player: better handling of video with no timestamps

Trying to handle such video is almost worthless, but it was requested by
at least 2 users.

If there are no timestamps, enable byte seeking by setting
ts_resets_possible. Use the video FPS (wherever it comes from) and the
audio samplerate for timing. The latter was already done by making the
first packet emit DTS=0; remove this again and do it "properly" in a
higher level.

4 files changed, 15 insertions, 11 deletions

diff --git a/audio/decode/dec_audio.c b/audio/decode/dec_audio.c
index ab4cd2ec55..c5ad97f7af 100644
--- a/audio/decode/dec_audio.c
+++ b/audio/decode/dec_audio.c
@@ -164,6 +164,9 @@ static int decode_new_frame(struct dec_audio *da)
         if (ret < 0)
             return ret;
 
+        if (da->pts == MP_NOPTS_VALUE && da->header->missing_timestamps)
+            da->pts = 0;
+
         if (da->waiting) {
             da->pts_offset += da->waiting->samples;
             da->decode_format = *da->waiting;
diff --git a/demux/demux_lavf.c b/demux/demux_lavf.c
index 0275b1afd2..2799dd33f9 100644
--- a/demux/demux_lavf.c
+++ b/demux/demux_lavf.c
@@ -151,7 +151,6 @@ typedef struct lavf_priv {
     AVFormatContext *avfc;
     AVIOContext *pb;
     int64_t last_pts;
-    bool init_pts;
     struct sh_stream **streams; // NULL for unknown streams
     int num_streams;
     int cur_program;
@@ -618,6 +617,7 @@ static void handle_stream(demuxer_t *demuxer, int i)
         sh->hls_bitrate = dict_get_decimal(st->metadata, "variant_bitrate", 0);
         if (!sh->title && sh->hls_bitrate > 0)
             sh->title = talloc_asprintf(sh, "bitrate %d", sh->hls_bitrate);
+        sh->missing_timestamps = !!(priv->avif->flags & AVFMT_NOTIMESTAMPS);
     }
 
     select_tracks(demuxer, i);
@@ -794,7 +794,8 @@ static int demux_open_lavf(demuxer_t *demuxer, enum demux_check check)
     mp_tags_copy_from_av_dictionary(demuxer->metadata, avfc->metadata);
     update_metadata(demuxer, NULL);
 
-    demuxer->ts_resets_possible = priv->avif->flags & AVFMT_TS_DISCONT;
+    demuxer->ts_resets_possible =
+        priv->avif->flags & (AVFMT_TS_DISCONT | AVFMT_NOTIMESTAMPS);
 
     demuxer->start_time = priv->avfc->start_time == AV_NOPTS_VALUE ?
                           0 : (double)priv->avfc->start_time / AV_TIME_BASE;
@@ -839,12 +840,6 @@ static int demux_lavf_fill_buffer(demuxer_t *demux)
         return 1;
     }
 
-    if (!priv->init_pts && (priv->avfc->flags & AVFMT_NOTIMESTAMPS)) {
-        if (pkt->pts == AV_NOPTS_VALUE && pkt->dts == AV_NOPTS_VALUE)
-            pkt->dts = 0;
-        priv->init_pts = true;
-    }
-
     if (pkt->pts != AV_NOPTS_VALUE)
         dp->pts = pkt->pts * av_q2d(st->time_base);
     if (pkt->dts != AV_NOPTS_VALUE)
@@ -873,8 +868,6 @@ static void demux_seek_lavf(demuxer_t *demuxer, double rel_seek_secs, int flags)
     lavf_priv_t *priv = demuxer->priv;
     int avsflags = 0;
 
-    priv->init_pts = false;
-
     if (flags & SEEK_ABSOLUTE)
         priv->last_pts = 0;
     else if (rel_seek_secs < 0)
diff --git a/demux/stheader.h b/demux/stheader.h
index fbfba01367..1af91e032b 100644
--- a/demux/stheader.h
+++ b/demux/stheader.h
@@ -58,6 +58,8 @@ struct sh_stream {
     bool default_track;         // container default track flag
     int hls_bitrate;
 
+    bool missing_timestamps;
+
     // stream is a picture (such as album art)
     struct demux_packet *attached_picture;
 
diff --git a/video/decode/dec_video.c b/video/decode/dec_video.c
index a0bd6cb047..c578ccadcc 100644
--- a/video/decode/dec_video.c
+++ b/video/decode/dec_video.c
@@ -200,6 +200,12 @@ bool video_init_best_codec(struct dec_video *d_video, char* video_decoders)
                d_video->header->codec ? d_video->header->codec : "<unknown>");
     }
 
+    if (d_video->header->missing_timestamps) {
+        MP_WARN(d_video, "This stream has no timestamps!\n");
+        MP_WARN(d_video, "Making up playback time using %f FPS.\n", d_video->fps);
+        MP_WARN(d_video, "Seeking will probably fail badly.\n");
+    }
+
     talloc_free(list);
     return !!d_video->vd_driver;
 }
@@ -351,7 +357,7 @@ struct mp_image *video_decode(struct dec_video *d_video,
         pts = retrieve_sorted_pts(d_video, pts);
 
     if (!opts->correct_pts || pts == MP_NOPTS_VALUE) {
-        if (opts->correct_pts)
+        if (opts->correct_pts && !d_video->header->missing_timestamps)
             MP_WARN(d_video, "No video PTS! Making something up.\n");
 
         double frame_time = 1.0f / (d_video->fps > 0 ? d_video->fps : 25);