libavcodec/atrac3.c

   1 /*
   2  * Atrac 3 compatible decoder
   3  * Copyright (c) 2006-2007 Maxim Poliakovski
   4  * Copyright (c) 2006-2007 Benjamin Larsson
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file atrac3.c
  25  * Atrac 3 compatible decoder.
  26  * This decoder handles RealNetworks, RealAudio atrc data.
  27  * Atrac 3 is identified by the codec name atrc in RealMedia files.
  28  *
  29  * To use this decoder, a calling application must supply the extradata
  30  * bytes provided from the RealMedia container: 10 bytes or 14 bytes
  31  * from the WAV container.
  32  */
  33
  34 #include <math.h>
  35 #include <stddef.h>
  36 #include <stdio.h>
  37
  38 #include "avcodec.h"
  39 #include "bitstream.h"
  40 #include "dsputil.h"
  41 #include "bytestream.h"
  42
  43 #include "atrac3data.h"
  44
  45 #define JOINT_STEREO    0x12
  46 #define STEREO          0x2
  47
  48
  49 /* These structures are needed to store the parsed gain control data. */
  50 typedef struct {
  51     int   num_gain_data;
  52     int   levcode[8];
  53     int   loccode[8];
  54 } gain_info;
  55
  56 typedef struct {
  57     gain_info   gBlock[4];
  58 } gain_block;
  59
  60 typedef struct {
  61     int     pos;
  62     int     numCoefs;
  63     float   coef[8];
  64 } tonal_component;
  65
  66 typedef struct {
  67     int               bandsCoded;
  68     int               numComponents;
  69     tonal_component   components[64];
  70     float             prevFrame[1024];
  71     int               gcBlkSwitch;
  72     gain_block        gainBlock[2];
  73
  74     DECLARE_ALIGNED_16(float, spectrum[1024]);
  75     DECLARE_ALIGNED_16(float, IMDCT_buf[1024]);
  76
  77     float             delayBuf1[46]; ///<qmf delay buffers
  78     float             delayBuf2[46];
  79     float             delayBuf3[46];
  80 } channel_unit;
  81
  82 typedef struct {
  83     GetBitContext       gb;
  84     //@{
  85     /** stream data */
  86     int                 channels;
  87     int                 codingMode;
  88     int                 bit_rate;
  89     int                 sample_rate;
  90     int                 samples_per_channel;
  91     int                 samples_per_frame;
  92
  93     int                 bits_per_frame;
  94     int                 bytes_per_frame;
  95     int                 pBs;
  96     channel_unit*       pUnits;
  97     //@}
  98     //@{
  99     /** joint-stereo related variables */
 100     int                 matrix_coeff_index_prev[4];
 101     int                 matrix_coeff_index_now[4];
 102     int                 matrix_coeff_index_next[4];
 103     int                 weighting_delay[6];
 104     //@}
 105     //@{
 106     /** data buffers */
 107     float               outSamples[2048];
 108     uint8_t*            decoded_bytes_buffer;
 109     float               tempBuf[1070];
 110     DECLARE_ALIGNED_16(float,mdct_tmp[512]);
 111     //@}
 112     //@{
 113     /** extradata */
 114     int                 atrac3version;
 115     int                 delay;
 116     int                 scrambled_stream;
 117     int                 frame_factor;
 118     //@}
 119 } ATRAC3Context;
 120
 121 static DECLARE_ALIGNED_16(float,mdct_window[512]);
 122 static float            qmf_window[48];
 123 static VLC              spectral_coeff_tab[7];
 124 static float            SFTable[64];
 125 static float            gain_tab1[16];
 126 static float            gain_tab2[31];
 127 static MDCTContext      mdct_ctx;
 128 static DSPContext       dsp;
 129
 130
 131 /* quadrature mirror synthesis filter */
 132
 133 /**
 134  * Quadrature mirror synthesis filter.
 135  *
 136  * @param inlo      lower part of spectrum
 137  * @param inhi      higher part of spectrum
 138  * @param nIn       size of spectrum buffer
 139  * @param pOut      out buffer
 140  * @param delayBuf  delayBuf buffer
 141  * @param temp      temp buffer
 142  */
 143
 144
 145 static void iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)
 146 {
 147     int   i, j;
 148     float   *p1, *p3;
 149
 150     memcpy(temp, delayBuf, 46*sizeof(float));
 151
 152     p3 = temp + 46;
 153
 154     /* loop1 */
 155     for(i=0; i<nIn; i+=2){
 156         p3[2*i+0] = inlo[i  ] + inhi[i  ];
 157         p3[2*i+1] = inlo[i  ] - inhi[i  ];
 158         p3[2*i+2] = inlo[i+1] + inhi[i+1];
 159         p3[2*i+3] = inlo[i+1] - inhi[i+1];
 160     }
 161
 162     /* loop2 */
 163     p1 = temp;
 164     for (j = nIn; j != 0; j--) {
 165         float s1 = 0.0;
 166         float s2 = 0.0;
 167
 168         for (i = 0; i < 48; i += 2) {
 169             s1 += p1[i] * qmf_window[i];
 170             s2 += p1[i+1] * qmf_window[i+1];
 171         }
 172
 173         pOut[0] = s2;
 174         pOut[1] = s1;
 175
 176         p1 += 2;
 177         pOut += 2;
 178     }
 179
 180     /* Update the delay buffer. */
 181     memcpy(delayBuf, temp + nIn*2, 46*sizeof(float));
 182 }
 183
 184 /**
 185  * Regular 512 points IMDCT without overlapping, with the exception of the swapping of odd bands
 186  * caused by the reverse spectra of the QMF.
