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libavcodec/cook.c

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00001 /*
00002  * COOK compatible decoder
00003  * Copyright (c) 2003 Sascha Sommer
00004  * Copyright (c) 2005 Benjamin Larsson
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00045 #include <math.h>
00046 #include <stddef.h>
00047 #include <stdio.h>
00048 
00049 #include "libavutil/random.h"
00050 #include "avcodec.h"
00051 #include "bitstream.h"
00052 #include "dsputil.h"
00053 #include "bytestream.h"
00054 
00055 #include "cookdata.h"
00056 
00057 /* the different Cook versions */
00058 #define MONO            0x1000001
00059 #define STEREO          0x1000002
00060 #define JOINT_STEREO    0x1000003
00061 #define MC_COOK         0x2000000   //multichannel Cook, not supported
00062 
00063 #define SUBBAND_SIZE    20
00064 //#define COOKDEBUG
00065 
00066 typedef struct {
00067     int *now;
00068     int *previous;
00069 } cook_gains;
00070 
00071 typedef struct cook {
00072     /*
00073      * The following 5 functions provide the lowlevel arithmetic on
00074      * the internal audio buffers.
00075      */
00076     void (* scalar_dequant)(struct cook *q, int index, int quant_index,
00077                             int* subband_coef_index, int* subband_coef_sign,
00078                             float* mlt_p);
00079 
00080     void (* decouple) (struct cook *q,
00081                        int subband,
00082                        float f1, float f2,
00083                        float *decode_buffer,
00084                        float *mlt_buffer1, float *mlt_buffer2);
00085 
00086     void (* imlt_window) (struct cook *q, float *buffer1,
00087                           cook_gains *gains_ptr, float *previous_buffer);
00088 
00089     void (* interpolate) (struct cook *q, float* buffer,
00090                           int gain_index, int gain_index_next);
00091 
00092     void (* saturate_output) (struct cook *q, int chan, int16_t *out);
00093 
00094     GetBitContext       gb;
00095     /* stream data */
00096     int                 nb_channels;
00097     int                 joint_stereo;
00098     int                 bit_rate;
00099     int                 sample_rate;
00100     int                 samples_per_channel;
00101     int                 samples_per_frame;
00102     int                 subbands;
00103     int                 log2_numvector_size;
00104     int                 numvector_size;                //1 << log2_numvector_size;
00105     int                 js_subband_start;
00106     int                 total_subbands;
00107     int                 num_vectors;
00108     int                 bits_per_subpacket;
00109     int                 cookversion;
00110     /* states */
00111     AVRandomState       random_state;
00112 
00113     /* transform data */
00114     MDCTContext         mdct_ctx;
00115     float*              mlt_window;
00116 
00117     /* gain buffers */
00118     cook_gains          gains1;
00119     cook_gains          gains2;
00120     int                 gain_1[9];
00121     int                 gain_2[9];
00122     int                 gain_3[9];
00123     int                 gain_4[9];
00124 
00125     /* VLC data */
00126     int                 js_vlc_bits;
00127     VLC                 envelope_quant_index[13];
00128     VLC                 sqvh[7];          //scalar quantization
00129     VLC                 ccpl;             //channel coupling
00130 
00131     /* generatable tables and related variables */
00132     int                 gain_size_factor;
00133     float               gain_table[23];
00134 
00135     /* data buffers */
00136 
00137     uint8_t*            decoded_bytes_buffer;
00138     DECLARE_ALIGNED_16(float,mono_mdct_output[2048]);
00139     float               mono_previous_buffer1[1024];
00140     float               mono_previous_buffer2[1024];
00141     float               decode_buffer_1[1024];
00142     float               decode_buffer_2[1024];
00143     float               decode_buffer_0[1060]; /* static allocation for joint decode */
00144 
00145     const float         *cplscales[5];
00146 } COOKContext;
00147 
00148 static float     pow2tab[127];
00149 static float rootpow2tab[127];
00150 
00151 /* debug functions */
00152 
00153 #ifdef COOKDEBUG
00154 static void dump_float_table(float* table, int size, int delimiter) {
00155     int i=0;
