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Diffstat (limited to 'songdbj/javazoom/jl/decoder/LayerIDecoder.java')
| -rw-r--r-- | songdbj/javazoom/jl/decoder/LayerIDecoder.java | 444 |
1 files changed, 0 insertions, 444 deletions
diff --git a/songdbj/javazoom/jl/decoder/LayerIDecoder.java b/songdbj/javazoom/jl/decoder/LayerIDecoder.java deleted file mode 100644 index b633dd2..0000000 --- a/songdbj/javazoom/jl/decoder/LayerIDecoder.java +++ /dev/null @@ -1,444 +0,0 @@ -/* - * 11/19/04 1.0 moved to LGPL. - * - * 12/12/99 Initial version. Adapted from javalayer.java - * and Subband*.java. mdm@techie.com - * - * 02/28/99 Initial version : javalayer.java by E.B - *----------------------------------------------------------------------- - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Library General Public License as published - * by the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Library General Public License for more details. - * - * You should have received a copy of the GNU Library General Public - * License along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - *---------------------------------------------------------------------- - */ - -package javazoom.jl.decoder; - -/** - * Implements decoding of MPEG Audio Layer I frames. - */ -class LayerIDecoder implements FrameDecoder -{ - protected Bitstream stream; - protected Header header; - protected SynthesisFilter filter1, filter2; - protected Obuffer buffer; - protected int which_channels; - protected int mode; - - protected int num_subbands; - protected Subband[] subbands; - protected Crc16 crc = null; // new Crc16[1] to enable CRC checking. - - public LayerIDecoder() - { - crc = new Crc16(); - } - - public 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 void decodeFrame() - { - - num_subbands = header.number_of_subbands(); - subbands = new Subband[32]; - mode = header.mode(); - - createSubbands(); - - readAllocation(); - readScaleFactorSelection(); - - if ((crc != null) || header.checksum_ok()) - { - readScaleFactors(); - - readSampleData(); - } - - } - - protected void createSubbands() - { - int i; - if (mode == Header.SINGLE_CHANNEL) - for (i = 0; i < num_subbands; ++i) - subbands[i] = new SubbandLayer1(i); - else if (mode == Header.JOINT_STEREO) - { - for (i = 0; i < header.intensity_stereo_bound(); ++i) - subbands[i] = new SubbandLayer1Stereo(i); - for (; i < num_subbands; ++i) - subbands[i] = new SubbandLayer1IntensityStereo(i); - } - else - { - for (i = 0; i < num_subbands; ++i) - subbands[i] = new SubbandLayer1Stereo(i); - } - } - - protected void readAllocation() - { - // start to read audio data: - for (int i = 0; i < num_subbands; ++i) - subbands[i].read_allocation(stream, header, crc); - - } - - protected void readScaleFactorSelection() - { - // scale factor selection not present for layer I. - } - - protected void readScaleFactors() - { - for (int i = 0; i < num_subbands; ++i) - subbands[i].read_scalefactor(stream, header); - } - - protected void readSampleData() - { - boolean read_ready = false; - boolean write_ready = false; - int mode = header.mode(); - int i; - do - { - for (i = 0; i < num_subbands; ++i) - read_ready = subbands[i].read_sampledata(stream); - do - { - for (i = 0; i < num_subbands; ++i) - write_ready = subbands[i].put_next_sample(which_channels,filter1, filter2); - - filter1.calculate_pcm_samples(buffer); - if ((which_channels == OutputChannels.BOTH_CHANNELS) && (mode != Header.SINGLE_CHANNEL)) - filter2.calculate_pcm_samples(buffer); - } while (!write_ready); - } while (!read_ready); - - } - - /** - * Abstract base class for subband classes of layer I and II - */ - static abstract class Subband - { - /* - * Changes from