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
48#include "audiodsp.h"
49#include "avcodec.h"
50#include "get_bits.h"
51#include "bytestream.h"
52#include "fft.h"
53#include "internal.h"
54#include "sinewin.h"
55#include "unary.h"
56
57#include "cookdata.h"
58
59/* the different Cook versions */
60#define MONO            0x1000001
61#define STEREO          0x1000002
62#define JOINT_STEREO    0x1000003
63#define MC_COOK         0x2000000   // multichannel Cook, not supported
64
65#define SUBBAND_SIZE    20
66#define MAX_SUBPACKETS   5
67
68typedef struct {
69    int *now;
70    int *previous;
71} cook_gains;
72
73typedef struct {
74    int                 ch_idx;
75    int                 size;
76    int                 num_channels;
77    int                 cookversion;
78    int                 subbands;
79    int                 js_subband_start;
80    int                 js_vlc_bits;
81    int                 samples_per_channel;
82    int                 log2_numvector_size;
83    unsigned int        channel_mask;
84    VLC                 channel_coupling;
85    int                 joint_stereo;
86    int                 bits_per_subpacket;
87    int                 bits_per_subpdiv;
88    int                 total_subbands;
89    int                 numvector_size;       // 1 << log2_numvector_size;
90
91    float               mono_previous_buffer1[1024];
92    float               mono_previous_buffer2[1024];
93
94    cook_gains          gains1;
95    cook_gains          gains2;
96    int                 gain_1[9];
97    int                 gain_2[9];
98    int                 gain_3[9];
99    int                 gain_4[9];
100} COOKSubpacket;
101
102typedef struct cook {
103    /*
104     * The following 5 functions provide the lowlevel arithmetic on
105     * the internal audio buffers.
106     */
107    void (*scalar_dequant)(struct cook *q, int index, int quant_index,
108                           int *subband_coef_index, int *subband_coef_sign,
109                           float *mlt_p);
110
111    void (*decouple)(struct cook *q,
112                     COOKSubpacket *p,
113                     int subband,
114                     float f1, float f2,
115                     float *decode_buffer,
116                     float *mlt_buffer1, float *mlt_buffer2);
117
118    void (*imlt_window)(struct cook *q, float *buffer1,
119                        cook_gains *gains_ptr, float *previous_buffer);
120
121    void (*interpolate)(struct cook *q, float *buffer,
122                        int gain_index, int gain_index_next);
123
124    void (*saturate_output)(struct cook *q, float *out);
125
126    AVCodecContext*     avctx;
127    AudioDSPContext     adsp;
128    GetBitContext       gb;
129    /* stream data */
130    int                 num_vectors;
131    int                 samples_per_channel;
132    /* states */
133    AVLFG               random_state;
134    int                 discarded_packets;
135
136    /* transform data */
137    FFTContext          mdct_ctx;
138    float*              mlt_window;
139
140    /* VLC data */
141    VLC                 envelope_quant_index[13];
142    VLC                 sqvh[7];          // scalar quantization
143
144    /* generatable tables and related variables */
145    int                 gain_size_factor;
146    float               gain_table[23];
147
148    /* data buffers */
149
150    uint8_t*            decoded_bytes_buffer;
151    DECLARE_ALIGNED(32, float, mono_mdct_output)[2048];
152    float               decode_buffer_1[1024];
153    float               decode_buffer_2[1024];
154    float               decode_buffer_0[1060]; /* static allocation for joint decode */
155
156    const float         *cplscales[5];
157    int                 num_subpackets;
158    COOKSubpacket       subpacket[MAX_SUBPACKETS];
159} COOKContext;
160
161static float     pow2tab[127];
162static float rootpow2tab[127];
163
164/*************** init functions ***************/
165
166/* table generator */
167static av_cold void init_pow2table(void)
168{
169    int i;
170    for (i = -63; i < 64; i++) {
171        pow2tab[63 + i] = pow(2, i);
172        rootpow2tab[63 + i] = sqrt(pow(2, i));
173    }
174}
175
176/* table generator */
177static av_cold void init_gain_table(COOKContext *q)
178{
179    int i;
180    q->gain_size_factor = q->samples_per_channel / 8;
181    for (i = 0; i < 23; i++)
182        q->gain_table[i] = pow(pow2tab[i + 52],
183                               (1.0 / (double) q->gain_size_factor));
184}
185
186
187static av_cold int init_cook_vlc_tables(COOKContext *q)
188{
189    int i, result;
190
191    result = 0;
192    for (i = 0; i < 13; i++) {
193        result |= init_vlc(&q->envelope_quant_index[i], 9, 24,
194                           envelope_quant_index_huffbits[i], 1, 1,
195                           envelope_quant_index_huffcodes[i], 2, 2, 0);
196    }
197    av_log(q->avctx, AV_LOG_DEBUG, "sqvh VLC init\n");
198    for (i = 0; i < 7; i++) {
199        result |= init_vlc(&q->sqvh[i], vhvlcsize_tab[i], vhsize_tab[i],
200                           cvh_huffbits[i], 1, 1,