 187  *
 188  * @param pInput    float input
 189  * @param pOutput   float output
 190  * @param odd_band  1 if the band is an odd band
 191  * @param mdct_tmp  aligned temporary buffer for the mdct
 192  */
 193
 194 static void IMLT(float *pInput, float *pOutput, int odd_band, float* mdct_tmp)
 195 {
 196     int     i;
 197
 198     if (odd_band) {
 199         /**
 200         * Reverse the odd bands before IMDCT, this is an effect of the QMF transform
 201         * or it gives better compression to do it this way.
 202         * FIXME: It should be possible to handle this in ff_imdct_calc
 203         * for that to happen a modification of the prerotation step of
 204         * all SIMD code and C code is needed.
 205         * Or fix the functions before so they generate a pre reversed spectrum.
 206         */
 207
 208         for (i=0; i<128; i++)
 209             FFSWAP(float, pInput[i], pInput[255-i]);
 210     }
 211
 212     mdct_ctx.fft.imdct_calc(&mdct_ctx,pOutput,pInput,mdct_tmp);
 213
 214     /* Perform windowing on the output. */
 215     dsp.vector_fmul(pOutput,mdct_window,512);
 216
 217 }
 218
 219
 220 /**
 221  * Atrac 3 indata descrambling, only used for data coming from the rm container
 222  *
 223  * @param in        pointer to 8 bit array of indata
 224  * @param bits      amount of bits
 225  * @param out       pointer to 8 bit array of outdata
 226  */
 227
 228 static int decode_bytes(uint8_t* inbuffer, uint8_t* out, int bytes){
 229     int i, off;
 230     uint32_t c;
 231     uint32_t* buf;
 232     uint32_t* obuf = (uint32_t*) out;
 233
 234     off = (int)((long)inbuffer & 3);
 235     buf = (uint32_t*) (inbuffer - off);
 236     c = be2me_32((0x537F6103 >> (off*8)) | (0x537F6103 << (32-(off*8))));
 237     bytes += 3 + off;
 238     for (i = 0; i < bytes/4; i++)
 239         obuf[i] = c ^ buf[i];
 240
 241     if (off)
 242         av_log(NULL,AV_LOG_DEBUG,"Offset of %d not handled, post sample on ffmpeg-dev.\n",off);
 243
 244     return off;
 245 }
 246
 247
 248 static void init_atrac3_transforms(ATRAC3Context *q) {
 249     float enc_window[256];
 250     float s;
 251     int i;
 252
 253     /* Generate the mdct window, for details see
 254      * http://wiki.multimedia.cx/index.php?title=RealAudio_atrc#Windows */
 255     for (i=0 ; i<256; i++)
 256         enc_window[i] = (sin(((i + 0.5) / 256.0 - 0.5) * M_PI) + 1.0) * 0.5;
 257
 258     if (!mdct_window[0])
 259         for (i=0 ; i<256; i++) {
 260             mdct_window[i] = enc_window[i]/(enc_window[i]*enc_window[i] + enc_window[255-i]*enc_window[255-i]);
 261             mdct_window[511-i] = mdct_window[i];
 262         }
 263
 264     /* Generate the QMF window. */
 265     for (i=0 ; i<24; i++) {
 266         s = qmf_48tap_half[i] * 2.0;
 267         qmf_window[i] = s;
 268         qmf_window[47 - i] = s;
 269     }
 270
 271     /* Initialize the MDCT transform. */
 272     ff_mdct_init(&mdct_ctx, 9, 1);
 273 }
 274
 275 /**
 276  * Atrac3 uninit, free all allocated memory
 277  */
 278
 279 static int atrac3_decode_close(AVCodecContext *avctx)
 280 {
 281     ATRAC3Context *q = avctx->priv_data;
 282
 283     av_free(q->pUnits);
 284     av_free(q->decoded_bytes_buffer);
 285
 286     return 0;
 287 }
 288
 289 /**
 290 / * Mantissa decoding
 291  *
 292  * @param gb            the GetBit context
 293  * @param selector      what table is the output values coded with
 294  * @param codingFlag    constant length coding or variable length coding
 295  * @param mantissas     mantissa output table
 296  * @param numCodes      amount of values to get
 297  */
 298
 299 static void readQuantSpectralCoeffs (GetBitContext *gb, int selector, int codingFlag, int* mantissas, int numCodes)
 300 {
 301     int   numBits, cnt, code, huffSymb;
 302
 303     if (selector == 1)
 304         numCodes /= 2;
 305
 306     if (codingFlag != 0) {
 307         /* constant length coding (CLC) */
 308         //FIXME we don't have any samples coded in CLC mode
 309         numBits = CLCLengthTab[selector];
 310
 311         if (selector > 1) {
 312             for (cnt = 0; cnt < numCodes; cnt++) {
 313                 if (numBits)
 314                     code = get_sbits(gb, numBits);
 315                 else
 316                     code = 0;
 317                 mantissas[cnt] = code;
 318             }
 319         } else {
 320             for (cnt = 0; cnt < numCodes; cnt++) {
 321                 if (numBits)
 322                     code = get_bits(gb, numBits); //numBits is always 4 in this case
