gst-libs/gst/riff/riff-read.c: Additional pad usability check.

Original commit message from CVS:
2004-01-25  Ronald Bultje  <rbultje@ronald.bitfreak.net>

* gst-libs/gst/riff/riff-read.c: (gst_riff_read_info):
Additional pad usability check.
* gst/mpeg1videoparse/gstmp1videoparse.c: (gst_mp1videoparse_init),
(mp1videoparse_find_next_gop), (gst_mp1videoparse_time_code),
(gst_mp1videoparse_real_chain):
Fix MPEG video stream parsing. The original plugin had several
issues, including not timestamping streams where the source was
not timestamped (this happens with PTS values in mpeg system
streams, but MPEG video is also a valid stream on its own so
that needs timestamps too). We use the display time code for that
for now. Also, if one incoming buffer contains multiple valid
frames, we push them all on correctly now, including proper EOS
handling. Lastly, several potential segfaults were fixed, and we
properly sync on new sequence/gop headers to include them in next,
not previous frames (since they're header for the next frame, not
the previous). Also see #119206.
* gst/mpegaudioparse/gstmpegaudioparse.c: (gst_mp3parse_chain),
(bpf_from_header):
Move caps setting so we only do it after finding several valid
MPEG-1 fraes sequentially, not right after the first one (which
might be coincidental).
* gst/typefind/gsttypefindfunctions.c: (mpeg1_sys_type_find),
(mpeg_video_type_find), (mpeg_video_stream_type_find),
(plugin_init):
Add unsynced MPEG video stream typefinding, and change some
probability values so we detect streams rightly. The idea is as
follows: I can have an unsynced system stream which contains
video. In the current code, I would randomly get a type for either
system or video stream type found, because the probabilities are
being calculated rather randomly. I now use fixed values, so we
always prefer system stream if that was found (and that is how it
should be). If no system stream was found, we can still identity
the stream as video-only.

1 files changed, 67 insertions, 12 deletions

diff --git a/gst/mpeg1videoparse/gstmp1videoparse.c b/gst/mpeg1videoparse/gstmp1videoparse.c
index 645392ba..a90ed36e 100644
--- a/gst/mpeg1videoparse/gstmp1videoparse.c
+++ b/gst/mpeg1videoparse/gstmp1videoparse.c
@@ -155,7 +155,7 @@ gst_mp1videoparse_init (Mp1VideoParse *mp1videoparse)
 
   mp1videoparse->partialbuf = NULL;
   mp1videoparse->need_resync = FALSE;
-  mp1videoparse->last_pts = 0;
+  mp1videoparse->last_pts = GST_CLOCK_TIME_NONE;
   mp1videoparse->picture_in_buffer = 0;
   mp1videoparse->width = mp1videoparse->height = -1;
   mp1videoparse->fps = mp1videoparse->asr = 0.;
@@ -259,8 +259,9 @@ mp1videoparse_find_next_gop (Mp1VideoParse *mp1videoparse, GstBuffer *buf)
       have_sync = TRUE;
     }
     else if (have_sync) {
-      if (byte == (SEQ_START_CODE & 0xff) || byte == (GOP_START_CODE & 0xff)) return offset-4;
-      else {
+      if (byte == (SEQ_START_CODE & 0xff) || byte == (GOP_START_CODE & 0xff)) {
+        return offset - 4;
+      } else {
         sync_zeros = 0;
 	have_sync = FALSE;
       }
@@ -272,6 +273,19 @@ mp1videoparse_find_next_gop (Mp1VideoParse *mp1videoparse, GstBuffer *buf)
 
   return -1;
 }
+
+static guint64
+gst_mp1videoparse_time_code (guchar *gop,
+			     gfloat  fps)
+{
+  guint32 data = GUINT32_FROM_BE (* (guint32 *) gop);
+
+  return ((((data & 0xfc000000) >> 26) * 3600 * GST_SECOND) + /* hours */
+	  (((data & 0x03f00000) >> 20) *   60 * GST_SECOND) + /* minutes */
+	  (((data & 0x0007e000) >> 13) *        GST_SECOND) + /* seconds */
+	  (((data & 0x00001f80) >>  7) * GST_SECOND / fps));  /* frames */
+}
+
 static void
 gst_mp1videoparse_flush (Mp1VideoParse *mp1videoparse)
 {
@@ -370,7 +384,7 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
 				mp1videoparse->partialbuf) ||
       mp1videoparse->need_resync) {
     sync_pos = mp1videoparse_find_next_gop(mp1videoparse, mp1videoparse->partialbuf);
-    if (sync_pos != -1) {
+    if (sync_pos >= 0) {
       mp1videoparse->need_resync = FALSE;
       GST_DEBUG ("mp1videoparse: found new gop at %d", sync_pos);
 
