Trailing bits are likely to bo non-zero if the NAL unit is truncated.
Clearing the bits make overreads of the bitstream less likely in this
case. Fixes playback of
http://streams.videolan.org/streams/mp4/Mr_MrsSmith-h264_aac.mp4 which
has a forbidden byte sequence of 0x00 0x00 0x00 in it SPS.
---
libavcodec/h264.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 77acd71..a9a1051 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -3759,7 +3759,7 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size){
int consumed;
int dst_length;
int bit_length;
- const uint8_t *ptr;
+ uint8_t *ptr;
int i, nalsize = 0;
int err;
@@ -3809,6 +3809,9 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size){
}
if (h->is_avc && (nalsize != consumed) && nalsize){
+ // set trailing bits in the last partial byte to zero
+ if (bit_length & 7)
+ ptr[bit_length >> 3] = ptr[bit_length >> 3] & (0xff << 8 -
(bit_length & 7));
av_log(h->s.avctx, AV_LOG_DEBUG, "AVC: Consumed only %d bytes
instead of %d\n", consumed, nalsize);
}
--
1.7.8
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