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1 /*
2  * COOK compatible decoder
3  * Copyright (c) 2003 Sascha Sommer
4  * Copyright (c) 2005 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
25  * Cook compatible decoder. Bastardization of the G.722.1 standard.
26  * This decoder handles RealNetworks, RealAudio G2 data.
27  * Cook is identified by the codec name cook in RM files.
28  *
29  * To use this decoder, a calling application must supply the extradata
30  * bytes provided from the RM container; 8+ bytes for mono streams and
31  * 16+ for stereo streams (maybe more).
32  *
33  * Codec technicalities (all this assume a buffer length of 1024):
34  * Cook works with several different techniques to achieve its compression.
35  * In the timedomain the buffer is divided into 8 pieces and quantized. If
36  * two neighboring pieces have different quantization index a smooth
37  * quantization curve is used to get a smooth overlap between the different
38  * pieces.
39  * To get to the transformdomain Cook uses a modulated lapped transform.
40  * The transform domain has 50 subbands with 20 elements each. This
41  * means only a maximum of 50*20=1000 coefficients are used out of the 1024
42  * available.
43  */
44 
45 #include "libavutil/channel_layout.h"
46 #include "libavutil/lfg.h"
47 #include "libavutil/mem_internal.h"
48 #include "libavutil/thread.h"
49 
50 #include "audiodsp.h"
51 #include "avcodec.h"
52 #include "get_bits.h"
53 #include "bytestream.h"
54 #include "codec_internal.h"
55 #include "fft.h"
56 #include "internal.h"
57 #include "sinewin.h"
58 #include "unary.h"
59 
60 #include "cookdata.h"
61 
62 /* the different Cook versions */
63 #define MONO            0x1000001
64 #define STEREO          0x1000002
65 #define JOINT_STEREO    0x1000003
66 #define MC_COOK         0x2000000
67 
68 #define SUBBAND_SIZE    20
69 #define MAX_SUBPACKETS   5
70 
71 #define QUANT_VLC_BITS    9
72 #define COUPLING_VLC_BITS 6
73 
74 typedef struct cook_gains {
75     int *now;
76     int *previous;
77 } cook_gains;
78 
79 typedef struct COOKSubpacket {
80     int                 ch_idx;
81     int                 size;
82     int                 num_channels;
83     int                 cookversion;
84     int                 subbands;
85     int                 js_subband_start;
86     int                 js_vlc_bits;
87     int                 samples_per_channel;
88     int                 log2_numvector_size;
89     unsigned int        channel_mask;
90     VLC                 channel_coupling;
91     int                 joint_stereo;
92     int                 bits_per_subpacket;
93     int                 bits_per_subpdiv;
94     int                 total_subbands;
95     int                 numvector_size;       // 1 << log2_numvector_size;
96 
97     float               mono_previous_buffer1[1024];
98     float               mono_previous_buffer2[1024];
99 
100     cook_gains          gains1;
101     cook_gains          gains2;
102     int                 gain_1[9];
103     int                 gain_2[9];
104     int                 gain_3[9];
105     int                 gain_4[9];
106 } COOKSubpacket;
107 
108 typedef struct cook {
109     /*
110      * The following 5 functions provide the lowlevel arithmetic on
111      * the internal audio buffers.
112      */
113     void (*scalar_dequant)(struct cook *q, int index, int quant_index,
114                            int *subband_coef_index, int *subband_coef_sign,
115                            float *mlt_p);
116 
117     void (*decouple)(struct cook *q,
118                      COOKSubpacket *p,
119                      int subband,
120                      float f1, float f2,
121                      float *decode_buffer,
122                      float *mlt_buffer1, float *mlt_buffer2);
123 
124     void (*imlt_window)(struct cook *q, float *buffer1,
125                         cook_gains *gains_ptr, float *previous_buffer);
126 
127     void (*interpolate)(struct cook *q, float *buffer,
128                         int gain_index, int gain_index_next);
129 
130     void (*saturate_output)(struct cook *q, float *out);
131 
132     AVCodecContext*     avctx;
133     AudioDSPContext     adsp;
134     GetBitContext       gb;
135     /* stream data */
136     int                 num_vectors;
137     int                 samples_per_channel;
138     /* states */
139     AVLFG               random_state;
140     int                 discarded_packets;
141 
142     /* transform data */
143     FFTContext          mdct_ctx;
144     float*              mlt_window;
145 
146     /* VLC data */
147     VLC                 envelope_quant_index[13];
148     VLC                 sqvh[7];          // scalar quantization
149 
150     /* generate tables and related variables */
151     int                 gain_size_factor;
152     float               gain_table[31];
153 
154     /* data buffers */
155 
156     uint8_t*            decoded_bytes_buffer;
157     DECLARE_ALIGNED(32, float, mono_mdct_output)[2048];
158     float               decode_buffer_1[1024];
159     float               decode_buffer_2[1024];
160     float               decode_buffer_0[1060]; /* static allocation for joint decode */
161 
162     const float         *cplscales[5];
163     int                 num_subpackets;
164     COOKSubpacket       subpacket[MAX_SUBPACKETS];
165 } COOKContext;
166 
167 static float     pow2tab[127];
168 static float rootpow2tab[127];
169 
170 /*************** init functions ***************/
171 
172 /* table generator */
init_pow2table(void)173 static av_cold void init_pow2table(void)
174 {
175     /* fast way of computing 2^i and 2^(0.5*i) for -63 <= i < 64 */
176     int i;
177     static const float exp2_tab[2] = {1, M_SQRT2};
178     float exp2_val = powf(2, -63);
179     float root_val = powf(2, -32);
180     for (i = -63; i < 64; i++) {
181         if (!(i & 1))
182             root_val *= 2;
183         pow2tab[63 + i] = exp2_val;
184         rootpow2tab[63 + i] = root_val * exp2_tab[i & 1];
185         exp2_val *= 2;
186     }
187 }
188 
189 /* table generator */
init_gain_table(COOKContext * q)190 static av_cold void init_gain_table(COOKContext *q)
191 {
192     int i;
193     q->gain_size_factor = q->samples_per_channel / 8;
194     for (i = 0; i < 31; i++)
195         q->gain_table[i] = pow(pow2tab[i + 48],
196                                (1.0 / (double) q->gain_size_factor));
197 }
198 
build_vlc(VLC * vlc,int nb_bits,const uint8_t counts[16],const void * syms,int symbol_size,int offset,void * logctx)199 static av_cold int build_vlc(VLC *vlc, int nb_bits, const uint8_t counts[16],
