/// <summary>
/// Process the scaling list data.
/// </summary>
/// <remarks>
/// Reference: 7.3.4 Scaling list data syntax
/// </remarks>
private void ProcessScalingListData(NalUnitBitstreamNavigator nav)
{
bool[,] scaling_list_pred_mode_flag = new bool[4, 6];
int[,] scaling_list_dc_coef_minus8 = new int[4, 6];
for (int sizeId = 0; sizeId < 4; sizeId++)
{
for (int matrixId = 0; matrixId < 6; matrixId += (sizeId == 3) ? 3 : 1)
{
scaling_list_pred_mode_flag[sizeId, matrixId] = nav.ReadBit(); //scaling_list_pred_mode_flag[sizeId][matrixId] u(1)
if (!scaling_list_pred_mode_flag[sizeId, matrixId])
{
nav.ReadNonNegativeExponentialGolombAsUInt32(); //scaling_list_pred_matrix_id_delta[sizeId][matrixId] ue(v)
}
else
{
int nextCoef = 8;
int coefNum = Math.Min(64, (1 << (4 + (sizeId << 1))));
if (sizeId > 1)
{
int sizeIdMinux2 = sizeId - 2;
scaling_list_dc_coef_minus8[sizeIdMinux2, matrixId] = nav.ReadSignedExponentialGolombAsInt32(); //scaling_list_dc_coef_minus8[sizeId − 2][matrixId] se(v)
nextCoef = scaling_list_dc_coef_minus8[sizeIdMinux2, matrixId] + 8;
}
for (int i = 0; i < coefNum; i++)
{
int scaling_list_delta_coef = nav.ReadSignedExponentialGolombAsInt32(); //scaling_list_delta_coef se(v)
nextCoef = (nextCoef + scaling_list_delta_coef + 256) % 256;
// ScalingList[sizeId][matrixId][i] = nextCoef;
}
}
}
}
}
/// <summary>
/// Process the short term reference picture sets.
/// </summary>
/// <remarks>
/// Reference:
/// 7.3.7 Short-term reference picture set syntax
/// 7.4.8 Short-term reference picture set semantics
/// </remarks>
private ShortTermRefPicSet ProcessShortTermRefPicSets(NalUnitBitstreamNavigator nav, SequenceParameterSet sps, uint stRpsIdx)
{
var result = new ShortTermRefPicSet();
if (stRpsIdx != 0)
{
result.inter_ref_pic_set_prediction_flag = nav.ReadBit(); //inter_ref_pic_set_prediction_flag u(1)
}
if (result.inter_ref_pic_set_prediction_flag)
{
if (stRpsIdx == sps.num_short_term_ref_pic_sets)
{
result.delta_idx_minus1 = nav.ReadNonNegativeExponentialGolombAsUInt32(); //delta_idx_minus1 ue(v)
}
result.delta_rps_sign = nav.ReadBit() ? (byte)1 : (byte)0; //delta_rps_sign u(1)
result.abs_delta_rps_minus1 = nav.ReadNonNegativeExponentialGolombAsUInt32(); //abs_delta_rps_minus1 ue(v)
// long deltaRps = (1 - 2 * delta_rps_sign) * (abs_delta_rps_minus1 + 1);
uint numDeltaPocs = CalculateNumDeltaPictureOrderCounts(sps.ShortTermRefPicSets, stRpsIdx, result);
for (int j = 0; j <= numDeltaPocs; j++)
{
result.used_by_curr_pic_flag.Add(nav.ReadBit()); //used_by_curr_pic_flag[ j ] u(1)
if (!result.used_by_curr_pic_flag[j])
{
result.use_delta_flag.Add(nav.ReadBit()); //use_delta_flag[ j ] u(1)
}
}
}
else
{
result.num_negative_pics = nav.ReadNonNegativeExponentialGolombAsUInt32(); //num_negative_pics ue(v)
result.num_positive_pics = nav.ReadNonNegativeExponentialGolombAsUInt32(); //num_positive_pics ue(v)
if (result.num_negative_pics > sps.sps_max_dec_pic_buffering_minus1[sps.sps_max_sub_layers_minus1])
{
System.Console.WriteLine("ShortTermRefPicSet.num_negative_pics > sps_max_dec_pic_buffering_minus1");
return(result);
}
if (result.num_positive_pics > sps.sps_max_dec_pic_buffering_minus1[sps.sps_max_sub_layers_minus1])
