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| author | Mans Rullgard <mans@mansr.com> | 2011-10-11 16:00:21 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-11-04 01:08:09 +0100 |
| commit | 1c3d46a9246af544f3e9b3b81fe8589e58756484 (patch) | |
| tree | 552d323db4293bdfb1969baf7ed74138ec1495fc | |
| parent | 800ab099e332c93c90634b14309c5d56659223a8 (diff) | |
| download | ffmpeg-1c3d46a9246af544f3e9b3b81fe8589e58756484.tar.gz | |
h264: fix HRD parameters parsing
The bit_rate_value_minus1 and cpb_size_value_minus1 elements
allow a wider range than get_ue_golomb() supports. This
adds a get_ue_golomb_long() function supporting up to 31
leading zeros, which is the maximum for these syntax
elements, and uses it in decode_hrd_parameters().
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit fdba370f8a1bdfc22ecbdf3c7148c2f8680a4ac4)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavcodec/golomb.h | 14 | ||||
| -rw-r--r-- | libavcodec/h264_ps.c | 4 |
2 files changed, 16 insertions, 2 deletions
diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h index 90eeb30b54..8dff0322a7 100644 --- a/libavcodec/golomb.h +++ b/libavcodec/golomb.h @@ -75,6 +75,20 @@ static inline int get_ue_golomb(GetBitContext *gb){ } } +/** + * Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1. + */ +static inline unsigned get_ue_golomb_long(GetBitContext *gb) +{ + unsigned buf, log; + + buf = show_bits_long(gb, 32); + log = 31 - av_log2(buf); + skip_bits_long(gb, log); + + return get_bits_long(gb, log + 1) - 1; +} + /** * read unsigned exp golomb code, constraint to a max of 31. * the return value is undefined if the stored value exceeds 31. diff --git a/libavcodec/h264_ps.c b/libavcodec/h264_ps.c index 423f54b324..89e2502e0d 100644 --- a/libavcodec/h264_ps.c +++ b/libavcodec/h264_ps.c @@ -143,8 +143,8 @@ static inline int decode_hrd_parameters(H264Context *h, SPS *sps){ get_bits(&s->gb, 4); /* bit_rate_scale */ get_bits(&s->gb, 4); /* cpb_size_scale */ for(i=0; i<cpb_count; i++){ - get_ue_golomb(&s->gb); /* bit_rate_value_minus1 */ - get_ue_golomb(&s->gb); /* cpb_size_value_minus1 */ + get_ue_golomb_long(&s->gb); /* bit_rate_value_minus1 */ + get_ue_golomb_long(&s->gb); /* cpb_size_value_minus1 */ get_bits1(&s->gb); /* cbr_flag */ } sps->initial_cpb_removal_delay_length = get_bits(&s->gb, 5) + 1; |