version 1.1 to 1.2: - * - array size increased by one, although a scalefactor with index 63 - * is illegal (to prevent segmentation faults) - */ - // Scalefactors for layer I and II, Annex 3-B.1 in ISO/IEC DIS 11172: - public static final float scalefactors[] = - { - 2.00000000000000f, 1.58740105196820f, 1.25992104989487f, 1.00000000000000f, - 0.79370052598410f, 0.62996052494744f, 0.50000000000000f, 0.39685026299205f, - 0.31498026247372f, 0.25000000000000f, 0.19842513149602f, 0.15749013123686f, - 0.12500000000000f, 0.09921256574801f, 0.07874506561843f, 0.06250000000000f, - 0.04960628287401f, 0.03937253280921f, 0.03125000000000f, 0.02480314143700f, - 0.01968626640461f, 0.01562500000000f, 0.01240157071850f, 0.00984313320230f, - 0.00781250000000f, 0.00620078535925f, 0.00492156660115f, 0.00390625000000f, - 0.00310039267963f, 0.00246078330058f, 0.00195312500000f, 0.00155019633981f, - 0.00123039165029f, 0.00097656250000f, 0.00077509816991f, 0.00061519582514f, - 0.00048828125000f, 0.00038754908495f, 0.00030759791257f, 0.00024414062500f, - 0.00019377454248f, 0.00015379895629f, 0.00012207031250f, 0.00009688727124f, - 0.00007689947814f, 0.00006103515625f, 0.00004844363562f, 0.00003844973907f, - 0.00003051757813f, 0.00002422181781f, 0.00001922486954f, 0.00001525878906f, - 0.00001211090890f, 0.00000961243477f, 0.00000762939453f, 0.00000605545445f, - 0.00000480621738f, 0.00000381469727f, 0.00000302772723f, 0.00000240310869f, - 0.00000190734863f, 0.00000151386361f, 0.00000120155435f, 0.00000000000000f /* illegal scalefactor */ - }; - - public abstract void read_allocation (Bitstream stream, Header header, Crc16 crc); - public abstract void read_scalefactor (Bitstream stream, Header header); - public abstract boolean read_sampledata (Bitstream stream); - public abstract boolean put_next_sample (int channels, SynthesisFilter filter1, SynthesisFilter filter2); - }; - - /** - * Class for layer I subbands in single channel mode. - * Used for single channel mode - * and in derived class for intensity stereo mode - */ - static class SubbandLayer1 extends Subband - { - - // Factors and offsets for sample requantization - public static final float table_factor[] = { - 0.0f, (1.0f/2.0f) * (4.0f/3.0f), (1.0f/4.0f) * (8.0f/7.0f), (1.0f/8.0f) * (16.0f/15.0f), - (1.0f/16.0f) * (32.0f/31.0f), (1.0f/32.0f) * (64.0f/63.0f), (1.0f/64.0f) * (128.0f/127.0f), - (1.0f/128.0f) * (256.0f/255.0f), (1.0f/256.0f) * (512.0f/511.0f), - (1.0f/512.0f) * (1024.0f/1023.0f), (1.0f/1024.0f) * (2048.0f/2047.0f), - (1.0f/2048.0f) * (4096.0f/4095.0f), (1.0f/4096.0f) * (8192.0f/8191.0f), - (1.0f/8192.0f) * (16384.0f/16383.0f), (1.0f/16384.0f) * (32768.0f/32767.0f) - }; - - public static final float table_offset[] = { - 0.0f, ((1.0f/2.0f)-1.0f) * (4.0f/3.0f), ((1.0f/4.0f)-1.0f) * (8.0f/7.0f), ((1.0f/8.0f)-1.0f) * (16.0f/15.0f), - ((1.0f/16.0f)-1.0f) * (32.0f/31.0f), ((1.0f/32.0f)-1.0f) * (64.0f/63.0f), ((1.0f/64.0f)-1.0f) * (128.0f/127.0f), - ((1.0f/128.0f)-1.0f) * (256.0f/255.0f), ((1.0f/256.0f)-1.0f) * (512.0f/511.0f), - ((1.0f/512.0f)-1.0f) * (1024.0f/1023.0f), ((1.0f/1024.0f)-1.0f) * (2048.0f/2047.0f), - ((1.0f/2048.0f)-1.0f) * (4096.0f/4095.0f), ((1.0f/4096.0f)-1.0f) * (8192.0f/8191.0f), - ((1.0f/8192.0f)-1.0f) * (16384.0f/16383.0f), ((1.0f/16384.0f)-1.0f) * (32768.0f/32767.0f) - }; - - protected int subbandnumber; - protected int samplenumber; - protected int allocation; - protected float scalefactor; - protected int samplelength; - protected float sample; - protected float factor, offset; - - /** - * Construtor. - */ - public SubbandLayer1(int subbandnumber) - { - this.subbandnumber = subbandnumber; - samplenumber = 0; - } - - /** - * - */ - public 