tsmux: Add negative DTS support

Use the saved DTS, make it signed and pass that to the stream muxer. This
preserves the running time sign. All usage of -1 as invalid TS are now
replaced with G_MININT64. Negative values will be seen as wrap-around
point, but the delta between PTS and DTS will remain correct. Demuxers
don't care about absolute values, they only cares about deltas.

https://bugzilla.gnome.org/show_bug.cgi?id=740575

4 files changed, 77 insertions, 59 deletions

diff --git a/gst/mpegtsmux/mpegtsmux.c b/gst/mpegtsmux/mpegtsmux.c
index b91d6b515..550fa1635 100644
--- a/gst/mpegtsmux/mpegtsmux.c
+++ b/gst/mpegtsmux/mpegtsmux.c
@@ -331,7 +331,8 @@ static void
 mpegtsmux_pad_reset (MpegTsPadData * pad_data)
 {
   pad_data->pid = 0;
-  pad_data->min_dts = GST_CLOCK_TIME_NONE;
+  pad_data->min_dts = GST_CLOCK_STIME_NONE;
+  pad_data->dts = GST_CLOCK_STIME_NONE;
   pad_data->prog_id = -1;
 #if 0
   pad_data->prog_id = -1;
@@ -1035,7 +1036,7 @@ mpegtsmux_clip_inc_running_time (GstCollectPads * pads,
   *outbuf = buf;
 
   /* PTS */
-  time = GST_BUFFER_TIMESTAMP (buf);
+  time = GST_BUFFER_PTS (buf);
 
   /* invalid left alone and passed */
   if (G_LIKELY (GST_CLOCK_TIME_IS_VALID (time))) {
@@ -1046,11 +1047,11 @@ mpegtsmux_clip_inc_running_time (GstCollectPads * pads,
       *outbuf = NULL;
       goto beach;
     } else {
-      GST_LOG_OBJECT (cdata->pad, "buffer pts %" GST_TIME_FORMAT " -> %"
+      GST_LOG_OBJECT (cdata->pad, "buffer pts %" GST_TIME_FORMAT " ->  %"
           GST_TIME_FORMAT " running time",
-          GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)), GST_TIME_ARGS (time));
+          GST_TIME_ARGS (GST_BUFFER_PTS (buf)), GST_TIME_ARGS (time));
       buf = *outbuf = gst_buffer_make_writable (buf);
-      GST_BUFFER_TIMESTAMP (*outbuf) = time;
+      GST_BUFFER_PTS (*outbuf) = time;
     }
   }
 
@@ -1059,28 +1060,39 @@ mpegtsmux_clip_inc_running_time (GstCollectPads * pads,
 
   /* invalid left alone and passed */
   if (G_LIKELY (GST_CLOCK_TIME_IS_VALID (time))) {
-    time = gst_segment_to_running_time (&cdata->segment, GST_FORMAT_TIME, time);
-    /* may have to decode out-of-segment, so pass INVALID */
-    if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (time))) {
-      GST_DEBUG_OBJECT (cdata->pad, "running dts outside segment");
-    } else {
-      GST_LOG_OBJECT (cdata->pad, "buffer dts %" GST_TIME_FORMAT " -> %"
-          GST_TIME_FORMAT " running time",
-          GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)), GST_TIME_ARGS (time));
+    gint sign;
+    gint64 dts;
 
-      if (!GST_CLOCK_TIME_IS_VALID (pad_data->min_dts))
-        pad_data->min_dts = time;
+    sign = gst_segment_to_running_time_full (&cdata->segment, GST_FORMAT_TIME,
+        time, &time);
 
-      if (time < pad_data->min_dts) {
-        /* Ignore DTS going backward */
-        GST_WARNING_OBJECT (cdata->pad, "ignoring DTS going backward");
-        time = pad_data->min_dts;
-      }
+    GST_LOG_OBJECT (cdata->pad, "buffer dts %" GST_TIME_FORMAT " -> %"
+        GST_STIME_FORMAT " running time", GST_STIME_ARGS (GST_BUFFER_DTS (buf)),
+        GST_STIME_ARGS (time));
 
