBitstreamAV1Context;
diff --git a/libavcodec/cbs_av1_syntax_template.c
b/libavcodec/cbs_av1_syntax_template.c
index 2df5619279..f0be7aab59 100644
--- a/libavcodec/cbs_av1_syntax_template.c
+++ b/libavcodec/cbs_av1_syntax_template.c
@@ -1719,6 +1719,8 @@ static int FUNC(frame_header_obu)(CodedBitstreamContext
*ctx, RWContext *rw,
CHECK(FUNC(uncompressed_header)(ctx, rw, current));
+ priv->tile_num = 0;
+
if (current->show_existing_frame) {
priv->seen_frame_header = 0;
} else {
@@ -1784,10 +1786,12 @@ static int FUNC(tile_group_obu)(CodedBitstreamContext
*ctx, RWContext *rw,
} else {
tile_bits = cbs_av1_tile_log2(1, priv->tile_cols) +
cbs_av1_tile_log2(1, priv->tile_rows);
- fb(tile_bits, tg_start);
- fb(tile_bits, tg_end);
+ fc(tile_bits, tg_start, priv->tile_num, priv->tile_num);
This isn't true if you lose a tile group OBU making up part of a frame, which
we should be able to handle as something better than just a parsing failure in
error resilient mode.
I think set the lower bound only and let the upper bound be num_tiles - 1?
+ fc(tile_bits, tg_end, current->tg_start, num_tiles - 1);
}
+ priv->tile_num += current->tg_end - current->tg_start + 1;
priv->tile_num = current->tg_end + 1;
+
CHECK(FUNC(byte_alignment)(ctx, rw));
// Reset header for next frame.
Thanks,
- Mark
_______________________________________________
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".
