gboolean
mpeg4_util_parse_VOP (GstBuffer * buf, Mpeg4VideoObjectLayer * vol,
Mpeg4VideoObjectPlane * vop)
{
GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buf);
guint8 vop_start_code;
guint8 modulo_time_base;
/* set default values */
vop->modulo_time_base = 0;
vop->rounding_type = 0;
vop->top_field_first = 1;
vop->alternate_vertical_scan_flag = 0;
vop->fcode_forward = 1;
vop->fcode_backward = 1;
/* start code prefix */
SKIP (&reader, 24);
READ_UINT8 (&reader, vop_start_code, 8);
if (vop_start_code != MPEG4_PACKET_VOP)
goto wrong_start_code;
READ_UINT8 (&reader, vop->coding_type, 2);
READ_UINT8 (&reader, modulo_time_base, 1);
while (modulo_time_base) {
vop->modulo_time_base++;
READ_UINT8 (&reader, modulo_time_base, 1);
}
/* marker bit */
SKIP (&reader, 1);
READ_UINT16 (&reader, vop->time_increment, vol->vop_time_increment_bits);
/* marker bit */
SKIP (&reader, 1);
READ_UINT8 (&reader, vop->coded, 1);
if (!vop->coded)
return TRUE;
if (vop->coding_type == P_VOP)
READ_UINT8 (&reader, vop->rounding_type, 1);
READ_UINT8 (&reader, vop->intra_dc_vlc_thr, 3);
if (vol->interlaced) {
READ_UINT8 (&reader, vop->top_field_first, 1);
READ_UINT8 (&reader, vop->alternate_vertical_scan_flag, 1);
}
READ_UINT16 (&reader, vop->quant, vol->quant_precision);
if (vop->coding_type != I_VOP) {
READ_UINT8 (&reader, vop->fcode_forward, 3);
CHECK_ALLOWED (vop->fcode_forward, 1, 7);
}
if (vop->coding_type == B_VOP) {
READ_UINT8 (&reader, vop->fcode_backward, 3);
CHECK_ALLOWED (vop->fcode_backward, 1, 7);
}
return TRUE;
error:
GST_WARNING ("error parsing \"Video Object Plane\"");
return FALSE;
wrong_start_code:
GST_WARNING ("got buffer with wrong start code");
goto error;
}
gboolean
mpeg4_util_parse_VOL (GstBuffer * buf, Mpeg4VisualObject * vo,
Mpeg4VideoObjectLayer * vol)
{
GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buf);
guint8 video_object_layer_start_code;
guint8 aspect_ratio_info;
guint8 control_parameters;
guint8 not_8_bit;
/* set default values */
vol->verid = vo->verid;
vol->priority = vo->priority;
vol->low_delay = FALSE;
vol->chroma_format = 1;
vol->vbv_parameters = FALSE;
vol->quant_precision = 5;
vol->bits_per_pixel = 8;
vol->quarter_sample = FALSE;
/* start code prefix */
SKIP (&reader, 24);
READ_UINT8 (&reader, video_object_layer_start_code, 8);
if (!(video_object_layer_start_code >= MPEG4_PACKET_VOL_MIN &&
video_object_layer_start_code <= MPEG4_PACKET_VOL_MAX))
goto wrong_start_code;
READ_UINT8 (&reader, vol->random_accesible_vol, 1);
READ_UINT8 (&reader, vol->video_object_type_indication, 8);
READ_UINT8 (&reader, vol->is_object_layer_identifier, 1);
if (vol->is_object_layer_identifier) {
READ_UINT8 (&reader, vol->verid, 4);
READ_UINT8 (&reader, vol->priority, 3);
}
READ_UINT8 (&reader, aspect_ratio_info, 4);
if (aspect_ratio_info != 0xff)
mpeg4_util_par_from_info (aspect_ratio_info, &vol->par_n, &vol->par_d);
else {
READ_UINT8 (&reader, vol->par_n, 8);
CHECK_ALLOWED (vol->par_n, 1, 255);
READ_UINT8 (&reader, vol->par_d, 8);
CHECK_ALLOWED (vol->par_d, 1, 255);
}
READ_UINT8 (&reader, control_parameters, 1);
if (control_parameters) {
READ_UINT8 (&reader, vol->chroma_format, 2);