00156     av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);
00157     for (i=0 ; i<size ; i++) {
00158         av_log(NULL, AV_LOG_ERROR, "%5.1f, ", table[i]);
00159         if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);
00160     }
00161 }
00162 
00163 static void dump_int_table(int* table, int size, int delimiter) {
00164     int i=0;
00165     av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);
00166     for (i=0 ; i<size ; i++) {
00167         av_log(NULL, AV_LOG_ERROR, "%d, ", table[i]);
00168         if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);
00169     }
00170 }
00171 
00172 static void dump_short_table(short* table, int size, int delimiter) {
00173     int i=0;
00174     av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i);
00175     for (i=0 ; i<size ; i++) {
00176         av_log(NULL, AV_LOG_ERROR, "%d, ", table[i]);
00177         if ((i+1)%delimiter == 0) av_log(NULL,AV_LOG_ERROR,"\n[%d]: ",i+1);
00178     }
00179 }
00180 
00181 #endif
00182 
00183 /*************** init functions ***************/
00184 
00185 /* table generator */
00186 static av_cold void init_pow2table(void){
00187     int i;
00188     for (i=-63 ; i<64 ; i++){
00189             pow2tab[63+i]=     pow(2, i);
00190         rootpow2tab[63+i]=sqrt(pow(2, i));
00191     }
00192 }
00193 
00194 /* table generator */
00195 static av_cold void init_gain_table(COOKContext *q) {
00196     int i;
00197     q->gain_size_factor = q->samples_per_channel/8;
00198     for (i=0 ; i<23 ; i++) {
00199         q->gain_table[i] = pow(pow2tab[i+52] ,
00200                                (1.0/(double)q->gain_size_factor));
00201     }
00202 }
00203 
00204 
00205 static av_cold int init_cook_vlc_tables(COOKContext *q) {
00206     int i, result;
00207 
00208     result = 0;
00209     for (i=0 ; i<13 ; i++) {
00210         result |= init_vlc (&q->envelope_quant_index[i], 9, 24,
00211             envelope_quant_index_huffbits[i], 1, 1,
00212             envelope_quant_index_huffcodes[i], 2, 2, 0);
00213     }
00214     av_log(NULL,AV_LOG_DEBUG,"sqvh VLC init\n");
00215     for (i=0 ; i<7 ; i++) {
00216         result |= init_vlc (&q->sqvh[i], vhvlcsize_tab[i], vhsize_tab[i],
00217             cvh_huffbits[i], 1, 1,
00218             cvh_huffcodes[i], 2, 2, 0);
00219     }
00220 
00221     if (q->nb_channels==2 && q->joint_stereo==1){
00222         result |= init_vlc (&q->ccpl, 6, (1<<q->js_vlc_bits)-1,
00223             ccpl_huffbits[q->js_vlc_bits-2], 1, 1,
00224             ccpl_huffcodes[q->js_vlc_bits-2], 2, 2, 0);
00225         av_log(NULL,AV_LOG_DEBUG,"Joint-stereo VLC used.\n");
00226     }
00227 
00228     av_log(NULL,AV_LOG_DEBUG,"VLC tables initialized.\n");
00229     return result;
00230 }
00231 
00232 static av_cold int init_cook_mlt(COOKContext *q) {
00233     int j;
00234     int mlt_size = q->samples_per_channel;
00235 
00236     if ((q->mlt_window = av_malloc(sizeof(float)*mlt_size)) == 0)
00237       return -1;
00238 
00239     /* Initialize the MLT window: simple sine window. */
00240     ff_sine_window_init(q->mlt_window, mlt_size);
00241     for(j=0 ; j<mlt_size ; j++)
00242         q->mlt_window[j] *= sqrt(2.0 / q->samples_per_channel);
00243 
00244     /* Initialize the MDCT. */
00245     if (ff_mdct_init(&q->mdct_ctx, av_log2(mlt_size)+1, 1)) {
00246       av_free(q->mlt_window);
00247       return -1;
00248     }
00249     av_log(NULL,AV_LOG_DEBUG,"MDCT initialized, order = %d.\n",
00250            av_log2(mlt_size)+1);
00251 
00252     return 0;
00253 }
00254 
00255 static const float *maybe_reformat_buffer32 (COOKContext *q, const float *ptr, int n)
00256 {
00257     if (1)
00258         return ptr;
00259 }
00260 
00261 static av_cold void init_cplscales_table (COOKContext *q) {
00262     int i;
00263     for (i=0;i<5;i++)
00264         q->cplscales[i] = maybe_reformat_buffer32 (q, cplscales[i], (1<<(i+2))-1);
00265 }
00266 
00267 /*************** init functions end ***********/
00268 
00289 #define DECODE_BYTES_PAD1(bytes) (3 - ((bytes)+3) % 4)
00290 #define DECODE_BYTES_PAD2(bytes) ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))
00291 
00292 static inline int decode_bytes(const uint8_t* inbuffer, uint8_t* out, int bytes){
00293     int i, off;
00294     uint32_t c;
00295     const uint32_t* buf;
00296     uint32_t* obuf = (uint32_t*) out;
00297     /* FIXME: 64 bit platforms would be able to do 64 bits at a time.
