/* ignore the emulation prevention code, assume it has been taken out. */
bool more_rbsp_data(AVCDecBitstream *stream)
{
int total_bit_left;
uint code;
if (stream->read_pos >= stream->nal_size)
{
total_bit_left = stream->incnt_next + stream->incnt;
if (total_bit_left <= 0)
{
return FALSE;
}
else if (total_bit_left <= 8)
{
BitstreamShowBits(stream, total_bit_left, &code);
if (code == trailing_bits[total_bit_left])
{
return FALSE;
}
}
}
return TRUE;
}
/*
decode headers
returns coding_type, or -1 if error
*/
int
BitstreamReadHeaders(Bitstream * bs, DECODER * dec, uint32 * rounding,
uint32 * quant, uint32 * fcode,
uint32 * intra_dc_threshold)
{
uint32 vol_ver_id;
uint32 time_inc_resolution;
uint32 coding_type;
uint32 start_code;
do
{
BitstreamByteAlignNoForceStuffing(bs);
start_code = BitstreamShowBits(bs, 32);
if (start_code == VISOBJSEQ_START_CODE)
{
// DEBUG("visual_object_sequence");
BitstreamSkip(bs, 32); /* visual_object_sequence_start_code */
BitstreamSkip(bs, 8); /* profile_and_level_indication */
}
else if (start_code == VISOBJSEQ_STOP_CODE)
{
BitstreamSkip(bs, 32); /* visual_object_sequence_stop_code */
}
else if (start_code == VISOBJ_START_CODE)
{
// DEBUG("visual_object");
BitstreamGetBits(bs, 32); /* visual_object_start_code */
if (BitstreamGetBit(bs)) /* is_visual_object_identified */
{
vol_ver_id = BitstreamGetBits(bs, 4); /* vis_obj_ver_id */
BitstreamSkip(bs, 3); /* visual_object_priority */
}
else
{
vol_ver_id = 1;
}
if (BitstreamShowBits(bs, 4) != VISOBJ_TYPE_VIDEO)
{
// DEBUG("visual_object_type != video");
return -1;
}
BitstreamSkip(bs, 4);
if (BitstreamGetBit(bs)) /* video_signal_type */
{
// DEBUG("+ video_signal_type");
BitstreamSkip(bs, 3); /* video_format */
BitstreamSkip(bs, 1); /* video_range */
if (BitstreamGetBit(bs)) /* color_description */
{
// DEBUG("+ color_description");
BitstreamSkip(bs, 8); /* color_primaries */
BitstreamSkip(bs, 8); /* transfer_characteristics */
BitstreamSkip(bs, 8); /* matrix_coefficients */
}
}
}
else if ((start_code & ~0x1f) == VIDOBJ_START_CODE)
{
BitstreamSkip(bs, 32); /* video_object_start_code */
}
else if ((start_code & ~0xf) == VIDOBJLAY_START_CODE)
{
// DEBUG("video_object_layer");
BitstreamSkip(bs, 32); /* video_object_layer_start_code */
BitstreamSkip(bs, 1); /* random_accessible_vol */
/* video_object_type_indication */
if (BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_SIMPLE &&
BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_CORE &&
BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_MAIN &&
BitstreamShowBits(bs, 8) != 0) /* buggy DIVX code */
{
// DEBUG1("video_object_type_indication not supported",
// BitstreamShowBits(bs, 8));
return -1;
}
BitstreamSkip(bs, 8);
if (BitstreamGetBit(bs)) /* is_object_layer_identifier */
{
// DEBUG("+ is_object_layer_identifier");
vol_ver_id = BitstreamGetBits(bs, 4); /* vid_obj_layer_verid */
BitstreamSkip(bs, 3); /* video_object_layer_priority */
}
else
{
vol_ver_id = 1;
}
//DEBUGI("vol_ver_id", vol_ver_id);
/* read aspect_ratio_info */
if (BitstreamGetBits(bs, 4) == VIDOBJLAY_AR_EXTPAR)
{
// DEBUG("+ aspect_ratio_info");
BitstreamSkip(bs, 8); /* par_width */
BitstreamSkip(bs, 8); /* par_height */
}
/* read vol_control_parameters */
if (BitstreamGetBit(bs))
{
// DEBUG("+ vol_control_parameters");
BitstreamSkip(bs, 2); /* chroma_format */