201                           cvh_huffcodes[i], 2, 2, 0);
202    }
203
204    for (i = 0; i < q->num_subpackets; i++) {
205        if (q->subpacket[i].joint_stereo == 1) {
206            result |= init_vlc(&q->subpacket[i].channel_coupling, 6,
207                               (1 << q->subpacket[i].js_vlc_bits) - 1,
208                               ccpl_huffbits[q->subpacket[i].js_vlc_bits - 2], 1, 1,
209                               ccpl_huffcodes[q->subpacket[i].js_vlc_bits - 2], 2, 2, 0);
210            av_log(q->avctx, AV_LOG_DEBUG, "subpacket %i Joint-stereo VLC used.\n", i);
211        }
212    }
213
214    av_log(q->avctx, AV_LOG_DEBUG, "VLC tables initialized.\n");
215    return result;
216}
217
218static av_cold int init_cook_mlt(COOKContext *q)
219{
220    int j, ret;
221    int mlt_size = q->samples_per_channel;
222
223    if ((q->mlt_window = av_malloc_array(mlt_size, sizeof(*q->mlt_window))) == 0)
224        return AVERROR(ENOMEM);
225
226    /* Initialize the MLT window: simple sine window. */
227    ff_sine_window_init(q->mlt_window, mlt_size);
228    for (j = 0; j < mlt_size; j++)
229        q->mlt_window[j] *= sqrt(2.0 / q->samples_per_channel);
230
231    /* Initialize the MDCT. */
232    if ((ret = ff_mdct_init(&q->mdct_ctx, av_log2(mlt_size) + 1, 1, 1.0 / 32768.0))) {
233        av_freep(&q->mlt_window);
234        return ret;
235    }
236    av_log(q->avctx, AV_LOG_DEBUG, "MDCT initialized, order = %d.\n",
237           av_log2(mlt_size) + 1);
238
239    return 0;
240}
241
242static av_cold void init_cplscales_table(COOKContext *q)
243{
244    int i;
245    for (i = 0; i < 5; i++)
246        q->cplscales[i] = cplscales[i];
247}
248
249/*************** init functions end ***********/
250
251#define DECODE_BYTES_PAD1(bytes) (3 - ((bytes) + 3) % 4)
252#define DECODE_BYTES_PAD2(bytes) ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))
253
254/**
255 * Cook indata decoding, every 32 bits are XORed with 0x37c511f2.
256 * Why? No idea, some checksum/error detection method maybe.
257 *
258 * Out buffer size: extra bytes are needed to cope with
259 * padding/misalignment.
260 * Subpackets passed to the decoder can contain two, consecutive
261 * half-subpackets, of identical but arbitrary size.
262 *          1234 1234 1234 1234  extraA extraB
263 * Case 1:  AAAA BBBB              0      0
264 * Case 2:  AAAA ABBB BB--         3      3
265 * Case 3:  AAAA AABB BBBB         2      2
266 * Case 4:  AAAA AAAB BBBB BB--    1      5
267 *
268 * Nice way to waste CPU cycles.
269 *
270 * @param inbuffer  pointer to byte array of indata
271 * @param out       pointer to byte array of outdata
272 * @param bytes     number of bytes
273 */
274static inline int decode_bytes(const uint8_t *inbuffer, uint8_t *out, int bytes)
275{
276    static const uint32_t tab[4] = {
277        AV_BE2NE32C(0x37c511f2u), AV_BE2NE32C(0xf237c511u),
278        AV_BE2NE32C(0x11f237c5u), AV_BE2NE32C(0xc511f237u),
279    };
280    int i, off;
281    uint32_t c;
282    const uint32_t *buf;
283    uint32_t *obuf = (uint32_t *) out;
284    /* FIXME: 64 bit platforms would be able to do 64 bits at a time.
285     * I'm too lazy though, should be something like
286     * for (i = 0; i < bitamount / 64; i++)
287     *     (int64_t) out[i] = 0x37c511f237c511f2 ^ av_be2ne64(int64_t) in[i]);
288     * Buffer alignment needs to be checked. */
289
290    off = (intptr_t) inbuffer & 3;
291    buf = (const uint32_t *) (inbuffer - off);
292    c = tab[off];
293    bytes += 3 + off;
294    for (i = 0; i < bytes / 4; i++)
295        obuf[i] = c ^ buf[i];
296
297    return off;
298}
299
300static av_cold int cook_decode_close(AVCodecContext *avctx)
301{
302    int i;
303    COOKContext *q = avctx->priv_data;
304    av_log(avctx, AV_LOG_DEBUG, "Deallocating memory.\n");
305
306    /* Free allocated memory buffers. */
307    av_freep(&q->mlt_window);
308    av_freep(&q->decoded_bytes_buffer);
309
310    /* Free the transform. */
311    ff_mdct_end(&q->mdct_ctx);
312
313    /* Free the VLC tables. */
314    for (i = 0; i < 13; i++)
315        ff_free_vlc(&q->envelope_quant_index[i]);
316    for (i = 0; i < 7; i++)
317        ff_free_vlc(&q->sqvh[i]);
318    for (i = 0; i < q->num_subpackets; i++)
319        ff_free_vlc(&q->subpacket[i].channel_coupling);
320
321    av_log(avctx, AV_LOG_DEBUG, "Memory deallocated.\n");
322
323    return 0;
324}
325
326/**
327 * Fill the gain array for the timedomain quantization.
328 *
329 * @param gb          pointer to the GetBitContext
330 * @param gaininfo    array[9] of gain indexes
331 */
332static void decode_gain_info(GetBitContext *gb, int *gaininfo)
333{
334    int i, n;
335
336    n = get_unary(gb, 0, get_bits_left(gb));     // amount of elements*2 to update
337
338    i = 0;
339    while (n--) {
340        int index = get_bits(gb, 3);
341        int gain = get_bits1(gb) ? get_bits(gb, 4) - 7 : -1;
342
343        while (i <= index)
344            gaininfo[i++] = gain;
345    }
346    while (i <= 8)
347        gaininfo[i++] = 0;
348}
349
350/**
351 * Create the quant index table needed for the envelope.
