qtdemux: Fix text and closed-caption handling.

https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1182
broke text and and closed caption extraction when introducing WebVTT
support, by making the output buffers not have timestamps any more.

Fix that by making the process functions copy buffer metadata
when generating new output buffers.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1262>

diff --git a/subprojects/gst-plugins-good/gst/isomp4/qtdemux.c b/subprojects/gst-plugins-good/gst/isomp4/qtdemux.c
index cb20edf..8d224be 100644 (file)
--- a/subprojects/gst-plugins-good/gst/isomp4/qtdemux.c
+++ b/subprojects/gst-plugins-good/gst/isomp4/qtdemux.c
@@ -5677,6 +5677,7 @@ static GstBuffer *
 gst_qtdemux_process_buffer_clcp (GstQTDemux * qtdemux, QtDemuxStream * stream,
     GstBuffer * buf)
 {
+  GstBuffer *outbuf = NULL;
   GstMapInfo map;
   guint8 *cc;
   gsize cclen = 0;
@@ -5694,14 +5695,15 @@ gst_qtdemux_process_buffer_clcp (GstQTDemux * qtdemux, QtDemuxStream * stream,
    * [cdat],[cdt2] or [ccdp] atom */
   cc = extract_cc_from_data (stream, map.data, map.size, &cclen);
   gst_buffer_unmap (buf, &map);
-  gst_buffer_unref (buf);
   if (cc) {
-    buf = _gst_buffer_new_wrapped (cc, cclen, g_free);
+    outbuf = _gst_buffer_new_wrapped (cc, cclen, g_free);
+    gst_buffer_copy_into (outbuf, buf, GST_BUFFER_COPY_METADATA, 0, -1);
   } else {
     /* Conversion failed or there's nothing */
-    buf = NULL;
   }
-  return buf;
+  gst_buffer_unref (buf);
+
+  return outbuf;
 }
 
 /* DVD subpicture specific sample handling.
@@ -5733,6 +5735,7 @@ static GstBuffer *
 gst_qtdemux_process_buffer_text (GstQTDemux * qtdemux, QtDemuxStream * stream,
     GstBuffer * buf)
 {
+  GstBuffer *outbuf = NULL;
   GstMapInfo map;
   guint nsize = 0;
   gchar *str;
@@ -5762,18 +5765,18 @@ gst_qtdemux_process_buffer_text (GstQTDemux * qtdemux, QtDemuxStream * stream,
    * no other encoding expected */
   str = gst_tag_freeform_string_to_utf8 ((gchar *) map.data + 2, nsize, NULL);
   gst_buffer_unmap (buf, &map);
+
   if (str) {
-    gst_buffer_unref (buf);
-    buf = _gst_buffer_new_wrapped (str, strlen (str), g_free);
+    outbuf = _gst_buffer_new_wrapped (str, strlen (str), g_free);
+    gst_buffer_copy_into (outbuf, buf, GST_BUFFER_COPY_METADATA, 0, -1);
   } else {
     /* this should not really happen unless the subtitle is corrupted */
-    gst_buffer_unref (buf);
-    buf = NULL;
   }
+  gst_buffer_unref (buf);
 
   /* FIXME ? convert optional subsequent style info to markup */
 
-  return buf;
+  return outbuf;
 }
 
 /* WebVTT sample handling according to 14496-30 */