[FFmpeg-devel] [PATCH 1/2] avcodec/hevc_sei: support HEVC timecode decode

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavcodec/hevc_sei.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/hevc_sei.h | 21 +++++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/libavcodec/hevc_sei.c b/libavcodec/hevc_sei.c
index 1736891..6d484b5 100644
--- a/libavcodec/hevc_sei.c
+++ b/libavcodec/hevc_sei.c
@@ -306,6 +306,53 @@ static int decode_nal_sei_alternative_transfer(HEVCSEIAlternativeTransfer *s, Ge
     return 0;
 }
 
+static int decode_nal_sei_timecode(HEVCSEITimeCode *s, GetBitContext *gb)
+{
+    s->num_clock_ts = get_bits(gb, 2) & 3;
+
+    for (int i = 0; i < s->num_clock_ts; i++) {
+        s->clock_timestamp_flag[i] =  get_bits(gb, 1);
+
+        if (s->clock_timestamp_flag[i]) {
+            s->units_field_based_flag[i] = get_bits(gb, 1);
+            s->counting_type[i]          = get_bits(gb, 5);
+            s->full_timestamp_flag[i]    = get_bits(gb, 1);
+            s->discontinuity_flag[i]     = get_bits(gb, 1);
+            s->cnt_dropped_flag[i]       = get_bits(gb, 1);
+
+            s->n_frames[i]               = get_bits(gb, 9);
+
+            if (s->full_timestamp_flag[i]) {
+                s->seconds_value[i]      = av_clip(get_bits(gb, 6), 0, 59);
+                s->minutes_value[i]      = av_clip(get_bits(gb, 6), 0, 59);
+                s->hours_value[i]        = av_clip(get_bits(gb, 6), 0, 59);
+            } else {
+                s->seconds_flag[i] = get_bits(gb, 1);
+                if (s->seconds_flag[i]) {
+                    s->seconds_value[i] = av_clip(get_bits(gb, 6), 0, 59);
+                    s->minutes_flag[i]  = get_bits(gb, 1);
+                    if (s->minutes_flag[i]) {
+                        s->minutes_value[i] = av_clip(get_bits(gb, 6), 0, 59);
+                        s->hours_flag[i] =  get_bits(gb, 1);
+                        if (s->hours_flag[i]) {
+                            s->hours_value[i] = av_clip(get_bits(gb, 6), 0, 59);
+                        }
+                    }
+                }
+            }
+
+            s->time_offset_length[i] = get_bits(gb, 5);
+            if (s->time_offset_length[i] > 0) {
+                s->time_offset_value[i] = get_bits(gb, s->time_offset_length[i]);
+            }
+        }
+    }
+
+    s->present = 1;
+    return 0;
+}
+
+
 static int decode_nal_sei_prefix(GetBitContext *gb, void *logctx, HEVCSEI *s,
                                  const HEVCParamSets *ps, int type, int size)
 {
@@ -330,6 +377,8 @@ static int decode_nal_sei_prefix(GetBitContext *gb, void *logctx, HEVCSEI *s,
         return decode_nal_sei_user_data_unregistered(&s->unregistered, gb, size);
     case HEVC_SEI_TYPE_ALTERNATIVE_TRANSFER_CHARACTERISTICS:
         return decode_nal_sei_alternative_transfer(&s->alternative_transfer, gb);
+    case HEVC_SEI_TYPE_TIME_CODE:
+        return decode_nal_sei_timecode(&s->timecode, gb);
     default:
         av_log(logctx, AV_LOG_DEBUG, "Skipped PREFIX SEI %d\n", type);
         skip_bits_long(gb, 8 * size);
diff --git a/libavcodec/hevc_sei.h b/libavcodec/hevc_sei.h
index 3618d16..5ee7a47 100644
--- a/libavcodec/hevc_sei.h
+++ b/libavcodec/hevc_sei.h
@@ -115,6 +115,26 @@ typedef struct HEVCSEIAlternativeTransfer {
     int preferred_transfer_characteristics;
 } HEVCSEIAlternativeTransfer;
 
+typedef struct HEVCSEITimeCode {
+    int      present;
+    uint8_t  num_clock_ts;
+    uint8_t  clock_timestamp_flag[3];
+    uint8_t  units_field_based_flag[3];
+    uint8_t  counting_type[3];
+    uint8_t  full_timestamp_flag[3];
+    uint8_t  discontinuity_flag[3];
+    uint8_t  cnt_dropped_flag[3];
+    uint16_t n_frames[3];
+    uint8_t  seconds_value[3];
+    uint8_t  minutes_value[3];
+    uint8_t  hours_value[3];
+    uint8_t  seconds_flag[3];
+    uint8_t  minutes_flag[3];
+    uint8_t  hours_flag[3];
+    uint8_t  time_offset_length[3];
+    int32_t  time_offset_value[3];
+} HEVCSEITimeCode;
+
 typedef struct HEVCSEI {
     HEVCSEIPictureHash picture_hash;
     HEVCSEIFramePacking frame_packing;
@@ -126,6 +146,7 @@ typedef struct HEVCSEI {
     HEVCSEIContentLight content_light;
     int active_seq_parameter_set_id;
     HEVCSEIAlternativeTransfer alternative_transfer;
+    HEVCSEITimeCode timecode;
 } HEVCSEI;
 
 struct HEVCParamSets;
-- 
1.8.3.1