352 *
353 * @param q                 pointer to the COOKContext
354 * @param quant_index_table pointer to the array
355 */
356static int decode_envelope(COOKContext *q, COOKSubpacket *p,
357                           int *quant_index_table)
358{
359    int i, j, vlc_index;
360
361    quant_index_table[0] = get_bits(&q->gb, 6) - 6; // This is used later in categorize
362
363    for (i = 1; i < p->total_subbands; i++) {
364        vlc_index = i;
365        if (i >= p->js_subband_start * 2) {
366            vlc_index -= p->js_subband_start;
367        } else {
368            vlc_index /= 2;
369            if (vlc_index < 1)
370                vlc_index = 1;
371        }
372        if (vlc_index > 13)
373            vlc_index = 13; // the VLC tables >13 are identical to No. 13
374
375        j = get_vlc2(&q->gb, q->envelope_quant_index[vlc_index - 1].table,
376                     q->envelope_quant_index[vlc_index - 1].bits, 2);
377        quant_index_table[i] = quant_index_table[i - 1] + j - 12; // differential encoding
378        if (quant_index_table[i] > 63 || quant_index_table[i] < -63) {
379            av_log(q->avctx, AV_LOG_ERROR,
380                   "Invalid quantizer %d at position %d, outside [-63, 63] range\n",
381                   quant_index_table[i], i);
382            return AVERROR_INVALIDDATA;
383        }
384    }
385
386    return 0;
387}
388
389/**
390 * Calculate the category and category_index vector.
391 *
392 * @param q                     pointer to the COOKContext
393 * @param quant_index_table     pointer to the array
394 * @param category              pointer to the category array
395 * @param category_index        pointer to the category_index array
396 */
397static void categorize(COOKContext *q, COOKSubpacket *p, const int *quant_index_table,
398                       int *category, int *category_index)
399{
400    int exp_idx, bias, tmpbias1, tmpbias2, bits_left, num_bits, index, v, i, j;
401    int exp_index2[102] = { 0 };
402    int exp_index1[102] = { 0 };
403
404    int tmp_categorize_array[128 * 2] = { 0 };
405    int tmp_categorize_array1_idx = p->numvector_size;
406    int tmp_categorize_array2_idx = p->numvector_size;
407
408    bits_left = p->bits_per_subpacket - get_bits_count(&q->gb);
409
410    if (bits_left > q->samples_per_channel)
411        bits_left = q->samples_per_channel +
412                    ((bits_left - q->samples_per_channel) * 5) / 8;
413
414    bias = -32;
415
416    /* Estimate bias. */
417    for (i = 32; i > 0; i = i / 2) {
418        num_bits = 0;
419        index    = 0;
420        for (j = p->total_subbands; j > 0; j--) {
421            exp_idx = av_clip((i - quant_index_table[index] + bias) / 2, 0, 7);
422            index++;
423            num_bits += expbits_tab[exp_idx];
424        }
425        if (num_bits >= bits_left - 32)
426            bias += i;
427    }
428
429    /* Calculate total number of bits. */
430    num_bits = 0;
431    for (i = 0; i < p->total_subbands; i++) {
432        exp_idx = av_clip((bias - quant_index_table[i]) / 2, 0, 7);
433        num_bits += expbits_tab[exp_idx];
434        exp_index1[i] = exp_idx;
435        exp_index2[i] = exp_idx;
436    }
437    tmpbias1 = tmpbias2 = num_bits;
438
439    for (j = 1; j < p->numvector_size; j++) {
440        if (tmpbias1 + tmpbias2 > 2 * bits_left) {  /* ---> */
441            int max = -999999;
442            index = -1;
443            for (i = 0; i < p->total_subbands; i++) {
444                if (exp_index1[i] < 7) {
445                    v = (-2 * exp_index1[i]) - quant_index_table[i] + bias;
446                    if (v >= max) {
447                        max   = v;
448                        index = i;
449                    }
450                }
451            }
452            if (index == -1)
453                break;
454            tmp_categorize_array[tmp_categorize_array1_idx++] = index;
455            tmpbias1 -= expbits_tab[exp_index1[index]] -
456                        expbits_tab[exp_index1[index] + 1];
457            ++exp_index1[index];
458        } else {  /* <--- */
459            int min = 999999;
460            index = -1;
461            for (i = 0; i < p->total_subbands; i++) {
462                if (exp_index2[i] > 0) {
463                    v = (-2 * exp_index2[i]) - quant_index_table[i] + bias;
464                    if (v < min) {
465                        min   = v;
466                        index = i;
467                    }
468                }
469            }
470            if (index == -1)
471                break;
472            tmp_categorize_array[--tmp_categorize_array2_idx] = index;
473            tmpbias2 -= expbits_tab[exp_index2[index]] -
474                        expbits_tab[exp_index2[index] - 1];
475            --exp_index2[index];
476        }
477    }
478
479    for (i = 0; i < p->total_subbands; i++)
480        category[i] = exp_index2[i];
481
482    for (i = 0; i < p->numvector_size - 1; i++)
483        category_index[i] = tmp_categorize_array[tmp_categorize_array2_idx++];
484}
485
486
487/**
488 * Expand the category vector.
