[FFmpeg-devel] [PATCH 2/2] avcodec/hevcdec: create AVFrame side data from HEVC timecodes like H.264

lance.lmwang at gmail.com lance.lmwang at gmail.com
Mon Jun 15 17:27:14 EEST 2020


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

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavcodec/hevcdec.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index c9e28f5..39abbb9 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -2808,6 +2808,50 @@ static int set_side_data(HEVCContext *s)
     }
     s->sei.unregistered.nb_buf_ref = 0;
 
+    if (s->sei.timecode.present) {
+        uint32_t tc = 0;
+        uint32_t *tc_sd;
+        AVFrameSideData *tcside = av_frame_new_side_data(out, AV_FRAME_DATA_S12M_TIMECODE,
+                                                         sizeof(uint32_t) * 4);
+        if (!tcside)
+            return AVERROR(ENOMEM);
+
+        tc_sd = (uint32_t*)tcside->data;
+        tc_sd[0] = s->sei.timecode.num_clock_ts;
+
+        for (int i = 0; i < tc_sd[0]; i++) {
+            uint32_t frames;
+
+            /* For SMPTE 12-M timecodes, frame count is a special case if > 30 FPS.
+               See SMPTE ST 12-1:2014 Sec 12.1 for more info. */
+            if (av_cmp_q(s->avctx->framerate, (AVRational) {30, 1}) == 1) {
+                frames = s->sei.timecode.n_frames[i] / 2;
+                if (s->sei.timecode.n_frames[i] % 2 == 1) {
+                    if (av_cmp_q(s->avctx->framerate, (AVRational) {50, 1}) == 0)
+                        tc |= (1 << 7);
+                    else
+                        tc |= (1 << 23);
+                }
+            } else {
+                frames = s->sei.timecode.n_frames[i];
+            }
+
+            tc |= s->sei.timecode.cnt_dropped_flag[i] << 30;
+            tc |= (frames / 10) << 28;
+            tc |= (frames % 10) << 24;
+            tc |= (s->sei.timecode.seconds_value[i] / 10) << 20;
+            tc |= (s->sei.timecode.seconds_value[i] % 10) << 16;
+            tc |= (s->sei.timecode.minutes_value[i] / 10) << 12;
+            tc |= (s->sei.timecode.minutes_value[i] % 10) << 8;
+            tc |= (s->sei.timecode.hours_value[i] / 10) << 4;
+            tc |= (s->sei.timecode.hours_value[i] % 10);
+
+            tc_sd[i + 1] = tc;
+        }
+
+        s->sei.timecode.num_clock_ts = 0;
+    }
+
     return 0;
 }
 
-- 
1.8.3.1



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