From fdba370f8a1bdfc22ecbdf3c7148c2f8680a4ac4 Mon Sep 17 00:00:00 2001 From: Mans Rullgard Date: Tue, 11 Oct 2011 16:00:21 +0100 Subject: [PATCH] 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 --- libavcodec/golomb.h | 14 ++++++++++++++ libavcodec/h264_ps.c | 4 ++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h index 83d277f..503aa14 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 bb673e9..677ca80 100644 --- a/libavcodec/h264_ps.c +++ b/libavcodec/h264_ps.c @@ -130,8 +130,8 @@ 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; igb); /* 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; -- 2.7.4