489 *
490 * @param q                     pointer to the COOKContext
491 * @param category              pointer to the category array
492 * @param category_index        pointer to the category_index array
493 */
494static inline void expand_category(COOKContext *q, int *category,
495                                   int *category_index)
496{
497    int i;
498    for (i = 0; i < q->num_vectors; i++)
499    {
500        int idx = category_index[i];
501        if (++category[idx] >= FF_ARRAY_ELEMS(dither_tab))
502            --category[idx];
503    }
504}
505
506/**
507 * The real requantization of the mltcoefs
508 *
509 * @param q                     pointer to the COOKContext
510 * @param index                 index
511 * @param quant_index           quantisation index
512 * @param subband_coef_index    array of indexes to quant_centroid_tab
513 * @param subband_coef_sign     signs of coefficients
514 * @param mlt_p                 pointer into the mlt buffer
515 */
516static void scalar_dequant_float(COOKContext *q, int index, int quant_index,
517                                 int *subband_coef_index, int *subband_coef_sign,
518                                 float *mlt_p)
519{
520    int i;
521    float f1;
522
523    for (i = 0; i < SUBBAND_SIZE; i++) {
524        if (subband_coef_index[i]) {
525            f1 = quant_centroid_tab[index][subband_coef_index[i]];
526            if (subband_coef_sign[i])
527                f1 = -f1;
528        } else {
529            /* noise coding if subband_coef_index[i] == 0 */
530            f1 = dither_tab[index];
531            if (av_lfg_get(&q->random_state) < 0x80000000)
532                f1 = -f1;
533        }
534        mlt_p[i] = f1 * rootpow2tab[quant_index + 63];
535    }
536}
537/**
538 * Unpack the subband_coef_index and subband_coef_sign vectors.
539 *
540 * @param q                     pointer to the COOKContext
541 * @param category              pointer to the category array
542 * @param subband_coef_index    array of indexes to quant_centroid_tab
543 * @param subband_coef_sign     signs of coefficients
544 */
545static int unpack_SQVH(COOKContext *q, COOKSubpacket *p, int category,
546                       int *subband_coef_index, int *subband_coef_sign)
547{
548    int i, j;
549    int vlc, vd, tmp, result;
550
551    vd = vd_tab[category];
552    result = 0;
553    for (i = 0; i < vpr_tab[category]; i++) {
554        vlc = get_vlc2(&q->gb, q->sqvh[category].table, q->sqvh[category].bits, 3);
555        if (p->bits_per_subpacket < get_bits_count(&q->gb)) {
556            vlc = 0;
557            result = 1;
558        }
559        for (j = vd - 1; j >= 0; j--) {
560            tmp = (vlc * invradix_tab[category]) / 0x100000;
561            subband_coef_index[vd * i + j] = vlc - tmp * (kmax_tab[category] + 1);
562            vlc = tmp;
563        }
564        for (j = 0; j < vd; j++) {
565            if (subband_coef_index[i * vd + j]) {
566                if (get_bits_count(&q->gb) < p->bits_per_subpacket) {
567                    subband_coef_sign[i * vd + j] = get_bits1(&q->gb);
568                } else {
569                    result = 1;
570                    subband_coef_sign[i * vd + j] = 0;
571                }
572            } else {
573                subband_coef_sign[i * vd + j] = 0;
574            }
575        }
576    }
577    return result;
578}
579
580
581/**
582 * Fill the mlt_buffer with mlt coefficients.
583 *
584 * @param q                 pointer to the COOKContext
585 * @param category          pointer to the category array
586 * @param quant_index_table pointer to the array
587 * @param mlt_buffer        pointer to mlt coefficients
588 */
589static void decode_vectors(COOKContext *q, COOKSubpacket *p, int *category,
590                           int *quant_index_table, float *mlt_buffer)
591{
592    /* A zero in this table means that the subband coefficient is
593       random noise coded. */
594    int subband_coef_index[SUBBAND_SIZE];
595    /* A zero in this table means that the subband coefficient is a
596       positive multiplicator. */
597    int subband_coef_sign[SUBBAND_SIZE];
598    int band, j;
599    int index = 0;
600
601    for (band = 0; band < p->total_subbands; band++) {
602        index = category[band];
603        if (category[band] < 7) {
604            if (unpack_SQVH(q, p, category[band], subband_coef_index, subband_coef_sign)) {
605                index = 7;
606                for (j = 0; j < p->total_subbands; j++)
607                    category[band + j] = 7;
608            }
609        }
610        if (index >= 7) {
611            memset(subband_coef_index, 0, sizeof(subband_coef_index));
612            memset(subband_coef_sign,  0, sizeof(subband_coef_sign));
613        }
614        q->scalar_dequant(q, index, quant_index_table[band],
615                          subband_coef_index, subband_coef_sign,
616                          &mlt_buffer[band * SUBBAND_SIZE]);
617    }
618
619    /* FIXME: should this be removed, or moved into loop above? */
620    if (p->total_subbands * SUBBAND_SIZE >= q->samples_per_channel)
621        return;
622}
623
624
625static int mono_decode(COOKContext *q, COOKSubpacket *p, float *mlt_buffer)
626{
627    int category_index[128] = { 0 };
628    int category[128]       = { 0 };
629    int quant_index_table[102];
630    int res, i;
631
632    if ((res = decode_envelope(q, p, quant_index_table)) < 0)
633        return res;
634    q->num_vectors = get_bits(&q->gb, p->log2_numvector_size);
635    categorize(q, p, quant_index_table, category, category_index);
636    expand_category(q, category, category_index);
637    for (i=0; i<p->total_subbands; i++) {
638        if (category[i] > 7)
639            return AVERROR_INVALIDDATA;
640    }
641    decode_vectors(q, p, category, quant_index_table, mlt_buffer);
642
643    return 0;
644}
645
646
647/**
648 * the actual requantization of the timedomain samples
649 *
650 * @param q                 pointer to the COOKContext
651 * @param buffer            pointer to the timedomain buffer
652 * @param gain_index        index for the block multiplier
653 * @param gain_index_next   index for the next block multiplier
654 */
655static void interpolate_float(COOKContext *q, float *buffer,
656                              int gain_index, int gain_index_next)
657{
658    int i;
659    float fc1, fc2;
660    fc1 = pow2tab[gain_index + 63];
661
662    if (gain_index == gain_index_next) {             // static gain
663        for (i = 0; i < q->gain_size_factor; i++)
664            buffer[i] *= fc1;
665    } else {                                        // smooth gain
666        fc2 = q->gain_table[11 + (gain_index_next - gain_index)];
667        for (i = 0; i < q->gain_size_factor; i++) {
668            buffer[i] *= fc1;
669            fc1       *= fc2;
670        }
671    }
672}
673
674/**
675 * Apply transform window, overlap buffers.
