/*   File: subband_layer_1.cc   Description:*/   #include <stdio.h>#include <stdlib.h>#include <string.h>#include <fstream.h>#ifdef IRIX#include <dmedia/audio.h>#endif#ifdef SOLARIS#include <sys/audioio.h>#endif#include "athread.hh"#include "error.hh"#include "debug.hh"#include "util.hh"#include "sync.hh"#include "mpeg2const.hh"#include "mpeg2buff.hh"#include "astream.hh"#include "crc.hh"#include "header.hh"#include "obuffer.hh"#include "synthesis_filter.hh"#include "subband.hh"#include "subband_layer_1.hh"#include "scalefactors.hh"// factors and offsets for sample requantization:static const real table_factor[15] = {  0.0, (1.0/2.0) * (4.0/3.0), (1.0/4.0) * (8.0/7.0), (1.0/8.0) * (16.0/15.0),  (1.0/16.0) * (32.0/31.0), (1.0/32.0) * (64.0/63.0), (1.0/64.0) * (128.0/127.0),  (1.0/128.0) * (256.0/255.0), (1.0/256.0) * (512.0/511.0),  (1.0/512.0) * (1024.0/1023.0), (1.0/1024.0) * (2048.0/2047.0),  (1.0/2048.0) * (4096.0/4095.0), (1.0/4096.0) * (8192.0/8191.0),  (1.0/8192.0) * (16384.0/16383.0), (1.0/16384.0) * (32768.0/32767.0)};static const real table_offset[15] = {  0.0, ((1.0/2.0)-1.0) * (4.0/3.0), ((1.0/4.0)-1.0) * (8.0/7.0), ((1.0/8.0)-1.0) * (16.0/15.0),  ((1.0/16.0)-1.0) * (32.0/31.0), ((1.0/32.0)-1.0) * (64.0/63.0), ((1.0/64.0)-1.0) * (128.0/127.0),  ((1.0/128.0)-1.0) * (256.0/255.0), ((1.0/256.0)-1.0) * (512.0/511.0),  ((1.0/512.0)-1.0) * (1024.0/1023.0), ((1.0/1024.0)-1.0) * (2048.0/2047.0),  ((1.0/2048.0)-1.0) * (4096.0/4095.0), ((1.0/4096.0)-1.0) * (8192.0/8191.0),  ((1.0/8192.0)-1.0) * (16384.0/16383.0), ((1.0/16384.0)-1.0) * (32768.0/32767.0)};/**********************/	// used for single channel mode/*** Standard Class ***/	// and in derived class for intensity/**********************/	// stereo mode/* INLINESubbandLayer1::SubbandLayer1 (uint32 subbandnumber){  this->subbandnumber = subbandnumber;  samplenumber = 0;}*/void SubbandLayer1::read_allocation (AudioStream *stream, Header *, Crc16 *crc){  if ((allocation = stream->get_bits (4)) == 15)    cerr << "WARNING: stream contains an illegal allocation!\n";	// MPEG-stream is corrupted!  if (crc) crc->add_bits (allocation, 4);  if (allocation){    samplelength = allocation + 1;    factor = table_factor[allocation];    offset = table_offset[allocation];  }}void SubbandLayer1::read_scalefactor (AudioStream *stream, Header *){  if (allocation)    if ((scalefactor = stream->get_bits (6)) == 63)      cerr << "WARNING: stream contains an illegal scalefactor!\n";	// MPEG-stream is corrupted!}bool SubbandLayer1::read_sampledata (AudioStream *stream){  if (allocation){    sample = real (stream->get_bits (samplelength));#ifdef DEBUG    if (sample == (1 << samplelength) - 1)	cerr << "WARNING: stream contains an illegal subband sample!\n";  // MPEG-stream is corrupted!#endif  }  if (++samplenumber == 12){    samplenumber = 0;    return True;  }  else return False;}bool SubbandLayer1::put_next_sample(e_channels channels,                                    SynthesisFilter *filter1, SynthesisFilter*){  if (allocation && channels != right){    register real scaled_sample = (sample * factor + offset) * scalefactors[scalefactor];#ifdef DEBUG    if (scaled_sample < -1.0 || scaled_sample > 1.0)      cerr << "WARNING: rescaled subband sample is not in [-1.0, 1.0]\n";      // this should never occur#endif    if (scaled_sample < -1.0E-7 || scaled_sample > 1.0E-7)      filter1->input_sample (scaled_sample, subbandnumber);  }  return True;}/******************************//*** Intensity Stereo Class ***//******************************//* INLINESubbandLayer1IntensityStereo::SubbandLayer1IntensityStereo (uint32 subbandnumber): SubbandLayer1 (subbandnumber){}*/void SubbandLayer1IntensityStereo::read_scalefactor (AudioStream *stream, Header *){  if (allocation)  {    scalefactor = stream->get_bits (6);    channel2_scalefactor = stream->get_bits (6);    if (scalefactor == 63 || channel2_scalefactor == 63)      cerr << "WARNING: stream contains an illegal scalefactor!