00298      * I'm too lazy though, should be something like
00299      * for(i=0 ; i<bitamount/64 ; i++)
00300      *     (int64_t)out[i] = 0x37c511f237c511f2^be2me_64(int64_t)in[i]);
00301      * Buffer alignment needs to be checked. */
00302 
00303     off = (int)((long)inbuffer & 3);
00304     buf = (const uint32_t*) (inbuffer - off);
00305     c = be2me_32((0x37c511f2 >> (off*8)) | (0x37c511f2 << (32-(off*8))));
00306     bytes += 3 + off;
00307     for (i = 0; i < bytes/4; i++)
00308         obuf[i] = c ^ buf[i];
00309 
00310     return off;
00311 }
00312 
00317 static av_cold int cook_decode_close(AVCodecContext *avctx)
00318 {
00319     int i;
00320     COOKContext *q = avctx->priv_data;
00321     av_log(avctx,AV_LOG_DEBUG, "Deallocating memory.\n");
00322 
00323     /* Free allocated memory buffers. */
00324     av_free(q->mlt_window);
00325     av_free(q->decoded_bytes_buffer);
00326 
00327     /* Free the transform. */
00328     ff_mdct_end(&q->mdct_ctx);
00329 
00330     /* Free the VLC tables. */
00331     for (i=0 ; i<13 ; i++) {
00332         free_vlc(&q->envelope_quant_index[i]);
00333     }
00334     for (i=0 ; i<7 ; i++) {
00335         free_vlc(&q->sqvh[i]);
00336     }
00337     if(q->nb_channels==2 && q->joint_stereo==1 ){
00338         free_vlc(&q->ccpl);
00339     }
00340 
00341     av_log(NULL,AV_LOG_DEBUG,"Memory deallocated.\n");
00342 
00343     return 0;
00344 }
00345 
00353 static void decode_gain_info(GetBitContext *gb, int *gaininfo)
00354 {
00355     int i, n;
00356 
00357     while (get_bits1(gb)) {}
00358     n = get_bits_count(gb) - 1;     //amount of elements*2 to update
00359 
00360     i = 0;
00361     while (n--) {
00362         int index = get_bits(gb, 3);
00363         int gain = get_bits1(gb) ? get_bits(gb, 4) - 7 : -1;
00364 
00365         while (i <= index) gaininfo[i++] = gain;
00366     }
00367     while (i <= 8) gaininfo[i++] = 0;
00368 }
00369 
00377 static void decode_envelope(COOKContext *q, int* quant_index_table) {
00378     int i,j, vlc_index;
00379 
00380     quant_index_table[0]= get_bits(&q->gb,6) - 6;       //This is used later in categorize
00381 
00382     for (i=1 ; i < q->total_subbands ; i++){
00383         vlc_index=i;
00384         if (i >= q->js_subband_start * 2) {
00385             vlc_index-=q->js_subband_start;
00386         } else {
00387             vlc_index/=2;
00388             if(vlc_index < 1) vlc_index = 1;
00389         }
00390         if (vlc_index>13) vlc_index = 13;           //the VLC tables >13 are identical to No. 13
00391 
00392         j = get_vlc2(&q->gb, q->envelope_quant_index[vlc_index-1].table,
00393                      q->envelope_quant_index[vlc_index-1].bits,2);
00394         quant_index_table[i] = quant_index_table[i-1] + j - 12;    //differential encoding
00395     }
00396 }
00397 
00407 static void categorize(COOKContext *q, int* quant_index_table,
00408                        int* category, int* category_index){
00409     int exp_idx, bias, tmpbias1, tmpbias2, bits_left, num_bits, index, v, i, j;
00410     int exp_index2[102];
00411     int exp_index1[102];
00412 
00413     int tmp_categorize_array[128*2];
00414     int tmp_categorize_array1_idx=q->numvector_size;
00415     int tmp_categorize_array2_idx=q->numvector_size;
00416 
00417     bits_left =  q->bits_per_subpacket - get_bits_count(&q->gb);
00418 
00419     if(bits_left > q->samples_per_channel) {
00420         bits_left = q->samples_per_channel +
00421                     ((bits_left - q->samples_per_channel)*5)/8;
00422         //av_log(NULL, AV_LOG_ERROR, "bits_left = %d\n",bits_left);
00423     }
00424 
00425     memset(&exp_index1,0,102*sizeof(int));
00426     memset(&exp_index2,0,102*sizeof(int));
00427     memset(&tmp_categorize_array,0,128*2*sizeof(int));
00428 
00429     bias=-32;
00430 
00431     /* Estimate bias. */
00432     for (i=32 ; i>0 ; i=i/2){
00433         num_bits = 0;
00434         index = 0;
00435         for (j=q->total_subbands ; j>0 ; j--){
00436             exp_idx = av_clip((i - quant_index_table[index] + bias) / 2, 0, 7);
00437             index++;
00438             num_bits+=expbits_tab[exp_idx];
00439         }
00440         if(num_bits >= bits_left - 32){
00441             bias+=i;
00442         }
00443     }
00444 
00445     /* Calculate total number of bits. */
00446     num_bits=0;
00447     for (i=0 ; i<q->total_subbands ; i++) {
00448         exp_idx = av_clip((bias - quant_index_table[i]) / 2, 0, 7);
00449         num_bits += expbits_tab[exp_idx];
00450         exp_index1[i] = exp_idx;
00451         exp_index2[i] = exp_idx;
00452     }
00453     tmpbias1 = tmpbias2 = num_bits;
00454 
00455     for (j = 1 ; j < q->numvector_size ; j++) {
00456         if (tmpbias1 + tmpbias2 > 2*bits_left) {  /* ---> */
00457             int max = -999999;
00458             index=-1;
