public bool Init(Stream pBuffer, int length)
{
Clear();
var oldPosition = pBuffer.Position;
if (length < 2)
{
Logger.FATAL("Invalid length:{0}", length);
return false;
}
var bitReader = new BitReader(pBuffer);
_audioObjectType = bitReader.ReadBitsToByte(5);
if ((_audioObjectType != 1)
&& (_audioObjectType != 2)
&& (_audioObjectType != 3)
&& (_audioObjectType != 4)
&& (_audioObjectType != 6)
&& (_audioObjectType != 17)
&& (_audioObjectType != 19)
&& (_audioObjectType != 20)
&& (_audioObjectType != 23)
&& (_audioObjectType != 39))
{
Logger.FATAL("Invalid _audioObjectType: {0}", _audioObjectType);
return false;
}
//3. Read the sample rate index
_sampleRateIndex = bitReader.ReadBitsToByte(4);
if ((_sampleRateIndex == 13)
|| (_sampleRateIndex == 14))
{
Logger.FATAL("Invalid sample rate: {0}", _sampleRateIndex);
return false;
}
if (_sampleRateIndex == 15)
{
if (length < 5)
{
Logger.FATAL("Invalid length:{0}", length);
return false;
}
_sampleRate = (uint)bitReader.ReadBitsToInt(24);
}
else
{
var rates = new uint[]{
96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000,
12000, 11025, 8000, 7350
};
_sampleRate = rates[_sampleRateIndex];
}
//4. read the channel configuration index
_channelConfigurationIndex = bitReader.ReadBitsToByte(4);
if ((_channelConfigurationIndex == 0)
|| (_channelConfigurationIndex >= 8))
{
Logger.FATAL("Invalid _channelConfigurationIndex: {0}", _channelConfigurationIndex);
return false;
}
pBuffer.Position = oldPosition;
_pAAC = new byte[length];
pBuffer.Read(_pAAC, 0, length);
_aacLength = (uint) length;
return true;
}
private bool ReadPPS(BitReader ppsReader, Variant ppsInfo)
{
//7.3.2.2 Picture parameter set RBSP syntax
//14496-10.pdf 44/280
ppsInfo["pic_parameter_set_id"] = ppsReader.ReadExpGolomb("pic_parameter_set_id");
ppsInfo["seq_parameter_set_id"] = ppsReader.ReadExpGolomb("seq_parameter_set_id");
ppsInfo["entropy_coding_mode_flag"] = ppsReader.ReadBool();
ppsInfo["pic_order_present_flag"] = ppsReader.ReadBool();
ppsInfo["num_slice_groups_minus1"] = ppsReader.ReadExpGolomb("num_slice_groups_minus1");
if (ppsInfo["num_slice_groups_minus1"] > 0)
{
long sliceGroupMapType = ppsInfo["slice_group_map_type"] = ppsReader.ReadExpGolomb("slice_group_map_type");
switch (sliceGroupMapType)
{
case 0:
ppsInfo["run_length_minus1"] = Variant.Get();
for (var i = 0; i < ppsInfo["num_slice_groups_minus1"]; i++)
{
var val = ppsReader.ReadExpGolomb("run_length_minus1");
ppsInfo["run_length_minus1"].Add(val);
}
break;
case 2:
ppsInfo["top_left"] = Variant.Get();
ppsInfo["bottom_right"] = Variant.Get();
for (var i = 0; i < ppsInfo["num_slice_groups_minus1"]; i++)
{
ppsInfo["top_left"].Add(ppsReader.ReadExpGolomb("top_left"));
ppsInfo["bottom_right"].Add(ppsReader.ReadExpGolomb("bottom_right"));
}
break;
case 3:
case 4:
case 5:
ppsInfo["slice_group_change_direction_flag"] = ppsReader.ReadBool();
ppsInfo["slice_group_change_rate_minus1"] = ppsReader.ReadExpGolomb("slice_group_change_rate_minus1");
break;
case 6:
ppsInfo["pic_size_in_map_units_minus1"] = ppsReader.ReadExpGolomb("pic_size_in_map_units_minus1");
ppsInfo["slice_group_id"] = Variant.Get();
for (var i = 0; i <= ppsInfo["pic_size_in_map_units_minus1"]; i++)
{
ppsInfo["slice_group_id"].Add(ppsReader.ReadExpGolomb("slice_group_id"));
}
break;
}
}
ppsInfo["num_ref_idx_l0_active_minus1"] = ppsReader.ReadExpGolomb("num_ref_idx_l0_active_minus1");
ppsInfo["num_ref_idx_l1_active_minus1"] = ppsReader.ReadExpGolomb("num_ref_idx_l1_active_minus1");
