From 348658dd0a268bb5be91b289b019a66f03603d94 Mon Sep 17 00:00:00 2001
From: He Junyan <junyan.he@intel.com>
Date: Fri, 4 Feb 2022 11:40:18 +0800
Subject: [PATCH] av1parse: Continue when we fail to detect the alignment.

Some streams may have problematic OBUs at the beginning, which causes
the parse fail to detect the alignment and return error. For example,
there may be verbose OBUs before a valid sequence, which should be
discarded until we meet a valid sequence. We should let the parse
continue when we meet such cases, rather than just return error.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1634>
---
 .../gst/videoparsers/gstav1parse.c            | 36 ++++++++++---------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/subprojects/gst-plugins-bad/gst/videoparsers/gstav1parse.c b/subprojects/gst-plugins-bad/gst/videoparsers/gstav1parse.c
index 3b5563cff8..7ea3a9422d 100644
--- a/subprojects/gst-plugins-bad/gst/videoparsers/gstav1parse.c
+++ b/subprojects/gst-plugins-bad/gst/videoparsers/gstav1parse.c
@@ -1654,7 +1654,7 @@ out:
 /* Try to recognize whether the input is annex-b format. */
 static GstFlowReturn
 gst_av1_parse_detect_alignment (GstBaseParse * parse,
-    GstBaseParseFrame * frame, gint * skipsize)
+    GstBaseParseFrame * frame, gint * skipsize, guint32 * total_consumed)
 {
   GstAV1Parse *self = GST_AV1_PARSE (parse);
   GstMapInfo map_info;
@@ -1663,7 +1663,7 @@ gst_av1_parse_detect_alignment (GstBaseParse * parse,
   GstBuffer *buffer = gst_buffer_ref (frame->buffer);
   gboolean got_seq, got_frame;
   gboolean frame_complete;
-  guint32 consumed, total_consumed;
+  guint32 consumed;
   guint32 frame_sz;
   GstFlowReturn ret = GST_FLOW_OK;
 
@@ -1678,19 +1678,20 @@ gst_av1_parse_detect_alignment (GstBaseParse * parse,
   /* Detect the alignment obu first */
   got_seq = FALSE;
   got_frame = FALSE;
-  total_consumed = 0;
+  *total_consumed = 0;
 again:
-  while (total_consumed < map_info.size) {
+  while (*total_consumed < map_info.size) {
     res = gst_av1_parser_identify_one_obu (self->parser,
-        map_info.data + total_consumed, map_info.size - total_consumed,
+        map_info.data + *total_consumed, map_info.size - *total_consumed,
         &obu, &consumed);
-    if (res == GST_AV1_PARSER_OK)
+    if (res == GST_AV1_PARSER_OK) {
+      *total_consumed += consumed;
       res = gst_av1_parse_handle_one_obu (self, &obu, &frame_complete);
+    }
+
     if (res != GST_AV1_PARSER_OK)
       break;
 
-    total_consumed += consumed;
-
     if (obu.obu_type == GST_AV1_OBU_SEQUENCE_HEADER)
       got_seq = TRUE;
     if (obu.obu_type == GST_AV1_OBU_REDUNDANT_FRAME_HEADER ||
@@ -1715,7 +1716,7 @@ again:
     ret = GST_FLOW_OK;
     goto out;
   } else if (res == GST_AV1_PARSER_DROP) {
-    total_consumed += consumed;
+    *total_consumed += consumed;
     res = GST_AV1_PARSER_OK;
     goto again;
   }
@@ -1812,17 +1813,20 @@ gst_av1_parse_handle_frame (GstBaseParse * parse,
   }
 
   if (self->in_align == GST_AV1_PARSE_ALIGN_NONE) {
+    guint32 consumed = 0;
+
     /* Only happend at the first time of handle_frame, and the
        alignment in the sink caps is unset. Try the default and
        if error, try the annex B. */
-    ret = gst_av1_parse_detect_alignment (parse, frame, skipsize);
-    if (ret == GST_FLOW_OK && self->in_align != GST_AV1_PARSE_ALIGN_NONE)
+    ret = gst_av1_parse_detect_alignment (parse, frame, skipsize, &consumed);
+    if (ret == GST_FLOW_OK && self->in_align != GST_AV1_PARSE_ALIGN_NONE) {
       GST_INFO_OBJECT (self, "Detect the input alignment %d", self->in_align);
-  }
-
-  if (self->in_align == GST_AV1_PARSE_ALIGN_NONE) {
-    GST_ERROR_OBJECT (self, "Input alignment is unknown");
-    return GST_FLOW_ERROR;
+    } else {
+      *skipsize = consumed > 0 ? consumed : gst_buffer_get_size (frame->buffer);
+      GST_WARNING_OBJECT (self, "Fail to detect the alignment, skip %d",
+          *skipsize);
+      return GST_FLOW_OK;
+    }
   }
 
   /* We may in pull mode and no caps is set */