200                              const void *syms, int symbol_size, int offset,
201                              void *logctx)
202 {
203     uint8_t lens[MAX_COOK_VLC_ENTRIES];
204     unsigned num = 0;
205 
206     for (int i = 0; i < 16; i++)
207         for (unsigned count = num + counts[i]; num < count; num++)
208             lens[num] = i + 1;
209 
210     return ff_init_vlc_from_lengths(vlc, nb_bits, num, lens, 1,
211                                     syms, symbol_size, symbol_size,
212                                     offset, 0, logctx);
213 }
214 
init_cook_vlc_tables(COOKContext * q)215 static av_cold int init_cook_vlc_tables(COOKContext *q)
216 {
217     int i, result;
218 
219     result = 0;
220     for (i = 0; i < 13; i++) {
221         result |= build_vlc(&q->envelope_quant_index[i], QUANT_VLC_BITS,
222                             envelope_quant_index_huffcounts[i],
223                             envelope_quant_index_huffsyms[i], 1, -12, q->avctx);
224     }
225     av_log(q->avctx, AV_LOG_DEBUG, "sqvh VLC init\n");
226     for (i = 0; i < 7; i++) {
227         int sym_size = 1 + (i == 3);
228         result |= build_vlc(&q->sqvh[i], vhvlcsize_tab[i],
229                             cvh_huffcounts[i],
230                             cvh_huffsyms[i], sym_size, 0, q->avctx);
231     }
232 
233     for (i = 0; i < q->num_subpackets; i++) {
234         if (q->subpacket[i].joint_stereo == 1) {
235             result |= build_vlc(&q->subpacket[i].channel_coupling, COUPLING_VLC_BITS,
236                                 ccpl_huffcounts[q->subpacket[i].js_vlc_bits - 2],
237                                 ccpl_huffsyms[q->subpacket[i].js_vlc_bits - 2], 1,
238                                 0, q->avctx);
239             av_log(q->avctx, AV_LOG_DEBUG, "subpacket %i Joint-stereo VLC used.\n", i);
240         }
241     }
242 
243     av_log(q->avctx, AV_LOG_DEBUG, "VLC tables initialized.\n");
244     return result;
245 }
246 
init_cook_mlt(COOKContext * q)247 static av_cold int init_cook_mlt(COOKContext *q)
248 {
249     int j, ret;
250     int mlt_size = q->samples_per_channel;
251 
252     if (!(q->mlt_window = av_malloc_array(mlt_size, sizeof(*q->mlt_window))))
253         return AVERROR(ENOMEM);
254 
255     /* Initialize the MLT window: simple sine window. */
256     ff_sine_window_init(q->mlt_window, mlt_size);
257     for (j = 0; j < mlt_size; j++)
258         q->mlt_window[j] *= sqrt(2.0 / q->samples_per_channel);
259 
260     /* Initialize the MDCT. */
261     ret = ff_mdct_init(&q->mdct_ctx, av_log2(mlt_size) + 1, 1, 1.0 / 32768.0);
262     if (ret < 0)
263         return ret;
264     av_log(q->avctx, AV_LOG_DEBUG, "MDCT initialized, order = %d.\n",
265            av_log2(mlt_size) + 1);
266 
267     return 0;
268 }
269 
init_cplscales_table(COOKContext * q)270 static av_cold void init_cplscales_table(COOKContext *q)
271 {
272     int i;
273     for (i = 0; i < 5; i++)
274         q->cplscales[i] = cplscales[i];
275 }
276 
277 /*************** init functions end ***********/
278 
279 #define DECODE_BYTES_PAD1(bytes) (3 - ((bytes) + 3) % 4)
280 #define DECODE_BYTES_PAD2(bytes) ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))
281 
282 /**
283  * Cook indata decoding, every 32 bits are XORed with 0x37c511f2.
284  * Why? No idea, some checksum/error detection method maybe.
285  *
286  * Out buffer size: extra bytes are needed to cope with
287  * padding/misalignment.
288  * Subpackets passed to the decoder can contain two, consecutive
289  * half-subpackets, of identical but arbitrary size.
290  *          1234 1234 1234 1234  extraA extraB
291  * Case 1:  AAAA BBBB              0      0
292  * Case 2:  AAAA ABBB BB--         3      3
293  * Case 3:  AAAA AABB BBBB         2      2
294  * Case 4:  AAAA AAAB BBBB BB--    1      5
295  *
296  * Nice way to waste CPU cycles.
297  *
298  * @param inbuffer  pointer to byte array of indata
299  * @param out       pointer to byte array of outdata
300  * @param bytes     number of bytes
301  */
decode_bytes(const uint8_t * inbuffer,uint8_t * out,int bytes)302 static inline int decode_bytes(const uint8_t *inbuffer, uint8_t *out, int bytes)
303 {
304     static const uint32_t tab[4] = {
305         AV_BE2NE32C(0x37c511f2u), AV_BE2NE32C(0xf237c511u),
306         AV_BE2NE32C(0x11f237c5u), AV_BE2NE32C(0xc511f237u),
307     };
308     int i, off;
309     uint32_t c;
310     const uint32_t *buf;
311     uint32_t *obuf = (uint32_t *) out;
312     /* FIXME: 64 bit platforms would be able to do 64 bits at a time.
313      * I'm too lazy though, should be something like
314      * for (i = 0; i < bitamount / 64; i++)
315      *     (int64_t) out[i] = 0x37c511f237c511f2 ^ av_be2ne64(int64_t) in[i]);
316      * Buffer alignment needs to be checked. */
317 
318     off = (intptr_t) inbuffer & 3;
319     buf = (const uint32_t *) (inbuffer - off);
320     c = tab[off];
321     bytes += 3 + off;
322     for (i = 0; i < bytes / 4; i++)
323         obuf[i] = c ^ buf[i];
324 
325     return off;
326 }
327 
cook_decode_close(AVCodecContext * avctx)328 static av_cold int cook_decode_close(AVCodecContext *avctx)
329 {
330     int i;
331     COOKContext *q = avctx->priv_data;
332     av_log(avctx, AV_LOG_DEBUG, "Deallocating memory.\n");
333 
334     /* Free allocated memory buffers. */
335     av_freep(&q->mlt_window);
336     av_freep(&q->decoded_bytes_buffer);
337 
338     /* Free the transform. */
339     ff_mdct_end(&q->mdct_ctx);
340 
341     /* Free the VLC tables. */
342     for (i = 0; i < 13; i++)
343         ff_free_vlc(&q->envelope_quant_index[i]);
344     for (i = 0; i < 7; i++)
345         ff_free_vlc(&q->sqvh[i]);
346     for (i = 0; i < q->num_subpackets; i++)
347         ff_free_vlc(&q->subpacket[i].channel_coupling);
348 
349     av_log(avctx, AV_LOG_DEBUG, "Memory deallocated.\n");
350 
351     return 0;
352 }
353 
354 /**
355  * Fill the gain array for the timedomain quantization.
356  *
357  * @param gb          pointer to the GetBitContext
358  * @param gaininfo    array[9] of gain indexes
359  */
decode_gain_info(GetBitContext * gb,int * gaininfo)360 static void decode_gain_info(GetBitContext *gb, int *gaininfo)
361 {
362     int i, n;
363 
364     n = get_unary(gb, 0, get_bits_left(gb));     // amount of elements*2 to update
365 
366     i = 0;
367     while (n--) {
368         int index = get_bits(gb, 3);
369         int gain = get_bits1(gb) ? get_bits(gb, 4) - 7 : -1;
370 
371         while (i <= index)
372             gaininfo[i++] = gain;
373     }
374     while (i <= 8)
375         gaininfo[i++] = 0;
376 }
377 
378 /**
379  * Create the quant index table needed for the envelope.
