//7.3.2.1 Sequence parameter set RBSP syntax
void read_seq_parameter_set_rbsp(sps_t *sps, bs_t* b)
{
int i;
// NOTE can't read directly into sps because seq_parameter_set_id not yet known and so sps is not selected
int profile_idc = bs_read(b, 8);
int constraint_set0_flag = bs_read(b, 1);
int constraint_set1_flag = bs_read(b, 1);
int constraint_set2_flag = bs_read(b, 1);
int constraint_set3_flag = bs_read(b, 1);
int constraint_set4_flag = bs_read(b, 1);
int constraint_set5_flag = bs_read(b, 1);
int reserved_zero_2bits = bs_read(b, 2); /* all 0's */
int level_idc = bs_read(b, 8);
int seq_parameter_set_id = bs_read_ue(b);
memset(sps, 0, sizeof(sps_t));
sps->chroma_format_idc = 1;
sps->profile_idc = profile_idc; // bs_read(b, 8);
sps->constraint_set0_flag = constraint_set0_flag;//bs_read(b, 1);
sps->constraint_set1_flag = constraint_set1_flag;//bs_read(b, 1);
sps->constraint_set2_flag = constraint_set2_flag;//bs_read(b, 1);
sps->constraint_set3_flag = constraint_set3_flag;//bs_read(b, 1);
sps->constraint_set4_flag = constraint_set4_flag;//bs_read(b, 1);
sps->constraint_set5_flag = constraint_set5_flag;//bs_read(b, 1);
sps->reserved_zero_2bits = reserved_zero_2bits;//bs_read(b,2);
sps->level_idc = level_idc; //bs_read(b, 8);
sps->seq_parameter_set_id = seq_parameter_set_id; // bs_read_ue(b);
if (sps->profile_idc == 100 || sps->profile_idc == 110 ||
sps->profile_idc == 122 || sps->profile_idc == 144)
{
sps->chroma_format_idc = bs_read_ue(b);
if (sps->chroma_format_idc == 3)
{
sps->residual_colour_transform_flag = bs_read(b, 1);
}
sps->bit_depth_luma_minus8 = bs_read_ue(b);
sps->bit_depth_chroma_minus8 = bs_read_ue(b);
sps->qpprime_y_zero_transform_bypass_flag = bs_read(b, 1);
sps->seq_scaling_matrix_present_flag = bs_read(b, 1);
if (sps->seq_scaling_matrix_present_flag)
{
for (i = 0; i < 8; i++)
{
sps->seq_scaling_list_present_flag[i] = bs_read(b, 1);
if (sps->seq_scaling_list_present_flag[i])
{
if (i < 6)
{
read_scaling_list(b, sps->ScalingList4x4[i], 16,
sps->UseDefaultScalingMatrix4x4Flag[i]);
}
else
{
read_scaling_list(b, sps->ScalingList8x8[i - 6], 64,
sps->UseDefaultScalingMatrix8x8Flag[i - 6]);
}
}
}
}
}
sps->log2_max_frame_num_minus4 = bs_read_ue(b);
sps->pic_order_cnt_type = bs_read_ue(b);
if (sps->pic_order_cnt_type == 0)
{
sps->log2_max_pic_order_cnt_lsb_minus4 = bs_read_ue(b);
}
else if (sps->pic_order_cnt_type == 1)
{
sps->delta_pic_order_always_zero_flag = bs_read(b, 1);
sps->offset_for_non_ref_pic = bs_read_se(b);
sps->offset_for_top_to_bottom_field = bs_read_se(b);
sps->num_ref_frames_in_pic_order_cnt_cycle = bs_read_ue(b);
for (i = 0; i < sps->num_ref_frames_in_pic_order_cnt_cycle; i++)
{
sps->offset_for_ref_frame[i] = bs_read_se(b);
}
}
sps->num_ref_frames = bs_read_ue(b);
sps->gaps_in_frame_num_value_allowed_flag = bs_read(b, 1);
sps->pic_width_in_mbs_minus1 = bs_read_ue(b);
sps->pic_height_in_map_units_minus1 = bs_read_ue(b);
sps->frame_mbs_only_flag = bs_read(b, 1);
if (!sps->frame_mbs_only_flag)
{
sps->mb_adaptive_frame_field_flag = bs_read(b, 1);
}
sps->direct_8x8_inference_flag = bs_read(b, 1);
sps->frame_cropping_flag = bs_read(b, 1);
if (sps->frame_cropping_flag)
{
sps->frame_crop_left_offset = bs_read_ue(b);
sps->frame_crop_right_offset = bs_read_ue(b);
sps->frame_crop_top_offset = bs_read_ue(b);
sps->frame_crop_bottom_offset = bs_read_ue(b);
}
sps->vui_parameters_present_flag = bs_read(b, 1);
if (sps->vui_parameters_present_flag)
{
read_vui_parameters(sps, b);
}
//read_rbsp_trailing_bits(h, b);
}
// Determine video dimensions from the sequence parameterset.