ppsInfo["weighted_pred_flag"] = ppsReader.ReadBool();
ppsInfo["weighted_bipred_idc"] = ppsReader.ReadBitsToInt(2);
ppsInfo["pic_init_qp_minus26"] = ppsReader.ReadExpGolomb("pic_init_qp_minus26");
ppsInfo["pic_init_qs_minus26"] = ppsReader.ReadExpGolomb("pic_init_qs_minus26");
ppsInfo["chromqp_index_offset"] = ppsReader.ReadExpGolomb("chromqp_index_offset");
ppsInfo["deblocking_filter_control_present_flag"] = ppsReader.ReadBool();
ppsInfo["constrained_intrpred_flag"] = ppsReader.ReadBool();
ppsInfo["redundant_pic_cnt_present_flag"] = ppsReader.ReadBool();
return true;
}
private bool ReadSPSVUI(BitReader spsReader, Variant v)
{
//E.1.1 VUI parameters syntax
//14496-10.pdf 267/280
v["aspect_ratio_info_present_flag"] = spsReader.ReadBool();
if (v["aspect_ratio_info_present_flag"])
{
v["aspect_ratio_idc"] = spsReader.ReadBitsToByte();
if ((byte)v["aspect_ratio_idc"] == 255)
{
v["sar_width"] = (ushort)spsReader.ReadBitsToShort();
v["sar_height"] = (ushort)spsReader.ReadBitsToShort();
}
}
v["overscan_info_present_flag"] = spsReader.ReadBool();
if (v["overscan_info_present_flag"])
v["overscan_appropriate_flag"] = spsReader.ReadBool();
v["video_signal_type_present_flag"] = spsReader.ReadBool();
if (v["video_signal_type_present_flag"])
{
v["video_format"] = spsReader.ReadBitsToByte(3);
v["video_full_range_flag"] = spsReader.ReadBool();
v["colour_description_present_flag"] = spsReader.ReadBool();
if (v["colour_description_present_flag"])
{
v["colour_primaries"] = spsReader.ReadBitsToByte();
v["transfer_characteristics"] = spsReader.ReadBitsToByte();
v["matrix_coefficients"] = spsReader.ReadBitsToByte();
}
}
v["chromloc_info_present_flag"] = spsReader.ReadBool();
if (v["chromloc_info_present_flag"])
{
v["chromsample_loc_type_top_field"] = spsReader.ReadExpGolomb("chromsample_loc_type_top_field");
v["chromsample_loc_type_bottom_field"] = spsReader.ReadExpGolomb("chromsample_loc_type_bottom_field");
}
v["timing_info_present_flag"] = spsReader.ReadBool();
if (v["timing_info_present_flag"])
{
v["num_units_in_tick"] = spsReader.ReadBitsToInt();
v["time_scale"] = spsReader.ReadBitsToInt();
v["fixed_frame_rate_flag"] = spsReader.ReadBool();
}
v["nal_hrd_parameters_present_flag"] = spsReader.ReadBool();
if (v["nal_hrd_parameters_present_flag"])
{
if (!ReadSPSVUIHRD(spsReader, v["nal_hrd"] = Variant.Get()))
{
Logger.FATAL("Unable to read VUIHRD");
return false;
}
}
v["vcl_hrd_parameters_present_flag"] = spsReader.ReadBool();
if (v["vcl_hrd_parameters_present_flag"])
{
if (!ReadSPSVUIHRD(spsReader, v["vcl_hrd"] = Variant.Get()))
{
Logger.FATAL("Unable to read VUIHRD");
return false;
}
}
if (v["nal_hrd_parameters_present_flag"]
|| v["vcl_hrd_parameters_present_flag"])
v["low_delay_hrd_flag"] = spsReader.ReadBool();
v["pic_struct_present_flag"] = spsReader.ReadBool();
v["bitstream_restriction_flag"] = spsReader.ReadBool();
if (v["bitstream_restriction_flag"])
{
v["motion_vectors_over_pic_boundaries_flag"] = spsReader.ReadBool();
v["max_bytes_per_pic_denom"] = spsReader.ReadExpGolomb("max_bytes_per_pic_denom");
v["max_bits_per_mb_denom"] = spsReader.ReadExpGolomb("max_bits_per_mb_denom");
v["log2_max_mv_length_horizontal"] = spsReader.ReadExpGolomb("log2_max_mv_length_horizontal");
v["log2_max_mv_length_vertical"] = spsReader.ReadExpGolomb("log2_max_mv_length_vertical");
v["num_reorder_frames"] = spsReader.ReadExpGolomb("num_reorder_frames");
v["max_dec_frame_buffering"] = spsReader.ReadExpGolomb("max_dec_frame_buffering");
}
return true;
}
