[FFmpeg-devel] [PATCH] avcodec/h264_slice: clear old slice POC values on parsing failure

James Almer jamrial at gmail.com
Sun Aug 8 21:38:37 EEST 2021


If a slice header fails to parse, and the next one uses different Sequence and
Picture parameter sets, certain values may not be read if they are not coded,
resulting in the previous slice values being used.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavcodec/h264_slice.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 41338fbcb6..a31e804620 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1897,6 +1897,8 @@ static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,
     if (nal->type == H264_NAL_IDR_SLICE)
         get_ue_golomb_long(&sl->gb); /* idr_pic_id */
 
+    sl->poc_lsb = 0;
+    sl->delta_poc_bottom = 0;
     if (sps->poc_type == 0) {
         sl->poc_lsb = get_bits(&sl->gb, sps->log2_max_poc_lsb);
 
@@ -1904,6 +1906,7 @@ static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,
             sl->delta_poc_bottom = get_se_golomb(&sl->gb);
     }
 
+    sl->delta_poc[0] = sl->delta_poc[1] = 0;
     if (sps->poc_type == 1 && !sps->delta_pic_order_always_zero_flag) {
         sl->delta_poc[0] = get_se_golomb(&sl->gb);
 
-- 
2.32.0



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