Bistream
public virtual void create(Bitstream stream0, Header header0, SynthesisFilter filtera, SynthesisFilter filterb, Obuffer buffer0, int which_ch0) { stream = stream0; header = header0; filter1 = filtera; filter2 = filterb; buffer = buffer0; which_channels = which_ch0; }
public Player(System.IO.Stream stream, AudioDevice device) { bitstream = new Bitstream(stream); decoder = new Decoder(); if (device != null) { audio = device; } else { FactoryRegistry r = FactoryRegistry.systemRegistry(); audio = r.createAudioDevice(); } audio.open(decoder); }
public abstract void read_allocation(Bitstream stream, Header header, Crc16 crc);
//UPGRADE_NOTE: Synchronized keyword was removed from method 'convert'. Lock expression was added. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1027"' public virtual void convert(System.IO.Stream sourceStream, System.String destName, ProgressListener progressListener, Decoder.Params decoderParams) { lock (this) { if (progressListener == null) progressListener = PrintWriterProgressListener.newStdOut(PrintWriterProgressListener.NO_DETAIL); try { if (!(sourceStream is System.IO.BufferedStream)) sourceStream = new System.IO.BufferedStream(sourceStream); int frameCount = - 1; //UPGRADE_ISSUE: Method 'java.io.InputStream.markSupported' was not converted. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1000_javaioInputStreammarkSupported"' if (sourceStream.markSupported()) { //UPGRADE_ISSUE: Method 'java.io.InputStream.mark' was not converted. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1000_javaioInputStreammark_int"' sourceStream.mark(- 1); frameCount = countFrames(sourceStream); //UPGRADE_ISSUE: Method 'java.io.InputStream.reset' was not converted. 'ms-help://MS.VSCC.2003/commoner/redir/redirect.htm?keyword="jlca1000_javaioInputStreamreset"' sourceStream.reset(); } progressListener.converterUpdate(javazoom.jl.converter.Converter.ProgressListener_Fields.UPDATE_FRAME_COUNT, frameCount, 0); Obuffer output = null; Decoder decoder = new Decoder(decoderParams); Bitstream stream = new Bitstream(sourceStream); if (frameCount == - 1) frameCount = System.Int32.MaxValue; int frame = 0; long startTime = (System.DateTime.Now.Ticks - 621355968000000000) / 10000; try { for (; frame < frameCount; frame++) { try { Header header = stream.readFrame(); if (header == null) break; progressListener.readFrame(frame, header); if (output == null) { // REVIEW: Incorrect functionality. // the decoder should provide decoded // frequency and channels output as it may differ from // the source (e.g. when downmixing stereo to mono.) int channels = (header.mode() == Header.SINGLE_CHANNEL)?1:2; int freq = header.frequency(); output = new WaveFileObuffer(channels, freq, destName); decoder.OutputBuffer = output; } Obuffer decoderOutput = decoder.decodeFrame(header, stream); // REVIEW: the way the output buffer is set // on the decoder is a bit dodgy. Even though // this exception should never happen, we test to be sure. if (decoderOutput != output) throw new System.ApplicationException("Output buffers are different."); progressListener.decodedFrame(frame, header, output); stream.closeFrame(); } catch (System.Exception ex) { bool stop = !progressListener.converterException(ex); if (stop) { throw new JavaLayerException(ex.Message, ex); } } } } finally { if (output != null) output.close(); } int time = (int) ((System.DateTime.Now.Ticks - 621355968000000000) / 10000 - startTime); progressListener.converterUpdate(javazoom.jl.converter.Converter.ProgressListener_Fields.UPDATE_CONVERT_COMPLETE, time, frame); } catch (System.IO.IOException ex) { throw new JavaLayerException(ex.Message, ex); } } }