 323                 else
 324                     code = 0;
 325                 mantissas[cnt*2] = seTab_0[code >> 2];
 326                 mantissas[cnt*2+1] = seTab_0[code & 3];
 327             }
 328         }
 329     } else {
 330         /* variable length coding (VLC) */
 331         if (selector != 1) {
 332             for (cnt = 0; cnt < numCodes; cnt++) {
 333                 huffSymb = get_vlc2(gb, spectral_coeff_tab[selector-1].table, spectral_coeff_tab[selector-1].bits, 3);
 334                 huffSymb += 1;
 335                 code = huffSymb >> 1;
 336                 if (huffSymb & 1)
 337                     code = -code;
 338                 mantissas[cnt] = code;
 339             }
 340         } else {
 341             for (cnt = 0; cnt < numCodes; cnt++) {
 342                 huffSymb = get_vlc2(gb, spectral_coeff_tab[selector-1].table, spectral_coeff_tab[selector-1].bits, 3);
 343                 mantissas[cnt*2] = decTable1[huffSymb*2];
 344                 mantissas[cnt*2+1] = decTable1[huffSymb*2+1];
 345             }
 346         }
 347     }
 348 }
 349
 350 /**
 351  * Restore the quantized band spectrum coefficients
 352  *
 353  * @param gb            the GetBit context
 354  * @param pOut          decoded band spectrum
 355  * @return outSubbands   subband counter, fix for broken specification/files
 356  */
 357
 358 static int decodeSpectrum (GetBitContext *gb, float *pOut)
 359 {
 360     int   numSubbands, codingMode, cnt, first, last, subbWidth, *pIn;
 361     int   subband_vlc_index[32], SF_idxs[32];
 362     int   mantissas[128];
 363     float SF;
 364
 365     numSubbands = get_bits(gb, 5); // number of coded subbands
 366     codingMode = get_bits1(gb); // coding Mode: 0 - VLC/ 1-CLC
 367
 368     /* Get the VLC selector table for the subbands, 0 means not coded. */
 369     for (cnt = 0; cnt <= numSubbands; cnt++)
 370         subband_vlc_index[cnt] = get_bits(gb, 3);
 371
 372     /* Read the scale factor indexes from the stream. */
 373     for (cnt = 0; cnt <= numSubbands; cnt++) {
 374         if (subband_vlc_index[cnt] != 0)
 375             SF_idxs[cnt] = get_bits(gb, 6);
 376     }
 377
 378     for (cnt = 0; cnt <= numSubbands; cnt++) {
 379         first = subbandTab[cnt];
 380         last = subbandTab[cnt+1];
 381
 382         subbWidth = last - first;
 383
 384         if (subband_vlc_index[cnt] != 0) {
 385             /* Decode spectral coefficients for this subband. */
 386             /* TODO: This can be done faster is several blocks share the
 387              * same VLC selector (subband_vlc_index) */
 388             readQuantSpectralCoeffs (gb, subband_vlc_index[cnt], codingMode, mantissas, subbWidth);
 389
 390             /* Decode the scale factor for this subband. */
 391             SF = SFTable[SF_idxs[cnt]] * iMaxQuant[subband_vlc_index[cnt]];
 392
 393             /* Inverse quantize the coefficients. */
 394             for (pIn=mantissas ; first<last; first++, pIn++)
 395                 pOut[first] = *pIn * SF;
 396         } else {
 397             /* This subband was not coded, so zero the entire subband. */
 398             memset(pOut+first, 0, subbWidth*sizeof(float));
 399         }
 400     }
 401
 402     /* Clear the subbands that were not coded. */
 403     first = subbandTab[cnt];
 404     memset(pOut+first, 0, (1024 - first) * sizeof(float));
 405     return numSubbands;
 406 }
 407
 408 /**
 409  * Restore the quantized tonal components
 410  *
 411  * @param gb            the GetBit context
 412  * @param pComponent    tone component
 413  * @param numBands      amount of coded bands
 414  */
 415
 416 static int decodeTonalComponents (GetBitContext *gb, tonal_component *pComponent, int numBands)
 417 {
 418     int i,j,k,cnt;
 419     int   components, coding_mode_selector, coding_mode, coded_values_per_component;
 420     int   sfIndx, coded_values, max_coded_values, quant_step_index, coded_components;
 421     int   band_flags[4], mantissa[8];
 422     float  *pCoef;
 423     float  scalefactor;
 424     int   component_count = 0;
 425
 426     components = get_bits(gb,5);
 427
 428     /* no tonal components */
 429     if (components == 0)
 430         return 0;
 431
 432     coding_mode_selector = get_bits(gb,2);
 433     if (coding_mode_selector == 2)
 434         return -1;
 435
 436     coding_mode = coding_mode_selector & 1;
 437
 438     for (i = 0; i < components; i++) {
 439         for (cnt = 0; cnt <= numBands; cnt++)
 440             band_flags[cnt] = get_bits1(gb);