BitstreamSkip(bs, 1); /* low_delay */
if (BitstreamGetBit(bs)) /* vbv_parameters */
{
// DEBUG("+ vbv_parameters");
BitstreamSkip(bs, 15); /* first_half_bitrate */
READ_MARKER();
BitstreamSkip(bs, 15); /* latter_half_bitrate */
READ_MARKER();
BitstreamSkip(bs, 15); /* first_half_vbv_buf_size */
READ_MARKER();
BitstreamSkip(bs, 3); /* latter_half_vbv_buf_size */
BitstreamSkip(bs, 11); /* first_half_vbv_occupancy */
READ_MARKER();
BitstreamSkip(bs, 15); /* latter_half_vbv_occupancy */
READ_MARKER();
}
}
dec->shape = BitstreamGetBits(bs, 2); /* vol_shape */
// DEBUG1("shape", dec->shape);
if (dec->shape==VIDOBJLAY_SHAPE_GRAYSCALE && vol_ver_id!=1)
{
BitstreamSkip(bs, 4); /* vol_shape_extension */
}
READ_MARKER();
/* vop_time_increment_resolution */
dec->time_inc_resolution = BitstreamGetBits(bs, 16);
time_inc_resolution = dec->time_inc_resolution - 1;
if (time_inc_resolution > 0)
{
dec->time_inc_bits = log2bin(time_inc_resolution);
}
else
{
/* dec->time_inc_bits = 0; */
/* for "old" xvid compatibility, set time_inc_bits = 1 */
dec->time_inc_bits = 1;
}
READ_MARKER();
if (BitstreamGetBit(bs)) /* fixed_vop_rate */
{
BitstreamSkip(bs, dec->time_inc_bits); /* fixed_vop_time_inc */
}
if (dec->shape != VIDOBJLAY_SHAPE_BINARY_ONLY)
{
if (dec->shape == VIDOBJLAY_SHAPE_RECTANGULAR)
{
READ_MARKER();
dec->width = BitstreamGetBits(bs, 13); /* vol_width */
//DEBUGI("width", width);
READ_MARKER();
dec->height = BitstreamGetBits(bs, 13); /* vol_height */
//DEBUGI("height", height);
READ_MARKER();
}
if ((dec->interlacing = BitstreamGetBit(bs)) != 0)
{
// DEBUG("vol: interlacing");
}
if (!BitstreamGetBit(bs)) /* obmc_disable */
{
// DEBUG("IGNORED/TODO: !obmc_disable");
// TODO
// f*****g divx4.02 has this enabled
}
/* read sprite_enable */
if (BitstreamGetBits(bs, (vol_ver_id == 1 ? 1 : 2)))
{
// DEBUG("sprite_enable; not supported");
return -1;
}
if (vol_ver_id != 1
&& dec->shape != VIDOBJLAY_SHAPE_RECTANGULAR)
{
BitstreamSkip(bs, 1); /* sadct_disable */
}
if (BitstreamGetBit(bs)) /* not_8_bit */
{
// DEBUG("+ not_8_bit [IGNORED/TODO]");
dec->quant_bits = BitstreamGetBits(bs, 4); /* quant_precision */
BitstreamSkip(bs, 4); /* bits_per_pixel */
}
else
{
dec->quant_bits = 5;
}
if (dec->shape == VIDOBJLAY_SHAPE_GRAYSCALE)
{
BitstreamSkip(bs, 1); /* no_gray_quant_update */
BitstreamSkip(bs, 1); /* composition_method */
BitstreamSkip(bs, 1); /* linear_composition */
}
/* H.263 quantizer or mpeg-4 quantizer */
dec->quant_type = BitstreamGetBit(bs);
if (dec->quant_type != 0)
{
// DEBUG
// ("Simple profile only allows H.263 quantizer.");
return -1;
}
if (vol_ver_id != 1)
{
dec->quarterpel = BitstreamGetBit(bs); /* quarter_sampe */
if (dec->quarterpel)
{
// DEBUG("IGNORED/TODO: quarter_sample");
}
}
else
{
dec->quarterpel = 0;
}
if (!BitstreamGetBit(bs)) /* complexity_estimation_disable */
{
// DEBUG("TODO: complexity_estimation header");
// TODO
return -1;
}
if (!BitstreamGetBit(bs)) /* resync_marker_disable */
{
// DEBUG("IGNORED/TODO: !resync_marker_disable");
// TODO
//printf("...todo resync process\n");
}
if (BitstreamGetBit(bs)) /* data_partitioned */
{
// DEBUG("Data partitioning is not supported");
return -1;
}
if (vol_ver_id != 1)
{
if (BitstreamGetBit(bs)) /* newpred_enable */
{
// DEBUG("+ newpred_enable");
BitstreamSkip(bs, 2); /* requested_upstream_message_type */