/// <summary> Read a 32-bit header from the bitstream. /// </summary> internal void read_header(Bitstream stream, Crc16[] crcp) { int headerstring; int channel_bitrate; bool sync = false; do { headerstring = stream.syncHeader(syncmode); _headerstring = headerstring; // E.B if (syncmode == Bitstream.INITIAL_SYNC) { 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); } } 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; // calculate number of subbands: if (h_layer == 1) h_number_of_subbands = 32; else { 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 calculate_framesize(); // 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); 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) { /* 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; } */ } }
/// <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_scalefactor(Bitstream stream, Header header) { if (allocation != 0) scalefactor = scalefactors[stream.get_bits(6)]; if (channel2_allocation != 0) channel2_scalefactor = scalefactors[stream.get_bits(6)]; }
/// <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_allocation(Bitstream stream, Header header, Crc16 crc) { base.read_allocation(stream, header, crc); }
/// <summary>* /// </summary> public override bool read_sampledata(Bitstream stream) { if (allocation != 0) if (groupingtable[0] != null) { int samplecode = stream.get_bits(codelength[0]); // create requantized samples: samplecode += samplecode << 1; float[] target = samples; float[] source = groupingtable[0]; /* int tmp = 0; int temp = 0; target[tmp++] = source[samplecode + temp]; temp++; target[tmp++] = source[samplecode + temp]; temp++; target[tmp] = source[samplecode + temp]; */ //Bugfix: int tmp = 0; int temp = samplecode; if (temp > source.Length - 3) temp = source.Length - 3; target[tmp] = source[temp]; temp++; tmp++; target[tmp] = source[temp]; temp++; tmp++; target[tmp] = source[temp]; // memcpy (samples, groupingtable + samplecode, 3 * sizeof (real)); } else { samples[0] = (float) ((stream.get_bits(codelength[0])) * factor[0] - 1.0); samples[1] = (float) ((stream.get_bits(codelength[0])) * factor[0] - 1.0); samples[2] = (float) ((stream.get_bits(codelength[0])) * factor[0] - 1.0); } samplenumber = 0; if (++groupnumber == 12) return true; else return false; }
/// <summary>* /// </summary> public override void read_scalefactor(Bitstream stream, Header header) { if (allocation != 0) { switch (scfsi) { case 0: scalefactor1 = scalefactors[stream.get_bits(6)]; scalefactor2 = scalefactors[stream.get_bits(6)]; scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 1: scalefactor1 = scalefactor2 = scalefactors[stream.get_bits(6)]; scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 2: scalefactor1 = scalefactor2 = scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 3: scalefactor1 = scalefactors[stream.get_bits(6)]; scalefactor2 = scalefactor3 = scalefactors[stream.get_bits(6)]; break; } prepare_sample_reading(header, allocation, 0, factor, codelength, c, d); } }
/// <summary>* /// </summary> public override bool read_sampledata(Bitstream stream) { return(base.read_sampledata(stream)); }
public abstract bool read_sampledata(Bitstream stream);
public abstract void read_scalefactor(Bitstream stream, Header header);
