movenc: Apply offsets on timestamps when peeking into interleaving queues

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/internal.h

@@ -443,12 +443,13 @@ void ff_format_io_close(AVFormatContext *s, AVIOContext **pb);
 
 /**
  * Find the next packet in the interleaving queue for the given stream.
- * The packet is not removed from the interleaving queue, but only
- * a pointer to it is returned.
+ * The pkt parameter is filled in with the queued packet, including
+ * references to the data (which the caller is not allowed to keep or
+ * modify).
  *
- * @return a pointer to the next packet, or NULL if no packet is queued
- *         for this stream.
+ * @return 0 if a packet was found, a negative value if no packet was found
  */
-const AVPacket *ff_interleaved_peek(AVFormatContext *s, int stream);
+int ff_interleaved_peek(AVFormatContext *s, int stream,
+                        AVPacket *pkt, int add_offset);
 
 #endif /* AVFORMAT_INTERNAL_H */

libavformat/movenc.c

@@ -3262,13 +3262,13 @@ static int mov_flush_fragment(AVFormatContext *s, int force)
     for (i = 0; i < s->nb_streams; i++) {
         MOVTrack *track = &mov->tracks[i];
         if (!track->end_reliable) {
-            const AVPacket *next = ff_interleaved_peek(s, i);
-            if (next) {
-                track->track_duration = next->dts - track->start_dts;
-                if (next->pts != AV_NOPTS_VALUE)
-                    track->end_pts = next->pts;
+            AVPacket pkt;
+            if (!ff_interleaved_peek(s, i, &pkt, 1)) {
+                track->track_duration = pkt.dts - track->start_dts;
+                if (pkt.pts != AV_NOPTS_VALUE)
+                    track->end_pts = pkt.pts;
                 else
-                    track->end_pts = next->dts;
+                    track->end_pts = pkt.dts;
             }
         }
     }

libavformat/mux.c

@@ -357,6 +357,8 @@ FF_ENABLE_DEPRECATION_WARNINGS
 static int write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     int ret;
+    // If the timestamp offsetting below is adjusted, adjust
+    // ff_interleaved_peek similarly.
     if (s->avoid_negative_ts > 0) {
         AVRational time_base = s->streams[pkt->stream_index]->time_base;
         int64_t offset = 0;
@@ -614,15 +616,27 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
     }
 }
 
-const AVPacket *ff_interleaved_peek(AVFormatContext *s, int stream)
+int ff_interleaved_peek(AVFormatContext *s, int stream,
+                        AVPacket *pkt, int add_offset)
 {
     AVPacketList *pktl = s->internal->packet_buffer;
     while (pktl) {
-        if (pktl->pkt.stream_index == stream)
-            return &pktl->pkt;
+        if (pktl->pkt.stream_index == stream) {
+            *pkt = pktl->pkt;
+            if (add_offset && s->internal->offset != AV_NOPTS_VALUE) {
+                int64_t offset = av_rescale_q(s->internal->offset,
+                                              s->internal->offset_timebase,
+                                              s->streams[stream]->time_base);
+                if (pkt->dts != AV_NOPTS_VALUE)
+                    pkt->dts += offset;
+                if (pkt->pts != AV_NOPTS_VALUE)
+                    pkt->pts += offset;
+            }
+            return 0;
+        }
         pktl = pktl->next;
     }
-    return NULL;
+    return AVERROR(ENOENT);
 }
 
 /**