void FindAVCDimensions(
const sp<ABuffer> &seqParamSet, int32_t *width, int32_t *height) {
ABitReader br(seqParamSet->data() + 1, seqParamSet->size() - 1);
unsigned profile_idc = br.getBits(8);
br.skipBits(16);
parseUE(&br); // seq_parameter_set_id
unsigned chroma_format_idc = 1; // 4:2:0 chroma format
if (profile_idc == 100 || profile_idc == 110
|| profile_idc == 122 || profile_idc == 244
|| profile_idc == 44 || profile_idc == 83 || profile_idc == 86) {
uint32_t temp = 0;
chroma_format_idc = parseUE(&br);
if (chroma_format_idc == 3) {
br.skipBits(1); // residual_colour_transform_flag
}
parseUE(&br); // bit_depth_luma_minus8
parseUE(&br); // bit_depth_chroma_minus8
br.skipBits(1); // qpprime_y_zero_transform_bypass_flag
temp = br.getBits(1); // seq_scaling_matrix_present_flag
if(temp)
{
int32_t i;
for (i = 0; i < 6; i++) {
temp = br.getBits(1); ;
if (temp) {
read_scaling_list(&br, 0);
}
}
for (i = 0; i < 2; i++) {
temp = br.getBits(1); ;
if (temp) {
read_scaling_list(&br, 1);
}
}
}
}
parseUE(&br); // log2_max_frame_num_minus4
unsigned pic_order_cnt_type = parseUE(&br);
if (pic_order_cnt_type == 0) {
parseUE(&br); // log2_max_pic_order_cnt_lsb_minus4
} else if (pic_order_cnt_type == 1) {
// offset_for_non_ref_pic, offset_for_top_to_bottom_field and
// offset_for_ref_frame are technically se(v), but since we are
// just skipping over them the midpoint does not matter.
br.getBits(1); // delta_pic_order_always_zero_flag
parseUE(&br); // offset_for_non_ref_pic
parseUE(&br); // offset_for_top_to_bottom_field
unsigned num_ref_frames_in_pic_order_cnt_cycle = parseUE(&br);
for (unsigned i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; ++i) {
parseUE(&br); // offset_for_ref_frame
}
}
parseUE(&br); // num_ref_frames
br.getBits(1); // gaps_in_frame_num_value_allowed_flag
unsigned pic_width_in_mbs_minus1 = parseUE(&br);
unsigned pic_height_in_map_units_minus1 = parseUE(&br);
unsigned frame_mbs_only_flag = br.getBits(1);
*width = pic_width_in_mbs_minus1 * 16 + 16;
*height = (2 - frame_mbs_only_flag)
* (pic_height_in_map_units_minus1 * 16 + 16);
if (!frame_mbs_only_flag) {
br.getBits(1); // mb_adaptive_frame_field_flag
}
br.getBits(1); // direct_8x8_inference_flag
if (br.getBits(1)) { // frame_cropping_flag
unsigned frame_crop_left_offset = parseUE(&br);
unsigned frame_crop_right_offset = parseUE(&br);
unsigned frame_crop_top_offset = parseUE(&br);
unsigned frame_crop_bottom_offset = parseUE(&br);
unsigned cropUnitX, cropUnitY;
if (chroma_format_idc == 0 /* monochrome */) {
cropUnitX = 1;
cropUnitY = 2 - frame_mbs_only_flag;
} else {
unsigned subWidthC = (chroma_format_idc == 3) ? 1 : 2;
unsigned subHeightC = (chroma_format_idc == 1) ? 2 : 1;
cropUnitX = subWidthC;
cropUnitY = subHeightC * (2 - frame_mbs_only_flag);
}
ALOGV("frame_crop = (%u, %u, %u, %u), cropUnitX = %u, cropUnitY = %u",
frame_crop_left_offset, frame_crop_right_offset,
frame_crop_top_offset, frame_crop_bottom_offset,
cropUnitX, cropUnitY);
*width -=
(frame_crop_left_offset + frame_crop_right_offset) * cropUnitX;
*height -=
(frame_crop_top_offset + frame_crop_bottom_offset) * cropUnitY;
}
}