-      *outbuf = gst_buffer_make_writable (buf);
-      GST_BUFFER_DTS (*outbuf) = time;
-      pad_data->min_dts = time;
+    if (sign > 0)
+      dts = (gint64) time;
+    else
+      dts = -((gint64) time);
+
+    if (GST_CLOCK_STIME_IS_VALID (pad_data))
+      pad_data->min_dts = dts;
+
+    if (dts < pad_data->min_dts) {
+      /* Ignore DTS going backward */
+      GST_WARNING_OBJECT (cdata->pad, "ignoring DTS going backward");
+      dts = pad_data->min_dts;
     }
+
+    *outbuf = gst_buffer_make_writable (buf);
+    if (sign > 0)
+      GST_BUFFER_DTS (*outbuf) = time;
+    else
+      GST_BUFFER_DTS (*outbuf) = GST_CLOCK_TIME_NONE;
+
+    pad_data->dts = pad_data->min_dts = dts;
+  } else {
+    pad_data->dts = GST_CLOCK_STIME_NONE;
   }
 
   buf = *outbuf;
@@ -1103,8 +1115,8 @@ mpegtsmux_collected_buffer (GstCollectPads * pads, GstCollectData * data,
   GstFlowReturn ret = GST_FLOW_OK;
   MpegTsPadData *best = (MpegTsPadData *) data;
   TsMuxProgram *prog;
-  gint64 pts = -1;
-  guint64 dts = -1;
+  gint64 pts = GST_CLOCK_STIME_NONE;
+  gint64 dts = GST_CLOCK_STIME_NONE;
   gboolean delta = TRUE, header = FALSE;
   StreamData *stream_data;
 
@@ -1140,7 +1152,7 @@ mpegtsmux_collected_buffer (GstCollectPads * pads, GstCollectData * data,
     GstEvent *event;
 
     event = check_pending_key_unit_event (mux->force_key_unit_event,
-        &best->collect.segment, GST_BUFFER_TIMESTAMP (buf),
+        &best->collect.segment, GST_BUFFER_PTS (buf),
         GST_BUFFER_FLAGS (buf), mux->pending_key_unit_ts);
     if (event) {
       GstClockTime running_time;
@@ -1186,18 +1198,19 @@ mpegtsmux_collected_buffer (GstCollectPads * pads, GstCollectData * data,
 
   if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buf))) {
     pts = GSTTIME_TO_MPEGTIME (GST_BUFFER_PTS (buf));
-    GST_DEBUG_OBJECT (mux, "Buffer has PTS %" GST_TIME_FORMAT " pts %"
+    GST_DEBUG_OBJECT (mux, "Buffer has PTS  %" GST_TIME_FORMAT " pts %"
         G_GINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_PTS (buf)), pts);
   }
 
-  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DTS (buf))) {
-    dts = GSTTIME_TO_MPEGTIME (GST_BUFFER_DTS (buf));
-    GST_DEBUG_OBJECT (mux, "Buffer has DTS %" GST_TIME_FORMAT " dts %"
-        G_GINT64_FORMAT, GST_TIME_ARGS (GST_BUFFER_DTS (buf)), dts);
+  if (GST_CLOCK_STIME_IS_VALID (best->dts)) {
+    dts = GSTTIME_TO_MPEGTIME (best->dts);
+    GST_DEBUG_OBJECT (mux, "Buffer has DTS %s%" GST_TIME_FORMAT " dts %"
+        G_GINT64_FORMAT, best->dts >= 0 ? " " : "-",
+        GST_TIME_ARGS (ABS (best->dts)), dts);
   }
 
   /* should not have a DTS without PTS */
-  if (pts == -1 && dts != -1) {
+  if (!GST_CLOCK_STIME_IS_VALID (pts) && GST_CLOCK_STIME_IS_VALID (dts)) {
     GST_DEBUG_OBJECT (mux, "using DTS for unknown PTS");
     pts = dts;
   }
diff --git a/gst/mpegtsmux/mpegtsmux.h b/gst/mpegtsmux/mpegtsmux.h
index ab664ed7a..daceb25bc 100644
--- a/gst/mpegtsmux/mpegtsmux.h
+++ b/gst/mpegtsmux/mpegtsmux.h
@@ -98,10 +98,9 @@ G_BEGIN_DECLS
 #define CLOCK_FREQ (CLOCK_BASE * 10000)   /* 90 kHz PTS clock */
 #define CLOCK_FREQ_SCR (CLOCK_FREQ * 300) /* 27 MHz SCR clock */
 
-#define MPEGTIME_TO_GSTTIME(time) (gst_util_uint64_scale ((time), \
-                        GST_MSECOND/10, CLOCK_BASE))
-#define GSTTIME_TO_MPEGTIME(time) (gst_util_uint64_scale ((time), \
-                        CLOCK_BASE, GST_MSECOND/10))
+#define GSTTIME_TO_MPEGTIME(time) \
+    (((time) > 0 ? (gint64) 1 : (gint64) -1) * \
+    (gint64) gst_util_uint64_scale (ABS(time), CLOCK_BASE, GST_MSECOND/10))
 