380  *
381  * @param q                 pointer to the COOKContext
382  * @param quant_index_table pointer to the array
383  */
decode_envelope(COOKContext * q,COOKSubpacket * p,int * quant_index_table)384 static int decode_envelope(COOKContext *q, COOKSubpacket *p,
385                            int *quant_index_table)
386 {
387     int i, j, vlc_index;
388 
389     quant_index_table[0] = get_bits(&q->gb, 6) - 6; // This is used later in categorize
390 
391     for (i = 1; i < p->total_subbands; i++) {
392         vlc_index = i;
393         if (i >= p->js_subband_start * 2) {
394             vlc_index -= p->js_subband_start;
395         } else {
396             vlc_index /= 2;
397             if (vlc_index < 1)
398                 vlc_index = 1;
399         }
400         if (vlc_index > 13)
401             vlc_index = 13; // the VLC tables >13 are identical to No. 13
402 
403         j = get_vlc2(&q->gb, q->envelope_quant_index[vlc_index - 1].table,
404                      QUANT_VLC_BITS, 2);
405         quant_index_table[i] = quant_index_table[i - 1] + j; // differential encoding
406         if (quant_index_table[i] > 63 || quant_index_table[i] < -63) {
407             av_log(q->avctx, AV_LOG_ERROR,
408                    "Invalid quantizer %d at position %d, outside [-63, 63] range\n",
409                    quant_index_table[i], i);
410             return AVERROR_INVALIDDATA;
411         }
412     }
413 
414     return 0;
415 }
416 
417 /**
418  * Calculate the category and category_index vector.
419  *
420  * @param q                     pointer to the COOKContext
421  * @param quant_index_table     pointer to the array
422  * @param category              pointer to the category array
423  * @param category_index        pointer to the category_index array
424  */
categorize(COOKContext * q,COOKSubpacket * p,const int * quant_index_table,int * category,int * category_index)425 static void categorize(COOKContext *q, COOKSubpacket *p, const int *quant_index_table,
426                        int *category, int *category_index)
427 {
428     int exp_idx, bias, tmpbias1, tmpbias2, bits_left, num_bits, index, v, i, j;
429     int exp_index2[102] = { 0 };
430     int exp_index1[102] = { 0 };
431 
432     int tmp_categorize_array[128 * 2] = { 0 };
433     int tmp_categorize_array1_idx = p->numvector_size;
434     int tmp_categorize_array2_idx = p->numvector_size;
435 
436     bits_left = p->bits_per_subpacket - get_bits_count(&q->gb);
437 
438     if (bits_left > q->samples_per_channel)
439         bits_left = q->samples_per_channel +
440                     ((bits_left - q->samples_per_channel) * 5) / 8;
441 
442     bias = -32;
443 
444     /* Estimate bias. */
445     for (i = 32; i > 0; i = i / 2) {
446         num_bits = 0;
447         index    = 0;
448         for (j = p->total_subbands; j > 0; j--) {
449             exp_idx = av_clip_uintp2((i - quant_index_table[index] + bias) / 2, 3);
450             index++;
451             num_bits += expbits_tab[exp_idx];
452         }
453         if (num_bits >= bits_left - 32)
454             bias += i;
455     }
456 
457     /* Calculate total number of bits. */
458     num_bits = 0;
459     for (i = 0; i < p->total_subbands; i++) {
460         exp_idx = av_clip_uintp2((bias - quant_index_table[i]) / 2, 3);
461         num_bits += expbits_tab[exp_idx];
462         exp_index1[i] = exp_idx;
463         exp_index2[i] = exp_idx;
464     }
465     tmpbias1 = tmpbias2 = num_bits;
466 
467     for (j = 1; j < p->numvector_size; j++) {
468         if (tmpbias1 + tmpbias2 > 2 * bits_left) {  /* ---> */
469             int max = -999999;
470             index = -1;
471             for (i = 0; i < p->total_subbands; i++) {
472                 if (exp_index1[i] < 7) {
473                     v = (-2 * exp_index1[i]) - quant_index_table[i] + bias;
474                     if (v >= max) {
475                         max   = v;
476                         index = i;
477                     }
478                 }
479             }
480             if (index == -1)
481                 break;
482             tmp_categorize_array[tmp_categorize_array1_idx++] = index;
483             tmpbias1 -= expbits_tab[exp_index1[index]] -
484                         expbits_tab[exp_index1[index] + 1];
485             ++exp_index1[index];
486         } else {  /* <--- */
487             int min = 999999;
488             index = -1;
489             for (i = 0; i < p->total_subbands; i++) {
490                 if (exp_index2[i] > 0) {
491                     v = (-2 * exp_index2[i]) - quant_index_table[i] + bias;
492                     if (v < min) {
493                         min   = v;
494                         index = i;
495                     }
496                 }
497             }
498             if (index == -1)
499                 break;
500             tmp_categorize_array[--tmp_categorize_array2_idx] = index;
501             tmpbias2 -= expbits_tab[exp_index2[index]] -
502                         expbits_tab[exp_index2[index] - 1];
503             --exp_index2[index];
504         }
505     }
506 
507     for (i = 0; i < p->total_subbands; i++)
508         category[i] = exp_index2[i];
509 
510     for (i = 0; i < p->numvector_size - 1; i++)
511         category_index[i] = tmp_categorize_array[tmp_categorize_array2_idx++];
512 }
513 
514 
515 /**
516  * Expand the category vector.
517  *
518  * @param q                     pointer to the COOKContext
519  * @param category              pointer to the category array
520  * @param category_index        pointer to the category_index array
521  */
expand_category(COOKContext * q,int * category,int * category_index)522 static inline void expand_category(COOKContext *q, int *category,
523                                    int *category_index)
524 {
525     int i;
526     for (i = 0; i < q->num_vectors; i++)
527     {
528         int idx = category_index[i];
529         if (++category[idx] >= FF_ARRAY_ELEMS(dither_tab))
530             --category[idx];
531     }
532 }
533 
534 /**
535  * The real requantization of the mltcoefs
536  *
537  * @param q                     pointer to the COOKContext
538  * @param index                 index
539  * @param quant_index           quantisation index
540  * @param subband_coef_index    array of indexes to quant_centroid_tab
541  * @param subband_coef_sign     signs of coefficients
542  * @param mlt_p                 pointer into the mlt buffer
543  */
scalar_dequant_float(COOKContext * q,int index,int quant_index,int * subband_coef_index,int * subband_coef_sign,float * mlt_p)544 static void scalar_dequant_float(COOKContext *q, int index, int quant_index,
545                                  int *subband_coef_index, int *subband_coef_sign,
546                                  float *mlt_p)
547 {
548     int i;
549     float f1;
550 
551     for (i = 0; i < SUBBAND_SIZE; i++) {
552         if (subband_coef_index[i]) {
553             f1 = quant_centroid_tab[index][subband_coef_index[i]];
554             if (subband_coef_sign[i])
555                 f1 = -f1;
556         } else {
557             /* noise coding if subband_coef_index[i] == 0 */
558             f1 = dither_tab[index];
559             if (av_lfg_get(&q->random_state) < 0x80000000)
560                 f1 = -f1;
561         }
562         mlt_p[i] = f1 * rootpow2tab[quant_index + 63];
563     }
564 }
565 /**
566  * Unpack the subband_coef_index and subband_coef_sign vectors.
