/**
* gst_mpeg4_next_resync:
* @packet: The #GstMpeg4Packet to fill
* @vop: The previously parsed #GstMpeg4VideoObjectPlane
* @offset: offset from which to start the parsing
* @data: The data to parse
* @size: The size of the @data to parse
*
* Parses @data and fills @packet with the information of the next resync packet
* found.
*
* Returns: a #GstMpeg4ParseResult
*/
static GstMpeg4ParseResult
gst_mpeg4_next_resync (GstMpeg4Packet * packet,
const GstMpeg4VideoObjectPlane * vop, const guint8 * data, gsize size,
gboolean first_resync_marker)
{
guint markersize = 0, off1, off2;
guint32 mask = 0xff, pattern = 0xff;
GstByteReader br;
gst_byte_reader_init (&br, data, size);
g_return_val_if_fail (packet != NULL, GST_MPEG4_PARSER_ERROR);
g_return_val_if_fail (vop != NULL, GST_MPEG4_PARSER_ERROR);
markersize = compute_resync_marker_size (vop, &pattern, &mask);
if (first_resync_marker) {
off1 = 0;
} else {
off1 = gst_byte_reader_masked_scan_uint32 (&br, mask, pattern, 0, size);
}
if (off1 == -1)
return GST_MPEG4_PARSER_NO_PACKET;
GST_DEBUG ("Resync code found at %i", off1);
packet->offset = off1;
packet->type = GST_MPEG4_RESYNC;
packet->marker_size = markersize;
off2 = gst_byte_reader_masked_scan_uint32 (&br, mask, pattern,
off1 + 2, size - off1 - 2);
if (off2 == -1)
return GST_MPEG4_PARSER_NO_PACKET_END;
packet->size = off2 - off1;
return GST_MPEG4_PARSER_OK;
}
/**
* mpeg4_next_resync:
* @packet: The #Mpeg4Packet to fill
* @vop: The previously parsed #Mpeg4VideoObjectPlane
* @offset: offset from which to start the parsing
* @data: The data to parse
* @size: The size of the @data to parse
*
* Parses @data and fills @packet with the information of the next resync packet
* found.
*
* Returns: a #Mpeg4ParseResult
*/
static Mpeg4ParseResult
mpeg4_next_resync (Mpeg4Packet * packet,
const Mpeg4VideoObjectPlane * vop, const uint8_t * data, size_t size,
bool first_resync_marker)
{
uint32_t markersize = 0, off1, off2;
uint32_t mask = 0xff, pattern = 0xff;
ByteReader br;
byte_reader_init (&br, data, size);
g_return_val_if_fail (packet != NULL, MPEG4_PARSER_ERROR);
g_return_val_if_fail (vop != NULL, MPEG4_PARSER_ERROR);
markersize = compute_resync_marker_size (vop, &pattern, &mask);
if (first_resync_marker) {
off1 = 0;
} else {
off1 = byte_reader_masked_scan_uint32 (&br, mask, pattern, 0, size);
}
if (off1 == -1)
return MPEG4_PARSER_NO_PACKET;
DEBUG ("Resync code found at %i", off1);
packet->offset = off1;
packet->type = MPEG4_RESYNC;
packet->marker_size = markersize;
off2 = byte_reader_masked_scan_uint32 (&br, mask, pattern,
off1 + 2, size - off1 - 2);
if (off2 == -1)
return MPEG4_PARSER_NO_PACKET_END;
packet->size = off2 - off1;
return MPEG4_PARSER_OK;
}
/**
* gst_mpeg4_parse_video_packet_header:
* @videopackethdr: The #GstMpeg4VideoPacketHdr structure to fill
* @vol: The last parsed #GstMpeg4VideoObjectLayer, will be updated
* with the informations found during the parsing
* @vop: The last parsed #GstMpeg4VideoObjectPlane, will be updated
* with the informations found during the parsing
* @sprite_trajectory: A #GstMpeg4SpriteTrajectory to fill or %NULL
* with the informations found during the parsing
* @data: The data to parse, should be set after the resync marker.
