Chris@0: /*
Chris@0:  * libmad - MPEG audio decoder library
Chris@0:  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
Chris@0:  *
Chris@0:  * This program is free software; you can redistribute it and/or modify
Chris@0:  * it under the terms of the GNU General Public License as published by
Chris@0:  * the Free Software Foundation; either version 2 of the License, or
Chris@0:  * (at your option) any later version.
Chris@0:  *
Chris@0:  * This program is distributed in the hope that it will be useful,
Chris@0:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@0:  * GNU General Public License for more details.
Chris@0:  *
Chris@0:  * You should have received a copy of the GNU General Public License
Chris@0:  * along with this program; if not, write to the Free Software
Chris@0:  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
Chris@0:  *
Chris@0:  * $Id: layer12.c,v 1.17 2004/02/05 09:02:39 rob Exp $
Chris@0:  */
Chris@0: 
Chris@0: # ifdef HAVE_CONFIG_H
Chris@0: #  include "config.h"
Chris@0: # endif
Chris@0: 
Chris@0: # include "global.h"
Chris@0: 
Chris@0: # ifdef HAVE_LIMITS_H
Chris@0: #  include <limits.h>
Chris@0: # else
Chris@0: #  define CHAR_BIT  8
Chris@0: # endif
Chris@0: 
Chris@0: # include "fixed.h"
Chris@0: # include "bit.h"
Chris@0: # include "stream.h"
Chris@0: # include "frame.h"
Chris@0: # include "layer12.h"
Chris@0: 
Chris@0: /*
Chris@0:  * scalefactor table
Chris@0:  * used in both Layer I and Layer II decoding
Chris@0:  */
Chris@0: static
Chris@0: mad_fixed_t const sf_table[64] = {
Chris@0: # include "sf_table.dat"
Chris@0: };
Chris@0: 
Chris@0: /* --- Layer I ------------------------------------------------------------- */
Chris@0: 
Chris@0: /* linear scaling table */
Chris@0: static
Chris@0: mad_fixed_t const linear_table[14] = {
Chris@0:   MAD_F(0x15555555),  /* 2^2  / (2^2  - 1) == 1.33333333333333 */
Chris@0:   MAD_F(0x12492492),  /* 2^3  / (2^3  - 1) == 1.14285714285714 */
Chris@0:   MAD_F(0x11111111),  /* 2^4  / (2^4  - 1) == 1.06666666666667 */
Chris@0:   MAD_F(0x10842108),  /* 2^5  / (2^5  - 1) == 1.03225806451613 */
Chris@0:   MAD_F(0x10410410),  /* 2^6  / (2^6  - 1) == 1.01587301587302 */
Chris@0:   MAD_F(0x10204081),  /* 2^7  / (2^7  - 1) == 1.00787401574803 */
Chris@0:   MAD_F(0x10101010),  /* 2^8  / (2^8  - 1) == 1.00392156862745 */
Chris@0:   MAD_F(0x10080402),  /* 2^9  / (2^9  - 1) == 1.00195694716243 */
Chris@0:   MAD_F(0x10040100),  /* 2^10 / (2^10 - 1) == 1.00097751710655 */
Chris@0:   MAD_F(0x10020040),  /* 2^11 / (2^11 - 1) == 1.00048851978505 */
Chris@0:   MAD_F(0x10010010),  /* 2^12 / (2^12 - 1) == 1.00024420024420 */
Chris@0:   MAD_F(0x10008004),  /* 2^13 / (2^13 - 1) == 1.00012208521548 */
Chris@0:   MAD_F(0x10004001),  /* 2^14 / (2^14 - 1) == 1.00006103888177 */
Chris@0:   MAD_F(0x10002000)   /* 2^15 / (2^15 - 1) == 1.00003051850948 */
Chris@0: };
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	I_sample()
Chris@0:  * DESCRIPTION:	decode one requantized Layer I sample from a bitstream
Chris@0:  */
Chris@0: static
Chris@0: mad_fixed_t I_sample(struct mad_bitptr *ptr, unsigned int nb)