READ_UINT8 (&reader, vol->low_delay, 1);
READ_UINT8 (&reader, vol->vbv_parameters, 1);
if (vol->vbv_parameters) {
guint16 first_half, latter_half;
guint8 latter_part;
READ_UINT16 (&reader, first_half, 15);
SKIP (&reader, 1);
READ_UINT16 (&reader, latter_half, 15);
SKIP (&reader, 1);
vol->bit_rate = (first_half << 15) | latter_half;
READ_UINT16 (&reader, first_half, 15);
SKIP (&reader, 1);
READ_UINT8 (&reader, latter_part, 3);
SKIP (&reader, 1);
vol->vbv_buffer_size = (first_half << 15) | latter_part;
}
}
READ_UINT8 (&reader, vol->shape, 2);
if (vol->shape != 0x0)
goto invalid_shape;
/* marker_bit */
SKIP (&reader, 1);
READ_UINT16 (&reader, vol->vop_time_increment_resolution, 16);
CHECK_ALLOWED (vol->vop_time_increment_resolution, 1, G_MAXUINT16);
vol->vop_time_increment_bits =
g_bit_storage (vol->vop_time_increment_resolution);
/* marker_bit */
SKIP (&reader, 1);
READ_UINT8 (&reader, vol->fixed_vop_rate, 1);
if (vol->fixed_vop_rate)
READ_UINT16 (&reader, vol->fixed_vop_time_increment,
vol->vop_time_increment_bits);
/* marker bit */
SKIP (&reader, 1);
READ_UINT16 (&reader, vol->width, 13);
/* marker bit */
SKIP (&reader, 1);
READ_UINT16 (&reader, vol->height, 13);
/* marker bit */
SKIP (&reader, 1);
READ_UINT8 (&reader, vol->interlaced, 1);
READ_UINT8 (&reader, vol->obmc_disable, 1);
if (vol->verid == 0x1) {
READ_UINT8 (&reader, vol->sprite_enable, 1);
} else
READ_UINT8 (&reader, vol->sprite_enable, 2);
if (vol->sprite_enable != 0x0)
goto invalid_sprite_enable;
READ_UINT8 (&reader, not_8_bit, 1);
if (not_8_bit) {
READ_UINT8 (&reader, vol->quant_precision, 4);
CHECK_ALLOWED (vol->quant_precision, 3, 9);
READ_UINT8 (&reader, vol->bits_per_pixel, 4);
CHECK_ALLOWED (vol->bits_per_pixel, 4, 12);
}
READ_UINT8 (&reader, vol->quant_type, 1);
if (vol->quant_type) {
if (!mpeg4_util_parse_quant (&reader, vol->intra_quant_mat,
default_intra_quant_mat))
goto error;
if (!mpeg4_util_parse_quant (&reader, vol->non_intra_quant_mat,
default_non_intra_quant_mat))
goto error;
} else {
memset (&vol->intra_quant_mat, 0, 64);
memset (&vol->non_intra_quant_mat, 0, 64);
}
if (vol->verid != 0x1)
READ_UINT8 (&reader, vol->quarter_sample, 1);
READ_UINT8 (&reader, vol->complexity_estimation_disable, 1);
if (!vol->complexity_estimation_disable)
goto complexity_estimation_error;
READ_UINT8 (&reader, vol->resync_marker_disable, 1);
return TRUE;
error:
GST_WARNING ("error parsing \"Video Object Layer\"");
return FALSE;
wrong_start_code:
GST_WARNING ("got buffer with wrong start code");
goto error;
invalid_shape:
GST_WARNING ("we only support rectangular shape");
goto error;
invalid_sprite_enable:
GST_WARNING ("we only support sprite_enable == 0");
goto error;
complexity_estimation_error:
GST_WARNING ("don't support complexity estimation");
goto error;
}
/**
* 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;
}
/**
* gst_mpeg4_parse_video_object_layer:
* @vol: The #GstMpeg4VideoObjectLayer structure to fill
* @vo: The #GstMpeg4VisualObject currently being parsed or %NULL
* @data: The data to parse
* @size: The size of the @data to parse
*
* Parses @data containing the video object layer packet, and fills
* the @vol structure.
