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From 258bf9862e5b7179562f0cae9fb470f6486dca3a Mon Sep 17 00:00:00 2001
From: Kazunori Kobayashi <kkobayas@igel.co.jp>
Date: Thu, 12 Jul 2012 12:08:15 +0900
Subject: [PATCH] asfdemux/asfpacket: set frame start code to VC-1 advanced
profile stream
VC-1 advanced profile constrains the bitstream format to pair
the frame data with the frame start code.
---
gst/asfdemux/asfpacket.c | 36 +++++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/gst/asfdemux/asfpacket.c b/gst/asfdemux/asfpacket.c
index 552a559..77209f1 100644
--- a/gst/asfdemux/asfpacket.c
+++ b/gst/asfdemux/asfpacket.c
@@ -71,9 +71,10 @@ asf_packet_read_varlen_int (guint lentype_flags, guint lentype_bit_offset,
static GstBuffer *
asf_packet_create_payload_buffer (AsfPacket * packet, const guint8 ** p_data,
- guint * p_size, guint payload_len)
+ guint * p_size, guint payload_len, gboolean need_st_code)
{
guint off;
+ guint8 *st_code;
g_assert (payload_len <= *p_size);
@@ -83,6 +84,21 @@ asf_packet_create_payload_buffer (AsfPacket * packet, const guint8 ** p_data,
*p_data += payload_len;
*p_size -= payload_len;
+ /* set start code for VC-1 advanced profile */
+ if (need_st_code && off >= 4) {
+ st_code = GST_BUFFER_DATA (packet->buf) + (off - 4);
+ /* check if this packet has a start code */
+ if (st_code[4] != 0x00 || st_code[5] != 0x00 || st_code[6] != 0x01 ||
+ st_code[7] != 0x0d) {
+ st_code[0] = 0x00;
+ st_code[1] = 0x00;
+ st_code[2] = 0x01;
+ st_code[3] = 0x0d;
+
+ return gst_buffer_create_sub (packet->buf, off - 4, payload_len + 4);
+ }
+ }
+
return gst_buffer_create_sub (packet->buf, off, payload_len);
}
@@ -274,6 +290,9 @@ gst_asf_demux_parse_payload (GstASFDemux * demux, AsfPacket * packet,
gboolean is_compressed;
guint payload_len;
guint stream_num;
+ GstStructure *structure;
+ guint32 fourcc;
+ gboolean need_st_code = FALSE;
if (G_UNLIKELY (*p_size < 1)) {
GST_WARNING_OBJECT (demux, "Short packet!");
@@ -353,6 +372,17 @@ gst_asf_demux_parse_payload (GstASFDemux * demux, AsfPacket * packet,
return TRUE;
}
+ structure = gst_caps_get_structure (stream->caps, 0);
+ if (gst_structure_get_fourcc (structure, "format", &fourcc)) {
+ /*
+ * set start code for VC-1 advanced profile if fourcc is 'WVC1' and this
+ * packet is at the head of a payload.
+ */
+ if (fourcc == GST_MAKE_FOURCC ('W', 'V', 'C', '1')
+ && payload.mo_offset == 0)
+ need_st_code = TRUE;
+ }
+
if (G_UNLIKELY (!is_compressed)) {
GST_LOG_OBJECT (demux, "replicated data length: %u", payload.rep_data_len);
@@ -384,7 +414,7 @@ gst_asf_demux_parse_payload (GstASFDemux * demux, AsfPacket * packet,
if ((stream = gst_asf_demux_get_stream (demux, stream_num))
&& payload_len) {
payload.buf = asf_packet_create_payload_buffer (packet, p_data, p_size,
- payload_len);
+ payload_len, need_st_code);
/* n-th fragment of a fragmented media object? */
if (payload.mo_offset != 0) {
@@ -443,7 +473,7 @@ gst_asf_demux_parse_payload (GstASFDemux * demux, AsfPacket * packet,
if (G_LIKELY (sub_payload_len > 0)) {
payload.buf = asf_packet_create_payload_buffer (packet,
- &payload_data, &payload_len, sub_payload_len);
+ &payload_data, &payload_len, sub_payload_len, need_st_code);
payload.ts = ts;
if (G_LIKELY (ts_delta))
--
1.7.9.5
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