 441
 442         coded_values_per_component = get_bits(gb,3);
 443
 444         quant_step_index = get_bits(gb,3);
 445         if (quant_step_index <= 1)
 446             return -1;
 447
 448         if (coding_mode_selector == 3)
 449             coding_mode = get_bits1(gb);
 450
 451         for (j = 0; j < (numBands + 1) * 4; j++) {
 452             if (band_flags[j >> 2] == 0)
 453                 continue;
 454
 455             coded_components = get_bits(gb,3);
 456
 457             for (k=0; k<coded_components; k++) {
 458                 sfIndx = get_bits(gb,6);
 459                 pComponent[component_count].pos = j * 64 + (get_bits(gb,6));
 460                 max_coded_values = 1024 - pComponent[component_count].pos;
 461                 coded_values = coded_values_per_component + 1;
 462                 coded_values = FFMIN(max_coded_values,coded_values);
 463
 464                 scalefactor = SFTable[sfIndx] * iMaxQuant[quant_step_index];
 465
 466                 readQuantSpectralCoeffs(gb, quant_step_index, coding_mode, mantissa, coded_values);
 467
 468                 pComponent[component_count].numCoefs = coded_values;
 469
 470                 /* inverse quant */
 471                 pCoef = pComponent[k].coef;
 472                 for (cnt = 0; cnt < coded_values; cnt++)
 473                     pCoef[cnt] = mantissa[cnt] * scalefactor;
 474
 475                 component_count++;
 476             }
 477         }
 478     }
 479
 480     return component_count;
 481 }
 482
 483 /**
 484  * Decode gain parameters for the coded bands
 485  *
 486  * @param gb            the GetBit context
 487  * @param pGb           the gainblock for the current band
 488  * @param numBands      amount of coded bands
 489  */
 490
 491 static int decodeGainControl (GetBitContext *gb, gain_block *pGb, int numBands)
 492 {
 493     int   i, cf, numData;
 494     int   *pLevel, *pLoc;
 495
 496     gain_info   *pGain = pGb->gBlock;
 497
 498     for (i=0 ; i<=numBands; i++)
 499     {
 500         numData = get_bits(gb,3);
 501         pGain[i].num_gain_data = numData;
 502         pLevel = pGain[i].levcode;
 503         pLoc = pGain[i].loccode;
 504
 505         for (cf = 0; cf < numData; cf++){
 506             pLevel[cf]= get_bits(gb,4);
 507             pLoc  [cf]= get_bits(gb,5);
 508             if(cf && pLoc[cf] <= pLoc[cf-1])
 509                 return -1;
 510         }
 511     }
 512
 513     /* Clear the unused blocks. */
 514     for (; i<4 ; i++)
 515         pGain[i].num_gain_data = 0;
 516
 517     return 0;
 518 }
 519
 520 /**
 521  * Apply gain parameters and perform the MDCT overlapping part
 522  *
 523  * @param pIn           input float buffer
 524  * @param pPrev         previous float buffer to perform overlap against
 525  * @param pOut          output float buffer
 526  * @param pGain1        current band gain info
 527  * @param pGain2        next band gain info
 528  */
 529
 530 static void gainCompensateAndOverlap (float *pIn, float *pPrev, float *pOut, gain_info *pGain1, gain_info *pGain2)
 531 {
 532     /* gain compensation function */
 533     float  gain1, gain2, gain_inc;
 534     int   cnt, numdata, nsample, startLoc, endLoc;
 535
 536
 537     if (pGain2->num_gain_data == 0)
 538         gain1 = 1.0;
 539     else
 540         gain1 = gain_tab1[pGain2->levcode[0]];
 541
 542     if (pGain1->num_gain_data == 0) {
 543         for (cnt = 0; cnt < 256; cnt++)
 544             pOut[cnt] = pIn[cnt] * gain1 + pPrev[cnt];
 545     } else {
 546         numdata = pGain1->num_gain_data;
 547         pGain1->loccode[numdata] = 32;
 548         pGain1->levcode[numdata] = 4;
 549
 550         nsample = 0; // current sample = 0
 551
 552         for (cnt = 0; cnt < numdata; cnt++) {
 553             startLoc = pGain1->loccode[cnt] * 8;
 554             endLoc = startLoc + 8;
 555
 556             gain2 = gain_tab1[pGain1->levcode[cnt]];
 557             gain_inc = gain_tab2[(pGain1->levcode[cnt+1] - pGain1->levcode[cnt])+15];
 558
 559             /* interpolate */
 560             for (; nsample < startLoc; nsample++)
 561                 pOut[nsample] = (pIn[nsample] * gain1 + pPrev[nsample]) * gain2;
 562
 563             /* interpolation is done over eight samples */
 564             for (; nsample < endLoc; nsample++) {
 565                 pOut[nsample] = (pIn[nsample] * gain1 + pPrev[nsample]) * gain2;
 566                 gain2 *= gain_inc;
 567             }
 568         }
 569
 570         for (; nsample < 256; nsample++)