\n";      // MPEG-stream is corrupted!  }}bool SubbandLayer1IntensityStereo::put_next_sample (e_channels channels,	SynthesisFilter *filter1, SynthesisFilter *filter2){  if (allocation){    sample = sample * factor + offset;		// requantization    if (channels == both){      register real sample1 = sample * scalefactors[scalefactor],		    sample2 = sample * scalefactors[channel2_scalefactor];#ifdef DEBUG      if (sample1 < -1.0 || sample1 > 1.0 || sample2 < -1.0 || sample2 > 1.0)	cerr << "WARNING: rescaled subband sample is not in [-1.0, 1.0]\n";	// this should never occur#endif      if (sample1 < -1.0E-7 || sample1 > 1.0E-7)	filter1->input_sample (sample1, subbandnumber);      if (sample2 < -1.0E-7 || sample2 > 1.0E-7)	filter2->input_sample (sample2, subbandnumber);    }    else if (channels == left)    {      register real sample1 = sample * scalefactors[scalefactor];#ifdef DEBUG      if (sample1 < -1.0 || sample1 > 1.0)	cerr << "WARNING: rescaled subband sample is not in [-1.0, 1.0]\n";	// this should never occur#endif      if (sample1 < -1.0E-7 || sample1 > 1.0E-7)	filter1->input_sample (sample1, subbandnumber);    }    else    {      register real sample2 = sample * scalefactors[channel2_scalefactor];#ifdef DEBUG      if (sample2 < -1.0 || sample2 > 1.0)	cerr << "WARNING: rescaled subband sample is not in [-1.0, 1.0]\n";	// this should never occur#endif      if (sample2 < -1.0E-7 || sample2 > 1.0E-7)	filter1->input_sample (sample2, subbandnumber);    }  }  return True;}/********************//*** Stereo Class ***//********************//* INLINESubbandLayer1Stereo::SubbandLayer1Stereo (uint32 subbandnumber): SubbandLayer1 (subbandnumber){}*/void SubbandLayer1Stereo::read_allocation (AudioStream *stream, Header *, Crc16 *crc){  allocation = stream->get_bits (4);  channel2_allocation = stream->get_bits (4);  if (crc){    crc->add_bits (allocation, 4);    crc->add_bits (channel2_allocation, 4);  }  if (allocation == 15 || channel2_allocation == 15)    cerr << "WARNING: stream contains an illegal allocation!\n";	// MPEG-stream is corrupted!  if (allocation)  {    samplelength = allocation + 1;    factor = table_factor[allocation];    offset = table_offset[allocation];  }  if (channel2_allocation)  {    channel2_samplelength = channel2_allocation + 1;    channel2_factor = table_factor[channel2_allocation];    channel2_offset = table_offset[channel2_allocation];  }}void SubbandLayer1Stereo::read_scalefactor (AudioStream *stream, Header *){  if (allocation)    if ((scalefactor = stream->get_bits (6)) == 63)      cerr << "WARNING: stream contains an illegal allocation!\n";	// MPEG-stream is corrupted!  if (channel2_allocation)    if ((channel2_scalefactor = stream->get_bits (6)) == 63)      cerr << "WARNING: stream contains an illegal allocation!\n";	// MPEG-stream is corrupted!}bool SubbandLayer1Stereo::read_sampledata (AudioStream *stream){  bool returnvalue = SubbandLayer1::read_sampledata (stream);  if (channel2_allocation)  {    channel2_sample = real (stream->get_bits (channel2_samplelength));#ifdef DEBUG    if (channel2_sample == (1 << channel2_samplelength) - 1)	cerr << "WARNING: stream contains an illegal subband sample!\n";  // MPEG-stream is corrupted!#endif  }  return returnvalue;}bool SubbandLayer1Stereo::put_next_sample (e_channels channels,					   SynthesisFilter *filter1, SynthesisFilter *filter2){  SubbandLayer1::put_next_sample (channels, filter1, filter2);  if (channel2_allocation && channels != left)  {    register float sample2 = (channel2_sample * channel2_factor + channel2_offset)			     * scalefactors[channel2_scalefactor];#ifdef DEBUG    if (sample2 < -1.0 || sample2 > 1.0)      cerr << "WARNING: rescaled subband sample is not in [-1.0, 1.0]\n";      // this should never occur#endif    if (sample2 < -1.0E-7 || sample2 > 1.0E-7)      if (channels == both)	filter2->input_sample (sample2, subbandnumber);      else	filter1->input_sample (sample2, subbandnumber);  }  return True;}