Chris@0: {
Chris@0:   mad_fixed_t sample;
Chris@0: 
Chris@0:   sample = mad_bit_read(ptr, nb);
Chris@0: 
Chris@0:   /* invert most significant bit, extend sign, then scale to fixed format */
Chris@0: 
Chris@0:   sample ^= 1 << (nb - 1);
Chris@0:   sample |= -(sample & (1 << (nb - 1)));
Chris@0: 
Chris@0:   sample <<= MAD_F_FRACBITS - (nb - 1);
Chris@0: 
Chris@0:   /* requantize the sample */
Chris@0: 
Chris@0:   /* s'' = (2^nb / (2^nb - 1)) * (s''' + 2^(-nb + 1)) */
Chris@0: 
Chris@0:   sample += MAD_F_ONE >> (nb - 1);
Chris@0: 
Chris@0:   return mad_f_mul(sample, linear_table[nb - 2]);
Chris@0: 
Chris@0:   /* s' = factor * s'' */
Chris@0:   /* (to be performed by caller) */
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	layer->I()
Chris@0:  * DESCRIPTION:	decode a single Layer I frame
Chris@0:  */
Chris@0: int mad_layer_I(struct mad_stream *stream, struct mad_frame *frame)
Chris@0: {
Chris@0:   struct mad_header *header = &frame->header;
Chris@0:   unsigned int nch, bound, ch, s, sb, nb;
Chris@0:   unsigned char allocation[2][32], scalefactor[2][32];
Chris@0: 
Chris@0:   nch = MAD_NCHANNELS(header);
Chris@0: 
Chris@0:   bound = 32;
Chris@0:   if (header->mode == MAD_MODE_JOINT_STEREO) {
Chris@0:     header->flags |= MAD_FLAG_I_STEREO;
Chris@0:     bound = 4 + header->mode_extension * 4;
Chris@0:   }
Chris@0: 
Chris@0:   /* check CRC word */
Chris@0: 
Chris@0:   if (header->flags & MAD_FLAG_PROTECTION) {
Chris@0:     header->crc_check =
Chris@0:       mad_bit_crc(stream->ptr, 4 * (bound * nch + (32 - bound)),
Chris@0: 		  header->crc_check);
Chris@0: 
Chris@0:     if (header->crc_check != header->crc_target &&
Chris@0: 	!(frame->options & MAD_OPTION_IGNORECRC)) {
Chris@0:       stream->error = MAD_ERROR_BADCRC;
Chris@0:       return -1;
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /* decode bit allocations */
Chris@0: 
Chris@0:   for (sb = 0; sb < bound; ++sb) {
Chris@0:     for (ch = 0; ch < nch; ++ch) {
Chris@0:       nb = mad_bit_read(&stream->ptr, 4);
Chris@0: 
Chris@0:       if (nb == 15) {
Chris@0: 	stream->error = MAD_ERROR_BADBITALLOC;
Chris@0: 	return -1;
Chris@0:       }
Chris@0: 
Chris@0:       allocation[ch][sb] = nb ? nb + 1 : 0;
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   for (sb = bound; sb < 32; ++sb) {
Chris@0:     nb = mad_bit_read(&stream->ptr, 4);
Chris@0: 
Chris@0:     if (nb == 15) {
Chris@0:       stream->error = MAD_ERROR_BADBITALLOC;
Chris@0:       return -1;
Chris@0:     }
Chris@0: 
Chris@0:     allocation[0][sb] =
Chris@0:     allocation[1][sb] = nb ? nb + 1 : 0;
Chris@0:   }
Chris@0: 
Chris@0:   /* decode scalefactors */
Chris@0: 
Chris@0:   for (sb = 0; sb < 32; ++sb) {
Chris@0:     for (ch = 0; ch < nch; ++ch) {
Chris@0:       if (allocation[ch][sb]) {
Chris@0: 	scalefactor[ch][sb] = mad_bit_read(&stream->ptr, 6);
Chris@0: 
Chris@0: # if defined(OPT_STRICT)
Chris@0: 	/*
Chris@0: 	 * Scalefactor index 63 does not appear in Table B.1 of
Chris@0: 	 * ISO/IEC 11172-3. Nonetheless, other implementations accept it,
Chris@0: 	 * so we only reject it if OPT_STRICT is defined.