567  *
568  * @param q                     pointer to the COOKContext
569  * @param category              pointer to the category array
570  * @param subband_coef_index    array of indexes to quant_centroid_tab
571  * @param subband_coef_sign     signs of coefficients
572  */
unpack_SQVH(COOKContext * q,COOKSubpacket * p,int category,int * subband_coef_index,int * subband_coef_sign)573 static int unpack_SQVH(COOKContext *q, COOKSubpacket *p, int category,
574                        int *subband_coef_index, int *subband_coef_sign)
575 {
576     int i, j;
577     int vlc, vd, tmp, result;
578 
579     vd = vd_tab[category];
580     result = 0;
581     for (i = 0; i < vpr_tab[category]; i++) {
582         vlc = get_vlc2(&q->gb, q->sqvh[category].table, q->sqvh[category].bits, 3);
583         if (p->bits_per_subpacket < get_bits_count(&q->gb)) {
584             vlc = 0;
585             result = 1;
586         }
587         for (j = vd - 1; j >= 0; j--) {
588             tmp = (vlc * invradix_tab[category]) / 0x100000;
589             subband_coef_index[vd * i + j] = vlc - tmp * (kmax_tab[category] + 1);
590             vlc = tmp;
591         }
592         for (j = 0; j < vd; j++) {
593             if (subband_coef_index[i * vd + j]) {
594                 if (get_bits_count(&q->gb) < p->bits_per_subpacket) {
595                     subband_coef_sign[i * vd + j] = get_bits1(&q->gb);
596                 } else {
597                     result = 1;
598                     subband_coef_sign[i * vd + j] = 0;
599                 }
600             } else {
601                 subband_coef_sign[i * vd + j] = 0;
602             }
603         }
604     }
605     return result;
606 }
607 
608 
609 /**
610  * Fill the mlt_buffer with mlt coefficients.
611  *
612  * @param q                 pointer to the COOKContext
613  * @param category          pointer to the category array
614  * @param quant_index_table pointer to the array
615  * @param mlt_buffer        pointer to mlt coefficients
616  */
decode_vectors(COOKContext * q,COOKSubpacket * p,int * category,int * quant_index_table,float * mlt_buffer)617 static void decode_vectors(COOKContext *q, COOKSubpacket *p, int *category,
618                            int *quant_index_table, float *mlt_buffer)
619 {
620     /* A zero in this table means that the subband coefficient is
621        random noise coded. */
622     int subband_coef_index[SUBBAND_SIZE];
623     /* A zero in this table means that the subband coefficient is a
624        positive multiplicator. */
625     int subband_coef_sign[SUBBAND_SIZE];
626     int band, j;
627     int index = 0;
628 
629     for (band = 0; band < p->total_subbands; band++) {
630         index = category[band];
631         if (category[band] < 7) {
632             if (unpack_SQVH(q, p, category[band], subband_coef_index, subband_coef_sign)) {
633                 index = 7;
634                 for (j = 0; j < p->total_subbands; j++)
635                     category[band + j] = 7;
636             }
637         }
638         if (index >= 7) {
639             memset(subband_coef_index, 0, sizeof(subband_coef_index));
640             memset(subband_coef_sign,  0, sizeof(subband_coef_sign));
641         }
642         q->scalar_dequant(q, index, quant_index_table[band],
643                           subband_coef_index, subband_coef_sign,
644                           &mlt_buffer[band * SUBBAND_SIZE]);
645     }
646 
647     /* FIXME: should this be removed, or moved into loop above? */
648     if (p->total_subbands * SUBBAND_SIZE >= q->samples_per_channel)
649         return;
650 }
651 
652 
mono_decode(COOKContext * q,COOKSubpacket * p,float * mlt_buffer)653 static int mono_decode(COOKContext *q, COOKSubpacket *p, float *mlt_buffer)
654 {
655     int category_index[128] = { 0 };
656     int category[128]       = { 0 };
657     int quant_index_table[102];
658     int res, i;
659 
660     if ((res = decode_envelope(q, p, quant_index_table)) < 0)
661         return res;
662     q->num_vectors = get_bits(&q->gb, p->log2_numvector_size);
663     categorize(q, p, quant_index_table, category, category_index);
664     expand_category(q, category, category_index);
665     for (i=0; i<p->total_subbands; i++) {
666         if (category[i] > 7)
667             return AVERROR_INVALIDDATA;
668     }
669     decode_vectors(q, p, category, quant_index_table, mlt_buffer);
670 
671     return 0;
672 }
673 
674 
675 /**
676  * the actual requantization of the timedomain samples
677  *
678  * @param q                 pointer to the COOKContext
679  * @param buffer            pointer to the timedomain buffer
680  * @param gain_index        index for the block multiplier
681  * @param gain_index_next   index for the next block multiplier
682  */
interpolate_float(COOKContext * q,float * buffer,int gain_index,int gain_index_next)683 static void interpolate_float(COOKContext *q, float *buffer,
684                               int gain_index, int gain_index_next)
685 {
686     int i;
687     float fc1, fc2;
688     fc1 = pow2tab[gain_index + 63];
689 
690     if (gain_index == gain_index_next) {             // static gain
691         for (i = 0; i < q->gain_size_factor; i++)
692             buffer[i] *= fc1;
693     } else {                                        // smooth gain
694         fc2 = q->gain_table[15 + (gain_index_next - gain_index)];
695         for (i = 0; i < q->gain_size_factor; i++) {
696             buffer[i] *= fc1;
697             fc1       *= fc2;
698         }
699     }
700 }
701 
702 /**
703  * Apply transform window, overlap buffers.
704  *
705  * @param q                 pointer to the COOKContext
706  * @param inbuffer          pointer to the mltcoefficients
707  * @param gains_ptr         current and previous gains
708  * @param previous_buffer   pointer to the previous buffer to be used for overlapping
709  */
imlt_window_float(COOKContext * q,float * inbuffer,cook_gains * gains_ptr,float * previous_buffer)710 static void imlt_window_float(COOKContext *q, float *inbuffer,
711                               cook_gains *gains_ptr, float *previous_buffer)
712 {
713     const float fc = pow2tab[gains_ptr->previous[0] + 63];
714     int i;
715     /* The weird thing here, is that the two halves of the time domain
716      * buffer are swapped. Also, the newest data, that we save away for
717      * next frame, has the wrong sign. Hence the subtraction below.
