Sega FILM: set dts and duration when demuxing

Reviewed-by: Kyle Swanson <k@ylo.ph>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/segafilm.c

@@ -270,6 +270,8 @@ static int film_read_packet(AVFormatContext *s,
     FilmDemuxContext *film = s->priv_data;
     AVIOContext *pb = s->pb;
     film_sample *sample;
+    film_sample *next_sample = NULL;
+    int next_sample_id;
     int ret = 0;
 
     if (film->current_sample >= film->sample_count)
@@ -277,6 +279,20 @@ static int film_read_packet(AVFormatContext *s,
 
     sample = &film->sample_table[film->current_sample];
 
+    /* Find the next sample from the same stream, assuming there is one;
+     * this is used to calculate the duration below */
+    next_sample_id = film->current_sample + 1;
+    while (next_sample == NULL) {
+        if (next_sample_id >= film->sample_count)
+            break;
+
+        next_sample = &film->sample_table[next_sample_id];
+        if (next_sample->stream != sample->stream) {
+            next_sample = NULL;
+            next_sample_id++;
+        }
+    }
+
     /* position the stream (will probably be there anyway) */
     avio_seek(pb, sample->sample_offset, SEEK_SET);
 
@@ -285,8 +301,11 @@ static int film_read_packet(AVFormatContext *s,
         ret = AVERROR(EIO);
 
     pkt->stream_index = sample->stream;
+    pkt->dts = sample->pts;
     pkt->pts = sample->pts;
     pkt->flags |= sample->keyframe ? AV_PKT_FLAG_KEY : 0;
+    if (next_sample != NULL)
+        pkt->duration = next_sample->pts - sample->pts;
 
     film->current_sample++;