Chris@0: 	 */
Chris@0: 	if (scalefactor[ch][sb] == 63) {
Chris@0: 	  stream->error = MAD_ERROR_BADSCALEFACTOR;
Chris@0: 	  return -1;
Chris@0: 	}
Chris@0: # endif
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /* decode samples */
Chris@0: 
Chris@0:   for (s = 0; s < 12; ++s) {
Chris@0:     for (sb = 0; sb < bound; ++sb) {
Chris@0:       for (ch = 0; ch < nch; ++ch) {
Chris@0: 	nb = allocation[ch][sb];
Chris@0: 	frame->sbsample[ch][s][sb] = nb ?
Chris@0: 	  mad_f_mul(I_sample(&stream->ptr, nb),
Chris@0: 		    sf_table[scalefactor[ch][sb]]) : 0;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     for (sb = bound; sb < 32; ++sb) {
Chris@0:       if ((nb = allocation[0][sb])) {
Chris@0: 	mad_fixed_t sample;
Chris@0: 
Chris@0: 	sample = I_sample(&stream->ptr, nb);
Chris@0: 
Chris@0: 	for (ch = 0; ch < nch; ++ch) {
Chris@0: 	  frame->sbsample[ch][s][sb] =
Chris@0: 	    mad_f_mul(sample, sf_table[scalefactor[ch][sb]]);
Chris@0: 	}
Chris@0:       }
Chris@0:       else {
Chris@0: 	for (ch = 0; ch < nch; ++ch)
Chris@0: 	  frame->sbsample[ch][s][sb] = 0;
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   return 0;
Chris@0: }
Chris@0: 
Chris@0: /* --- Layer II ------------------------------------------------------------ */
Chris@0: 
Chris@0: /* possible quantization per subband table */
Chris@0: static
Chris@0: struct {
Chris@0:   unsigned int sblimit;
Chris@0:   unsigned char const offsets[30];
Chris@0: } const sbquant_table[5] = {
Chris@0:   /* ISO/IEC 11172-3 Table B.2a */
Chris@0:   { 27, { 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3,	/* 0 */
Chris@0: 	  3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0 } },
Chris@0:   /* ISO/IEC 11172-3 Table B.2b */
Chris@0:   { 30, { 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3,	/* 1 */
Chris@0: 	  3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0 } },
Chris@0:   /* ISO/IEC 11172-3 Table B.2c */
Chris@0:   {  8, { 5, 5, 2, 2, 2, 2, 2, 2 } },				/* 2 */
Chris@0:   /* ISO/IEC 11172-3 Table B.2d */
Chris@0:   { 12, { 5, 5, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 } },		/* 3 */
Chris@0:   /* ISO/IEC 13818-3 Table B.1 */
Chris@0:   { 30, { 4, 4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1,	/* 4 */
Chris@0: 	  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 } }
Chris@0: };
Chris@0: 
Chris@0: /* bit allocation table */
Chris@0: static
Chris@0: struct {
Chris@0:   unsigned short nbal;
Chris@0:   unsigned short offset;
Chris@0: } const bitalloc_table[8] = {
Chris@0:   { 2, 0 },  /* 0 */
Chris@0:   { 2, 3 },  /* 1 */
Chris@0:   { 3, 3 },  /* 2 */
Chris@0:   { 3, 1 },  /* 3 */
Chris@0:   { 4, 2 },  /* 4 */
Chris@0:   { 4, 3 },  /* 5 */
Chris@0:   { 4, 4 },  /* 6 */
Chris@0:   { 4, 5 }   /* 7 */
Chris@0: };
Chris@0: 
Chris@0: /* offsets into quantization class table */
Chris@0: static
Chris@0: unsigned char const offset_table[6][15] = {
Chris@0:   { 0, 1, 16                                             },  /* 0 */
Chris@0:   { 0, 1,  2, 3, 4, 5, 16                                },  /* 1 */
Chris@0:   { 0, 1,  2, 3, 4, 5,  6, 7,  8,  9, 10, 11, 12, 13, 14 },  /* 2 */
Chris@0:   { 0, 1,  3, 4, 5, 6,  7, 8,  9, 10, 11, 12, 13, 14, 15 },  /* 3 */
Chris@0:   { 0, 1,  2, 3, 4, 5,  6, 7,  8,  9, 10, 11, 12, 13, 16 },  /* 4 */
