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>

1 files changed, 14 insertions, 0 deletions

diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index 83d277f963..503aa1416a 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.