 571             pOut[nsample] = (pIn[nsample] * gain1) + pPrev[nsample];
 572     }
 573
 574     /* Delay for the overlapping part. */
 575     memcpy(pPrev, &pIn[256], 256*sizeof(float));
 576 }
 577
 578 /**
 579  * Combine the tonal band spectrum and regular band spectrum
 580  *
 581  * @param pSpectrum     output spectrum buffer
 582  * @param numComponents amount of tonal components
 583  * @param pComponent    tonal components for this band
 584  */
 585
 586 static void addTonalComponents (float *pSpectrum, int numComponents, tonal_component *pComponent)
 587 {
 588     int   cnt, i;
 589     float   *pIn, *pOut;
 590
 591     for (cnt = 0; cnt < numComponents; cnt++){
 592         pIn = pComponent[cnt].coef;
 593         pOut = &(pSpectrum[pComponent[cnt].pos]);
 594
 595         for (i=0 ; i<pComponent[cnt].numCoefs ; i++)
 596             pOut[i] += pIn[i];
 597     }
 598 }
 599
 600
 601 #define INTERPOLATE(old,new,nsample) ((old) + (nsample)*0.125*((new)-(old)))
 602
 603 static void reverseMatrixing(float *su1, float *su2, int *pPrevCode, int *pCurrCode)
 604 {
 605     int    i, band, nsample, s1, s2;
 606     float    c1, c2;
 607     float    mc1_l, mc1_r, mc2_l, mc2_r;
 608
 609     for (i=0,band = 0; band < 4*256; band+=256,i++) {
 610         s1 = pPrevCode[i];
 611         s2 = pCurrCode[i];
 612         nsample = 0;
 613
 614         if (s1 != s2) {
 615             /* Selector value changed, interpolation needed. */
 616             mc1_l = matrixCoeffs[s1*2];
 617             mc1_r = matrixCoeffs[s1*2+1];
 618             mc2_l = matrixCoeffs[s2*2];
 619             mc2_r = matrixCoeffs[s2*2+1];
 620
 621             /* Interpolation is done over the first eight samples. */
 622             for(; nsample < 8; nsample++) {
 623                 c1 = su1[band+nsample];
 624                 c2 = su2[band+nsample];
 625                 c2 = c1 * INTERPOLATE(mc1_l,mc2_l,nsample) + c2 * INTERPOLATE(mc1_r,mc2_r,nsample);
 626                 su1[band+nsample] = c2;
 627                 su2[band+nsample] = c1 * 2.0 - c2;
 628             }
 629         }
 630
 631         /* Apply the matrix without interpolation. */
 632         switch (s2) {
 633             case 0:     /* M/S decoding */
 634                 for (; nsample < 256; nsample++) {
 635                     c1 = su1[band+nsample];
 636                     c2 = su2[band+nsample];
 637                     su1[band+nsample] = c2 * 2.0;
 638                     su2[band+nsample] = (c1 - c2) * 2.0;
 639                 }
 640                 break;
 641
 642             case 1:
 643                 for (; nsample < 256; nsample++) {
 644                     c1 = su1[band+nsample];
 645                     c2 = su2[band+nsample];
 646                     su1[band+nsample] = (c1 + c2) * 2.0;
 647                     su2[band+nsample] = c2 * -2.0;
 648                 }
 649                 break;
 650             case 2:
 651             case 3:
 652                 for (; nsample < 256; nsample++) {
 653                     c1 = su1[band+nsample];
 654                     c2 = su2[band+nsample];
 655                     su1[band+nsample] = c1 + c2;
 656                     su2[band+nsample] = c1 - c2;
 657                 }
 658                 break;
 659             default:
 660                 assert(0);
 661         }
 662     }
 663 }
 664
 665 static void getChannelWeights (int indx, int flag, float ch[2]){
 666
 667     if (indx == 7) {
 668         ch[0] = 1.0;
 669         ch[1] = 1.0;
 670     } else {
 671         ch[0] = (float)(indx & 7) / 7.0;
 672         ch[1] = sqrt(2 - ch[0]*ch[0]);
 673         if(flag)
 674             FFSWAP(float, ch[0], ch[1]);
 675     }
 676 }
 677
 678 static void channelWeighting (float *su1, float *su2, int *p3)
 679 {
 680     int   band, nsample;
 681     /* w[x][y] y=0 is left y=1 is right */
 682     float w[2][2];
 683
 684     if (p3[1] != 7 || p3[3] != 7){
 685         getChannelWeights(p3[1], p3[0], w[0]);
 686         getChannelWeights(p3[3], p3[2], w[1]);
 687
 688         for(band = 1; band < 4; band++) {
 689             /* scale the channels by the weights */
 690             for(nsample = 0; nsample < 8; nsample++) {
 691                 su1[band*256+nsample] *= INTERPOLATE(w[0][0], w[0][1], nsample);
 692                 su2[band*256+nsample] *= INTERPOLATE(w[1][0], w[1][1], nsample);
 693             }
 694
 695             for(; nsample < 256; nsample++) {
 696                 su1[band*256+nsample] *= w[1][0];
 697                 su2[band*256+nsample] *= w[1][1];
