public static SeqParameterSet Read(Stream @is)
{
var reader = new CAVLCReader(@is);
var sps = new SeqParameterSet
{
profile_idc = (int)reader.ReadNBit(8, "SPS: profile_idc"),
constraint_set_0_flag = reader.ReadBool("SPS: constraint_set_0_flag"),
constraint_set_1_flag = reader.ReadBool("SPS: constraint_set_1_flag"),
constraint_set_2_flag = reader.ReadBool("SPS: constraint_set_2_flag"),
constraint_set_3_flag = reader.ReadBool("SPS: constraint_set_3_flag"),
constraint_set_4_flag = reader.ReadBool("SPS: constraint_set_4_flag"),
constraint_set_5_flag = reader.ReadBool("SPS: constraint_set_5_flag")
};
reader.ReadNBit(2, "SPS: reserved_zero_2bits");
sps.level_idc = (int)reader.ReadNBit(8, "SPS: level_idc");
sps.seq_parameter_set_id = reader.ReadUE("SPS: seq_parameter_set_id");
if (sps.profile_idc == 100 || sps.profile_idc == 110 || sps.profile_idc == 122 || sps.profile_idc == 144)
{
sps.chroma_format_idc = ChromaFormat.fromId(reader.ReadUE("SPS: chroma_format_idc"));
if (sps.chroma_format_idc == ChromaFormat.YUV_444)
{
sps.residual_color_transform_flag = reader.ReadBool("SPS: residual_color_transform_flag");
}
sps.bit_depth_luma_minus8 = reader.ReadUE("SPS: bit_depth_luma_minus8");
sps.bit_depth_chroma_minus8 = reader.ReadUE("SPS: bit_depth_chroma_minus8");
sps.qpprime_y_zero_transform_bypass_flag = reader.ReadBool("SPS: qpprime_y_zero_transform_bypass_flag");
bool seqScalingMatrixPresent = reader.ReadBool("SPS: seq_scaling_matrix_present_lag");
if (seqScalingMatrixPresent)
{
readScalingListMatrix(reader, sps);
}
}
else
{
sps.chroma_format_idc = ChromaFormat.YUV_420;
}
sps.log2_max_frame_num_minus4 = reader.ReadUE("SPS: log2_max_frame_num_minus4");
sps.pic_order_cnt_type = reader.ReadUE("SPS: pic_order_cnt_type");
if (sps.pic_order_cnt_type == 0)
{
sps.log2_max_pic_order_cnt_lsb_minus4 = reader.ReadUE("SPS: log2_max_pic_order_cnt_lsb_minus4");
}
else if (sps.pic_order_cnt_type == 1)
{
sps.delta_pic_order_always_zero_flag = reader.ReadBool("SPS: delta_pic_order_always_zero_flag");
sps.offset_for_non_ref_pic = reader.ReadSE("SPS: offset_for_non_ref_pic");
sps.offset_for_top_to_bottom_field = reader.ReadSE("SPS: offset_for_top_to_bottom_field");
sps.Num_ref_frames_in_pic_order_cnt_cycle = reader.ReadUE("SPS: num_ref_frames_in_pic_order_cnt_cycle");
sps.offsetForRefFrame = new int[sps.Num_ref_frames_in_pic_order_cnt_cycle];
for (int i = 0; i < sps.Num_ref_frames_in_pic_order_cnt_cycle; i++)
{
sps.offsetForRefFrame[i] = reader.ReadSE("SPS: offsetForRefFrame [" + i + "]");
}
}
sps.num_ref_frames = reader.ReadUE("SPS: num_ref_frames");
sps.gaps_in_frame_num_value_allowed_flag = reader.ReadBool("SPS: gaps_in_frame_num_value_allowed_flag");
sps.pic_width_in_mbs_minus1 = reader.ReadUE("SPS: pic_width_in_mbs_minus1");
sps.pic_height_in_map_units_minus1 = reader.ReadUE("SPS: pic_height_in_map_units_minus1");
sps.frame_mbs_only_flag = reader.ReadBool("SPS: frame_mbs_only_flag");
if (!sps.frame_mbs_only_flag)
{
sps.mb_adaptive_frame_field_flag = reader.ReadBool("SPS: mb_adaptive_frame_field_flag");
}
sps.direct_8x8_inference_flag = reader.ReadBool("SPS: direct_8x8_inference_flag");
sps.frame_cropping_flag = reader.ReadBool("SPS: frame_cropping_flag");
if (sps.frame_cropping_flag)
{
sps.frame_crop_left_offset = reader.ReadUE("SPS: frame_crop_left_offset");
sps.frame_crop_right_offset = reader.ReadUE("SPS: frame_crop_right_offset");
sps.frame_crop_top_offset = reader.ReadUE("SPS: frame_crop_top_offset");
sps.frame_crop_bottom_offset = reader.ReadUE("SPS: frame_crop_bottom_offset");
}
bool vui_parameters_present_flag = reader.ReadBool("SPS: vui_parameters_present_flag");
if (vui_parameters_present_flag)
{
sps.VuiParams = ReadVUIParameters(reader);
}
reader.ReadTrailingBits();
return(sps);
}