676 *
677 * @param q                 pointer to the COOKContext
678 * @param inbuffer          pointer to the mltcoefficients
679 * @param gains_ptr         current and previous gains
680 * @param previous_buffer   pointer to the previous buffer to be used for overlapping
681 */
682static void imlt_window_float(COOKContext *q, float *inbuffer,
683                              cook_gains *gains_ptr, float *previous_buffer)
684{
685    const float fc = pow2tab[gains_ptr->previous[0] + 63];
686    int i;
687    /* The weird thing here, is that the two halves of the time domain
688     * buffer are swapped. Also, the newest data, that we save away for
689     * next frame, has the wrong sign. Hence the subtraction below.
690     * Almost sounds like a complex conjugate/reverse data/FFT effect.
691     */
692
693    /* Apply window and overlap */
694    for (i = 0; i < q->samples_per_channel; i++)
695        inbuffer[i] = inbuffer[i] * fc * q->mlt_window[i] -
696                      previous_buffer[i] * q->mlt_window[q->samples_per_channel - 1 - i];
697}
698
699/**
700 * The modulated lapped transform, this takes transform coefficients
701 * and transforms them into timedomain samples.
702 * Apply transform window, overlap buffers, apply gain profile
703 * and buffer management.
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 */
710static void imlt_gain(COOKContext *q, float *inbuffer,
711                      cook_gains *gains_ptr, float *previous_buffer)
712{
713    float *buffer0 = q->mono_mdct_output;
714    float *buffer1 = q->mono_mdct_output + q->samples_per_channel;
715    int i;
716
717    /* Inverse modified discrete cosine transform */
718    q->mdct_ctx.imdct_calc(&q->mdct_ctx, q->mono_mdct_output, inbuffer);
719
720    q->imlt_window(q, buffer1, gains_ptr, previous_buffer);
721
722    /* Apply gain profile */
723    for (i = 0; i < 8; i++)
724        if (gains_ptr->now[i] || gains_ptr->now[i + 1])
725            q->interpolate(q, &buffer1[q->gain_size_factor * i],
726                           gains_ptr->now[i], gains_ptr->now[i + 1]);
727
728    /* Save away the current to be previous block. */
729    memcpy(previous_buffer, buffer0,
730           q->samples_per_channel * sizeof(*previous_buffer));
731}
732
733
734/**
735 * function for getting the jointstereo coupling information
736 *
737 * @param q                 pointer to the COOKContext
738 * @param decouple_tab      decoupling array
739 */
740static int decouple_info(COOKContext *q, COOKSubpacket *p, int *decouple_tab)
741{
742    int i;
743    int vlc    = get_bits1(&q->gb);
744    int start  = cplband[p->js_subband_start];
745    int end    = cplband[p->subbands - 1];
746    int length = end - start + 1;
747
748    if (start > end)
749        return 0;
750
751    if (vlc)
752        for (i = 0; i < length; i++)
753            decouple_tab[start + i] = get_vlc2(&q->gb,
754                                               p->channel_coupling.table,
755                                               p->channel_coupling.bits, 2);
756    else
757        for (i = 0; i < length; i++) {
758            int v = get_bits(&q->gb, p->js_vlc_bits);
759            if (v == (1<<p->js_vlc_bits)-1) {
760                av_log(q->avctx, AV_LOG_ERROR, "decouple value too large\n");
761                return AVERROR_INVALIDDATA;
762            }
763            decouple_tab[start + i] = v;
764        }
765    return 0;
766}
767
768/**
769 * function decouples a pair of signals from a single signal via multiplication.