 698             }
 699         }
 700     }
 701 }
 702
 703
 704 /**
 705  * Decode a Sound Unit
 706  *
 707  * @param gb            the GetBit context
 708  * @param pSnd          the channel unit to be used
 709  * @param pOut          the decoded samples before IQMF in float representation
 710  * @param channelNum    channel number
 711  * @param codingMode    the coding mode (JOINT_STEREO or regular stereo/mono)
 712  */
 713
 714
 715 static int decodeChannelSoundUnit (ATRAC3Context *q, GetBitContext *gb, channel_unit *pSnd, float *pOut, int channelNum, int codingMode)
 716 {
 717     int   band, result=0, numSubbands, numBands;
 718
 719     if (codingMode == JOINT_STEREO && channelNum == 1) {
 720         if (get_bits(gb,2) != 3) {
 721             av_log(NULL,AV_LOG_ERROR,"JS mono Sound Unit id != 3.\n");
 722             return -1;
 723         }
 724     } else {
 725         if (get_bits(gb,6) != 0x28) {
 726             av_log(NULL,AV_LOG_ERROR,"Sound Unit id != 0x28.\n");
 727             return -1;
 728         }
 729     }
 730
 731     /* number of coded QMF bands */
 732     pSnd->bandsCoded = get_bits(gb,2);
 733
 734     result = decodeGainControl (gb, &(pSnd->gainBlock[pSnd->gcBlkSwitch]), pSnd->bandsCoded);
 735     if (result) return result;
 736
 737     pSnd->numComponents = decodeTonalComponents (gb, pSnd->components, pSnd->bandsCoded);
 738     if (pSnd->numComponents == -1) return -1;
 739
 740     numSubbands = decodeSpectrum (gb, pSnd->spectrum);
 741
 742     /* Merge the decoded spectrum and tonal components. */
 743     addTonalComponents (pSnd->spectrum, pSnd->numComponents, pSnd->components);
 744
 745
 746     /* Convert number of subbands into number of MLT/QMF bands */
 747     numBands = (subbandTab[numSubbands] - 1) >> 8;
 748
 749
 750     /* Reconstruct time domain samples. */
 751     for (band=0; band<4; band++) {
 752         /* Perform the IMDCT step without overlapping. */
 753         if (band <= numBands) {
 754             IMLT(&(pSnd->spectrum[band*256]), pSnd->IMDCT_buf, band&1,q->mdct_tmp);
 755         } else
 756             memset(pSnd->IMDCT_buf, 0, 512 * sizeof(float));
 757
 758         /* gain compensation and overlapping */
 759         gainCompensateAndOverlap (pSnd->IMDCT_buf, &(pSnd->prevFrame[band*256]), &(pOut[band*256]),
 760                                     &((pSnd->gainBlock[1 - (pSnd->gcBlkSwitch)]).gBlock[band]),
 761                                     &((pSnd->gainBlock[pSnd->gcBlkSwitch]).gBlock[band]));
 762     }
 763
 764     /* Swap the gain control buffers for the next frame. */
 765     pSnd->gcBlkSwitch ^= 1;
 766
 767     return 0;
 768 }
 769
 770 /**
 771  * Frame handling
 772  *
 773  * @param q             Atrac3 private context
 774  * @param databuf       the input data
 775  */
 776
 777 static int decodeFrame(ATRAC3Context *q, uint8_t* databuf)
 778 {
 779     int   result, i;
 780     float   *p1, *p2, *p3, *p4;
 781     uint8_t    *ptr1, *ptr2;
 782
 783     if (q->codingMode == JOINT_STEREO) {
 784
 785         /* channel coupling mode */
 786         /* decode Sound Unit 1 */
 787         init_get_bits(&q->gb,databuf,q->bits_per_frame);
 788
 789         result = decodeChannelSoundUnit(q,&q->gb, q->pUnits, q->outSamples, 0, JOINT_STEREO);
 790         if (result != 0)
 791             return (result);
 792
 793         /* Framedata of the su2 in the joint-stereo mode is encoded in
 794          * reverse byte order so we need to swap it first. */
 795         ptr1 = databuf;
 796         ptr2 = databuf+q->bytes_per_frame-1;
 797         for (i = 0; i < (q->bytes_per_frame/2); i++, ptr1++, ptr2--) {
 798             FFSWAP(uint8_t,*ptr1,*ptr2);
 799         }
 800
 801         /* Skip the sync codes (0xF8). */
 802         ptr1 = databuf;
 803         for (i = 4; *ptr1 == 0xF8; i++, ptr1++) {
 804             if (i >= q->bytes_per_frame)
 805                 return -1;
 806         }
 807
 808
 809         /* set the bitstream reader at the start of the second Sound Unit*/
 810         init_get_bits(&q->gb,ptr1,q->bits_per_frame);
 811
 812         /* Fill the Weighting coeffs delay buffer */
 813         memmove(q->weighting_delay,&(q->weighting_delay[2]),4*sizeof(int));
 814         q->weighting_delay[4] = get_bits1(&q->gb);
 815         q->weighting_delay[5] = get_bits(&q->gb,3);
 816
 817         for (i = 0; i < 4; i++) {
 818             q->matrix_coeff_index_prev[i] = q->matrix_coeff_index_now[i];
 819             q->matrix_coeff_index_now[i] = q->matrix_coeff_index_next[i];