00459             for (i=0 ; i<q->total_subbands ; i++){
00460                 if (exp_index1[i] < 7) {
00461                     v = (-2*exp_index1[i]) - quant_index_table[i] + bias;
00462                     if ( v >= max) {
00463                         max = v;
00464                         index = i;
00465                     }
00466                 }
00467             }
00468             if(index==-1)break;
00469             tmp_categorize_array[tmp_categorize_array1_idx++] = index;
00470             tmpbias1 -= expbits_tab[exp_index1[index]] -
00471                         expbits_tab[exp_index1[index]+1];
00472             ++exp_index1[index];
00473         } else {  /* <--- */
00474             int min = 999999;
00475             index=-1;
00476             for (i=0 ; i<q->total_subbands ; i++){
00477                 if(exp_index2[i] > 0){
00478                     v = (-2*exp_index2[i])-quant_index_table[i]+bias;
00479                     if ( v < min) {
00480                         min = v;
00481                         index = i;
00482                     }
00483                 }
00484             }
00485             if(index == -1)break;
00486             tmp_categorize_array[--tmp_categorize_array2_idx] = index;
00487             tmpbias2 -= expbits_tab[exp_index2[index]] -
00488                         expbits_tab[exp_index2[index]-1];
00489             --exp_index2[index];
00490         }
00491     }
00492 
00493     for(i=0 ; i<q->total_subbands ; i++)
00494         category[i] = exp_index2[i];
00495 
00496     for(i=0 ; i<q->numvector_size-1 ; i++)
00497         category_index[i] = tmp_categorize_array[tmp_categorize_array2_idx++];
00498 
00499 }
00500 
00501 
00510 static inline void expand_category(COOKContext *q, int* category,
00511                                    int* category_index){
00512     int i;
00513     for(i=0 ; i<q->num_vectors ; i++){
00514         ++category[category_index[i]];
00515     }
00516 }
00517 
00529 static void scalar_dequant_float(COOKContext *q, int index, int quant_index,
00530                            int* subband_coef_index, int* subband_coef_sign,
00531                            float* mlt_p){
00532     int i;
00533     float f1;
00534 
00535     for(i=0 ; i<SUBBAND_SIZE ; i++) {
00536         if (subband_coef_index[i]) {
00537             f1 = quant_centroid_tab[index][subband_coef_index[i]];
00538             if (subband_coef_sign[i]) f1 = -f1;
00539         } else {
00540             /* noise coding if subband_coef_index[i] == 0 */
00541             f1 = dither_tab[index];
00542             if (av_random(&q->random_state) < 0x80000000) f1 = -f1;
00543         }
00544         mlt_p[i] = f1 * rootpow2tab[quant_index+63];
00545     }
00546 }
00556 static int unpack_SQVH(COOKContext *q, int category, int* subband_coef_index,
00557                        int* subband_coef_sign) {
00558     int i,j;
00559     int vlc, vd ,tmp, result;
00560 
00561     vd = vd_tab[category];
00562     result = 0;
00563     for(i=0 ; i<vpr_tab[category] ; i++){
00564         vlc = get_vlc2(&q->gb, q->sqvh[category].table, q->sqvh[category].bits, 3);
00565         if (q->bits_per_subpacket < get_bits_count(&q->gb)){
00566             vlc = 0;
00567             result = 1;
00568         }
00569         for(j=vd-1 ; j>=0 ; j--){
00570             tmp = (vlc * invradix_tab[category])/0x100000;
00571             subband_coef_index[vd*i+j] = vlc - tmp * (kmax_tab[category]+1);
00572             vlc = tmp;
00573         }
00574         for(j=0 ; j<vd ; j++){
00575             if (subband_coef_index[i*vd + j]) {
00576                 if(get_bits_count(&q->gb) < q->bits_per_subpacket){
00577                     subband_coef_sign[i*vd+j] = get_bits1(&q->gb);
00578                 } else {
00579                     result=1;
00580                     subband_coef_sign[i*vd+j]=0;
00581                 }
00582             } else {
00583                 subband_coef_sign[i*vd+j]=0;
00584             }
00585         }
00586     }
00587     return result;
00588 }
00589 
00590 
00601 static void decode_vectors(COOKContext* q, int* category,
00602                            int *quant_index_table, float* mlt_buffer){
00603     /* A zero in this table means that the subband coefficient is
00604        random noise coded. */
00605     int subband_coef_index[SUBBAND_SIZE];
00606     /* A zero in this table means that the subband coefficient is a
00607        positive multiplicator. */
00608     int subband_coef_sign[SUBBAND_SIZE];
00609     int band, j;
00610     int index=0;
00611 
00612     for(band=0 ; band<q->total_subbands ; band++){
00613         index = category[band];
00614         if(category[band] < 7){
00615             if(unpack_SQVH(q, category[band], subband_coef_index, subband_coef_sign)){
00616                 index=7;