718      * Almost sounds like a complex conjugate/reverse data/FFT effect.
719      */
720 
721     /* Apply window and overlap */
722     for (i = 0; i < q->samples_per_channel; i++)
723         inbuffer[i] = inbuffer[i] * fc * q->mlt_window[i] -
724                       previous_buffer[i] * q->mlt_window[q->samples_per_channel - 1 - i];
725 }
726 
727 /**
728  * The modulated lapped transform, this takes transform coefficients
729  * and transforms them into timedomain samples.
730  * Apply transform window, overlap buffers, apply gain profile
731  * and buffer management.
732  *
733  * @param q                 pointer to the COOKContext
734  * @param inbuffer          pointer to the mltcoefficients
735  * @param gains_ptr         current and previous gains
736  * @param previous_buffer   pointer to the previous buffer to be used for overlapping
737  */
imlt_gain(COOKContext * q,float * inbuffer,cook_gains * gains_ptr,float * previous_buffer)738 static void imlt_gain(COOKContext *q, float *inbuffer,
739                       cook_gains *gains_ptr, float *previous_buffer)
740 {
741     float *buffer0 = q->mono_mdct_output;
742     float *buffer1 = q->mono_mdct_output + q->samples_per_channel;
743     int i;
744 
745     /* Inverse modified discrete cosine transform */
746     q->mdct_ctx.imdct_calc(&q->mdct_ctx, q->mono_mdct_output, inbuffer);
747 
748     q->imlt_window(q, buffer1, gains_ptr, previous_buffer);
749 
750     /* Apply gain profile */
751     for (i = 0; i < 8; i++)
752         if (gains_ptr->now[i] || gains_ptr->now[i + 1])
753             q->interpolate(q, &buffer1[q->gain_size_factor * i],
754                            gains_ptr->now[i], gains_ptr->now[i + 1]);
755 
756     /* Save away the current to be previous block. */
757     memcpy(previous_buffer, buffer0,
758            q->samples_per_channel * sizeof(*previous_buffer));
759 }
760 
761 
762 /**
763  * function for getting the jointstereo coupling information
764  *
765  * @param q                 pointer to the COOKContext
766  * @param decouple_tab      decoupling array
767  */
decouple_info(COOKContext * q,COOKSubpacket * p,int * decouple_tab)768 static int decouple_info(COOKContext *q, COOKSubpacket *p, int *decouple_tab)
769 {
770     int i;
771     int vlc    = get_bits1(&q->gb);
772     int start  = cplband[p->js_subband_start];
773     int end    = cplband[p->subbands - 1];
774     int length = end - start + 1;
775 
776     if (start > end)
777         return 0;
778 
779     if (vlc)
780         for (i = 0; i < length; i++)
781             decouple_tab[start + i] = get_vlc2(&q->gb,
782                                                p->channel_coupling.table,
783                                                COUPLING_VLC_BITS, 3);
784     else
785         for (i = 0; i < length; i++) {
786             int v = get_bits(&q->gb, p->js_vlc_bits);
787             if (v == (1<<p->js_vlc_bits)-1) {
788                 av_log(q->avctx, AV_LOG_ERROR, "decouple value too large\n");
789                 return AVERROR_INVALIDDATA;
790             }
791             decouple_tab[start + i] = v;
792         }
793     return 0;
794 }
795 
796 /**
797  * function decouples a pair of signals from a single signal via multiplication.
798  *
799  * @param q                 pointer to the COOKContext
800  * @param subband           index of the current subband
801  * @param f1                multiplier for channel 1 extraction
802  * @param f2                multiplier for channel 2 extraction
803  * @param decode_buffer     input buffer
804  * @param mlt_buffer1       pointer to left channel mlt coefficients
805  * @param mlt_buffer2       pointer to right channel mlt coefficients
806  */
decouple_float(COOKContext * q,COOKSubpacket * p,int subband,float f1,float f2,float * decode_buffer,float * mlt_buffer1,float * mlt_buffer2)807 static void decouple_float(COOKContext *q,
808                            COOKSubpacket *p,
809                            int subband,
810                            float f1, float f2,
811                            float *decode_buffer,
812                            float *mlt_buffer1, float *mlt_buffer2)
813 {
814     int j, tmp_idx;
815     for (j = 0; j < SUBBAND_SIZE; j++) {
816         tmp_idx = ((p->js_subband_start + subband) * SUBBAND_SIZE) + j;
817         mlt_buffer1[SUBBAND_SIZE * subband + j] = f1 * decode_buffer[tmp_idx];
818         mlt_buffer2[SUBBAND_SIZE * subband + j] = f2 * decode_buffer[tmp_idx];
819     }
820 }
821 
822 /**
823  * function for decoding joint stereo data
824  *
825  * @param q                 pointer to the COOKContext
826  * @param mlt_buffer1       pointer to left channel mlt coefficients
827  * @param mlt_buffer2       pointer to right channel mlt coefficients
828  */
joint_decode(COOKContext * q,COOKSubpacket * p,float * mlt_buffer_left,float * mlt_buffer_right)829 static int joint_decode(COOKContext *q, COOKSubpacket *p,
830                         float *mlt_buffer_left, float *mlt_buffer_right)
831 {
832     int i, j, res;
833     int decouple_tab[SUBBAND_SIZE] = { 0 };
834     float *decode_buffer = q->decode_buffer_0;
835     int idx, cpl_tmp;
836     float f1, f2;
837     const float *cplscale;
838 
839     memset(decode_buffer, 0, sizeof(q->decode_buffer_0));
840 
841     /* Make sure the buffers are zeroed out. */
842     memset(mlt_buffer_left,  0, 1024 * sizeof(*mlt_buffer_left));
843     memset(mlt_buffer_right, 0, 1024 * sizeof(*mlt_buffer_right));
844     if ((res = decouple_info(q, p, decouple_tab)) < 0)
845         return res;
846     if ((res = mono_decode(q, p, decode_buffer)) < 0)
847         return res;
848     /* The two channels are stored interleaved in decode_buffer. */
849     for (i = 0; i < p->js_subband_start; i++) {
850         for (j = 0; j < SUBBAND_SIZE; j++) {
851             mlt_buffer_left[i  * 20 + j] = decode_buffer[i * 40 + j];
852             mlt_buffer_right[i * 20 + j] = decode_buffer[i * 40 + 20 + j];
853         }
854     }
855 
856     /* When we reach js_subband_start (the higher frequencies)
857        the coefficients are stored in a coupling scheme. */
858     idx = (1 << p->js_vlc_bits) - 1;
859     for (i = p->js_subband_start; i < p->subbands; i++) {
860         cpl_tmp = cplband[i];
861         idx -= decouple_tab[cpl_tmp];
862         cplscale = q->cplscales[p->js_vlc_bits - 2];  // choose decoupler table
863         f1 = cplscale[decouple_tab[cpl_tmp] + 1];
864         f2 = cplscale[idx];
865         q->decouple(q, p, i, f1, f2, decode_buffer,
866                     mlt_buffer_left, mlt_buffer_right);
867         idx = (1 << p->js_vlc_bits) - 1;
868     }
869 
870     return 0;
871 }
872 
873 /**
874  * First part of subpacket decoding:
875  *  decode raw stream bytes and read gain info.