770 *
771 * @param q                 pointer to the COOKContext
772 * @param subband           index of the current subband
773 * @param f1                multiplier for channel 1 extraction
774 * @param f2                multiplier for channel 2 extraction
775 * @param decode_buffer     input buffer
776 * @param mlt_buffer1       pointer to left channel mlt coefficients
777 * @param mlt_buffer2       pointer to right channel mlt coefficients
778 */
779static void decouple_float(COOKContext *q,
780                           COOKSubpacket *p,
781                           int subband,
782                           float f1, float f2,
783                           float *decode_buffer,
784                           float *mlt_buffer1, float *mlt_buffer2)
785{
786    int j, tmp_idx;
787    for (j = 0; j < SUBBAND_SIZE; j++) {
788        tmp_idx = ((p->js_subband_start + subband) * SUBBAND_SIZE) + j;
789        mlt_buffer1[SUBBAND_SIZE * subband + j] = f1 * decode_buffer[tmp_idx];
790        mlt_buffer2[SUBBAND_SIZE * subband + j] = f2 * decode_buffer[tmp_idx];
791    }
792}
793
794/**
795 * function for decoding joint stereo data
796 *
797 * @param q                 pointer to the COOKContext
798 * @param mlt_buffer1       pointer to left channel mlt coefficients
799 * @param mlt_buffer2       pointer to right channel mlt coefficients
800 */
801static int joint_decode(COOKContext *q, COOKSubpacket *p,
802                        float *mlt_buffer_left, float *mlt_buffer_right)
803{
804    int i, j, res;
805    int decouple_tab[SUBBAND_SIZE] = { 0 };
806    float *decode_buffer = q->decode_buffer_0;
807    int idx, cpl_tmp;
808    float f1, f2;
809    const float *cplscale;
810
811    memset(decode_buffer, 0, sizeof(q->decode_buffer_0));
812
813    /* Make sure the buffers are zeroed out. */
814    memset(mlt_buffer_left,  0, 1024 * sizeof(*mlt_buffer_left));
815    memset(mlt_buffer_right, 0, 1024 * sizeof(*mlt_buffer_right));
816    if ((res = decouple_info(q, p, decouple_tab)) < 0)
817        return res;
818    if ((res = mono_decode(q, p, decode_buffer)) < 0)
819        return res;
820    /* The two channels are stored interleaved in decode_buffer. */
821    for (i = 0; i < p->js_subband_start; i++) {
822        for (j = 0; j < SUBBAND_SIZE; j++) {
823            mlt_buffer_left[i  * 20 + j] = decode_buffer[i * 40 + j];
824            mlt_buffer_right[i * 20 + j] = decode_buffer[i * 40 + 20 + j];
825        }
826    }
827
828    /* When we reach js_subband_start (the higher frequencies)
829       the coefficients are stored in a coupling scheme. */
830    idx = (1 << p->js_vlc_bits) - 1;
831    for (i = p->js_subband_start; i < p->subbands; i++) {
832        cpl_tmp = cplband[i];
833        idx -= decouple_tab[cpl_tmp];
834        cplscale = q->cplscales[p->js_vlc_bits - 2];  // choose decoupler table
835        f1 = cplscale[decouple_tab[cpl_tmp] + 1];
836        f2 = cplscale[idx];
837        q->decouple(q, p, i, f1, f2, decode_buffer,
838                    mlt_buffer_left, mlt_buffer_right);
839        idx = (1 << p->js_vlc_bits) - 1;
840    }
841
842    return 0;
843}
844
845/**
846 * First part of subpacket decoding:
847 *  decode raw stream bytes and read gain info.
848 *
849 * @param q                 pointer to the COOKContext
850 * @param inbuffer          pointer to raw stream data
851 * @param gains_ptr         array of current/prev gain pointers
852 */
853static inline void decode_bytes_and_gain(COOKContext *q, COOKSubpacket *p,
854                                         const uint8_t *inbuffer,
855                                         cook_gains *gains_ptr)
856{
857    int offset;
858
859    offset = decode_bytes(inbuffer, q->decoded_bytes_buffer,
860                          p->bits_per_subpacket / 8);
861    init_get_bits(&q->gb, q->decoded_bytes_buffer + offset,
862                  p->bits_per_subpacket);
863    decode_gain_info(&q->gb, gains_ptr->now);
864
865    /* Swap current and previous gains */
866    FFSWAP(int *, gains_ptr->now, gains_ptr->previous);
867}
868
869/**
870 * Saturate the output signal and interleave.
871 *
872 * @param q                 pointer to the COOKContext
873 * @param out               pointer to the output vector
874 */
875static void saturate_output_float(COOKContext *q, float *out)
876{
877    q->adsp.vector_clipf(out, q->mono_mdct_output + q->samples_per_channel,
878                         -1.0f, 1.0f, FFALIGN(q->samples_per_channel, 8));
879}
880
881
882/**
883 * Final part of subpacket decoding:
884 *  Apply modulated lapped transform, gain compensation,
885 *  clip and convert to integer.
886 *
887 * @param q                 pointer to the COOKContext
888 * @param decode_buffer     pointer to the mlt coefficients
889 * @param gains_ptr         array of current/prev gain pointers
890 * @param previous_buffer   pointer to the previous buffer to be used for overlapping
891 * @param out               pointer to the output buffer
892 */
893static inline void mlt_compensate_output(COOKContext *q, float *decode_buffer,
894                                         cook_gains *gains_ptr, float *previous_buffer,
895                                         float *out)
896{
897    imlt_gain(q, decode_buffer, gains_ptr, previous_buffer);
898    if (out)
899        q->saturate_output(q, out);
900}
901
902
903/**
904 * Cook subpacket decoding. This function returns one decoded subpacket,
905 * usually 1024 samples per channel.