*
* Returns: a #GstMpeg4ParseResult
*/
GstMpeg4ParseResult
gst_mpeg4_parse_video_object_layer (GstMpeg4VideoObjectLayer * vol,
GstMpeg4VisualObject * vo, const guint8 * data, gsize size)
{
guint8 video_object_layer_start_code;
/* Used for enums types */
guint8 tmp;
GstBitReader br = GST_BIT_READER_INIT (data, size);
g_return_val_if_fail (vol != NULL, GST_MPEG4_PARSER_ERROR);
GST_DEBUG ("Parsing video object layer");
READ_UINT8 (&br, video_object_layer_start_code, 8);
if (!(video_object_layer_start_code >= GST_MPEG4_VIDEO_LAYER_FIRST &&
video_object_layer_start_code <= GST_MPEG4_VIDEO_LAYER_LAST))
goto wrong_start_code;
/* set default values */
if (vo) {
vol->verid = vo->verid;
vol->priority = vo->priority;
} else {
vol->verid = 1;
vol->priority = 0;
}
vol->low_delay = FALSE;
vol->chroma_format = 1;
vol->vbv_parameters = FALSE;
vol->quant_precision = 5;
vol->bits_per_pixel = 8;
vol->quarter_sample = FALSE;
vol->newpred_enable = FALSE;
vol->interlaced = 0;
vol->width = 0;
vol->height = 0;
READ_UINT8 (&br, vol->random_accessible_vol, 1);
READ_UINT8 (&br, vol->video_object_type_indication, 8);
READ_UINT8 (&br, vol->is_object_layer_identifier, 1);
if (vol->is_object_layer_identifier) {
READ_UINT8 (&br, vol->verid, 4);
READ_UINT8 (&br, vol->priority, 3);
}
READ_UINT8 (&br, tmp, 4);
vol->aspect_ratio_info = tmp;
if (vol->aspect_ratio_info != GST_MPEG4_EXTENDED_PAR) {
mpeg4_util_par_from_info (vol->aspect_ratio_info, &vol->par_width,
&vol->par_height);
} else {
gint v;
READ_UINT8 (&br, vol->par_width, 8);
v = vol->par_width;
CHECK_ALLOWED (v, 1, 255);
READ_UINT8 (&br, vol->par_height, 8);
v = vol->par_height;
CHECK_ALLOWED (v, 1, 255);
}
GST_DEBUG ("Pixel aspect ratio %d/%d", vol->par_width, vol->par_width);
READ_UINT8 (&br, vol->control_parameters, 1);
if (vol->control_parameters) {
guint8 chroma_format;
READ_UINT8 (&br, chroma_format, 2);
vol->chroma_format = chroma_format;
READ_UINT8 (&br, vol->low_delay, 1);
READ_UINT8 (&br, vol->vbv_parameters, 1);
if (vol->vbv_parameters) {
CHECK_REMAINING (&br, 79);
vol->first_half_bitrate =
gst_bit_reader_get_bits_uint16_unchecked (&br, 15);
MARKER_UNCHECKED (&br);
vol->latter_half_bitrate =
gst_bit_reader_get_bits_uint16_unchecked (&br, 15);
MARKER_UNCHECKED (&br);
vol->bit_rate =
(vol->first_half_bitrate << 15) | vol->latter_half_bitrate;
vol->first_half_vbv_buffer_size =
gst_bit_reader_get_bits_uint16_unchecked (&br, 15);
MARKER_UNCHECKED (&br);
vol->latter_half_vbv_buffer_size =
gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
vol->vbv_buffer_size = (vol->first_half_vbv_buffer_size << 15) |
vol->latter_half_vbv_buffer_size;
vol->first_half_vbv_occupancy =
gst_bit_reader_get_bits_uint16_unchecked (&br, 11);
MARKER_UNCHECKED (&br);
vol->latter_half_vbv_occupancy =
gst_bit_reader_get_bits_uint16_unchecked (&br, 15);
MARKER_UNCHECKED (&br);
}
}
READ_UINT8 (&br, tmp, 2);
vol->shape = tmp;
if (vol->shape == GST_MPEG4_GRAYSCALE) {
/* TODO support grayscale shapes, for now we just pass */
/* Something the standard starts to define... */
GST_WARNING ("Grayscale shaped not supported");
goto failed;
}
if (vol->shape == GST_MPEG4_GRAYSCALE && vol->verid != 0x01)
READ_UINT8 (&br, vol->shape_extension, 4);
CHECK_REMAINING (&br, 19);
MARKER_UNCHECKED (&br);
vol->vop_time_increment_resolution =
gst_bit_reader_get_bits_uint16_unchecked (&br, 16);
