tsdemux: Make jp2k handling more robust and efficient

* Avoid copying the pending data and instead create a buffer directly from
  that data with the appropriate offset.
* Locate the jp2k magic to determine the exact location of the (first) frame
  data instead of assuming that the header is of an expected size

https://bugzilla.gnome.org/show_bug.cgi?id=786111
This commit is contained in:
Edward Hervey 2017-08-30 08:37:04 +02:00 committed by Edward Hervey
parent c393f0d768
commit 52d0ef2665

View file

@ -2675,9 +2675,8 @@ parse_jp2k_access_unit (TSDemuxStream * stream)
guint8 CollC G_GNUC_UNUSED;
guint8 b G_GNUC_UNUSED;
guint8 *packet_data = NULL;
guint packet_size;
guint remaining = 0;
guint data_location;
GstBuffer *retbuf = NULL;
if (stream->current_size < header_size) {
GST_ERROR_OBJECT (stream->pad, "Not enough data for header");
@ -2686,6 +2685,16 @@ parse_jp2k_access_unit (TSDemuxStream * stream)
gst_byte_reader_init (&reader, stream->data, stream->current_size);
/* Check for the location of the jp2k magic */
data_location =
gst_byte_reader_masked_scan_uint32 (&reader, 0xffffffff, 0xff4fff51, 0,
stream->current_size);
GST_DEBUG_OBJECT (stream->pad, "data location %d", data_location);
if (data_location == -1) {
GST_ERROR_OBJECT (stream->pad, "Stream does not contain jp2k magic header");
goto error;
}
/* Elementary stream header box 'elsm' == 0x656c736d */
header_tag = gst_byte_reader_get_uint32_be_unchecked (&reader);
if (header_tag != 0x656c736d) {
@ -2759,33 +2768,20 @@ parse_jp2k_access_unit (TSDemuxStream * stream)
}
CollC = gst_byte_reader_get_uint8_unchecked (&reader);
b = gst_byte_reader_get_uint8_unchecked (&reader);
remaining = gst_byte_reader_get_remaining (&reader);
packet_size = remaining;
GST_DEBUG_OBJECT (stream->pad,
"Size of first codestream in TS stream: %d; bytes remaining: %d", AUF[0],
remaining);
if (!gst_byte_reader_dup_data (&reader, packet_size, &packet_data)) {
GST_ERROR ("Required size %d > %d than remaining size in buffer", AUF[0],
packet_size);
/* Check if we have enough data to create a valid buffer */
if ((stream->current_size - data_location) < (AUF[0] + AUF[1])) {
GST_ERROR ("Required size (%d) greater than remaining size in buffer (%d)",
AUF[0] + AUF[1], (stream->current_size - data_location));
goto error;
}
#ifdef TSDEMUX_JP2K_SUPPORT_INTERLACE
if (stream->jp2kInfos.interlace) {
remaining = gst_byte_reader_get_remaining (&reader);
if (!gst_byte_reader_dup_data (&reader, AUF[1], &packet_data)) {
GST_ERROR ("Required size %d > %d than remaining size in buffer", AUF[1],
remaining);
goto error;
}
}
#endif
g_free (stream->data);
retbuf = gst_buffer_new_wrapped_full (0, stream->data, stream->current_size,
data_location, stream->current_size - data_location,
stream->data, g_free);
stream->data = NULL;
stream->current_size = 0;
return gst_buffer_new_wrapped (packet_data, packet_size);
return retbuf;
error:
GST_ERROR ("Failed to parse JP2K access unit");