@@ -383,6 +397,14 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
         size = GST_BUFFER_SIZE(mp1videoparse->partialbuf);
 	offset = 0;
       }
+
+      head = GUINT32_FROM_BE(*((guint32 *)data));
+      /* re-call this function so that if we hadn't already, we can
+       * now read the sequence header and parse video properties,
+       * set caps, stream data, be happy, bla, bla, bla... */
+      if (!mp1videoparse_valid_sync (mp1videoparse, head,
+				     mp1videoparse->partialbuf))
+        g_error ("Found sync but no valid sync point at pos 0x0");
     }
     else {
       GST_DEBUG ("mp1videoparse: could not sync");
@@ -392,7 +414,8 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
     }
   }
 
-  if (mp1videoparse->picture_in_buffer == 1) {
+  if (mp1videoparse->picture_in_buffer == 1 &&
+      time_stamp != GST_CLOCK_TIME_NONE) {
     mp1videoparse->last_pts = time_stamp;
   }
 
@@ -403,7 +426,6 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
 
   while (offset < size-1) {
     sync_byte = *(data + offset);
-    /*printf(" %d %02x\n", offset, sync_byte); */
     if (sync_byte == 0) {
       sync_state++;
     }
@@ -412,7 +434,9 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
       if (data[offset+1] == (PICTURE_START_CODE & 0xff)) {
 	mp1videoparse->picture_in_buffer++;
 	if (mp1videoparse->picture_in_buffer == 1) {
-          mp1videoparse->last_pts = time_stamp;
+	  if (time_stamp != GST_CLOCK_TIME_NONE) {
+            mp1videoparse->last_pts = time_stamp;
+	  }
 	  sync_state = 0;
 	}
 	else if (mp1videoparse->picture_in_buffer == 2) {
@@ -424,6 +448,33 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
           g_assert_not_reached();
 	}
       }
+      /* A new sequence (or GOP) is a valid sync too. Note that the
+       * sequence header should be put in the next buffer, not here. */
+      else if (data[offset+1] == (SEQ_START_CODE & 0xFF) ||
+	       data[offset+1] == (GOP_START_CODE & 0xFF)) {
+        if (mp1videoparse->picture_in_buffer == 0 &&
+	    data[offset+1] == (GOP_START_CODE & 0xFF)) {
+	  mp1videoparse->last_pts = gst_mp1videoparse_time_code (&data[2],
+			  			mp1videoparse->fps);
+	}
+        else if (mp1videoparse->picture_in_buffer == 1) {
+	  have_sync = TRUE;
+	  break;
+	} else {
+	  g_assert (mp1videoparse->picture_in_buffer == 0);
+	}
+      }
+      /* end-of-sequence is a valid sync point and should be included
+       * in the current picture, not the next. */
+      else if (data[offset+1] == (SEQ_END_CODE & 0xFF)) {
+        if (mp1videoparse->picture_in_buffer == 1) {
+          offset += 4;
+	  have_sync = TRUE;
+	  break;
+	} else {
+	  g_assert (mp1videoparse->picture_in_buffer == 0);
+	}
+      }
       else sync_state = 0;
     }
     /* something else... */
@@ -434,12 +485,11 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
 
   if (have_sync) {
     offset -= 2;
-    GST_DEBUG ("mp1videoparse: synced at %ld code 0x000001%02x",offset,data[offset+3]);
-
-    outbuf = gst_buffer_create_sub(mp1videoparse->partialbuf, 0, offset+4);
+    outbuf = gst_buffer_create_sub(mp1videoparse->partialbuf, 0, offset);
     g_assert(outbuf != NULL);
     GST_BUFFER_TIMESTAMP(outbuf) = mp1videoparse->last_pts;
     GST_BUFFER_DURATION(outbuf) = GST_SECOND / mp1videoparse->fps;
+    mp1videoparse->last_pts += GST_BUFFER_DURATION (outbuf);
 
     if (mp1videoparse->in_flush) {
       /* FIXME, send a flush event here */
@@ -456,12 +506,17 @@ gst_mp1videoparse_real_chain (Mp1VideoParse *mp1videoparse, GstBuffer *buf, GstP
     }
     mp1videoparse->picture_in_buffer = 0;
 
-    temp = gst_buffer_create_sub(mp1videoparse->partialbuf, offset, size-offset);
+    if (size > offset)
+      temp = gst_buffer_create_sub(mp1videoparse->partialbuf, offset, size-offset);
+    else
+      temp = NULL;
     gst_buffer_unref(mp1videoparse->partialbuf);
     mp1videoparse->partialbuf = temp;
   }
   else {
-    mp1videoparse->last_pts = time_stamp;
+    if (time_stamp != GST_CLOCK_TIME_NONE) {
+      mp1videoparse->last_pts = time_stamp;
+    }
   }
 }