/// <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_scalefactor(Bitstream stream, Header header) { if (allocation != 0) { base.read_scalefactor(stream, header); switch (channel2_scfsi) { case 0: channel2_scalefactor1 = scalefactors[stream.get_bits(6)]; channel2_scalefactor2 = scalefactors[stream.get_bits(6)]; channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 1: channel2_scalefactor1 = channel2_scalefactor2 = scalefactors[stream.get_bits(6)]; channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 2: channel2_scalefactor1 = channel2_scalefactor2 = channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 3: channel2_scalefactor1 = scalefactors[stream.get_bits(6)]; channel2_scalefactor2 = channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; } } }
/// <summary>* /// </summary> public override bool read_sampledata(Bitstream stream) { if (allocation != 0) { sample = (float) (stream.get_bits(samplelength)); } if (++samplenumber == 12) { samplenumber = 0; return true; } return false; }
/// <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 override bool read_sampledata(Bitstream stream) { return base.read_sampledata(stream); }
/// <summary> Constructor. /// </summary> // REVIEW: these constructor arguments should be moved to the // decodeFrame() method, where possible, so that one public LayerIIIDecoder(Bitstream stream0, Header header0, SynthesisFilter filtera, SynthesisFilter filterb, Obuffer buffer0, int which_ch0) { InitBlock(); huffcodetab.inithuff(); is_1d = new int[SBLIMIT * SSLIMIT + 4]; ro = new float[2][][]; for (int i = 0; i < 2; i++) { ro[i] = new float[SBLIMIT][]; for (int i2 = 0; i2 < SBLIMIT; i2++) { ro[i][i2] = new float[SSLIMIT]; } } lr = new float[2][][]; for (int i3 = 0; i3 < 2; i3++) { lr[i3] = new float[SBLIMIT][]; for (int i4 = 0; i4 < SBLIMIT; i4++) { lr[i3][i4] = new float[SSLIMIT]; } } out_1d = new float[SBLIMIT * SSLIMIT]; prevblck = new float[2][]; for (int i5 = 0; i5 < 2; i5++) { prevblck[i5] = new float[SBLIMIT * SSLIMIT]; } k = new float[2][]; for (int i6 = 0; i6 < 2; i6++) { k[i6] = new float[SBLIMIT * SSLIMIT]; } nonzero = new int[2]; //III_scalefact_t III_scalefac_t = new temporaire2[2]; III_scalefac_t[0] = new temporaire2(); III_scalefac_t[1] = new temporaire2(); scalefac = III_scalefac_t; // L3TABLE INIT sfBandIndex = new SBI[9]; // SZD: MPEG2.5 +3 indices int[] l0 = new int[]{0, 6, 12, 18, 24, 30, 36, 44, 54, 66, 80, 96, 116, 140, 168, 200, 238, 284, 336, 396, 464, 522, 576}; int[] s0 = new int[]{0, 4, 8, 12, 18, 24, 32, 42, 56, 74, 100, 132, 174, 192}; int[] l1 = new int[]{0, 6, 12, 18, 24, 30, 36, 44, 54, 66, 80, 96, 114, 136, 162, 194, 232, 278, 330, 394, 464, 540, 576}; int[] s1 = new int[]{0, 4, 8, 12, 18, 26, 36, 48, 62, 80, 104, 136, 180, 192}; int[] l2 = new int[]{0, 6, 12, 18, 24, 30, 36, 44, 54, 66, 80, 96, 116, 140, 168, 200, 238, 284, 336, 396, 464, 522, 576}; int[] s2 = new int[]{0, 4, 8, 12, 18, 26, 36, 48, 62, 80, 104, 134, 174, 192}; int[] l3 = new int[]{0, 4, 8, 12, 16, 20, 24, 30, 36, 44, 52, 62, 74, 90, 110, 134, 162, 196, 238, 288, 342, 418, 576}; int[] s3 = new int[]{0, 4, 8, 12, 16, 22, 30, 40, 52, 66, 84, 106, 136, 192}; int[] l4 = new int[]{0, 4, 8, 12, 16, 20, 24, 30, 36, 42, 50, 60, 72, 88, 106, 128, 156, 190, 230, 276, 330, 384, 576}; int[] s4 = new int[]{0, 4, 8, 12, 16, 22, 28, 38, 50, 64, 80, 100, 126, 192}; int[] l5 = new int[]{0, 4, 8, 12, 16, 20, 24, 30, 36, 44, 54, 66, 82, 102, 126, 156, 194, 240, 296, 364, 448, 550, 576}; int[] s5 = new int[]{0, 4, 8, 12, 16, 22, 30, 42, 58, 78, 104, 138, 180, 192}; // SZD: MPEG2.5 int[] l6 = new int[]{0, 6, 12, 18, 24, 30, 36, 44, 54, 66, 80, 96, 116, 140, 168, 200, 238, 284, 