 820             q->matrix_coeff_index_next[i] = get_bits(&q->gb,2);
 821         }
 822
 823         /* Decode Sound Unit 2. */
 824         result = decodeChannelSoundUnit(q,&q->gb, &q->pUnits[1], &q->outSamples[1024], 1, JOINT_STEREO);
 825         if (result != 0)
 826             return (result);
 827
 828         /* Reconstruct the channel coefficients. */
 829         reverseMatrixing(q->outSamples, &q->outSamples[1024], q->matrix_coeff_index_prev, q->matrix_coeff_index_now);
 830
 831         channelWeighting(q->outSamples, &q->outSamples[1024], q->weighting_delay);
 832
 833     } else {
 834         /* normal stereo mode or mono */
 835         /* Decode the channel sound units. */
 836         for (i=0 ; i<q->channels ; i++) {
 837
 838             /* Set the bitstream reader at the start of a channel sound unit. */
 839             init_get_bits(&q->gb, databuf+((i*q->bytes_per_frame)/q->channels), (q->bits_per_frame)/q->channels);
 840
 841             result = decodeChannelSoundUnit(q,&q->gb, &q->pUnits[i], &q->outSamples[i*1024], i, q->codingMode);
 842             if (result != 0)
 843                 return (result);
 844         }
 845     }
 846
 847     /* Apply the iQMF synthesis filter. */
 848     p1= q->outSamples;
 849     for (i=0 ; i<q->channels ; i++) {
 850         p2= p1+256;
 851         p3= p2+256;
 852         p4= p3+256;
 853         iqmf (p1, p2, 256, p1, q->pUnits[i].delayBuf1, q->tempBuf);
 854         iqmf (p4, p3, 256, p3, q->pUnits[i].delayBuf2, q->tempBuf);
 855         iqmf (p1, p3, 512, p1, q->pUnits[i].delayBuf3, q->tempBuf);
 856         p1 +=1024;
 857     }
 858
 859     return 0;
 860 }
 861
 862
 863 /**
 864  * Atrac frame decoding
 865  *
 866  * @param avctx     pointer to the AVCodecContext
 867  */
 868
 869 static int atrac3_decode_frame(AVCodecContext *avctx,
 870             void *data, int *data_size,
 871             uint8_t *buf, int buf_size) {
 872     ATRAC3Context *q = avctx->priv_data;
 873     int result = 0, i;
 874     uint8_t* databuf;
 875     int16_t* samples = data;
 876
 877     if (buf_size < avctx->block_align)
 878         return buf_size;
 879
 880     /* Check if we need to descramble and what buffer to pass on. */
 881     if (q->scrambled_stream) {
 882         decode_bytes(buf, q->decoded_bytes_buffer, avctx->block_align);
 883         databuf = q->decoded_bytes_buffer;
 884     } else {
 885         databuf = buf;
 886     }
 887
 888     result = decodeFrame(q, databuf);
 889
 890     if (result != 0) {
 891         av_log(NULL,AV_LOG_ERROR,"Frame decoding error!\n");
 892         return -1;
 893     }
 894
 895     if (q->channels == 1) {
 896         /* mono */
 897         for (i = 0; i<1024; i++)
 898             samples[i] = av_clip_int16(round(q->outSamples[i]));
 899         *data_size = 1024 * sizeof(int16_t);
 900     } else {
 901         /* stereo */
 902         for (i = 0; i < 1024; i++) {
 903             samples[i*2] = av_clip_int16(round(q->outSamples[i]));
 904             samples[i*2+1] = av_clip_int16(round(q->outSamples[1024+i]));
 905         }
 906         *data_size = 2048 * sizeof(int16_t);
 907     }
 908
 909     return avctx->block_align;
 910 }
 911
 912
 913 /**
 914  * Atrac3 initialization
 915  *
 916  * @param avctx     pointer to the AVCodecContext
 917  */
 918
 919 static int atrac3_decode_init(AVCodecContext *avctx)
 920 {
 921     int i;
 922     uint8_t *edata_ptr = avctx->extradata;
 923     ATRAC3Context *q = avctx->priv_data;
 924
 925     /* Take data from the AVCodecContext (RM container). */
 926     q->sample_rate = avctx->sample_rate;
 927     q->channels = avctx->channels;
 928     q->bit_rate = avctx->bit_rate;
 929     q->bits_per_frame = avctx->block_align * 8;
 930     q->bytes_per_frame = avctx->block_align;
 931
 932     /* Take care of the codec-specific extradata. */
 933     if (avctx->extradata_size == 14) {
 934         /* Parse the extradata, WAV format */
 935         av_log(avctx,AV_LOG_DEBUG,"[0-1] %d\n",bytestream_get_le16(&edata_ptr));  //Unknown value always 1
 936         q->samples_per_channel = bytestream_get_le32(&edata_ptr);
 937         q->codingMode = bytestream_get_le16(&edata_ptr);
 938         av_log(avctx,AV_LOG_DEBUG,"[8-9] %d\n",bytestream_get_le16(&edata_ptr));  //Dupe of coding mode
 939         q->frame_factor = bytestream_get_le16(&edata_ptr);  //Unknown always 1
 940         av_log(avctx,AV_LOG_DEBUG,"[12-13] %d\n",bytestream_get_le16(&edata_ptr));  //Unknown always 0
 941
 942         /* setup */