if (vol->vop_time_increment_resolution < 1) {
GST_WARNING ("value not in allowed range. value: %d, range %d-%d",
vol->vop_time_increment_resolution, 1, G_MAXUINT16);
goto failed;
}
vol->vop_time_increment_bits =
g_bit_storage (vol->vop_time_increment_resolution);
MARKER_UNCHECKED (&br);
vol->fixed_vop_rate = gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
if (vol->fixed_vop_rate)
READ_UINT16 (&br, vol->fixed_vop_time_increment,
vol->vop_time_increment_bits);
if (vol->shape != GST_MPEG4_BINARY_ONLY) {
if (vol->shape == GST_MPEG4_RECTANGULAR) {
CHECK_REMAINING (&br, 29);
MARKER_UNCHECKED (&br);
vol->width = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vol->height = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
}
READ_UINT8 (&br, vol->interlaced, 1);
READ_UINT8 (&br, vol->obmc_disable, 1);
if (vol->verid == 0x1)
READ_UINT8 (&br, tmp, 1);
else
READ_UINT8 (&br, tmp, 2);
vol->sprite_enable = tmp;
if (vol->sprite_enable == GST_MPEG4_SPRITE_STATIC ||
vol->sprite_enable == GST_MPEG4_SPRITE_GMG) {
if (vol->sprite_enable == GST_MPEG4_SPRITE_GMG)
CHECK_REMAINING (&br, 9);
else {
CHECK_REMAINING (&br, 65);
vol->sprite_width = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vol->sprite_height = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vol->sprite_left_coordinate =
gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vol->sprite_top_coordinate =
gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
}
vol->no_of_sprite_warping_points =
gst_bit_reader_get_bits_uint8_unchecked (&br, 6);
vol->sprite_warping_accuracy =
gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
vol->sprite_brightness_change =
gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
if (vol->sprite_enable != GST_MPEG4_SPRITE_GMG)
vol->low_latency_sprite_enable =
gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
}
if (vol->verid != 0x1 && vol->shape != GST_MPEG4_RECTANGULAR)
READ_UINT8 (&br, vol->sadct_disable, 1);
READ_UINT8 (&br, vol->not_8_bit, 1);
if (vol->not_8_bit) {
READ_UINT8 (&br, vol->quant_precision, 4);
CHECK_ALLOWED (vol->quant_precision, 3, 9);
READ_UINT8 (&br, vol->bits_per_pixel, 4);
CHECK_ALLOWED (vol->bits_per_pixel, 4, 12);
}
if (vol->shape == GST_MPEG4_GRAYSCALE) {
/* We don't actually support it */
READ_UINT8 (&br, vol->no_gray_quant_update, 1);
READ_UINT8 (&br, vol->composition_method, 1);
READ_UINT8 (&br, vol->linear_composition, 1);
}
READ_UINT8 (&br, vol->quant_type, 1);
if (vol->quant_type) {
if (!parse_quant (&br, vol->intra_quant_mat, default_intra_quant_mat,
&vol->load_intra_quant_mat))
goto failed;
if (!parse_quant (&br, vol->non_intra_quant_mat,
default_non_intra_quant_mat, &vol->load_non_intra_quant_mat))
goto failed;
if (vol->shape == GST_MPEG4_GRAYSCALE) {
/* Something the standard starts to define... */
GST_WARNING ("Grayscale shaped not supported");
goto failed;
}
} else {
memset (&vol->intra_quant_mat, 0, 64);
memset (&vol->non_intra_quant_mat, 0, 64);
}
if (vol->verid != 0x1)
READ_UINT8 (&br, vol->quarter_sample, 1);
READ_UINT8 (&br, vol->complexity_estimation_disable, 1);
if (!vol->complexity_estimation_disable) {
guint8 estimation_method;
guint8 estimation_disable;
/* skip unneeded properties */
READ_UINT8 (&br, estimation_method, 2);
if (estimation_method < 2) {
READ_UINT8 (&br, estimation_disable, 1);