{
System.Console.WriteLine("ShortTermRefPicSet.num_positive_pics > sps_max_dec_pic_buffering_minus1");
return(result);
}
for (int i = 0; i < result.num_negative_pics; i++)
{
result.delta_poc_s0_minus1.Add(nav.ReadNonNegativeExponentialGolombAsUInt32()); //delta_poc_s0_minus1[ i ] ue(v)
result.used_by_curr_pic_s0_flag.Add(nav.ReadBit()); //used_by_curr_pic_s0_flag[ i ] u(1)
}
for (int i = 0; i < result.num_positive_pics; i++)
{
result.delta_poc_s1_minus1.Add(nav.ReadNonNegativeExponentialGolombAsUInt32()); //delta_poc_s1_minus1[ i ] ue(v)
result.used_by_curr_pic_s1_flag.Add(nav.ReadBit()); //used_by_curr_pic_s1_flag[ i ] u(1)
}
}
return(result);
}
/// <summary>
/// Process a Sequence Parameter Set NAL Unit.
/// </summary>
/// <remarks>
/// Reference 7.3.2.2 Sequence parameter set RBSP syntax - seq_parameter_set_rbsp()
/// </remarks>
private byte[] ProcessSequenceParameterSetNalUnit(byte[] nalUnitBytes)
{
var sps = new SequenceParameterSet();
var nav = new NalUnitBitstreamNavigator(nalUnitBytes);
nav.SkipBits(16); // Skip the 2 byte Nal Unit header
nav.SkipBits(4); // sps_video_parameter_set_id u(4)
sps.sps_max_sub_layers_minus1 = nav.ReadBitsAsByte(3); // sps_max_sub_layers_minus1 u(3)
nav.SkipBit(); // sps_temporal_id_nesting_flag u(1)
ProcessProfileTierLevel(nav, true, sps.sps_max_sub_layers_minus1); //profile_tier_level( 1, sps_max_sub_layers_minus1 )
nav.ReadNonNegativeExponentialGolombAsUInt32(); //sps_seq_parameter_set_id ue(v)
uint chroma_format_idc = nav.ReadNonNegativeExponentialGolombAsUInt32(); //chroma_format_idc ue(v)
if (chroma_format_idc == 3)
{
nav.SkipBit(); // separate_colour_plane_flag u(1)
}
nav.ReadNonNegativeExponentialGolombAsUInt32(); //pic_width_in_luma_samples ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //pic_height_in_luma_samples ue(v)
bool conformance_window_flag = nav.ReadBit(); //conformance_window_flag u(1)
if (conformance_window_flag)
{
nav.ReadNonNegativeExponentialGolombAsUInt32(); //conf_win_left_offset ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //conf_win_right_offset ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //conf_win_top_offset ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //conf_win_bottom_offset ue(v)
}
nav.ReadNonNegativeExponentialGolombAsUInt32(); //bit_depth_luma_minus8 ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //bit_depth_chroma_minus8 ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_max_pic_order_cnt_lsb_minus4 ue(v)
sps.sps_max_dec_pic_buffering_minus1 = new uint[sps.sps_max_sub_layers_minus1 + 1];
bool sps_sub_layer_ordering_info_present_flag = nav.ReadBit(); //sps_sub_layer_ordering_info_present_flag u(1)
for (int i = (sps_sub_layer_ordering_info_present_flag ? 0 : sps.sps_max_sub_layers_minus1); i <= sps.sps_max_sub_layers_minus1; i++)
{
sps.sps_max_dec_pic_buffering_minus1[i] = nav.ReadNonNegativeExponentialGolombAsUInt32(); //sps_max_dec_pic_buffering_minus1[i] ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //sps_max_num_reorder_pics[i] ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //sps_max_latency_increase_plus1[i] ue(v)
}