* @size: The size of the data to parse
*
* Parsers @data containing the video packet header
* and fills the @videopackethdr structure
*/
GstMpeg4ParseResult
gst_mpeg4_parse_video_packet_header (GstMpeg4VideoPacketHdr * videopackethdr,
GstMpeg4VideoObjectLayer * vol, GstMpeg4VideoObjectPlane * vop,
GstMpeg4SpriteTrajectory * sprite_trajectory, const guint8 * data,
gsize size)
{
guint8 markersize;
GstBitReader br = GST_BIT_READER_INIT (data, size);
g_return_val_if_fail (videopackethdr != NULL, GST_MPEG4_PARSER_ERROR);
g_return_val_if_fail (vol != NULL, GST_MPEG4_PARSER_ERROR);
markersize = compute_resync_marker_size (vop, NULL, NULL);
CHECK_REMAINING (&br, markersize);
if (gst_bit_reader_get_bits_uint32_unchecked (&br, markersize) != 0x01)
goto failed;
if (vol->shape != GST_MPEG4_RECTANGULAR) {
READ_UINT8 (&br, videopackethdr->header_extension_code, 1);
if (vol->sprite_enable == GST_MPEG4_SPRITE_STATIC &&
vop->coding_type == GST_MPEG4_I_VOP) {
CHECK_REMAINING (&br, 56);
U_READ_UINT16 (&br, vop->width, 13);
CHECK_MARKER (&br);
U_READ_UINT16 (&br, vop->height, 13);
CHECK_MARKER (&br);
U_READ_UINT16 (&br, vop->horizontal_mc_spatial_ref, 13);
CHECK_MARKER (&br);
U_READ_UINT16 (&br, vop->vertical_mc_spatial_ref, 13);
CHECK_MARKER (&br);
/* Update macroblock infirmations */
vop->mb_height = (vop->height + 15) / 16;
vop->mb_width = (vop->width + 15) / 16;
vop->mb_num = vop->mb_height * vop->mb_width;
}
}
READ_UINT16 (&br, videopackethdr->macroblock_number,
g_bit_storage (vop->mb_num - 1));
if (vol->shape != GST_MPEG4_BINARY_ONLY)
READ_UINT16 (&br, videopackethdr->quant_scale, vol->quant_precision);
if (vol->shape == GST_MPEG4_RECTANGULAR)
READ_UINT8 (&br, videopackethdr->header_extension_code, 1);
if (videopackethdr->header_extension_code) {
guint timeincr = 0;
guint8 bit = 0, coding_type;
do {
READ_UINT8 (&br, bit, 1);
timeincr++;
} while (bit);
vol->vop_time_increment_bits = timeincr;
CHECK_MARKER (&br);
READ_UINT16 (&br, vop->time_increment, timeincr);
CHECK_MARKER (&br);
READ_UINT8 (&br, coding_type, 2);
vop->coding_type = coding_type;
if (vol->shape != GST_MPEG4_RECTANGULAR) {
READ_UINT8 (&br, vop->change_conv_ratio_disable, 1);
if (vop->coding_type != GST_MPEG4_I_VOP)
READ_UINT8 (&br, vop->shape_coding_type, 1);
}
if (vol->shape != GST_MPEG4_BINARY_ONLY) {
READ_UINT8 (&br, vop->intra_dc_vlc_thr, 3);
if (sprite_trajectory && vol->sprite_enable == GST_MPEG4_SPRITE_GMG &&
vop->coding_type == GST_MPEG4_S_VOP &&
vol->no_of_sprite_warping_points > 0) {
parse_sprite_trajectory (&br, sprite_trajectory,
vol->no_of_sprite_warping_points);
}
if (vol->reduced_resolution_vop_enable &&
vol->shape == GST_MPEG4_RECTANGULAR &&
(vop->coding_type == GST_MPEG4_P_VOP ||
vop->coding_type == GST_MPEG4_I_VOP))
READ_UINT8 (&br, vop->reduced_resolution, 1);
if (vop->coding_type != GST_MPEG4_I_VOP) {
READ_UINT8 (&br, vop->fcode_forward, 3);
CHECK_ALLOWED (vop->fcode_forward, 1, 7);
}
if (vop->coding_type == GST_MPEG4_B_VOP) {
READ_UINT8 (&br, vop->fcode_backward, 3);
CHECK_ALLOWED (vop->fcode_backward, 1, 7);
}
}
}
if (vol->newpred_enable) {
guint16 nbbits =
vol->vop_time_increment_bits + 3 < 15 ? vop->time_increment + 3 : 15;
READ_UINT16 (&br, vop->id, nbbits);
READ_UINT8 (&br, vop->id_for_prediction_indication, 1);
if (vop->id_for_prediction_indication) {
/* Would be nice if the standard actually told us... */
READ_UINT16 (&br, vop->id, nbbits);
CHECK_MARKER (&br);
}
}
videopackethdr->size = gst_bit_reader_get_pos (&br);
failed:
GST_DEBUG ("Failed to parse video packet header");
return GST_MPEG4_PARSER_NO_PACKET;
}
