public add_bits ( int bitstring, int length ) : void | ||
bitstring | int | |
length | int | |
return | void |
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { allocation = stream.get_bits(4); channel2_allocation = stream.get_bits(4); if (crc != null) { crc.add_bits(allocation, 4); crc.add_bits(channel2_allocation, 4); } if (allocation != 0) { samplelength = allocation + 1; factor = table_factor[allocation]; offset = table_offset[allocation]; } if (channel2_allocation != 0) { channel2_samplelength = channel2_allocation + 1; channel2_factor = table_factor[channel2_allocation]; channel2_offset = table_offset[channel2_allocation]; } }
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { if ((allocation = stream.get_bits(4)) == 15) { } // cerr << "WARNING: stream contains an illegal allocation!\n"; // MPEG-stream is corrupted! if (crc != null) { crc.add_bits(allocation, 4); } if (allocation != 0) { samplelength = allocation + 1; factor = table_factor[allocation]; offset = table_offset[allocation]; } }
/// <summary> Read a 32-bit header from the bitstream. /// </summary> public void read_header(Bitstream stream, Crc16[] crcp) { int headerstring; int channel_bitrate; bool sync = false; ////System.Diagnostics.Trace.WriteLine("Header - read_header"); do { ////System.Diagnostics.Trace.WriteLine("Header - read_header - syncHeader"); headerstring = stream.syncHeader(syncmode); _headerstring = headerstring; // E.B ////System.Diagnostics.Trace.WriteLine("Header - sync"); if (syncmode == Bitstream.INITIAL_SYNC) { ////System.Diagnostics.Trace.WriteLine("Header - read_header - bit shifting"); h_version = ((SupportClass.URShift(headerstring, 19)) & 1); if (((SupportClass.URShift(headerstring, 20)) & 1) == 0) { // SZD: MPEG2.5 detection if (h_version == MPEG2_LSF) { h_version = MPEG25_LSF; } else { throw stream.newBitstreamException(javazoom.jl.decoder.BitstreamErrors_Fields.UNKNOWN_ERROR); } } if ((h_sample_frequency = ((SupportClass.URShift(headerstring, 10)) & 3)) == 3) { throw stream.newBitstreamException(javazoom.jl.decoder.BitstreamErrors_Fields.UNKNOWN_ERROR); } } ////System.Diagnostics.Trace.WriteLine("Header - read_header - more bit shifting"); h_layer = 4 - (SupportClass.URShift(headerstring, 17)) & 3; h_protection_bit = (SupportClass.URShift(headerstring, 16)) & 1; h_bitrate_index = (SupportClass.URShift(headerstring, 12)) & 0xF; h_padding_bit = (SupportClass.URShift(headerstring, 9)) & 1; h_mode = ((SupportClass.URShift(headerstring, 6)) & 3); h_mode_extension = (SupportClass.URShift(headerstring, 4)) & 3; if (h_mode == JOINT_STEREO) { h_intensity_stereo_bound = (h_mode_extension << 2) + 4; } else { h_intensity_stereo_bound = 0; } // should never be used if (((SupportClass.URShift(headerstring, 3)) & 1) == 1) { h_copyright = true; } if (((SupportClass.URShift(headerstring, 2)) & 1) == 1) { h_original = true; } ////System.Diagnostics.Trace.WriteLine("Header - read_header - calculate subbands"); // calculate number of subbands: if (h_layer == 1) { h_number_of_subbands = 32; } else { ////System.Diagnostics.Trace.WriteLine("Header - read_header - manage bitrates"); channel_bitrate = h_bitrate_index; // calculate bitrate per channel: if (h_mode != SINGLE_CHANNEL) { if (channel_bitrate == 4) { channel_bitrate = 1; } else { channel_bitrate -= 4; } } if ((channel_bitrate == 1) || (channel_bitrate == 2)) { if (h_sample_frequency == THIRTYTWO) { h_number_of_subbands = 12; } else { h_number_of_subbands = 8; } } else if ((h_sample_frequency == FOURTYEIGHT) || ((channel_bitrate >= 3) && (channel_bitrate <= 5))) { h_number_of_subbands = 27; } else { h_number_of_subbands = 30; } } if (h_intensity_stereo_bound > h_number_of_subbands) { h_intensity_stereo_bound = h_number_of_subbands; } // calculate framesize and nSlots ////System.Diagnostics.Trace.WriteLine("Header - read_header - calculate framesize"); calculate_framesize(); ////System.Diagnostics.Trace.WriteLine("Header - read_header - calculate read frame data"); // read framedata: stream.read_frame_data(framesize); if (stream.isSyncCurrentPosition(syncmode)) { if (syncmode == Bitstream.INITIAL_SYNC) { syncmode = Bitstream.STRICT_SYNC; stream.set_syncword(headerstring & unchecked ((int)0xFFF80CC0)); } sync = true; } else { stream.unreadFrame(); } }while (!sync); ////System.Diagnostics.Trace.WriteLine("Header - read_header - syncing:" +sync.ToString()); stream.parse_frame(); if (h_protection_bit == 0) { // frame contains a crc checksum checksum = (short)stream.get_bits(16); if (crc == null) { crc = new Crc16(); } crc.add_bits(headerstring, 16); crcp[0] = crc; } else { crcp[0] = null; } if (h_sample_frequency == FOURTYFOUR_POINT_ONE) { /*//HACKED * if (offset == null) * { * int max = max_number_of_frames(stream); * offset = new int[max]; * for(int i=0; i<max; i++) offset[i] = 0; * } * // Bizarre, y avait ici une acollade ouvrante * int cf = stream.current_frame(); * int lf = stream.last_frame(); * if ((cf > 0) && (cf == lf)) * { * offset[cf] = offset[cf-1] + h_padding_bit; * } * else * { * offset[0] = h_padding_bit; * }*/ } ////System.Diagnostics.Trace.WriteLine("Header - read_header end"); }
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { allocation = stream.get_bits(4); channel2_allocation = stream.get_bits(4); // try/catch block to handle invalid allocation // (catch array bounds error) try { if (crc != null) { crc.add_bits(allocation, 4); crc.add_bits(channel2_allocation, 4); } if (allocation != 0) { samplelength = allocation + 1; factor = table_factor[allocation]; offset = table_offset[allocation]; } if (channel2_allocation != 0) { channel2_samplelength = channel2_allocation + 1; channel2_factor = table_factor[channel2_allocation]; channel2_offset = table_offset[channel2_allocation]; } } catch (IndexOutOfRangeException ) { // array bounds error? Invalid allocation // (or unsupported). Ignore for now. } }
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { if ((allocation = stream.get_bits(4)) == 15) { } // cerr << "WARNING: stream contains an illegal allocation!\n"; // MPEG-stream is corrupted! if (crc != null) crc.add_bits(allocation, 4); if (allocation != 0) { samplelength = allocation + 1; factor = table_factor[allocation]; offset = table_offset[allocation]; } }
/// <summary>* /// </summary> public override void read_scalefactor_selection(Bitstream stream, Crc16 crc) { if (allocation != 0) { scfsi = stream.get_bits(2); if (crc != null) crc.add_bits(scfsi, 2); } if (channel2_allocation != 0) { channel2_scfsi = stream.get_bits(2); if (crc != null) crc.add_bits(channel2_scfsi, 2); } }
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { int length = get_allocationlength(header); allocation = stream.get_bits(length); channel2_allocation = stream.get_bits(length); if (crc != null) { crc.add_bits(allocation, length); crc.add_bits(channel2_allocation, length); } }
/// <summary>* /// </summary> public virtual void read_scalefactor_selection(Bitstream stream, Crc16 crc) { if (allocation != 0) { scfsi = stream.get_bits(2); if (crc != null) crc.add_bits(scfsi, 2); } }
/// <summary>* /// </summary> public override void read_allocation(Bitstream stream, Header header, Crc16 crc) { allocation = stream.get_bits(4); channel2_allocation = stream.get_bits(4); if (crc != null) { crc.add_bits(allocation, 4); crc.add_bits(channel2_allocation, 4); } if (allocation != 0) { samplelength = allocation + 1; factor = table_factor[allocation]; offset = table_offset[allocation]; } if (channel2_allocation != 0) { channel2_samplelength = channel2_allocation + 1; channel2_factor = table_factor[channel2_allocation]; channel2_offset = table_offset[channel2_allocation]; } }