00617                 for(j=0 ; j<q->total_subbands ; j++) category[band+j]=7;
00618             }
00619         }
00620         if(index==7) {
00621             memset(subband_coef_index, 0, sizeof(subband_coef_index));
00622             memset(subband_coef_sign, 0, sizeof(subband_coef_sign));
00623         }
00624         q->scalar_dequant(q, index, quant_index_table[band],
00625                           subband_coef_index, subband_coef_sign,
00626                           &mlt_buffer[band * SUBBAND_SIZE]);
00627     }
00628 
00629     if(q->total_subbands*SUBBAND_SIZE >= q->samples_per_channel){
00630         return;
00631     } /* FIXME: should this be removed, or moved into loop above? */
00632 }
00633 
00634 
00642 static void mono_decode(COOKContext *q, float* mlt_buffer) {
00643 
00644     int category_index[128];
00645     int quant_index_table[102];
00646     int category[128];
00647 
00648     memset(&category, 0, 128*sizeof(int));
00649     memset(&category_index, 0, 128*sizeof(int));
00650 
00651     decode_envelope(q, quant_index_table);
00652     q->num_vectors = get_bits(&q->gb,q->log2_numvector_size);
00653     categorize(q, quant_index_table, category, category_index);
00654     expand_category(q, category, category_index);
00655     decode_vectors(q, category, quant_index_table, mlt_buffer);
00656 }
00657 
00658 
00668 static void interpolate_float(COOKContext *q, float* buffer,
00669                         int gain_index, int gain_index_next){
00670     int i;
00671     float fc1, fc2;
00672     fc1 = pow2tab[gain_index+63];
00673 
00674     if(gain_index == gain_index_next){              //static gain
00675         for(i=0 ; i<q->gain_size_factor ; i++){
00676             buffer[i]*=fc1;
00677         }
00678         return;
00679     } else {                                        //smooth gain
00680         fc2 = q->gain_table[11 + (gain_index_next-gain_index)];
00681         for(i=0 ; i<q->gain_size_factor ; i++){
00682             buffer[i]*=fc1;
00683             fc1*=fc2;
00684         }
00685         return;
00686     }
00687 }
00688 
00698 static void imlt_window_float (COOKContext *q, float *buffer1,
00699                                cook_gains *gains_ptr, float *previous_buffer)
00700 {
00701     const float fc = pow2tab[gains_ptr->previous[0] + 63];
00702     int i;
00703     /* The weird thing here, is that the two halves of the time domain
00704      * buffer are swapped. Also, the newest data, that we save away for
00705      * next frame, has the wrong sign. Hence the subtraction below.
00706      * Almost sounds like a complex conjugate/reverse data/FFT effect.
00707      */
00708 
00709     /* Apply window and overlap */
00710     for(i = 0; i < q->samples_per_channel; i++){
00711         buffer1[i] = buffer1[i] * fc * q->mlt_window[i] -
00712           previous_buffer[i] * q->mlt_window[q->samples_per_channel - 1 - i];
00713     }
00714 }
00715 
00728 static void imlt_gain(COOKContext *q, float *inbuffer,
00729                       cook_gains *gains_ptr, float* previous_buffer)
00730 {
00731     float *buffer0 = q->mono_mdct_output;
00732     float *buffer1 = q->mono_mdct_output + q->samples_per_channel;
00733     int i;
00734 
00735     /* Inverse modified discrete cosine transform */
00736     ff_imdct_calc(&q->mdct_ctx, q->mono_mdct_output, inbuffer);
00737 
00738     q->imlt_window (q, buffer1, gains_ptr, previous_buffer);
00739 
00740     /* Apply gain profile */
00741     for (i = 0; i < 8; i++) {
00742         if (gains_ptr->now[i] || gains_ptr->now[i + 1])
00743             q->interpolate(q, &buffer1[q->gain_size_factor * i],
00744                            gains_ptr->now[i], gains_ptr->now[i + 1]);
00745     }
00746 
00747     /* Save away the current to be previous block. */
00748     memcpy(previous_buffer, buffer0, sizeof(float)*q->samples_per_channel);
00749 }
00750 
00751 
00760 static void decouple_info(COOKContext *q, int* decouple_tab){
00761     int length, i;
00762 
00763     if(get_bits1(&q->gb)) {
00764         if(cplband[q->js_subband_start] > cplband[q->subbands-1]) return;
00765 
00766         length = cplband[q->subbands-1] - cplband[q->js_subband_start] + 1;
00767         for (i=0 ; i<length ; i++) {
00768             decouple_tab[cplband[q->js_subband_start] + i] = get_vlc2(&q->gb, q->ccpl.table, q->ccpl.bits, 2);
00769         }
00770         return;
00771     }
00772 
00773     if(cplband[q->js_subband_start] > cplband[q->subbands-1]) return;
00774 
00775     length = cplband[q->subbands-1] - cplband[q->js_subband_start] + 1;
00776     for (i=0 ; i<length ; i++) {
00777        decouple_tab[cplband[q->js_subband_start] + i] = get_bits(&q->gb, q->js_vlc_bits);
00778     }
00779     return;
00780 }
00781 
00782 /*
00783  * function decouples a pair of signals from a single signal via multiplication.
