gst/mpegdemux/gstmpegtsdemux.*: Properly handle some resync cases in the optimised buffering strategy.

Original commit message from CVS:
Patch by: Josep Torra
* gst/mpegdemux/gstmpegtsdemux.c:
* gst/mpegdemux/gstmpegtsdemux.h:
Properly handle some resync cases in the optimised
buffering strategy.

ChangeLog

@@ -1,3 +1,12 @@
+2008-10-16  Zaheer Abbas Merali  <zaheerabbas at merali dot org>
+
+	Patch by: Josep Torra
+
+	* gst/mpegdemux/gstmpegtsdemux.c:
+	* gst/mpegdemux/gstmpegtsdemux.h:
+	Properly handle some resync cases in the optimised
+	buffering strategy.
+
 2008-10-16  Michael Smith <msmith@songbirdnest.com>
 	* sys/acmenc/Makefile.am:
 	  Remove incorrect use of DIRECTSOUND_LDFLAGS

gst/mpegdemux/gstmpegtsdemux.c

@@ -1046,7 +1046,7 @@ gst_fluts_demux_get_stream_for_PID (GstFluTSDemux * demux, guint16 PID)
     stream->PAT.version_number = -1;
     stream->PMT_pid = FLUTS_MAX_PID + 1;
     stream->flags |= FLUTS_STREAM_FLAG_STREAM_TYPE_UNKNOWN;
-
+    stream->pes_buffer_in_sync = FALSE;
     switch (PID) {
         /* check for fixed mapping */
       case PID_PROGRAM_ASSOCIATION_TABLE:
@@ -1959,6 +1959,8 @@ gst_fluts_stream_pes_buffer_flush (GstFluTSStream * stream)
   if (stream->pes_buffer) {
     GST_BUFFER_SIZE (stream->pes_buffer) = stream->pes_buffer_used;
     ret = gst_pes_filter_push (&stream->filter, stream->pes_buffer);
+    if (ret == GST_FLOW_LOST_SYNC)
+      stream->pes_buffer_in_sync = FALSE;
     stream->pes_buffer = NULL;
   }
   return ret;
@@ -1981,6 +1983,8 @@ gst_fluts_stream_pes_buffer_push (GstFluTSStream * stream,
       stream->pes_buffer_size <<= 1;
 
     ret = gst_fluts_stream_pes_buffer_flush (stream);
+    if (ret == GST_FLOW_LOST_SYNC)
+      goto done;
   }
 
   if (G_UNLIKELY (!stream->pes_buffer)) {
@@ -1998,7 +2002,7 @@ gst_fluts_stream_pes_buffer_push (GstFluTSStream * stream,
   memcpy (out_data, in_data, in_size);
 #endif
   stream->pes_buffer_used += in_size;
-
+done:
   return ret;
 }
 
@@ -2011,13 +2015,32 @@ gst_fluts_demux_pes_buffer_flush (GstFluTSDemux * demux)
   for (i = 0; i < FLUTS_MAX_PID + 1; i++) {
     GstFluTSStream *stream = demux->streams[i];
     if (stream && stream->pad) {
-      ret = gst_fluts_stream_pes_buffer_flush (stream);
-      if (G_UNLIKELY (ret == GST_FLOW_OK))
-        goto done;
+      gst_fluts_stream_pes_buffer_flush (stream);
+      stream->pes_buffer_in_sync = FALSE;
     }
   }
+  return ret;
+}
 
-done:
+static FORCE_INLINE GstFlowReturn
+gst_fluts_demux_push_fragment (GstFluTSStream * stream,
+    const guint8 * in_data, guint in_size)
+{
+  GstFlowReturn ret;
+  GstBuffer *es_buf = gst_buffer_new_and_alloc (in_size);
+#ifdef USE_LIBOIL
+  oil_memcpy (GST_BUFFER_DATA (es_buf), in_data, in_size);
+#else
+  memcpy (GST_BUFFER_DATA (es_buf), in_data, in_size);
+#endif
+  ret = gst_pes_filter_push (&stream->filter, es_buf);
+
+  /* If PES filter return ok then PES fragment buffering 
+   * can be enabled */
+  if (ret == GST_FLOW_OK)
+    stream->pes_buffer_in_sync = TRUE;
+  else if (ret == GST_FLOW_LOST_SYNC)
+    stream->pes_buffer_in_sync = FALSE;
   return ret;
 }
 