876  *
877  * @param q                 pointer to the COOKContext
878  * @param inbuffer          pointer to raw stream data
879  * @param gains_ptr         array of current/prev gain pointers
880  */
decode_bytes_and_gain(COOKContext * q,COOKSubpacket * p,const uint8_t * inbuffer,cook_gains * gains_ptr)881 static inline void decode_bytes_and_gain(COOKContext *q, COOKSubpacket *p,
882                                          const uint8_t *inbuffer,
883                                          cook_gains *gains_ptr)
884 {
885     int offset;
886 
887     offset = decode_bytes(inbuffer, q->decoded_bytes_buffer,
888                           p->bits_per_subpacket / 8);
889     init_get_bits(&q->gb, q->decoded_bytes_buffer + offset,
890                   p->bits_per_subpacket);
891     decode_gain_info(&q->gb, gains_ptr->now);
892 
893     /* Swap current and previous gains */
894     FFSWAP(int *, gains_ptr->now, gains_ptr->previous);
895 }
896 
897 /**
898  * Saturate the output signal and interleave.
899  *
900  * @param q                 pointer to the COOKContext
901  * @param out               pointer to the output vector
902  */
saturate_output_float(COOKContext * q,float * out)903 static void saturate_output_float(COOKContext *q, float *out)
904 {
905     q->adsp.vector_clipf(out, q->mono_mdct_output + q->samples_per_channel,
906                          FFALIGN(q->samples_per_channel, 8), -1.0f, 1.0f);
907 }
908 
909 
910 /**
911  * Final part of subpacket decoding:
912  *  Apply modulated lapped transform, gain compensation,
913  *  clip and convert to integer.
914  *
915  * @param q                 pointer to the COOKContext
916  * @param decode_buffer     pointer to the mlt coefficients
917  * @param gains_ptr         array of current/prev gain pointers
918  * @param previous_buffer   pointer to the previous buffer to be used for overlapping
919  * @param out               pointer to the output buffer
920  */
mlt_compensate_output(COOKContext * q,float * decode_buffer,cook_gains * gains_ptr,float * previous_buffer,float * out)921 static inline void mlt_compensate_output(COOKContext *q, float *decode_buffer,
922                                          cook_gains *gains_ptr, float *previous_buffer,
923                                          float *out)
924 {
925     imlt_gain(q, decode_buffer, gains_ptr, previous_buffer);
926     if (out)
927         q->saturate_output(q, out);
928 }
929 
930 
931 /**
932  * Cook subpacket decoding. This function returns one decoded subpacket,
933  * usually 1024 samples per channel.
934  *
935  * @param q                 pointer to the COOKContext
936  * @param inbuffer          pointer to the inbuffer
937  * @param outbuffer         pointer to the outbuffer
938  */
decode_subpacket(COOKContext * q,COOKSubpacket * p,const uint8_t * inbuffer,float ** outbuffer)939 static int decode_subpacket(COOKContext *q, COOKSubpacket *p,
940                             const uint8_t *inbuffer, float **outbuffer)
941 {
942     int sub_packet_size = p->size;
943     int res;
944 
945     memset(q->decode_buffer_1, 0, sizeof(q->decode_buffer_1));
946     decode_bytes_and_gain(q, p, inbuffer, &p->gains1);
947 
948     if (p->joint_stereo) {
949         if ((res = joint_decode(q, p, q->decode_buffer_1, q->decode_buffer_2)) < 0)
950             return res;
951     } else {
952         if ((res = mono_decode(q, p, q->decode_buffer_1)) < 0)
953             return res;
954 
955         if (p->num_channels == 2) {
956             decode_bytes_and_gain(q, p, inbuffer + sub_packet_size / 2, &p->gains2);
957             if ((res = mono_decode(q, p, q->decode_buffer_2)) < 0)
958                 return res;
959         }
960     }
961 
962     mlt_compensate_output(q, q->decode_buffer_1, &p->gains1,
963                           p->mono_previous_buffer1,
964                           outbuffer ? outbuffer[p->ch_idx] : NULL);
965 
966     if (p->num_channels == 2) {
967         if (p->joint_stereo)
968             mlt_compensate_output(q, q->decode_buffer_2, &p->gains1,
969                                   p->mono_previous_buffer2,
970                                   outbuffer ? outbuffer[p->ch_idx + 1] : NULL);
971         else
972             mlt_compensate_output(q, q->decode_buffer_2, &p->gains2,
973                                   p->mono_previous_buffer2,
974                                   outbuffer ? outbuffer[p->ch_idx + 1] : NULL);
975     }
976 
977     return 0;
978 }
979 
980 
cook_decode_frame(AVCodecContext * avctx,AVFrame * frame,int * got_frame_ptr,AVPacket * avpkt)981 static int cook_decode_frame(AVCodecContext *avctx, AVFrame *frame,
982                              int *got_frame_ptr, AVPacket *avpkt)
983 {
984     const uint8_t *buf = avpkt->data;
985     int buf_size = avpkt->size;
986     COOKContext *q = avctx->priv_data;
987     float **samples = NULL;
988     int i, ret;
989     int offset = 0;
990     int chidx = 0;
991 
992     if (buf_size < avctx->block_align)
993         return buf_size;
994 
995     /* get output buffer */
996     if (q->discarded_packets >= 2) {
997         frame->nb_samples = q->samples_per_channel;
998         if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
999             return ret;
1000         samples = (float **)frame->extended_data;
1001     }
1002 
1003     /* estimate subpacket sizes */
1004     q->subpacket[0].size = avctx->block_align;
1005 
1006     for (i = 1; i < q->num_subpackets; i++) {
1007         q->subpacket[i].size = 2 * buf[avctx->block_align - q->num_subpackets + i];
1008         q->subpacket[0].size -= q->subpacket[i].size + 1;
1009         if (q->subpacket[0].size < 0) {
1010             av_log(avctx, AV_LOG_DEBUG,
1011                    "frame subpacket size total > avctx->block_align!\n");
1012             return AVERROR_INVALIDDATA;
1013         }
1014     }
1015 
1016     /* decode supbackets */
1017     for (i = 0; i < q->num_subpackets; i++) {
1018         q->subpacket[i].bits_per_subpacket = (q->subpacket[i].size * 8) >>
1019                                               q->subpacket[i].bits_per_subpdiv;
1020         q->subpacket[i].ch_idx = chidx;
1021         av_log(avctx, AV_LOG_DEBUG,
1022                "subpacket[%i] size %i js %i %i block_align %i\n",
1023                i, q->subpacket[i].size, q->subpacket[i].joint_stereo, offset,