00784  *
00785  * @param q                 pointer to the COOKContext
00786  * @param subband           index of the current subband
00787  * @param f1                multiplier for channel 1 extraction
00788  * @param f2                multiplier for channel 2 extraction
00789  * @param decode_buffer     input buffer
00790  * @param mlt_buffer1       pointer to left channel mlt coefficients
00791  * @param mlt_buffer2       pointer to right channel mlt coefficients
00792  */
00793 static void decouple_float (COOKContext *q,
00794                             int subband,
00795                             float f1, float f2,
00796                             float *decode_buffer,
00797                             float *mlt_buffer1, float *mlt_buffer2)
00798 {
00799     int j, tmp_idx;
00800     for (j=0 ; j<SUBBAND_SIZE ; j++) {
00801         tmp_idx = ((q->js_subband_start + subband)*SUBBAND_SIZE)+j;
00802         mlt_buffer1[SUBBAND_SIZE*subband + j] = f1 * decode_buffer[tmp_idx];
00803         mlt_buffer2[SUBBAND_SIZE*subband + j] = f2 * decode_buffer[tmp_idx];
00804     }
00805 }
00806 
00815 static void joint_decode(COOKContext *q, float* mlt_buffer1,
00816                          float* mlt_buffer2) {
00817     int i,j;
00818     int decouple_tab[SUBBAND_SIZE];
00819     float *decode_buffer = q->decode_buffer_0;
00820     int idx, cpl_tmp;
00821     float f1,f2;
00822     const float* cplscale;
00823 
00824     memset(decouple_tab, 0, sizeof(decouple_tab));
00825     memset(decode_buffer, 0, sizeof(decode_buffer));
00826 
00827     /* Make sure the buffers are zeroed out. */
00828     memset(mlt_buffer1,0, 1024*sizeof(float));
00829     memset(mlt_buffer2,0, 1024*sizeof(float));
00830     decouple_info(q, decouple_tab);
00831     mono_decode(q, decode_buffer);
00832 
00833     /* The two channels are stored interleaved in decode_buffer. */
00834     for (i=0 ; i<q->js_subband_start ; i++) {
00835         for (j=0 ; j<SUBBAND_SIZE ; j++) {
00836             mlt_buffer1[i*20+j] = decode_buffer[i*40+j];
00837             mlt_buffer2[i*20+j] = decode_buffer[i*40+20+j];
00838         }
00839     }
00840 
00841     /* When we reach js_subband_start (the higher frequencies)
00842        the coefficients are stored in a coupling scheme. */
00843     idx = (1 << q->js_vlc_bits) - 1;
00844     for (i=q->js_subband_start ; i<q->subbands ; i++) {
00845         cpl_tmp = cplband[i];
00846         idx -=decouple_tab[cpl_tmp];
00847         cplscale = q->cplscales[q->js_vlc_bits-2];  //choose decoupler table
00848         f1 = cplscale[decouple_tab[cpl_tmp]];
00849         f2 = cplscale[idx-1];
00850         q->decouple (q, i, f1, f2, decode_buffer, mlt_buffer1, mlt_buffer2);
00851         idx = (1 << q->js_vlc_bits) - 1;
00852     }
00853 }
00854 
00864 static inline void
00865 decode_bytes_and_gain(COOKContext *q, const uint8_t *inbuffer,
00866                       cook_gains *gains_ptr)
00867 {
00868     int offset;
00869 
00870     offset = decode_bytes(inbuffer, q->decoded_bytes_buffer,
00871                           q->bits_per_subpacket/8);
00872     init_get_bits(&q->gb, q->decoded_bytes_buffer + offset,
00873                   q->bits_per_subpacket);
00874     decode_gain_info(&q->gb, gains_ptr->now);
00875 
00876     /* Swap current and previous gains */
00877     FFSWAP(int *, gains_ptr->now, gains_ptr->previous);
00878 }
00879 
00887 static void
00888 saturate_output_float (COOKContext *q, int chan, int16_t *out)
00889 {
00890     int j;
00891     float *output = q->mono_mdct_output + q->samples_per_channel;
00892     /* Clip and convert floats to 16 bits.
00893      */
00894     for (j = 0; j < q->samples_per_channel; j++) {
00895         out[chan + q->nb_channels * j] =
00896           av_clip_int16(lrintf(output[j]));
00897     }
00898 }
00899 
00913 static inline void
00914 mlt_compensate_output(COOKContext *q, float *decode_buffer,
00915                       cook_gains *gains, float *previous_buffer,
00916                       int16_t *out, int chan)
00917 {
00918     imlt_gain(q, decode_buffer, gains, previous_buffer);
00919     q->saturate_output (q, chan, out);
00920 }
00921 
00922 
00934 static int decode_subpacket(COOKContext *q, const uint8_t *inbuffer,
00935                             int sub_packet_size, int16_t *outbuffer) {
00936     /* packet dump */
00937 //    for (i=0 ; i<sub_packet_size ; i++) {
00938 //        av_log(NULL, AV_LOG_ERROR, "%02x", inbuffer[i]);
00939 //    }
00940 //    av_log(NULL, AV_LOG_ERROR, "\n");
00941 
00942     decode_bytes_and_gain(q, inbuffer, &q->gains1);
00943 
00944     if (q->joint_stereo) {
00945         joint_decode(q, q->decode_buffer_1, q->decode_buffer_2);
00946     } else {
00947         mono_decode(q, q->decode_buffer_1);
00948 