 /* 27 MHz SCR conversions: */
 #define MPEG_SYS_TIME_TO_GSTTIME(time) (gst_util_uint64_scale ((time), \
@@ -183,8 +182,11 @@ struct MpegTsPadData {
   gint pid;
   TsMuxStream *stream;
 
-  /* most recent valid TS for this stream */
-  GstClockTime min_dts;
+  /* most recent valid DTS for this stream */
+  gint64 min_dts;
+
+  /* most recent DTS */
+  gint64 dts;
 
 #if 0
   /* (optional) index writing */
diff --git a/gst/mpegtsmux/tsmux/tsmux.c b/gst/mpegtsmux/tsmux/tsmux.c
index 7eb7b8667..10ff48abf 100644
--- a/gst/mpegtsmux/tsmux/tsmux.c
+++ b/gst/mpegtsmux/tsmux/tsmux.c
@@ -143,11 +143,11 @@ tsmux_new (void)
   mux->next_stream_pid = TSMUX_START_ES_PID;
 
   mux->pat_changed = TRUE;
-  mux->last_pat_ts = -1;
+  mux->last_pat_ts = G_MININT64;
   mux->pat_interval = TSMUX_DEFAULT_PAT_INTERVAL;
 
   mux->si_changed = TRUE;
-  mux->last_si_ts = -1;
+  mux->last_si_ts = G_MININT64;
   mux->si_interval = TSMUX_DEFAULT_SI_INTERVAL;
 
   mux->si_sections = g_hash_table_new_full (g_direct_hash, g_direct_equal,
@@ -363,7 +363,7 @@ tsmux_program_new (TsMux * mux, gint prog_id)
   program = g_slice_new0 (TsMuxProgram);
 
   program->pmt_changed = TRUE;
-  program->last_pmt_ts = -1;
+  program->last_pmt_ts = G_MININT64;
   program->pmt_interval = TSMUX_DEFAULT_PMT_INTERVAL;
 
   if (prog_id == 0) {
@@ -983,13 +983,13 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
     GList *cur;
 
     cur_pcr = 0;
-    if (cur_pts != -1) {
+    if (cur_pts != G_MININT64) {
       TS_DEBUG ("TS for PCR stream is %" G_GINT64_FORMAT, cur_pts);
     }
 
     /* FIXME: The current PCR needs more careful calculation than just
      * writing a fixed offset */
-    if (cur_pts != -1) {
+    if (cur_pts != G_MININT64) {
       /* CLOCK_BASE >= TSMUX_PCR_OFFSET */
       cur_pts += CLOCK_BASE;
       cur_pcr = (cur_pts - TSMUX_PCR_OFFSET) *
@@ -1010,7 +1010,7 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
     }
 
     /* check if we need to rewrite pat */
-    if (mux->last_pat_ts == -1 || mux->pat_changed)
+    if (mux->last_pat_ts == G_MININT64 || mux->pat_changed)
       write_pat = TRUE;
     else if (cur_pts >= mux->last_pat_ts + mux->pat_interval)
       write_pat = TRUE;
@@ -1024,7 +1024,7 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
     }
 
     /* check if we need to rewrite sit */
-    if (mux->last_si_ts == -1 || mux->si_changed)
+    if (mux->last_si_ts == G_MININT64 || mux->si_changed)
       write_si = TRUE;
     else if (cur_pts >= mux->last_si_ts + mux->si_interval)
       write_si = TRUE;
@@ -1042,7 +1042,7 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
       TsMuxProgram *program = (TsMuxProgram *) cur->data;
       gboolean write_pmt;
 
-      if (program->last_pmt_ts == -1 || program->pmt_changed)
+      if (program->last_pmt_ts == G_MININT64 || program->pmt_changed)
         write_pmt = TRUE;
       else if (cur_pts >= program->last_pmt_ts + program->pmt_interval)
         write_pmt = TRUE;
@@ -1060,9 +1060,9 @@ tsmux_write_stream_packet (TsMux * mux, TsMuxStream * stream)
   pi->packet_start_unit_indicator = tsmux_stream_at_pes_start (stream);
   if (pi->packet_start_unit_indicator) {
     tsmux_stream_initialize_pes_packet (stream);
-    if (stream->dts != -1)
+    if (stream->dts != G_MININT64)
       stream->dts += CLOCK_BASE;
-    if (stream->pts != -1)
+    if (stream->pts != G_MININT64)
       stream->pts += CLOCK_BASE;
   }
   pi->stream_avail = tsmux_stream_bytes_avail (stream);
diff --git a/gst/mpegtsmux/tsmux/tsmuxstream.c b/gst/mpegtsmux/tsmux/tsmuxstream.c
index 7e85537f2..ad58ca70e 100644
--- a/gst/mpegtsmux/tsmux/tsmuxstream.c
+++ b/gst/mpegtsmux/tsmux/tsmuxstream.c
@@ -196,8 +196,8 @@ tsmux_stream_new (guint16 pid, TsMuxStreamType stream_type)
       break;
   }
 
