[FFmpeg-devel] [PATCH] Fix for H.264 configuration parsing

Ivan grigoriev.ivan.a at gmail.com
Tue Apr 12 22:32:04 CEST 2016


Sometimes video fails to decode if H.264 configuration changes mid stream. The reason is that configuration parser assumes that nal_ref_idc is equal to 11b while actually some codecs but 01b there. The H.264 spec is somewhat vague about this but it looks like it allows any non-zero nal_ref_idc for sps/pps.

Signed-off-by: Ivan <grigoriev.ivan.a at gmail.com>
---
 libavcodec/h264.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index f1399b8..88768af 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -1781,7 +1781,7 @@ static int is_extra(const uint8_t *buf, int buf_size)
     const uint8_t *p= buf+6;
     while(cnt--){
         int nalsize= AV_RB16(p) + 2;
-        if(nalsize > buf_size - (p-buf) || p[2]!=0x67)
+        if(nalsize > buf_size - (p-buf) || (p[2] & 0x9F) != 7)
             return 0;
         p += nalsize;
     }
@@ -1790,7 +1790,7 @@ static int is_extra(const uint8_t *buf, int buf_size)
         return 0;
     while(cnt--){
         int nalsize= AV_RB16(p) + 2;
-        if(nalsize > buf_size - (p-buf) || p[2]!=0x68)
+        if(nalsize > buf_size - (p-buf) || (p[2] & 0x9F) != 8)
             return 0;
         p += nalsize;
     }
-- 
1.9.1



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