Chris@0:   { 0, 2,  4, 5, 6, 7,  8, 9, 10, 11, 12, 13, 14, 15, 16 }   /* 5 */
Chris@0: };
Chris@0: 
Chris@0: /* quantization class table */
Chris@0: static
Chris@0: struct quantclass {
Chris@0:   unsigned short nlevels;
Chris@0:   unsigned char group;
Chris@0:   unsigned char bits;
Chris@0:   mad_fixed_t C;
Chris@0:   mad_fixed_t D;
Chris@0: } const qc_table[17] = {
Chris@0: # include "qc_table.dat"
Chris@0: };
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	II_samples()
Chris@0:  * DESCRIPTION:	decode three requantized Layer II samples from a bitstream
Chris@0:  */
Chris@0: static
Chris@0: void II_samples(struct mad_bitptr *ptr,
Chris@0: 		struct quantclass const *quantclass,
Chris@0: 		mad_fixed_t output[3])
Chris@0: {
Chris@0:   unsigned int nb, s, sample[3];
Chris@0: 
Chris@0:   if ((nb = quantclass->group)) {
Chris@0:     unsigned int c, nlevels;
Chris@0: 
Chris@0:     /* degrouping */
Chris@0:     c = mad_bit_read(ptr, quantclass->bits);
Chris@0:     nlevels = quantclass->nlevels;
Chris@0: 
Chris@0:     for (s = 0; s < 3; ++s) {
Chris@0:       sample[s] = c % nlevels;
Chris@0:       c /= nlevels;
Chris@0:     }
Chris@0:   }
Chris@0:   else {
Chris@0:     nb = quantclass->bits;
Chris@0: 
Chris@0:     for (s = 0; s < 3; ++s)
Chris@0:       sample[s] = mad_bit_read(ptr, nb);
Chris@0:   }
Chris@0: 
Chris@0:   for (s = 0; s < 3; ++s) {
Chris@0:     mad_fixed_t requantized;
Chris@0: 
Chris@0:     /* invert most significant bit, extend sign, then scale to fixed format */
Chris@0: 
Chris@0:     requantized  = sample[s] ^ (1 << (nb - 1));
Chris@0:     requantized |= -(requantized & (1 << (nb - 1)));
Chris@0: 
Chris@0:     requantized <<= MAD_F_FRACBITS - (nb - 1);
Chris@0: 
Chris@0:     /* requantize the sample */
Chris@0: 
Chris@0:     /* s'' = C * (s''' + D) */
Chris@0: 
Chris@0:     output[s] = mad_f_mul(requantized + quantclass->D, quantclass->C);
Chris@0: 
Chris@0:     /* s' = factor * s'' */
Chris@0:     /* (to be performed by caller) */
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /*
Chris@0:  * NAME:	layer->II()
Chris@0:  * DESCRIPTION:	decode a single Layer II frame
Chris@0:  */
Chris@0: int mad_layer_II(struct mad_stream *stream, struct mad_frame *frame)
Chris@0: {
Chris@0:   struct mad_header *header = &frame->header;
Chris@0:   struct mad_bitptr start;
Chris@0:   unsigned int index, sblimit, nbal, nch, bound, gr, ch, s, sb;
Chris@0:   unsigned char const *offsets;
Chris@0:   unsigned char allocation[2][32], scfsi[2][32], scalefactor[2][32][3];
Chris@0:   mad_fixed_t samples[3];
Chris@0: 
Chris@0:   nch = MAD_NCHANNELS(header);
Chris@0: 
Chris@0:   if (header->flags & MAD_FLAG_LSF_EXT)
Chris@0:     index = 4;
Chris@0:   else if (header->flags & MAD_FLAG_FREEFORMAT)
Chris@0:     goto freeformat;
Chris@0:   else {
Chris@0:     unsigned long bitrate_per_channel;
Chris@0: 
Chris@0:     bitrate_per_channel = header->bitrate;
Chris@0:     if (nch == 2) {
Chris@0:       bitrate_per_channel /= 2;
Chris@0: 
Chris@0: # if defined(OPT_STRICT)
Chris@0:       /*
Chris@0:        * ISO/IEC 11172-3 allows only single channel mode for 32, 48, 56, and
Chris@0:        * 80 kbps bitrates in Layer II, but some encoders ignore this
Chris@0:        * restriction. We enforce it if OPT_STRICT is defined.