-  stream->last_pts = -1;
-  stream->last_dts = -1;
+  stream->last_pts = GST_CLOCK_STIME_NONE;
+  stream->last_dts = GST_CLOCK_STIME_NONE;
 
   stream->pcr_ref = 0;
   stream->last_pcr = -1;
@@ -279,10 +279,10 @@ tsmux_stream_consume (TsMuxStream * stream, guint len)
   if (stream->cur_buffer_consumed == 0)
     return;
 
-  if (stream->cur_buffer->pts != -1) {
+  if (GST_CLOCK_STIME_IS_VALID (stream->cur_buffer->pts)) {
     stream->last_pts = stream->cur_buffer->pts;
     stream->last_dts = stream->cur_buffer->dts;
-  } else if (stream->cur_buffer->dts != -1)
+  } else if (GST_CLOCK_STIME_IS_VALID (stream->cur_buffer->dts))
     stream->last_dts = stream->cur_buffer->dts;
 
   if (stream->cur_buffer_consumed == stream->cur_buffer->size) {
@@ -407,10 +407,12 @@ tsmux_stream_initialize_pes_packet (TsMuxStream * stream)
   stream->pi.flags &= ~(TSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS |
       TSMUX_PACKET_FLAG_PES_WRITE_PTS);
 
-  if (stream->pts != -1 && stream->dts != -1 && stream->pts != stream->dts)
+  if (GST_CLOCK_STIME_IS_VALID (stream->pts)
+      && GST_CLOCK_STIME_IS_VALID (stream->dts)
+      && stream->pts != stream->dts)
     stream->pi.flags |= TSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS;
   else {
-    if (stream->pts != -1)
+    if (GST_CLOCK_STIME_IS_VALID (stream->pts))
       stream->pi.flags |= TSMUX_PACKET_FLAG_PES_WRITE_PTS;
   }
 
@@ -546,8 +548,8 @@ tsmux_stream_find_pts_dts_within (TsMuxStream * stream, guint bound,
 {
   GList *cur;
 
-  *pts = -1;
-  *dts = -1;
+  *pts = GST_CLOCK_STIME_NONE;
+  *dts = GST_CLOCK_STIME_NONE;
 
   for (cur = stream->buffers; cur; cur = cur->next) {
     TsMuxStreamBuffer *curbuf = cur->data;
@@ -562,7 +564,8 @@ tsmux_stream_find_pts_dts_within (TsMuxStream * stream, guint bound,
     }
 
     /* Have we found a buffer with pts/dts set? */
-    if (curbuf->pts != -1 || curbuf->dts != -1) {
+    if (GST_CLOCK_STIME_IS_VALID (curbuf->pts)
+        || GST_CLOCK_STIME_IS_VALID (curbuf->dts)) {
       *pts = curbuf->pts;
       *dts = curbuf->dts;
       return;
@@ -656,7 +659,7 @@ tsmux_stream_write_pes_header (TsMuxStream * stream, guint8 * data)
  *
  * Submit @len bytes of @data into @stream. @pts and @dts can be set to the
  * timestamp (against a 90Hz clock) of the first access unit in @data. A
- * timestamp of -1 for @pts or @dts means unknown.
+ * timestamp of GST_CLOCK_STIME_NNOE for @pts or @dts means unknown.
  *
  * @user_data will be passed to the release function as set with
  * tsmux_stream_set_buffer_release_func() when @data can be freed.
@@ -957,7 +960,7 @@ tsmux_stream_is_pcr (TsMuxStream * stream)
 guint64
 tsmux_stream_get_pts (TsMuxStream * stream)
 {
-  g_return_val_if_fail (stream != NULL, -1);
+  g_return_val_if_fail (stream != NULL, GST_CLOCK_STIME_NONE);
 
   return stream->last_pts;
 }