00949         if (q->nb_channels == 2) {
00950             decode_bytes_and_gain(q, inbuffer + sub_packet_size/2, &q->gains2);
00951             mono_decode(q, q->decode_buffer_2);
00952         }
00953     }
00954 
00955     mlt_compensate_output(q, q->decode_buffer_1, &q->gains1,
00956                           q->mono_previous_buffer1, outbuffer, 0);
00957 
00958     if (q->nb_channels == 2) {
00959         if (q->joint_stereo) {
00960             mlt_compensate_output(q, q->decode_buffer_2, &q->gains1,
00961                                   q->mono_previous_buffer2, outbuffer, 1);
00962         } else {
00963             mlt_compensate_output(q, q->decode_buffer_2, &q->gains2,
00964                                   q->mono_previous_buffer2, outbuffer, 1);
00965         }
00966     }
00967     return q->samples_per_frame * sizeof(int16_t);
00968 }
00969 
00970 
00977 static int cook_decode_frame(AVCodecContext *avctx,
00978             void *data, int *data_size,
00979             const uint8_t *buf, int buf_size) {
00980     COOKContext *q = avctx->priv_data;
00981 
00982     if (buf_size < avctx->block_align)
00983         return buf_size;
00984 
00985     *data_size = decode_subpacket(q, buf, avctx->block_align, data);
00986 
00987     /* Discard the first two frames: no valid audio. */
00988     if (avctx->frame_number < 2) *data_size = 0;
00989 
00990     return avctx->block_align;
00991 }
00992 
00993 #ifdef COOKDEBUG
00994 static void dump_cook_context(COOKContext *q)
00995 {
00996     //int i=0;
00997 #define PRINT(a,b) av_log(NULL,AV_LOG_ERROR," %s = %d\n", a, b);
00998     av_log(NULL,AV_LOG_ERROR,"COOKextradata\n");
00999     av_log(NULL,AV_LOG_ERROR,"cookversion=%x\n",q->cookversion);
01000     if (q->cookversion > STEREO) {
01001         PRINT("js_subband_start",q->js_subband_start);
01002         PRINT("js_vlc_bits",q->js_vlc_bits);
01003     }
01004     av_log(NULL,AV_LOG_ERROR,"COOKContext\n");
01005     PRINT("nb_channels",q->nb_channels);
01006     PRINT("bit_rate",q->bit_rate);
01007     PRINT("sample_rate",q->sample_rate);
01008     PRINT("samples_per_channel",q->samples_per_channel);
01009     PRINT("samples_per_frame",q->samples_per_frame);
01010     PRINT("subbands",q->subbands);
01011     PRINT("random_state",q->random_state);
01012     PRINT("js_subband_start",q->js_subband_start);
01013     PRINT("log2_numvector_size",q->log2_numvector_size);
01014     PRINT("numvector_size",q->numvector_size);
01015     PRINT("total_subbands",q->total_subbands);
01016 }
01017 #endif
01018 
01025 static av_cold int cook_decode_init(AVCodecContext *avctx)
01026 {
01027     COOKContext *q = avctx->priv_data;
01028     const uint8_t *edata_ptr = avctx->extradata;
01029 
01030     /* Take care of the codec specific extradata. */
01031     if (avctx->extradata_size <= 0) {
01032         av_log(avctx,AV_LOG_ERROR,"Necessary extradata missing!\n");
01033         return -1;
01034     } else {
01035         /* 8 for mono, 16 for stereo, ? for multichannel
01036            Swap to right endianness so we don't need to care later on. */
01037         av_log(avctx,AV_LOG_DEBUG,"codecdata_length=%d\n",avctx->extradata_size);
01038         if (avctx->extradata_size >= 8){
01039             q->cookversion = bytestream_get_be32(&edata_ptr);
01040             q->samples_per_frame =  bytestream_get_be16(&edata_ptr);
01041             q->subbands = bytestream_get_be16(&edata_ptr);
01042         }
01043         if (avctx->extradata_size >= 16){
01044             bytestream_get_be32(&edata_ptr);    //Unknown unused
01045             q->js_subband_start = bytestream_get_be16(&edata_ptr);
01046             q->js_vlc_bits = bytestream_get_be16(&edata_ptr);
01047         }
01048     }
01049 
01050     /* Take data from the AVCodecContext (RM container). */
01051     q->sample_rate = avctx->sample_rate;
01052     q->nb_channels = avctx->channels;
01053     q->bit_rate = avctx->bit_rate;
01054 
01055     /* Initialize RNG. */
01056     av_random_init(&q->random_state, 1);
01057 
01058     /* Initialize extradata related variables. */
01059     q->samples_per_channel = q->samples_per_frame / q->nb_channels;
01060     q->bits_per_subpacket = avctx->block_align * 8;
01061 
01062     /* Initialize default data states. */
01063     q->log2_numvector_size = 5;
01064     q->total_subbands = q->subbands;
01065 
01066     /* Initialize version-dependent variables */
01067     av_log(NULL,AV_LOG_DEBUG,"q->cookversion=%x\n",q->cookversion);
01068     q->joint_stereo = 0;
01069     switch (q->cookversion) {
01070         case MONO:
01071             if (q->nb_channels != 1) {
01072                 av_log(avctx,AV_LOG_ERROR,"Container channels != 1, report sample!\n");
01073                 return -1;
01074             }
01075             av_log(avctx,AV_LOG_DEBUG,"MONO\n");