BitstreamSkip(bs, 1); /* newpred_segment_type */
}
if (BitstreamGetBit(bs)) /* reduced_resolution_vop_enable */
{
// DEBUG("TODO: reduced_resolution_vop_enable");
// TODO
return -1;
}
}
if (BitstreamGetBit(bs)) /* scalability */
{
// TODO
// DEBUG("TODO: scalability");
return -1;
}
}
else /* dec->shape == BINARY_ONLY */
{
if (vol_ver_id != 1)
{
if (BitstreamGetBit(bs)) /* scalability */
{
// TODO
// DEBUG("TODO: scalability");
return -1;
}
}
BitstreamSkip(bs, 0); /* resync_marker_disable */
}
BitstreamByteAlign(bs);
}
else if (start_code == GRPOFVOP_START_CODE)
{
// DEBUG("group_of_vop");
BitstreamSkip(bs, 32); /* group_vop_start_codes */
{
int hours, minutes, seconds;
hours = BitstreamGetBits(bs, 5); /* time_code 18bits */
minutes = BitstreamGetBits(bs, 6);
READ_MARKER();
seconds = BitstreamGetBits(bs, 6);
dec->decoder_clock =
hours * 3600 + minutes * 60 + seconds;
}
BitstreamSkip(bs, 1); /* closed_gov */
BitstreamSkip(bs, 1); /* broken_link */
}
else if (start_code == VOP_START_CODE)
{
uint32 time_tick = 0;
// DEBUG("vop_start_code");
BitstreamSkip(bs, 32); /* vop_start_code */
coding_type = BitstreamGetBits(bs, 2); /* vop_coding_type */
// DEBUG1("coding_type", coding_type);
/* modulo time base */
while (BitstreamGetBit(bs) != 0)
{
dec->decoder_clock++;
}
READ_MARKER();
// DEBUG1("time_inc_bits", dec->time_inc_bits);
// DEBUG1("vop_time_incr", BitstreamShowBits(bs, dec->time_inc_bits));
if (dec->time_inc_bits)
{
time_tick = BitstreamGetBits(bs, dec->time_inc_bits);
}
dec->timestamp =
(time_tick * 1000) / dec->time_inc_resolution +
dec->decoder_clock * 1000;
READ_MARKER();
if (!BitstreamGetBit(bs)) /* vop_coded */
{
return N_VOP;
}
/* if (newpred_enable)
{
}
*/
if (coding_type != I_VOP)
{
*rounding = BitstreamGetBit(bs); /* rounding_type */
// DEBUG1("rounding", *rounding);
}
/* if (reduced_resolution_enable)
{
}
*/
if (dec->shape != VIDOBJLAY_SHAPE_RECTANGULAR)
{
uint32 width, height;
uint32 horiz_mc_ref, vert_mc_ref;
width = BitstreamGetBits(bs, 13);
READ_MARKER();
height = BitstreamGetBits(bs, 13);
READ_MARKER();
horiz_mc_ref = BitstreamGetBits(bs, 13);
READ_MARKER();
vert_mc_ref = BitstreamGetBits(bs, 13);
READ_MARKER();
// DEBUG2("vop_width/height", width, height);
// DEBUG2("ref ", horiz_mc_ref, vert_mc_ref);
BitstreamSkip(bs, 1); /* change_conv_ratio_disable */
if (BitstreamGetBit(bs)) /* vop_constant_alpha */
{
BitstreamSkip(bs, 8); /* vop_constant_alpha_value */
}
}
if (dec->shape != VIDOBJLAY_SHAPE_BINARY_ONLY)
{
/* intra_dc_vlc_threshold */
*intra_dc_threshold =
intra_dc_threshold_table[BitstreamGetBits(bs, 3)];
}
*quant = BitstreamGetBits(bs, dec->quant_bits); /* vop_quant */
// DEBUG1("quant", *quant);
if (coding_type != I_VOP)
{
*fcode = BitstreamGetBits(bs, 3); /* fcode_forward */
}
/*
if (coding_type == B_VOP)
{
*fcode_backward = BitstreamGetBits(bs, 3);
}
*/
return coding_type;
}
else if (start_code == USERDATA_START_CODE)
{
// DEBUG("user_data");
BitstreamSkip(bs, 32); /* user_data_start_code */
}
else /* start_code == ? */
{
if (BitstreamShowBits(bs, 24) == 0x000001)
{
// DEBUG1("*** WARNING: unknown start_code",
// BitstreamShowBits(bs, 32));
}
BitstreamSkip(bs, 8);
}
/* NextStartCode(); */
}
while ((BitstreamPos(bs) >> 3) < bs->length);
// DEBUG("*** WARNING: no vop_start_code found");
return -1; /* ignore it */
}