@@ -2207,7 +2230,7 @@ gst_fluts_demux_parse_stream (GstFluTSDemux * demux, GstFluTSStream * stream,
               "bytes of %u bytes in the PES buffer",
               PID, stream->pes_buffer_used, stream->pes_buffer_size);
           /* Flush buffered PES data */
-          ret = gst_fluts_stream_pes_buffer_flush (stream);
+          gst_fluts_stream_pes_buffer_flush (stream);
           gst_pes_filter_drain (&stream->filter);
           /* Resize the buffer to half if no overflow detected and
            * had been used less than half of it */
@@ -2219,15 +2242,33 @@ gst_fluts_demux_parse_stream (GstFluTSDemux * demux, GstFluTSStream * stream,
             GST_DEBUG_OBJECT (demux, "PES buffer size reduced to %u bytes",
                 stream->pes_buffer_size);
           }
-          if (ret == GST_FLOW_LOST_SYNC)
-            goto done;
+          /* mark the stream not in sync to give a chance on PES filter to 
+           * detect lost sync */
+          stream->pes_buffer_in_sync = FALSE;
           stream->pes_buffer_overflow = FALSE;
         }
         GST_LOG_OBJECT (demux, "Elementary packet of size %u for PID 0x%04x",
             datalen, PID);
 
         if (datalen > 0) {
-          ret = gst_fluts_stream_pes_buffer_push (stream, data, datalen);
+          if (!stream->pes_buffer_in_sync) {
+            /* Push the first fragment to PES filter to have a chance to
+             * detect GST_FLOW_LOST_SYNC.
+             */
+            GST_LOG_OBJECT (demux, "fragment directly pushed to PES filter");
+            ret = gst_fluts_demux_push_fragment (stream, data, datalen);
+          } else {
+            /* Otherwhise we buffer the PES fragment */
+            ret = gst_fluts_stream_pes_buffer_push (stream, data, datalen);
+            /* If sync is lost here is due a pes_buffer_flush and we can try
+             * to resync in the PES filter with the current fragment
+             */
+            if (ret == GST_FLOW_LOST_SYNC) {
+              GST_LOG_OBJECT (demux, "resync, fragment pushed to PES filter");
+              ret = gst_fluts_demux_push_fragment (stream, data, datalen);
+            }
+          }
+
           break;
         } else {
           GST_WARNING_OBJECT (demux, "overflow of datalen: %u so skipping",
@@ -2428,15 +2469,20 @@ gst_fluts_demux_sync_scan (GstFluTSDemux * demux, const guint8 * in_data,
   while (ptr_data <= end_scan && sync_count < LENGHT_SYNC_LUT) {
     /* if sync code is found try to store it in the LUT */
     if (G_LIKELY (IS_MPEGTS_SYNC (ptr_data))) {
-      demux->sync_lut[sync_count] = ptr_data;
-      sync_count++;
       /* skip paketsize bytes and try find next */
-      ptr_data += demux->packetsize;
+      guint8 *next_sync = ptr_data + demux->packetsize;
+      if (next_sync < end_scan) {
+        demux->sync_lut[sync_count] = ptr_data;
+        sync_count++;
+        ptr_data += demux->packetsize;
+      } else
+        goto done;
+
     } else {
       ptr_data++;
     }
   }
-
+done:
   *flush = ptr_data - in_data;
 
   return sync_count;
@@ -2453,9 +2499,11 @@ gst_fluts_demux_chain (GstPad * pad, GstBuffer * buffer)
   gint i;
   guint sync_count;
 
-  if (GST_BUFFER_IS_DISCONT (buffer))
+  if (GST_BUFFER_IS_DISCONT (buffer)) {
+    /* Flush buffered PES data */
+    gst_fluts_demux_pes_buffer_flush (demux);
     gst_adapter_clear (demux->adapter);
-
+  }
   /* first push the new buffer into the adapter */
   gst_adapter_push (demux->adapter, buffer);
 
@@ -2473,19 +2521,24 @@ gst_fluts_demux_chain (GstPad * pad, GstBuffer * buffer)
   /* process all packets */
   for (i = 0; i < sync_count; i++) {
     ret = gst_fluts_demux_parse_transport_packet (demux, demux->sync_lut[i]);
+    if (G_UNLIKELY (ret == GST_FLOW_LOST_SYNC)) {
+      flush = demux->sync_lut[i] - data + 1;
+      ret = GST_FLOW_OK;
+      continue;
+    }
     if (G_UNLIKELY (ret != GST_FLOW_OK)) {
-      if (ret == GST_FLOW_LOST_SYNC) {
-        ret = GST_FLOW_OK;
-        continue;
-      }
       flush = demux->sync_lut[i] - data + demux->packetsize;
+      flush = MIN (avail, flush);
       goto done;
     }
   }
 
 done:
   /* flush processed data */
-  gst_adapter_flush (demux->adapter, flush);
+  if (flush) {
+    GST_DEBUG_OBJECT (demux, "flushing %d/%d", flush, avail);
+    gst_adapter_flush (demux->adapter, flush);
+  }
 
   gst_object_unref (demux);
 

gst/mpegdemux/gstmpegtsdemux.h

@@ -164,6 +164,7 @@ struct _GstFluTSStream {
   guint32           pes_buffer_size;
   guint32           pes_buffer_used;
   gboolean          pes_buffer_overflow;
+  gboolean          pes_buffer_in_sync;
   GstPESFilter      filter;
   GstPad            * pad;
   GstFlowReturn     last_ret;