[FFmpeg-cvslog] h264: try reading SPS with wrong escaping, it sometimes works better

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Oct  1 17:41:28 2011 +0200| [c9c7a776db3615b627dde75b9b9e3e786da43827] | committer: Michael Niedermayer

h264: try reading SPS with wrong escaping, it sometimes works better

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c9c7a776db3615b627dde75b9b9e3e786da43827
---

 libavcodec/h264.c    |    6 +++++-
 libavcodec/h264_ps.c |    5 ++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 2ea141e..7927754 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3801,7 +3801,11 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){
             break;
         case NAL_SPS:
             init_get_bits(&s->gb, ptr, bit_length);
-            ff_h264_decode_seq_parameter_set(h);
+            if(ff_h264_decode_seq_parameter_set(h) < 0 && h->is_avc && (nalsize != consumed) && nalsize){
+                av_log(h->s.avctx, AV_LOG_DEBUG, "SPS decoding failure, trying alternative mode\n");
+                init_get_bits(&s->gb, &buf[buf_index + 1 - consumed], 8*nalsize);
+                ff_h264_decode_seq_parameter_set(h);
+            }
 
             if (s->flags& CODEC_FLAG_LOW_DELAY ||
                 (h->sps.bitstream_restriction_flag && !h->sps.num_reorder_frames))
diff --git a/libavcodec/h264_ps.c b/libavcodec/h264_ps.c
index ba16e1c..36b18e9 100644
--- a/libavcodec/h264_ps.c
+++ b/libavcodec/h264_ps.c
@@ -228,7 +228,6 @@ static inline int decode_vui_parameters(H264Context *h, SPS *sps){
         get_ue_golomb(&s->gb); /*max_dec_frame_buffering*/
 
         if(s->gb.size_in_bits < get_bits_count(&s->gb)){
-            av_log(h->s.avctx, AV_LOG_ERROR, "Overread VUI by %d bits\n", get_bits_count(&s->gb) - s->gb.size_in_bits);
             sps->num_reorder_frames=0;
             sps->bitstream_restriction_flag= 0;
         }
@@ -238,6 +237,10 @@ static inline int decode_vui_parameters(H264Context *h, SPS *sps){
             return -1;
         }
     }
+    if(s->gb.size_in_bits < get_bits_count(&s->gb)){
+        av_log(h->s.avctx, AV_LOG_ERROR, "Overread VUI by %d bits\n", get_bits_count(&s->gb) - s->gb.size_in_bits);
+        return -1;
+    }
 
     return 0;
 }