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]; - } - } - - /** - * - */ - public void read_scalefactor(Bitstream stream, Header header) - { - if (allocation != 0) scalefactor = scalefactors[stream.get_bits(6)]; - } - - /** - * - */ - public boolean read_sampledata(Bitstream stream) - { - if (allocation != 0) - { - sample = (float) (stream.get_bits(samplelength)); - } - if (++samplenumber == 12) - { - samplenumber = 0; - return true; - } - return false; - } - - /** - * - */ - public boolean put_next_sample(int channels, SynthesisFilter filter1, SynthesisFilter filter2) - { - if ((allocation !=0) && (channels != OutputChannels.RIGHT_CHANNEL)) - { - float scaled_sample = (sample * factor + offset) * scalefactor; - filter1.input_sample (scaled_sample, subbandnumber); - } - return true; - } - }; - - /** - * Class for layer I subbands in joint stereo mode. - */ - static class SubbandLayer1IntensityStereo extends SubbandLayer1 - { - protected float channel2_scalefactor; - - /** - * Constructor - */ - public SubbandLayer1IntensityStereo(int subbandnumber) - { - super(subbandnumber); - } - - /** - * - */ - public void read_allocation(Bitstream stream, Header header, Crc16 crc) - { - super.read_allocation (stream, header, crc); - } - - /** - * - */ - public void read_scalefactor (Bitstream stream, Header header) - { - if (allocation != 0) - { - scalefactor = scalefactors[stream.get_bits(6)]; - channel2_scalefactor = scalefactors[stream.get_bits(6)]; - } - } - - /** - * - */ - public boolean read_sampledata(Bitstream stream) - { - return super.read_sampledata (stream); - } - - /** - * - */ - public boolean put_next_sample (int channels, SynthesisFilter filter1, SynthesisFilter filter2) - { - if (allocation !=0 ) - { - sample = sample * factor + offset; // requantization - if (channels == OutputChannels.BOTH_CHANNELS) - { - float sample1 = sample * scalefactor, - sample2 = sample * channel2_scalefactor; - filter1.input_sample(sample1, subbandnumber); - filter2.input_sample(sample2, subbandnumber); - } - else if (channels == OutputChannels.LEFT_CHANNEL) - { - float sample1 = sample * scalefactor; - filter1.input_sample(sample1, subbandnumber); - } - else - { - float sample2 = sample * channel2_scalefactor; - filter1.input_sample(sample2, subbandnumber); - } - } - return true; - } - }; - - /** - * Class for layer I subbands in stereo mode. - */ - static class SubbandLayer1Stereo extends SubbandLayer1 - { - protected int channel2_allocation; - protected float channel2_scalefactor; - protected int channel2_samplelength; - protected float channel2_sample; - protected float channel2_factor, channel2_offset; - - - /** - * Constructor - */ - public SubbandLayer1Stereo(int subbandnumber) - { - super(subbandnumber); - } - - /** - * - */ - public 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]; - } - } - - /** - * - */ - public 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)]; - } - - /** - * - */ - public boolean read_sampledata (Bitstream stream) - { - boolean returnvalue = super.read_sampledata(stream); - if (channel2_allocation != 0) - { - channel2_sample = (float) (stream.get_bits(channel2_samplelength)); - } - return(returnvalue); - } - - /** - * - */ - public boolean put_next_sample(int channels, SynthesisFilter filter1, SynthesisFilter filter2) - { - super.put_next_sample (channels, filter1, filter2); - if ((channel2_allocation != 0) && (channels != OutputChannels.LEFT_CHANNEL)) - { - float sample2 = (channel2_sample * channel2_factor + channel2_offset) * - channel2_scalefactor; - if (channels == OutputChannels.BOTH_CHANNELS) - filter2.input_sample (sample2, subbandnumber); - else - filter1.input_sample (sample2, subbandnumber); - } - return true; - } - }; - -} |