01076             break;
01077         case STEREO:
01078             if (q->nb_channels != 1) {
01079                 q->bits_per_subpacket = q->bits_per_subpacket/2;
01080             }
01081             av_log(avctx,AV_LOG_DEBUG,"STEREO\n");
01082             break;
01083         case JOINT_STEREO:
01084             if (q->nb_channels != 2) {
01085                 av_log(avctx,AV_LOG_ERROR,"Container channels != 2, report sample!\n");
01086                 return -1;
01087             }
01088             av_log(avctx,AV_LOG_DEBUG,"JOINT_STEREO\n");
01089             if (avctx->extradata_size >= 16){
01090                 q->total_subbands = q->subbands + q->js_subband_start;
01091                 q->joint_stereo = 1;
01092             }
01093             if (q->samples_per_channel > 256) {
01094                 q->log2_numvector_size  = 6;
01095             }
01096             if (q->samples_per_channel > 512) {
01097                 q->log2_numvector_size  = 7;
01098             }
01099             break;
01100         case MC_COOK:
01101             av_log(avctx,AV_LOG_ERROR,"MC_COOK not supported!\n");
01102             return -1;
01103             break;
01104         default:
01105             av_log(avctx,AV_LOG_ERROR,"Unknown Cook version, report sample!\n");
01106             return -1;
01107             break;
01108     }
01109 
01110     /* Initialize variable relations */
01111     q->numvector_size = (1 << q->log2_numvector_size);
01112 
01113     /* Generate tables */
01114     init_pow2table();
01115     init_gain_table(q);
01116     init_cplscales_table(q);
01117 
01118     if (init_cook_vlc_tables(q) != 0)
01119         return -1;
01120 
01121 
01122     if(avctx->block_align >= UINT_MAX/2)
01123         return -1;
01124 
01125     /* Pad the databuffer with:
01126        DECODE_BYTES_PAD1 or DECODE_BYTES_PAD2 for decode_bytes(),
01127        FF_INPUT_BUFFER_PADDING_SIZE, for the bitstreamreader. */
01128     if (q->nb_channels==2 && q->joint_stereo==0) {
01129         q->decoded_bytes_buffer =
01130           av_mallocz(avctx->block_align/2
01131                      + DECODE_BYTES_PAD2(avctx->block_align/2)
01132                      + FF_INPUT_BUFFER_PADDING_SIZE);
01133     } else {
01134         q->decoded_bytes_buffer =
01135           av_mallocz(avctx->block_align
01136                      + DECODE_BYTES_PAD1(avctx->block_align)
01137                      + FF_INPUT_BUFFER_PADDING_SIZE);
01138     }
01139     if (q->decoded_bytes_buffer == NULL)
01140         return -1;
01141 
01142     q->gains1.now      = q->gain_1;
01143     q->gains1.previous = q->gain_2;
01144     q->gains2.now      = q->gain_3;
01145     q->gains2.previous = q->gain_4;
01146 
01147     /* Initialize transform. */
01148     if ( init_cook_mlt(q) != 0 )
01149         return -1;
01150 
01151     /* Initialize COOK signal arithmetic handling */
01152     if (1) {
01153         q->scalar_dequant  = scalar_dequant_float;
01154         q->decouple        = decouple_float;
01155         q->imlt_window     = imlt_window_float;
01156         q->interpolate     = interpolate_float;
01157         q->saturate_output = saturate_output_float;
01158     }
01159 
01160     /* Try to catch some obviously faulty streams, othervise it might be exploitable */
01161     if (q->total_subbands > 53) {
01162         av_log(avctx,AV_LOG_ERROR,"total_subbands > 53, report sample!\n");
01163         return -1;
01164     }
01165     if (q->subbands > 50) {
01166         av_log(avctx,AV_LOG_ERROR,"subbands > 50, report sample!\n");
01167         return -1;
01168     }
01169     if ((q->samples_per_channel == 256) || (q->samples_per_channel == 512) || (q->samples_per_channel == 1024)) {
01170     } else {
01171         av_log(avctx,AV_LOG_ERROR,"unknown amount of samples_per_channel = %d, report sample!\n",q->samples_per_channel);
01172         return -1;
01173     }
01174     if ((q->js_vlc_bits > 6) || (q->js_vlc_bits < 0)) {
01175         av_log(avctx,AV_LOG_ERROR,"q->js_vlc_bits = %d, only >= 0 and <= 6 allowed!\n",q->js_vlc_bits);
01176         return -1;
01177     }
01178 
01179     avctx->sample_fmt = SAMPLE_FMT_S16;
01180     avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
01181 
01182 #ifdef COOKDEBUG
01183     dump_cook_context(q);
01184 #endif
01185     return 0;
01186 }
01187 
01188 
01189 AVCodec cook_decoder =
01190 {
01191     .name = "cook",
01192     .type = CODEC_TYPE_AUDIO,
01193     .id = CODEC_ID_COOK,
01194     .priv_data_size = sizeof(COOKContext),
01195     .init = cook_decode_init,
01196     .close = cook_decode_close,
01197     .decode = cook_decode_frame,
01198     .long_name = NULL_IF_CONFIG_SMALL("COOK"),
01199 };

Generated on Sat Feb 16 2013 09:23:11 for ffmpeg by  doxygen 1.7.1