decodebin3: Handle streams without CAPS or TIME segment

decodebin3 will do its best to figure out whether a parsebin is required to
process the incoming stream.

The problem is that for push-based stream it could happen that the stream would
not provide any caps, resulting in nothing being linked internally.

Furthermore, there is the possibility that a stream *with* caps would not be
using a TIME segment, which is required for multiqueue to properly work.

In order to fix those two issues, we force the usage of parsebin on push-based
streams:
* When the pad is linked, if upstream can't provide any caps
* When we get a non-TIME segment

Fixes #2521

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4492>
This commit is contained in:
Edward Hervey 2023-04-26 12:20:25 +02:00 committed by GStreamer Marge Bot
parent 61416bc532
commit 0db6149880

View file

@ -912,6 +912,7 @@ gst_decodebin3_input_pad_link (GstPad * pad, GstObject * parent, GstPad * peer)
GstDecodebin3 *dbin = (GstDecodebin3 *) parent;
GstQuery *query;
gboolean pull_mode = FALSE;
gboolean has_caps = TRUE;
GstPadLinkReturn res = GST_PAD_LINK_OK;
DecodebinInput *input = g_object_get_data (G_OBJECT (pad), "decodebin.input");
@ -928,12 +929,26 @@ gst_decodebin3_input_pad_link (GstPad * pad, GstObject * parent, GstPad * peer)
GST_DEBUG_OBJECT (dbin, "Upstream can do pull-based : %d", pull_mode);
/* If upstream *can* do pull-based, we always use a parsebin. If not, we will
* delay that decision to a later stage (caps/stream/collection event
* processing) to figure out if one is really needed or whether an identity
* element will be enough */
if (!pull_mode) {
/* If push-based, query if it will provide some caps */
query = gst_query_new_caps (NULL);
if (gst_pad_query (peer, query)) {
GstCaps *rescaps = NULL;
gst_query_parse_caps_result (query, &rescaps);
if (!rescaps || gst_caps_is_any (rescaps) || gst_caps_is_empty (rescaps)) {
GST_DEBUG_OBJECT (dbin, "Upstream can't provide caps");
has_caps = FALSE;
}
}
gst_query_unref (query);
}
/* If upstream *can* do pull-based OR it doesn't have any caps, we always use
* a parsebin. If not, we will delay that decision to a later stage
* (caps/stream/collection event processing) to figure out if one is really
* needed or whether an identity element will be enough */
INPUT_LOCK (dbin);
if (pull_mode) {
if (pull_mode || !has_caps) {
if (!ensure_input_parsebin (dbin, input))
res = GST_PAD_LINK_REFUSED;
else if (input->identity) {
@ -1410,6 +1425,21 @@ sink_event_function (GstPad * sinkpad, GstDecodebin3 * dbin, GstEvent * event)
}
break;
}
case GST_EVENT_SEGMENT:
{
const GstSegment *segment = NULL;
gst_event_parse_segment (event, &segment);
/* All data reaching multiqueue must be in time format. If it's not, we
* need to use a parsebin on the incoming stream.
*/
if (segment && segment->format != GST_FORMAT_TIME && !input->parsebin) {
GST_DEBUG_OBJECT (sinkpad,
"Got a non-time segment, forcing parsebin handling");
ensure_input_parsebin (dbin, input);
}
break;
}
default:
break;
}