 943         q->samples_per_frame = 1024 * q->channels;
 944         q->atrac3version = 4;
 945         q->delay = 0x88E;
 946         if (q->codingMode)
 947             q->codingMode = JOINT_STEREO;
 948         else
 949             q->codingMode = STEREO;
 950
 951         q->scrambled_stream = 0;
 952
 953         if ((q->bytes_per_frame == 96*q->channels*q->frame_factor) || (q->bytes_per_frame == 152*q->channels*q->frame_factor) || (q->bytes_per_frame == 192*q->channels*q->frame_factor)) {
 954         } else {
 955             av_log(avctx,AV_LOG_ERROR,"Unknown frame/channel/frame_factor configuration %d/%d/%d\n", q->bytes_per_frame, q->channels, q->frame_factor);
 956             return -1;
 957         }
 958
 959     } else if (avctx->extradata_size == 10) {
 960         /* Parse the extradata, RM format. */
 961         q->atrac3version = bytestream_get_be32(&edata_ptr);
 962         q->samples_per_frame = bytestream_get_be16(&edata_ptr);
 963         q->delay = bytestream_get_be16(&edata_ptr);
 964         q->codingMode = bytestream_get_be16(&edata_ptr);
 965
 966         q->samples_per_channel = q->samples_per_frame / q->channels;
 967         q->scrambled_stream = 1;
 968
 969     } else {
 970         av_log(NULL,AV_LOG_ERROR,"Unknown extradata size %d.\n",avctx->extradata_size);
 971     }
 972     /* Check the extradata. */
 973
 974     if (q->atrac3version != 4) {
 975         av_log(avctx,AV_LOG_ERROR,"Version %d != 4.\n",q->atrac3version);
 976         return -1;
 977     }
 978
 979     if (q->samples_per_frame != 1024 && q->samples_per_frame != 2048) {
 980         av_log(avctx,AV_LOG_ERROR,"Unknown amount of samples per frame %d.\n",q->samples_per_frame);
 981         return -1;
 982     }
 983
 984     if (q->delay != 0x88E) {
 985         av_log(avctx,AV_LOG_ERROR,"Unknown amount of delay %x != 0x88E.\n",q->delay);
 986         return -1;
 987     }
 988
 989     if (q->codingMode == STEREO) {
 990         av_log(avctx,AV_LOG_DEBUG,"Normal stereo detected.\n");
 991     } else if (q->codingMode == JOINT_STEREO) {
 992         av_log(avctx,AV_LOG_DEBUG,"Joint stereo detected.\n");
 993     } else {
 994         av_log(avctx,AV_LOG_ERROR,"Unknown channel coding mode %x!\n",q->codingMode);
 995         return -1;
 996     }
 997
 998     if (avctx->channels <= 0 || avctx->channels > 2 /*|| ((avctx->channels * 1024) != q->samples_per_frame)*/) {
 999         av_log(avctx,AV_LOG_ERROR,"Channel configuration error!\n");
1000         return -1;
1001     }
1002
1003
1004     if(avctx->block_align >= UINT_MAX/2)
1005         return -1;
1006
1007     /* Pad the data buffer with FF_INPUT_BUFFER_PADDING_SIZE,
1008      * this is for the bitstream reader. */
1009     if ((q->decoded_bytes_buffer = av_mallocz((avctx->block_align+(4-avctx->block_align%4) + FF_INPUT_BUFFER_PADDING_SIZE)))  == NULL)
1010         return AVERROR(ENOMEM);
1011
1012
1013     /* Initialize the VLC tables. */
1014     for (i=0 ; i<7 ; i++) {
1015         init_vlc (&spectral_coeff_tab[i], 9, huff_tab_sizes[i],
1016             huff_bits[i], 1, 1,
1017             huff_codes[i], 1, 1, INIT_VLC_USE_STATIC);
1018     }
1019
1020     init_atrac3_transforms(q);
1021
1022     /* Generate the scale factors. */
1023     for (i=0 ; i<64 ; i++)
1024         SFTable[i] = pow(2.0, (i - 15) / 3.0);
1025
1026     /* Generate gain tables. */
1027     for (i=0 ; i<16 ; i++)
1028         gain_tab1[i] = powf (2.0, (4 - i));
1029
1030     for (i=-15 ; i<16 ; i++)
1031         gain_tab2[i+15] = powf (2.0, i * -0.125);
1032
1033     /* init the joint-stereo decoding data */
1034     q->weighting_delay[0] = 0;
1035     q->weighting_delay[1] = 7;
1036     q->weighting_delay[2] = 0;
1037     q->weighting_delay[3] = 7;
1038     q->weighting_delay[4] = 0;
1039     q->weighting_delay[5] = 7;
1040
1041     for (i=0; i<4; i++) {
1042         q->matrix_coeff_index_prev[i] = 3;
1043         q->matrix_coeff_index_now[i] = 3;
1044         q->matrix_coeff_index_next[i] = 3;
1045     }
1046
1047     dsputil_init(&dsp, avctx);
1048
1049     q->pUnits = av_mallocz(sizeof(channel_unit)*q->channels);
1050     if (!q->pUnits) {
1051         av_free(q->decoded_bytes_buffer);
1052         return AVERROR(ENOMEM);
1053     }
1054
1055     return 0;
1056 }
1057
1058
1059 AVCodec atrac3_decoder =
1060 {
1061     .name = "atrac 3",
1062     .type = CODEC_TYPE_AUDIO,
1063     .id = CODEC_ID_ATRAC3,
1064     .priv_data_size = sizeof(ATRAC3Context),
1065     .init = atrac3_decode_init,
1066     .close = atrac3_decode_close,
1067     .decode = atrac3_decode_frame,
1068 };