baseparse: do not accumulate buffers on passthrough mode

If on passthrough during reverse playback, do not accumulate buffers as
baseparse will never check for DISCONT flag to push those buffers.
So just push buffers downstream as if it was forward playback.

https://bugzilla.gnome.org/show_bug.cgi?id=721941

1 files changed, 29 insertions, 0 deletions

diff --git a/libs/gst/base/gstbaseparse.c b/libs/gst/base/gstbaseparse.c
index 3495c3f3f4..c932bb4d8e 100644
--- a/libs/gst/base/gstbaseparse.c
+++ b/libs/gst/base/gstbaseparse.c
@@ -473,6 +473,7 @@ static GstFlowReturn gst_base_parse_locate_time (GstBaseParse * parse,
 static GstFlowReturn gst_base_parse_start_fragment (GstBaseParse * parse);
 static GstFlowReturn gst_base_parse_finish_fragment (GstBaseParse * parse,
     gboolean prev_head);
+static GstFlowReturn gst_base_parse_send_buffers (GstBaseParse * parse);
 
 static inline GstFlowReturn gst_base_parse_check_sync (GstBaseParse * parse);
 
@@ -2296,6 +2297,34 @@ gst_base_parse_push_frame (GstBaseParse * parse, GstBaseParseFrame * frame)
           size);
       ret = gst_pad_push (parse->srcpad, buffer);
       GST_LOG_OBJECT (parse, "frame pushed, flow %s", gst_flow_get_name (ret));
+    } else if (!parse->priv->disable_passthrough && parse->priv->passthrough) {
+
+      /* in backwards playback mode, if on passthrough we need to push buffers
+       * directly without accumulating them into the buffers_queued as baseparse
+       * will never check for a DISCONT while on passthrough and those buffers
+       * will never be pushed.
+       *
+       * also, as we are on reverse playback, it might be possible that
+       * passthrough might have just been enabled, so make sure to drain the
+       * buffers_queued list */
+      if (G_UNLIKELY (parse->priv->buffers_queued != NULL)) {
+        gst_base_parse_finish_fragment (parse, TRUE);
+        ret = gst_base_parse_send_buffers (parse);
+      }
+
+      if (ret == GST_FLOW_OK) {
+        GST_LOG_OBJECT (parse,
+            "pushing frame (%" G_GSIZE_FORMAT " bytes) now..", size);
+        ret = gst_pad_push (parse->srcpad, buffer);
+        GST_LOG_OBJECT (parse, "frame pushed, flow %s",
+            gst_flow_get_name (ret));
+      } else {
+        GST_LOG_OBJECT (parse,
+            "frame (%" G_GSIZE_FORMAT " bytes) not pushed: %s", size,
+            gst_flow_get_name (ret));
+        gst_buffer_unref (buffer);
+      }
+
     } else {
       GST_LOG_OBJECT (parse, "frame (%" G_GSIZE_FORMAT " bytes) queued for now",
           size);