[FFmpeg-devel] [PATCH v3 5/8] lavc/hevcdec: Fix the parsing for use_integer_mv_flag

[Linjie Fu]

From: Linjie Fu <linjie.fu at intel.com>

According to 7.3.6.1, use_integer_mv_flag should be parsed if
motion_vector_resolution_control_idc equals to 2.

Otherwise wrong parameters in the subsequent parsing procedures
would be got.

Signed-off-by: Linjie Fu <linjie.justin.fu at gmail.com>
---
 libavcodec/hevcdec.c | 8 ++++++++
 libavcodec/hevcdec.h | 1 +
 2 files changed, 9 insertions(+)

diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index 7074a0760a..6a029b270e 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -808,6 +808,14 @@ static int hls_slice_header(HEVCContext *s)
                        sh->max_num_merge_cand);
                 return AVERROR_INVALIDDATA;
             }
+
+            // Syntax in 7.3.6.1
+            if (s->ps.sps->motion_vector_resolution_control_idc == 2)
+                sh->use_integer_mv_flag = get_bits1(gb);
+            else
+                // Inferred to be equal to motion_vector_resolution_control_idc if not present
+                sh->use_integer_mv_flag = s->ps.sps->motion_vector_resolution_control_idc;
+
         }
 
         sh->slice_qp_delta = get_se_golomb(gb);
diff --git a/libavcodec/hevcdec.h b/libavcodec/hevcdec.h
index 6e22e044dd..1164af2862 100644
--- a/libavcodec/hevcdec.h
+++ b/libavcodec/hevcdec.h
@@ -302,6 +302,7 @@ typedef struct SliceHeader {
     int tc_offset;      ///< tc_offset_div2 * 2
 
     unsigned int max_num_merge_cand; ///< 5 - 5_minus_max_num_merge_cand
+    uint8_t use_integer_mv_flag;
 
     unsigned *entry_point_offset;
     int * offset;
-- 
2.25.1