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h264parse: also handle 3-byte bytestream sync code

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This commit is contained in:
Mark Nauwelaerts 2010-06-18 18:41:59 +02:00
parent ba39867606
commit 33e78b12b4
1 changed files with 61 additions and 9 deletions
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66
gst/h264parse/gsth264parse.c
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@ -1706,6 +1706,24 @@ gst_h264_parse_push_nal (GstH264Parse * h264parse, GstBuffer * nal,
data = GST_BUFFER_DATA (nal); data = GST_BUFFER_DATA (nal);
size = GST_BUFFER_SIZE (nal); size = GST_BUFFER_SIZE (nal);
/* deal with 3-byte start code by normalizing to 4-byte here */
if (!h264parse->packetized && data[2] == 0x01) {
GstBuffer *tmp;
/* ouch, copy */
GST_DEBUG_OBJECT (h264parse, "replacing 3-byte startcode");
tmp = gst_buffer_new_and_alloc (1);
GST_BUFFER_DATA (tmp)[0] = 0;
gst_buffer_ref (nal);
tmp = gst_buffer_join (tmp, nal);
GST_BUFFER_TIMESTAMP (tmp) = GST_BUFFER_TIMESTAMP (nal);
gst_buffer_unref (nal);
nal = tmp;
data = GST_BUFFER_DATA (nal);
size = GST_BUFFER_SIZE (nal);
}
/* caller ensures number of bytes available */ /* caller ensures number of bytes available */
g_return_val_if_fail (size >= nal_length + 1, NULL); g_return_val_if_fail (size >= nal_length + 1, NULL);
@ -1866,15 +1884,50 @@ gst_h264_parse_chain_forward (GstH264Parse * h264parse, gboolean discont,
data = gst_adapter_peek (h264parse->adapter, avail); data = gst_adapter_peek (h264parse->adapter, avail);
if (!h264parse->packetized) { if (!h264parse->packetized) {
/* Bytestream format, first 4 bytes are sync code */ /* Bytestream format, first 3/4 bytes are sync code */
/* Find next NALU header */ /* re-sync; locate initial startcode */
if (G_UNLIKELY (h264parse->discont)) {
guint32 value;
/* check for initial 00 00 01 */
i = gst_adapter_masked_scan_uint32 (h264parse->adapter, 0xffffff00,
0x00000100, 0, 4);
if (i < 0) {
i = gst_adapter_masked_scan_uint32_peek (h264parse->adapter,
0x00ffffff, 0x01, 0, avail, &value);
if (i < 0) {
/* no sync code, flush and try next time */
gst_adapter_flush (h264parse->adapter, avail - 2);
break;
} else {
if (value >> 24 != 00)
/* so a 3 byte startcode */
i++;
gst_adapter_flush (h264parse->adapter, i);
avail -= i;
data = gst_adapter_peek (h264parse->adapter, avail);
}
}
GST_DEBUG_OBJECT (h264parse, "re-sync found startcode at %d", i);
}
/* Find next NALU header, might be 3 or 4 bytes */
for (i = 1; i < avail - 4; ++i) { for (i = 1; i < avail - 4; ++i) {
if (data[i + 0] == 0 && data[i + 1] == 0 && data[i + 2] == 0 if (data[i + 1] == 0 && data[i + 2] == 0 && data[i + 3] == 1) {
&& data[i + 3] == 1) { if (data[i + 0] == 0)
next_nalu_pos = i; next_nalu_pos = i;
else
next_nalu_pos = i + 1;
break; break;
} }
} }
/* skip sync */
if (data[2] == 0x1) {
data += 3;
avail -= 3;
} else {
data += 4;
avail -= 4;
}
} else { } else {
guint32 nalu_size; guint32 nalu_size;
@ -1900,11 +1953,10 @@ gst_h264_parse_chain_forward (GstH264Parse * h264parse, gboolean discont,
} else { } else {
next_nalu_pos = avail; next_nalu_pos = avail;
} }
} /* skip nalu_size bytes */
/* skip nalu_size bytes or sync */
data += h264parse->nal_length_size; data += h264parse->nal_length_size;
avail -= h264parse->nal_length_size; avail -= h264parse->nal_length_size;
}
/* Figure out if this is a delta unit */ /* Figure out if this is a delta unit */
{ {