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_min_luma_coding_block_size_minus3 ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_diff_max_min_luma_coding_block_size ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_min_luma_transform_block_size_minus2 ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_diff_max_min_luma_transform_block_size ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //max_transform_hierarchy_depth_inter ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //max_transform_hierarchy_depth_intra ue(v)
bool scaling_list_enabled_flag = nav.ReadBit(); //scaling_list_enabled_flag u(1)
if (scaling_list_enabled_flag)
{
bool sps_scaling_list_data_present_flag = nav.ReadBit(); //sps_scaling_list_data_present_flag u(1)
if (sps_scaling_list_data_present_flag)
{
ProcessScalingListData(nav); //scaling_list_data()
}
}
nav.SkipBit(); //amp_enabled_flag u(1)
nav.SkipBit(); //sample_adaptive_offset_enabled_flag u(1)
bool pcm_enabled_flag = nav.ReadBit(); //pcm_enabled_flag u(1)
if (pcm_enabled_flag)
{
nav.SkipBits(4); //pcm_sample_bit_depth_luma_minus1 u(4)
nav.SkipBits(4); //pcm_sample_bit_depth_chroma_minus1 u(4)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_min_pcm_luma_coding_block_size_minus3 ue(v)
nav.ReadNonNegativeExponentialGolombAsUInt32(); //log2_diff_max_min_pcm_luma_coding_block_size ue(v)
nav.SkipBit(); //pcm_loop_filter_disabled_flag u(1)
}
sps.num_short_term_ref_pic_sets = nav.ReadNonNegativeExponentialGolombAsUInt32(); //num_short_term_ref_pic_sets ue(v)
for (uint i = 0; i < sps.num_short_term_ref_pic_sets; i++)
{
sps.ShortTermRefPicSets.Add(ProcessShortTermRefPicSets(nav, sps, i)); //st_ref_pic_set( i )
}
bool long_term_ref_pics_present_flag = nav.ReadBit(); //long_term_ref_pics_present_flag u(1)
if (long_term_ref_pics_present_flag)
{
uint num_long_term_ref_pics_sps = nav.ReadNonNegativeExponentialGolombAsUInt32(); //num_long_term_ref_pics_sps ue(v)
for (int i = 0; i < num_long_term_ref_pics_sps; i++)
{
nav.ReadNonNegativeExponentialGolombAsUInt32(); //lt_ref_pic_poc_lsb_sps[i] u(v)
nav.SkipBit(); //used_by_curr_pic_lt_sps_flag[i] u(1)
}
}
nav.SkipBit(); //sps_temporal_mvp_enabled_flag u(1)
nav.SkipBit(); //strong_intra_smoothing_enabled_flag u(1)
bool vui_parameters_present_flag = nav.ReadBit(); //vui_parameters_present_flag u(1)
if (vui_parameters_present_flag)
{
ProcessVideoUsabilityInformationParameters(nav); //vui_parameters()
}
// **********************************************
// NOTE: Parsing has only implemented up to here... There are still more extensions...
// **********************************************
//sps_extension_present_flag u(1)
//if( sps_extension_present_flag ) {
// sps_range_extension_flag u(1)
// sps_multilayer_extension_flag u(1)
// sps_3d_extension_flag u(1)
// sps_scc_extension_flag u(1)
// sps_extension_4bits u(4)
//}
//if ( sps_range_extension_flag )
// sps_range_extension( )
//if( sps_multilayer_extension_flag )
// sps_multilayer_extension( ) /* specified in Annex F *
//if (sps_3d_extension_flag)
// sps_3d_extension() /* specified in Annex I *
//if (sps_scc_extension_flag)
// sps_scc_extension()
//if (sps_extension_4bits)
// while (more_rbsp_data())
// sps_extension_data_flag u(1)
return(nalUnitBytes);
}