336, 396, 464, 522, 576}; int[] s6 = new int[]{0, 4, 8, 12, 18, 26, 36, 48, 62, 80, 104, 134, 174, 192}; int[] l7 = new int[]{0, 6, 12, 18, 24, 30, 36, 44, 54, 66, 80, 96, 116, 140, 168, 200, 238, 284, 336, 396, 464, 522, 576}; int[] s7 = new int[]{0, 4, 8, 12, 18, 26, 36, 48, 62, 80, 104, 134, 174, 192}; int[] l8 = new int[]{0, 12, 24, 36, 48, 60, 72, 88, 108, 132, 160, 192, 232, 280, 336, 400, 476, 566, 568, 570, 572, 574, 576}; int[] s8 = new int[]{0, 8, 16, 24, 36, 52, 72, 96, 124, 160, 162, 164, 166, 192}; sfBandIndex[0] = new SBI(l0, s0); sfBandIndex[1] = new SBI(l1, s1); sfBandIndex[2] = new SBI(l2, s2); sfBandIndex[3] = new SBI(l3, s3); sfBandIndex[4] = new SBI(l4, s4); sfBandIndex[5] = new SBI(l5, s5); //SZD: MPEG2.5 sfBandIndex[6] = new SBI(l6, s6); sfBandIndex[7] = new SBI(l7, s7); sfBandIndex[8] = new SBI(l8, s8); // END OF L3TABLE INIT if (reorder_table == null) { // SZD: generate LUT reorder_table = new int[9][]; for (int i = 0; i < 9; i++) reorder_table[i] = reorder(sfBandIndex[i].s); } // Sftable int[] ll0 = new int[]{0, 6, 11, 16, 21}; int[] ss0 = new int[]{0, 6, 12}; sftable = new Sftable(this, ll0, ss0); // END OF Sftable // scalefac_buffer scalefac_buffer = new int[54]; // END OF scalefac_buffer stream = stream0; header = header0; filter1 = filtera; filter2 = filterb; buffer = buffer0; which_channels = which_ch0; frame_start = 0; channels = (header.mode() == Header.SINGLE_CHANNEL)?1:2; max_gr = (header.version() == Header.MPEG1)?2:1; sfreq = header.sample_frequency() + ((header.version() == Header.MPEG1)?3:(header.version() == Header.MPEG25_LSF)?6:0); // SZD if (channels == 2) { switch (which_channels) { case (int)OutputChannelsEnum.LEFT_CHANNEL: case (int)OutputChannelsEnum.DOWNMIX_CHANNELS: first_channel = last_channel = 0; break; case (int)OutputChannelsEnum.RIGHT_CHANNEL: first_channel = last_channel = 1; break; case (int)OutputChannelsEnum.BOTH_CHANNELS: default: first_channel = 0; last_channel = 1; break; } } else { first_channel = last_channel = 0; } for (int ch = 0; ch < 2; ch++) for (int j = 0; j < 576; j++) prevblck[ch][j] = 0.0f; nonzero[0] = nonzero[1] = 576; br = new BitReserve(); si = new III_side_info_t(); }
/// <summary>* /// </summary> public override bool read_sampledata(Bitstream stream) { bool returnvalue = base.read_sampledata(stream); if (channel2_allocation != 0) { channel2_sample = (float) (stream.get_bits(channel2_samplelength)); } return (returnvalue); }
protected internal virtual FrameDecoder retrieveDecoder(Header header, Bitstream stream, int layer) { FrameDecoder decoder = null; // REVIEW: allow channel output selection type // (LEFT, RIGHT, BOTH, DOWNMIX) switch (layer) { case 3: if (l3decoder == null) { l3decoder = new LayerIIIDecoder(stream, header, filter1, filter2, output, (int)OutputChannelsEnum.BOTH_CHANNELS); } decoder = l3decoder; break; case 2: if (l2decoder == null) { l2decoder = new LayerIIDecoder(); l2decoder.create(stream, header, filter1, filter2, output, (int)OutputChannelsEnum.BOTH_CHANNELS); } decoder = l2decoder; break; case 1: if (l1decoder == null) { l1decoder = new LayerIDecoder(); l1decoder.create(stream, header, filter1, filter2, output, (int)OutputChannelsEnum.BOTH_CHANNELS); } decoder = l1decoder; break; } if (decoder == null) { throw newDecoderException(javazoom.jl.decoder.DecoderErrors_Fields.UNSUPPORTED_LAYER, null); } return decoder; }