906 *
907 * @param q                 pointer to the COOKContext
908 * @param inbuffer          pointer to the inbuffer
909 * @param outbuffer         pointer to the outbuffer
910 */
911static int decode_subpacket(COOKContext *q, COOKSubpacket *p,
912                            const uint8_t *inbuffer, float **outbuffer)
913{
914    int sub_packet_size = p->size;
915    int res;
916
917    memset(q->decode_buffer_1, 0, sizeof(q->decode_buffer_1));
918    decode_bytes_and_gain(q, p, inbuffer, &p->gains1);
919
920    if (p->joint_stereo) {
921        if ((res = joint_decode(q, p, q->decode_buffer_1, q->decode_buffer_2)) < 0)
922            return res;
923    } else {
924        if ((res = mono_decode(q, p, q->decode_buffer_1)) < 0)
925            return res;
926
927        if (p->num_channels == 2) {
928            decode_bytes_and_gain(q, p, inbuffer + sub_packet_size / 2, &p->gains2);
929            if ((res = mono_decode(q, p, q->decode_buffer_2)) < 0)
930                return res;
931        }
932    }
933
934    mlt_compensate_output(q, q->decode_buffer_1, &p->gains1,
935                          p->mono_previous_buffer1,
936                          outbuffer ? outbuffer[p->ch_idx] : NULL);
937
938    if (p->num_channels == 2) {
939        if (p->joint_stereo)
940            mlt_compensate_output(q, q->decode_buffer_2, &p->gains1,
941                                  p->mono_previous_buffer2,
942                                  outbuffer ? outbuffer[p->ch_idx + 1] : NULL);
943        else
944            mlt_compensate_output(q, q->decode_buffer_2, &p->gains2,
945                                  p->mono_previous_buffer2,
946                                  outbuffer ? outbuffer[p->ch_idx + 1] : NULL);
947    }
948
949    return 0;
950}
951
952
953static int cook_decode_frame(AVCodecContext *avctx, void *data,
954                             int *got_frame_ptr, AVPacket *avpkt)
955{
956    AVFrame *frame     = data;
957    const uint8_t *buf = avpkt->data;
958    int buf_size = avpkt->size;
959    COOKContext *q = avctx->priv_data;
960    float **samples = NULL;
961    int i, ret;
962    int offset = 0;
963    int chidx = 0;
964
965    if (buf_size < avctx->block_align)
966        return buf_size;
967
968    /* get output buffer */
969    if (q->discarded_packets >= 2) {
970        frame->nb_samples = q->samples_per_channel;
971        if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
972            return ret;
973        samples = (float **)frame->extended_data;
974    }
975
976    /* estimate subpacket sizes */
977    q->subpacket[0].size = avctx->block_align;
978
979    for (i = 1; i < q->num_subpackets; i++) {
980        q->subpacket[i].size = 2 * buf[avctx->block_align - q->num_subpackets + i];
981        q->subpacket[0].size -= q->subpacket[i].size + 1;
982        if (q->subpacket[0].size < 0) {
983            av_log(avctx, AV_LOG_DEBUG,
984                   "frame subpacket size total > avctx->block_align!\n");
985            return AVERROR_INVALIDDATA;
986        }
987    }
988
989    /* decode supbackets */
990    for (i = 0; i < q->num_subpackets; i++) {
991        q->subpacket[i].bits_per_subpacket = (q->subpacket[i].size * 8) >>
992                                              q->subpacket[i].bits_per_subpdiv;
993        q->subpacket[i].ch_idx = chidx;
994        av_log(avctx, AV_LOG_DEBUG,
995               "subpacket[%i] size %i js %i %i block_align %i\n",
996               i, q->subpacket[i].size, q->subpacket[i].joint_stereo, offset,
997               avctx->block_align);
998
999        if ((ret = decode_subpacket(q, &q->subpacket[i], buf + offset, samples)) < 0)
1000            return ret;
1001        offset += q->subpacket[i].size;
1002        chidx += q->subpacket[i].num_channels;
1003        av_log(avctx, AV_LOG_DEBUG, "subpacket[%i] %i %i\n",
1004               i, q->subpacket[i].size * 8, get_bits_count(&q->gb));
1005    }
1006
1007    /* Discard the first two frames: no valid audio. */
1008    if (q->discarded_packets < 2) {
1009        q->discarded_packets++;
1010        *got_frame_ptr = 0;
1011        return avctx->block_align;
1012    }
1013
1014    *got_frame_ptr = 1;
1015
1016    return avctx->block_align;
1017}
1018
1019#ifdef DEBUG
1020static void dump_cook_context(COOKContext *q)
1021{
1022    //int i=0;
1023#define PRINT(a, b) av_dlog(q->avctx, " %s = %d\n", a, b);
1024    av_dlog(q->avctx, "COOKextradata\n");
1025    av_dlog(q->avctx, "cookversion=%x\n", q->subpacket[0].cookversion);
1026    if (q->subpacket[0].cookversion > STEREO) {
1027        PRINT("js_subband_start", q->subpacket[0].js_subband_start);
1028        PRINT("js_vlc_bits", q->subpacket[0].js_vlc_bits);
1029    }
1030    av_dlog(q->avctx, "COOKContext\n");
1031    PRINT("nb_channels", q->avctx->channels);
1032    PRINT("bit_rate", q->avctx->bit_rate);
1033    PRINT("sample_rate", q->avctx->sample_rate);
1034    PRINT("samples_per_channel", q->subpacket[0].samples_per_channel);