Chris@0:        */
Chris@0:       if (bitrate_per_channel <= 28000 || bitrate_per_channel == 40000) {
Chris@0: 	stream->error = MAD_ERROR_BADMODE;
Chris@0: 	return -1;
Chris@0:       }
Chris@0: # endif
Chris@0:     }
Chris@0:     else {  /* nch == 1 */
Chris@0:       if (bitrate_per_channel > 192000) {
Chris@0: 	/*
Chris@0: 	 * ISO/IEC 11172-3 does not allow single channel mode for 224, 256,
Chris@0: 	 * 320, or 384 kbps bitrates in Layer II.
Chris@0: 	 */
Chris@0: 	stream->error = MAD_ERROR_BADMODE;
Chris@0: 	return -1;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     if (bitrate_per_channel <= 48000)
Chris@0:       index = (header->samplerate == 32000) ? 3 : 2;
Chris@0:     else if (bitrate_per_channel <= 80000)
Chris@0:       index = 0;
Chris@0:     else {
Chris@0:     freeformat:
Chris@0:       index = (header->samplerate == 48000) ? 0 : 1;
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   sblimit = sbquant_table[index].sblimit;
Chris@0:   offsets = sbquant_table[index].offsets;
Chris@0: 
Chris@0:   bound = 32;
Chris@0:   if (header->mode == MAD_MODE_JOINT_STEREO) {
Chris@0:     header->flags |= MAD_FLAG_I_STEREO;
Chris@0:     bound = 4 + header->mode_extension * 4;
Chris@0:   }
Chris@0: 
Chris@0:   if (bound > sblimit)
Chris@0:     bound = sblimit;
Chris@0: 
Chris@0:   start = stream->ptr;
Chris@0: 
Chris@0:   /* decode bit allocations */
Chris@0: 
Chris@0:   for (sb = 0; sb < bound; ++sb) {
Chris@0:     nbal = bitalloc_table[offsets[sb]].nbal;
Chris@0: 
Chris@0:     for (ch = 0; ch < nch; ++ch)
Chris@0:       allocation[ch][sb] = mad_bit_read(&stream->ptr, nbal);
Chris@0:   }
Chris@0: 
Chris@0:   for (sb = bound; sb < sblimit; ++sb) {
Chris@0:     nbal = bitalloc_table[offsets[sb]].nbal;
Chris@0: 
Chris@0:     allocation[0][sb] =
Chris@0:     allocation[1][sb] = mad_bit_read(&stream->ptr, nbal);
Chris@0:   }
Chris@0: 
Chris@0:   /* decode scalefactor selection info */
Chris@0: 
Chris@0:   for (sb = 0; sb < sblimit; ++sb) {
Chris@0:     for (ch = 0; ch < nch; ++ch) {
Chris@0:       if (allocation[ch][sb])
Chris@0: 	scfsi[ch][sb] = mad_bit_read(&stream->ptr, 2);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /* check CRC word */
Chris@0: 
Chris@0:   if (header->flags & MAD_FLAG_PROTECTION) {
Chris@0:     header->crc_check =
Chris@0:       mad_bit_crc(start, mad_bit_length(&start, &stream->ptr),
Chris@0: 		  header->crc_check);
Chris@0: 
Chris@0:     if (header->crc_check != header->crc_target &&
Chris@0: 	!(frame->options & MAD_OPTION_IGNORECRC)) {
Chris@0:       stream->error = MAD_ERROR_BADCRC;
Chris@0:       return -1;
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /* decode scalefactors */
Chris@0: 
Chris@0:   for (sb = 0; sb < sblimit; ++sb) {
Chris@0:     for (ch = 0; ch < nch; ++ch) {
Chris@0:       if (allocation[ch][sb]) {
Chris@0: 	scalefactor[ch][sb][0] = mad_bit_read(&stream->ptr, 6);