1024                avctx->block_align);
1025 
1026         if ((ret = decode_subpacket(q, &q->subpacket[i], buf + offset, samples)) < 0)
1027             return ret;
1028         offset += q->subpacket[i].size;
1029         chidx += q->subpacket[i].num_channels;
1030         av_log(avctx, AV_LOG_DEBUG, "subpacket[%i] %i %i\n",
1031                i, q->subpacket[i].size * 8, get_bits_count(&q->gb));
1032     }
1033 
1034     /* Discard the first two frames: no valid audio. */
1035     if (q->discarded_packets < 2) {
1036         q->discarded_packets++;
1037         *got_frame_ptr = 0;
1038         return avctx->block_align;
1039     }
1040 
1041     *got_frame_ptr = 1;
1042 
1043     return avctx->block_align;
1044 }
1045 
dump_cook_context(COOKContext * q)1046 static void dump_cook_context(COOKContext *q)
1047 {
1048     //int i=0;
1049 #define PRINT(a, b) ff_dlog(q->avctx, " %s = %d\n", a, b);
1050     ff_dlog(q->avctx, "COOKextradata\n");
1051     ff_dlog(q->avctx, "cookversion=%x\n", q->subpacket[0].cookversion);
1052     if (q->subpacket[0].cookversion > STEREO) {
1053         PRINT("js_subband_start", q->subpacket[0].js_subband_start);
1054         PRINT("js_vlc_bits", q->subpacket[0].js_vlc_bits);
1055     }
1056     ff_dlog(q->avctx, "COOKContext\n");
1057     PRINT("nb_channels", q->avctx->ch_layout.nb_channels);
1058     PRINT("bit_rate", (int)q->avctx->bit_rate);
1059     PRINT("sample_rate", q->avctx->sample_rate);
1060     PRINT("samples_per_channel", q->subpacket[0].samples_per_channel);
1061     PRINT("subbands", q->subpacket[0].subbands);
1062     PRINT("js_subband_start", q->subpacket[0].js_subband_start);
1063     PRINT("log2_numvector_size", q->subpacket[0].log2_numvector_size);
1064     PRINT("numvector_size", q->subpacket[0].numvector_size);
1065     PRINT("total_subbands", q->subpacket[0].total_subbands);
1066 }
1067 
1068 /**
1069  * Cook initialization
1070  *
1071  * @param avctx     pointer to the AVCodecContext
1072  */
cook_decode_init(AVCodecContext * avctx)1073 static av_cold int cook_decode_init(AVCodecContext *avctx)
1074 {
1075     static AVOnce init_static_once = AV_ONCE_INIT;
1076     COOKContext *q = avctx->priv_data;
1077     GetByteContext gb;
1078     int s = 0;
1079     unsigned int channel_mask = 0;
1080     int samples_per_frame = 0;
1081     int ret;
1082     int channels = avctx->ch_layout.nb_channels;
1083 
1084     q->avctx = avctx;
1085 
1086     /* Take care of the codec specific extradata. */
1087     if (avctx->extradata_size < 8) {
1088         av_log(avctx, AV_LOG_ERROR, "Necessary extradata missing!\n");
1089         return AVERROR_INVALIDDATA;
1090     }
1091     av_log(avctx, AV_LOG_DEBUG, "codecdata_length=%d\n", avctx->extradata_size);
1092 
1093     bytestream2_init(&gb, avctx->extradata, avctx->extradata_size);
1094 
1095     /* Take data from the AVCodecContext (RM container). */
1096     if (!channels) {
1097         av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
1098         return AVERROR_INVALIDDATA;
1099     }
1100 
1101     if (avctx->block_align >= INT_MAX / 8)
1102         return AVERROR(EINVAL);
1103 
1104     /* Initialize RNG. */
1105     av_lfg_init(&q->random_state, 0);
1106 
1107     ff_audiodsp_init(&q->adsp);
1108 
1109     while (bytestream2_get_bytes_left(&gb)) {
1110         if (s >= FFMIN(MAX_SUBPACKETS, avctx->block_align)) {
1111             avpriv_request_sample(avctx, "subpackets > %d", FFMIN(MAX_SUBPACKETS, avctx->block_align));
1112             return AVERROR_PATCHWELCOME;
1113         }
1114         /* 8 for mono, 16 for stereo, ? for multichannel
1115            Swap to right endianness so we don't need to care later on. */
1116         q->subpacket[s].cookversion      = bytestream2_get_be32(&gb);
1117         samples_per_frame                = bytestream2_get_be16(&gb);
1118         q->subpacket[s].subbands         = bytestream2_get_be16(&gb);
1119         bytestream2_get_be32(&gb);    // Unknown unused
1120         q->subpacket[s].js_subband_start = bytestream2_get_be16(&gb);
1121         if (q->subpacket[s].js_subband_start >= 51) {
1122             av_log(avctx, AV_LOG_ERROR, "js_subband_start %d is too large\n", q->subpacket[s].js_subband_start);
1123             return AVERROR_INVALIDDATA;
1124         }
1125         q->subpacket[s].js_vlc_bits      = bytestream2_get_be16(&gb);
1126 
1127         /* Initialize extradata related variables. */
1128         q->subpacket[s].samples_per_channel = samples_per_frame / channels;
1129         q->subpacket[s].bits_per_subpacket = avctx->block_align * 8;
1130 
1131         /* Initialize default data states. */
1132         q->subpacket[s].log2_numvector_size = 5;
1133         q->subpacket[s].total_subbands = q->subpacket[s].subbands;
1134         q->subpacket[s].num_channels = 1;
1135 
1136         /* Initialize version-dependent variables */
1137 
1138         av_log(avctx, AV_LOG_DEBUG, "subpacket[%i].cookversion=%x\n", s,
1139                q->subpacket[s].cookversion);
1140         q->subpacket[s].joint_stereo = 0;
1141         switch (q->subpacket[s].cookversion) {
1142         case MONO:
1143             if (channels != 1) {
1144                 avpriv_request_sample(avctx, "Container channels != 1");
1145                 return AVERROR_PATCHWELCOME;
1146             }
1147             av_log(avctx, AV_LOG_DEBUG, "MONO\n");
1148             break;
1149         case STEREO:
1150             if (channels != 1) {
1151                 q->subpacket[s].bits_per_subpdiv = 1;
1152                 q->subpacket[s].num_channels = 2;
1153             }
1154             av_log(avctx, AV_LOG_DEBUG, "STEREO\n");
1155             break;
1156         case JOINT_STEREO:
1157             if (channels != 2) {
1158                 avpriv_request_sample(avctx, "Container channels != 2");
1159                 return AVERROR_PATCHWELCOME;
1160             }
1161             av_log(avctx, AV_LOG_DEBUG, "JOINT_STEREO\n");
1162             if (avctx->extradata_size >= 16) {
1163                 q->subpacket[s].total_subbands = q->subpacket[s].subbands +
1164                                                  q->subpacket[s].js_subband_start;
1165                 q->subpacket[s].joint_stereo = 1;
1166                 q->subpacket[s].num_channels = 2;
1167             }
1168             if (q->subpacket[s].samples_per_channel > 256) {