/// <summary>* /// </summary> public override bool read_sampledata(Bitstream stream) { bool returnvalue = base.read_sampledata(stream); if (channel2_allocation != 0) if (groupingtable[1] != null) { int samplecode = stream.get_bits(channel2_codelength[0]); // create requantized samples: samplecode += samplecode << 1; /* float[] target = channel2_samples; float[] source = channel2_groupingtable[0]; int tmp = 0; int temp = 0; target[tmp++] = source[samplecode + temp]; temp++; target[tmp++] = source[samplecode + temp]; temp++; target[tmp] = source[samplecode + temp]; // memcpy (channel2_samples, channel2_groupingtable + samplecode, 3 * sizeof (real)); */ float[] target = channel2_samples; float[] source = groupingtable[1]; int tmp = 0; int temp = samplecode; target[tmp] = source[temp]; temp++; tmp++; target[tmp] = source[temp]; temp++; tmp++; target[tmp] = source[temp]; } else { channel2_samples[0] = (float) ((stream.get_bits(channel2_codelength[0])) * channel2_factor[0] - 1.0); channel2_samples[1] = (float) ((stream.get_bits(channel2_codelength[0])) * channel2_factor[0] - 1.0); channel2_samples[2] = (float) ((stream.get_bits(channel2_codelength[0])) * channel2_factor[0] - 1.0); } return returnvalue; }
/// <summary> Read a 32-bit header from the bitstream. /// </summary> internal void read_header(Bitstream stream, Crc16[] crcp) { int headerstring; int channel_bitrate; bool sync = false; do { headerstring = stream.syncHeader(syncmode); _headerstring = headerstring; // E.B if (syncmode == Bitstream.INITIAL_SYNC) { 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); } } 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; } // calculate number of subbands: if (h_layer == 1) { h_number_of_subbands = 32; } else { 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 calculate_framesize(); // 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); 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) { /* * 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; * } */ } }
/// <summary> Decodes one frame from an MPEG audio bitstream. /// /// </summary> /// <param name="header The">header describing the frame to decode. /// </param> /// <param name="bitstream The">bistream that provides the bits for te body of the frame. /// /// </param> /// <returns> A SampleBuffer containing the decoded samples. /// /// </returns> public virtual Obuffer decodeFrame(Header header, Bitstream stream) { if (!initialized) { initialize(header); } int layer = header.layer(); output.clear_buffer(); FrameDecoder decoder = retrieveDecoder(header, stream, layer); decoder.decodeFrame(); output.write_buffer(1); return output; }
/// <summary>* /// </summary> public override void read_scalefactor(Bitstream stream, Header header) { base.read_scalefactor(stream, header); if (channel2_allocation != 0) { switch (channel2_scfsi) { case 0: channel2_scalefactor1 = scalefactors[stream.get_bits(6)]; channel2_scalefactor2 = scalefactors[stream.get_bits(6)]; channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 1: channel2_scalefactor1 = channel2_scalefactor2 = scalefactors[stream.get_bits(6)]; channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 2: channel2_scalefactor1 = channel2_scalefactor2 = channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; case 3: channel2_scalefactor1 = scalefactors[stream.get_bits(6)]; channel2_scalefactor2 = channel2_scalefactor3 = scalefactors[stream.get_bits(6)]; break; } prepare_sample_reading(header, channel2_allocation, 1, channel2_factor, channel2_codelength, channel2_c, channel2_d); } }
/// <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) { 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]; } }