Chris@0: 
Chris@0: 	switch (scfsi[ch][sb]) {
Chris@0: 	case 2:
Chris@0: 	  scalefactor[ch][sb][2] =
Chris@0: 	  scalefactor[ch][sb][1] =
Chris@0: 	  scalefactor[ch][sb][0];
Chris@0: 	  break;
Chris@0: 
Chris@0: 	case 0:
Chris@0: 	  scalefactor[ch][sb][1] = mad_bit_read(&stream->ptr, 6);
Chris@0: 	  /* fall through */
Chris@0: 
Chris@0: 	case 1:
Chris@0: 	case 3:
Chris@0: 	  scalefactor[ch][sb][2] = mad_bit_read(&stream->ptr, 6);
Chris@0: 	}
Chris@0: 
Chris@0: 	if (scfsi[ch][sb] & 1)
Chris@0: 	  scalefactor[ch][sb][1] = scalefactor[ch][sb][scfsi[ch][sb] - 1];
Chris@0: 
Chris@0: # if defined(OPT_STRICT)
Chris@0: 	/*
Chris@0: 	 * Scalefactor index 63 does not appear in Table B.1 of
Chris@0: 	 * ISO/IEC 11172-3. Nonetheless, other implementations accept it,
Chris@0: 	 * so we only reject it if OPT_STRICT is defined.
Chris@0: 	 */
Chris@0: 	if (scalefactor[ch][sb][0] == 63 ||
Chris@0: 	    scalefactor[ch][sb][1] == 63 ||
Chris@0: 	    scalefactor[ch][sb][2] == 63) {
Chris@0: 	  stream->error = MAD_ERROR_BADSCALEFACTOR;
Chris@0: 	  return -1;
Chris@0: 	}
Chris@0: # endif
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /* decode samples */
Chris@0: 
Chris@0:   for (gr = 0; gr < 12; ++gr) {
Chris@0:     for (sb = 0; sb < bound; ++sb) {
Chris@0:       for (ch = 0; ch < nch; ++ch) {
Chris@0: 	if ((index = allocation[ch][sb])) {
Chris@0: 	  index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1];
Chris@0: 
Chris@0: 	  II_samples(&stream->ptr, &qc_table[index], samples);
Chris@0: 
Chris@0: 	  for (s = 0; s < 3; ++s) {
Chris@0: 	    frame->sbsample[ch][3 * gr + s][sb] =
Chris@0: 	      mad_f_mul(samples[s], sf_table[scalefactor[ch][sb][gr / 4]]);
Chris@0: 	  }
Chris@0: 	}
Chris@0: 	else {
Chris@0: 	  for (s = 0; s < 3; ++s)
Chris@0: 	    frame->sbsample[ch][3 * gr + s][sb] = 0;
Chris@0: 	}
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     for (sb = bound; sb < sblimit; ++sb) {
Chris@0:       if ((index = allocation[0][sb])) {
Chris@0: 	index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1];
Chris@0: 
Chris@0: 	II_samples(&stream->ptr, &qc_table[index], samples);
Chris@0: 
Chris@0: 	for (ch = 0; ch < nch; ++ch) {
Chris@0: 	  for (s = 0; s < 3; ++s) {
Chris@0: 	    frame->sbsample[ch][3 * gr + s][sb] =
Chris@0: 	      mad_f_mul(samples[s], sf_table[scalefactor[ch][sb][gr / 4]]);
Chris@0: 	  }
Chris@0: 	}
Chris@0:       }
Chris@0:       else {
Chris@0: 	for (ch = 0; ch < nch; ++ch) {
Chris@0: 	  for (s = 0; s < 3; ++s)
Chris@0: 	    frame->sbsample[ch][3 * gr + s][sb] = 0;
Chris@0: 	}
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     for (ch = 0; ch < nch; ++ch) {
Chris@0:       for (s = 0; s < 3; ++s) {
Chris@0: 	for (sb = sblimit; sb < 32; ++sb)
Chris@0: 	  frame->sbsample[ch][3 * gr + s][sb] = 0;
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   return 0;
Chris@0: }