if (!estimation_disable)
SKIP (&br, 6);
READ_UINT8 (&br, estimation_disable, 1);
if (!estimation_disable)
SKIP (&br, 4);
CHECK_MARKER (&br);
READ_UINT8 (&br, estimation_disable, 1);
if (!estimation_disable)
SKIP (&br, 4);
READ_UINT8 (&br, estimation_disable, 1);
if (!estimation_disable)
SKIP (&br, 6);
CHECK_MARKER (&br);
if (estimation_method == 1) {
READ_UINT8 (&br, estimation_disable, 1);
if (!estimation_disable)
SKIP (&br, 2);
}
}
}
READ_UINT8 (&br, vol->resync_marker_disable, 1);
READ_UINT8 (&br, vol->data_partitioned, 1);
if (vol->data_partitioned)
READ_UINT8 (&br, vol->reversible_vlc, 1);
if (vol->verid != 0x01) {
READ_UINT8 (&br, vol->newpred_enable, 1);
if (vol->newpred_enable)
/* requested_upstream_message_type and newpred_segment_type */
SKIP (&br, 3);
READ_UINT8 (&br, vol->reduced_resolution_vop_enable, 1);
}
READ_UINT8 (&br, vol->scalability, 1);
if (vol->scalability) {
SKIP (&br, 26); /* Few not needed props */
READ_UINT8 (&br, vol->enhancement_type, 1);
}
/* More unused infos */
} else if (vol->verid != 0x01) {
GST_WARNING ("Binary only shapes not fully supported");
goto failed;
}
/* ... */
return GST_MPEG4_PARSER_OK;
failed:
GST_WARNING ("failed parsing \"Video Object Layer\"");
return GST_MPEG4_PARSER_ERROR;
wrong_start_code:
GST_WARNING ("got buffer with wrong start code");
goto failed;
}
/**
* gst_mpeg4_parse_video_object_plane:
* @vop: The #GstMpeg4VideoObjectPlane currently being parsed
* @sprite_trajectory: A #GstMpeg4SpriteTrajectory to fill or %NULL
* @vol: The #GstMpeg4VideoObjectLayer structure to fill
* @data: The data to parse
* @size: The size of the @data to parse
*
* Parses @data containing the video object plane packet, and fills the @vol
* structure.
*
* Returns: a #GstMpeg4ParseResult
*/
GstMpeg4ParseResult
gst_mpeg4_parse_video_object_plane (GstMpeg4VideoObjectPlane * vop,
GstMpeg4SpriteTrajectory * sprite_trajectory,
GstMpeg4VideoObjectLayer * vol, const guint8 * data, gsize size)
{
guint8 vop_start_code, coding_type, modulo_time_base;
GstBitReader br = GST_BIT_READER_INIT (data, size);
g_return_val_if_fail (vop != NULL, GST_MPEG4_PARSER_ERROR);
if (vol->shape == GST_MPEG4_BINARY_ONLY) {
/* TODO: implement binary only shapes */
GST_WARNING ("Binary only shapes not supported");
goto failed;
}
READ_UINT8 (&br, vop_start_code, 8);
if (vop_start_code != GST_MPEG4_VIDEO_OBJ_PLANE)
goto wrong_start_code;
/* set default values */
vop->modulo_time_base = 0;
vop->rounding_type = 0;
vop->top_field_first = 1;
vop->alternate_vertical_scan_flag = 0;
vop->fcode_forward = 1;
vop->fcode_backward = 1;
/* Compute macroblock informations */
if (vol->interlaced)
vop->mb_height = (2 * (vol->height + 31) / 32);
else
vop->mb_height = (vol->height + 15) / 16;
vop->mb_width = (vol->width + 15) / 16;
vop->mb_num = vop->mb_height * vop->mb_width;
READ_UINT8 (&br, coding_type, 2);
vop->coding_type = coding_type;
READ_UINT8 (&br, modulo_time_base, 1);
while (modulo_time_base) {
vop->modulo_time_base++;
READ_UINT8 (&br, modulo_time_base, 1);
}
CHECK_REMAINING (&br, vol->vop_time_increment_bits + 3);
MARKER_UNCHECKED (&br);
vop->time_increment =
gst_bit_reader_get_bits_uint16_unchecked (&br,
vol->vop_time_increment_bits);
MARKER_UNCHECKED (&br);
vop->coded = gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
if (!vop->coded)