1169                 q->subpacket[s].log2_numvector_size = 6;
1170             }
1171             if (q->subpacket[s].samples_per_channel > 512) {
1172                 q->subpacket[s].log2_numvector_size = 7;
1173             }
1174             break;
1175         case MC_COOK:
1176             av_log(avctx, AV_LOG_DEBUG, "MULTI_CHANNEL\n");
1177             channel_mask |= q->subpacket[s].channel_mask = bytestream2_get_be32(&gb);
1178 
1179             if (av_popcount64(q->subpacket[s].channel_mask) > 1) {
1180                 q->subpacket[s].total_subbands = q->subpacket[s].subbands +
1181                                                  q->subpacket[s].js_subband_start;
1182                 q->subpacket[s].joint_stereo = 1;
1183                 q->subpacket[s].num_channels = 2;
1184                 q->subpacket[s].samples_per_channel = samples_per_frame >> 1;
1185 
1186                 if (q->subpacket[s].samples_per_channel > 256) {
1187                     q->subpacket[s].log2_numvector_size = 6;
1188                 }
1189                 if (q->subpacket[s].samples_per_channel > 512) {
1190                     q->subpacket[s].log2_numvector_size = 7;
1191                 }
1192             } else
1193                 q->subpacket[s].samples_per_channel = samples_per_frame;
1194 
1195             break;
1196         default:
1197             avpriv_request_sample(avctx, "Cook version %d",
1198                                   q->subpacket[s].cookversion);
1199             return AVERROR_PATCHWELCOME;
1200         }
1201 
1202         if (s > 1 && q->subpacket[s].samples_per_channel != q->samples_per_channel) {
1203             av_log(avctx, AV_LOG_ERROR, "different number of samples per channel!\n");
1204             return AVERROR_INVALIDDATA;
1205         } else
1206             q->samples_per_channel = q->subpacket[0].samples_per_channel;
1207 
1208 
1209         /* Initialize variable relations */
1210         q->subpacket[s].numvector_size = (1 << q->subpacket[s].log2_numvector_size);
1211 
1212         /* Try to catch some obviously faulty streams, otherwise it might be exploitable */
1213         if (q->subpacket[s].total_subbands > 53) {
1214             avpriv_request_sample(avctx, "total_subbands > 53");
1215             return AVERROR_PATCHWELCOME;
1216         }
1217 
1218         if ((q->subpacket[s].js_vlc_bits > 6) ||
1219             (q->subpacket[s].js_vlc_bits < 2 * q->subpacket[s].joint_stereo)) {
1220             av_log(avctx, AV_LOG_ERROR, "js_vlc_bits = %d, only >= %d and <= 6 allowed!\n",
1221                    q->subpacket[s].js_vlc_bits, 2 * q->subpacket[s].joint_stereo);
1222             return AVERROR_INVALIDDATA;
1223         }
1224 
1225         if (q->subpacket[s].subbands > 50) {
1226             avpriv_request_sample(avctx, "subbands > 50");
1227             return AVERROR_PATCHWELCOME;
1228         }
1229         if (q->subpacket[s].subbands == 0) {
1230             avpriv_request_sample(avctx, "subbands = 0");
1231             return AVERROR_PATCHWELCOME;
1232         }
1233         q->subpacket[s].gains1.now      = q->subpacket[s].gain_1;
1234         q->subpacket[s].gains1.previous = q->subpacket[s].gain_2;
1235         q->subpacket[s].gains2.now      = q->subpacket[s].gain_3;
1236         q->subpacket[s].gains2.previous = q->subpacket[s].gain_4;
1237 
1238         if (q->num_subpackets + q->subpacket[s].num_channels > channels) {
1239             av_log(avctx, AV_LOG_ERROR, "Too many subpackets %d for channels %d\n", q->num_subpackets, channels);
1240             return AVERROR_INVALIDDATA;
1241         }
1242 
1243         q->num_subpackets++;
1244         s++;
1245     }
1246 
1247     /* Try to catch some obviously faulty streams, otherwise it might be exploitable */
1248     if (q->samples_per_channel != 256 && q->samples_per_channel != 512 &&
1249         q->samples_per_channel != 1024) {
1250         avpriv_request_sample(avctx, "samples_per_channel = %d",
1251                               q->samples_per_channel);
1252         return AVERROR_PATCHWELCOME;
1253     }
1254 
1255     /* Generate tables */
1256     ff_thread_once(&init_static_once, init_pow2table);
1257     init_gain_table(q);
1258     init_cplscales_table(q);
1259 
1260     if ((ret = init_cook_vlc_tables(q)))
1261         return ret;
1262 
1263     /* Pad the databuffer with:
1264        DECODE_BYTES_PAD1 or DECODE_BYTES_PAD2 for decode_bytes(),
1265        AV_INPUT_BUFFER_PADDING_SIZE, for the bitstreamreader. */
1266     q->decoded_bytes_buffer =
1267         av_mallocz(avctx->block_align
1268                    + DECODE_BYTES_PAD1(avctx->block_align)
1269                    + AV_INPUT_BUFFER_PADDING_SIZE);
1270     if (!q->decoded_bytes_buffer)
1271         return AVERROR(ENOMEM);
1272 
1273     /* Initialize transform. */
1274     if ((ret = init_cook_mlt(q)))
1275         return ret;
1276 
1277     /* Initialize COOK signal arithmetic handling */
1278     if (1) {
1279         q->scalar_dequant  = scalar_dequant_float;
1280         q->decouple        = decouple_float;
1281         q->imlt_window     = imlt_window_float;
1282         q->interpolate     = interpolate_float;
1283         q->saturate_output = saturate_output_float;
1284     }
1285 
1286     avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
1287     av_channel_layout_uninit(&avctx->ch_layout);
1288     if (channel_mask)
1289         av_channel_layout_from_mask(&avctx->ch_layout, channel_mask);
1290     else
1291         av_channel_layout_default(&avctx->ch_layout, channels);
1292 
1293 
1294     dump_cook_context(q);
1295 
1296     return 0;
1297 }
1298 
1299 const FFCodec ff_cook_decoder = {
1300     .p.name         = "cook",
1301     .p.long_name    = NULL_IF_CONFIG_SMALL("Cook / Cooker / Gecko (RealAudio G2)"),
1302     .p.type         = AVMEDIA_TYPE_AUDIO,
1303     .p.id           = AV_CODEC_ID_COOK,
1304     .priv_data_size = sizeof(COOKContext),
1305     .init           = cook_decode_init,
1306     .close          = cook_decode_close,
1307     FF_CODEC_DECODE_CB(cook_decode_frame),
1308     .p.capabilities = AV_CODEC_CAP_DR1,
1309     .p.sample_fmts  = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1310                                                       AV_SAMPLE_FMT_NONE },
1311     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1312 };
1313