return GST_MPEG4_PARSER_OK;
if (vol->newpred_enable) {
guint16 nbbits =
vop->time_increment + 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);
}
}
if (vol->shape != GST_MPEG4_BINARY_ONLY &&
(vop->coding_type == GST_MPEG4_P_VOP ||
(vop->coding_type == GST_MPEG4_S_VOP &&
vol->sprite_enable == GST_MPEG4_SPRITE_GMG)))
READ_UINT8 (&br, vop->rounding_type, 1);
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 (vol->shape != GST_MPEG4_RECTANGULAR) {
if (vol->sprite_enable == GST_MPEG4_SPRITE_STATIC &&
vop->coding_type == GST_MPEG4_I_VOP) {
CHECK_REMAINING (&br, 55);
vop->width = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vop->height = gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vop->horizontal_mc_spatial_ref =
gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
vop->vertical_mc_spatial_ref =
gst_bit_reader_get_bits_uint16_unchecked (&br, 13);
MARKER_UNCHECKED (&br);
/* Recompute the Macroblock informations
* accordingly to the new values */
if (vol->interlaced)
vop->mb_height = (2 * (vol->height + 31) / 32);
else
vop->mb_height = (vol->height + 15) / 16;
vop->mb_width = (vol->width + 15) / 16;
vop->mb_num = vop->mb_height * vop->mb_width;
}
if ((vol->shape != GST_MPEG4_BINARY_ONLY) &&
vol->scalability && vol->enhancement_type)
READ_UINT8 (&br, vop->background_composition, 1);
READ_UINT8 (&br, vop->change_conv_ratio_disable, 1);
READ_UINT8 (&br, vop->constant_alpha, 1);
if (vop->constant_alpha)
READ_UINT8 (&br, vop->constant_alpha_value, 1);
}
if (vol->shape != GST_MPEG4_BINARY_ONLY) {
if (!vol->complexity_estimation_disable) {
GST_WARNING ("Complexity estimation not supported");
goto failed;
}
READ_UINT8 (&br, vop->intra_dc_vlc_thr, 3);
if (vol->interlaced) {
READ_UINT8 (&br, vop->top_field_first, 1);
READ_UINT8 (&br, vop->alternate_vertical_scan_flag, 1);
}
}
if ((vol->sprite_enable == GST_MPEG4_SPRITE_STATIC ||
vol->sprite_enable == GST_MPEG4_SPRITE_GMG) &&
vop->coding_type == GST_MPEG4_S_VOP) {
/* only if @sprite_trajectory is not NULL we parse it */
if (sprite_trajectory && vol->no_of_sprite_warping_points)
parse_sprite_trajectory (&br, sprite_trajectory,
vol->no_of_sprite_warping_points);
if (vol->sprite_brightness_change) {
GST_WARNING ("sprite_brightness_change not supported");
goto failed;
}
if (vol->sprite_enable == GST_MPEG4_SPRITE_STATIC) {
GST_WARNING ("sprite enable static not supported");
goto failed;
}
}
if (vol->shape != GST_MPEG4_BINARY_ONLY) {
READ_UINT16 (&br, vop->quant, vol->quant_precision);
if (vol->shape == GST_MPEG4_GRAYSCALE) {
/* TODO implement grayscale support */
GST_WARNING ("Grayscale shapes no supported");
/* TODO implement me */
goto failed;
}
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->scalability) {
if (vol->shape != GST_MPEG4_RECTANGULAR)
READ_UINT8 (&br, vop->shape_coding_type, 1);
} else {
if (vol->enhancement_type) {
READ_UINT8 (&br, vop->load_backward_shape, 1);
if (vop->load_backward_shape) {
GST_WARNING ("Load backward shape not supported");
goto failed;
}
READ_UINT8 (&br, vop->ref_select_code, 2);
}
}
vop->size = gst_bit_reader_get_pos (&br);
/* More things to possibly parse ... */
return GST_MPEG4_PARSER_OK;
failed:
GST_WARNING ("failed parsing \"Video Object Plane\"");
return GST_MPEG4_PARSER_ERROR;
wrong_start_code:
GST_WARNING ("got buffer with wrong start code");
goto failed;
}