1035    PRINT("subbands", q->subpacket[0].subbands);
1036    PRINT("js_subband_start", q->subpacket[0].js_subband_start);
1037    PRINT("log2_numvector_size", q->subpacket[0].log2_numvector_size);
1038    PRINT("numvector_size", q->subpacket[0].numvector_size);
1039    PRINT("total_subbands", q->subpacket[0].total_subbands);
1040}
1041#endif
1042
1043/**
1044 * Cook initialization
1045 *
1046 * @param avctx     pointer to the AVCodecContext
1047 */
1048static av_cold int cook_decode_init(AVCodecContext *avctx)
1049{
1050    COOKContext *q = avctx->priv_data;
1051    const uint8_t *edata_ptr = avctx->extradata;
1052    const uint8_t *edata_ptr_end = edata_ptr + avctx->extradata_size;
1053    int extradata_size = avctx->extradata_size;
1054    int s = 0;
1055    unsigned int channel_mask = 0;
1056    int samples_per_frame = 0;
1057    int ret;
1058    q->avctx = avctx;
1059
1060    /* Take care of the codec specific extradata. */
1061    if (extradata_size <= 0) {
1062        av_log(avctx, AV_LOG_ERROR, "Necessary extradata missing!\n");
1063        return AVERROR_INVALIDDATA;
1064    }
1065    av_log(avctx, AV_LOG_DEBUG, "codecdata_length=%d\n", avctx->extradata_size);
1066
1067    /* Take data from the AVCodecContext (RM container). */
1068    if (!avctx->channels) {
1069        av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
1070        return AVERROR_INVALIDDATA;
1071    }
1072
1073    /* Initialize RNG. */
1074    av_lfg_init(&q->random_state, 0);
1075
1076    ff_audiodsp_init(&q->adsp);
1077
1078    while (edata_ptr < edata_ptr_end) {
1079        /* 8 for mono, 16 for stereo, ? for multichannel
1080           Swap to right endianness so we don't need to care later on. */
1081        if (extradata_size >= 8) {
1082            q->subpacket[s].cookversion = bytestream_get_be32(&edata_ptr);
1083            samples_per_frame           = bytestream_get_be16(&edata_ptr);
1084            q->subpacket[s].subbands = bytestream_get_be16(&edata_ptr);
1085            extradata_size -= 8;
1086        }
1087        if (extradata_size >= 8) {
1088            bytestream_get_be32(&edata_ptr);    // Unknown unused
1089            q->subpacket[s].js_subband_start = bytestream_get_be16(&edata_ptr);
1090            if (q->subpacket[s].js_subband_start >= 51) {
1091                av_log(avctx, AV_LOG_ERROR, "js_subband_start %d is too large\n", q->subpacket[s].js_subband_start);
1092                return AVERROR_INVALIDDATA;
1093            }
1094
1095            q->subpacket[s].js_vlc_bits = bytestream_get_be16(&edata_ptr);
1096            extradata_size -= 8;
1097        }
1098
1099        /* Initialize extradata related variables. */
1100        q->subpacket[s].samples_per_channel = samples_per_frame / avctx->channels;
1101        q->subpacket[s].bits_per_subpacket = avctx->block_align * 8;
1102
1103        /* Initialize default data states. */
1104        q->subpacket[s].log2_numvector_size = 5;
1105        q->subpacket[s].total_subbands = q->subpacket[s].subbands;
1106        q->subpacket[s].num_channels = 1;
1107
1108        /* Initialize version-dependent variables */
1109
1110        av_log(avctx, AV_LOG_DEBUG, "subpacket[%i].cookversion=%x\n", s,
1111               q->subpacket[s].cookversion);
1112        q->subpacket[s].joint_stereo = 0;
1113        switch (q->subpacket[s].cookversion) {
1114        case MONO:
1115            if (avctx->channels != 1) {
1116                avpriv_request_sample(avctx, "Container channels != 1");
1117                return AVERROR_PATCHWELCOME;
1118            }
1119            av_log(avctx, AV_LOG_DEBUG, "MONO\n");
1120            break;
1121        case STEREO:
1122            if (avctx->channels != 1) {
1123                q->subpacket[s].bits_per_subpdiv = 1;
1124                q->subpacket[s].num_channels = 2;
1125            }
1126            av_log(avctx, AV_LOG_DEBUG, "STEREO\n");
1127            break;
1128        case JOINT_STEREO:
1129            if (avctx->channels != 2) {
1130                avpriv_request_sample(avctx, "Container channels != 2");
1131                return AVERROR_PATCHWELCOME;
1132            }
1133            av_log(avctx, AV_LOG_DEBUG, "JOINT_STEREO\n");
1134            if (avctx->extradata_size >= 16) {
1135                q->subpacket[s].total_subbands = q->subpacket[s].subbands +
1136                                                 q->subpacket[s].js_subband_start;
1137                q->subpacket[s].joint_stereo = 1;
1138                q->subpacket[s].num_channels = 2;
1139            }
1140            if (q->subpacket[s].samples_per_channel > 256) {
1141                q->subpacket[s].log2_numvector_size = 6;
1142            }
1143            if (q->subpacket[s].samples_per_channel > 512) {
1144                q->subpacket[s].log2_numvector_size = 7;
1145            }
1146            break;
1147        case MC_COOK:
1148            av_log(avctx, AV_LOG_DEBUG, "MULTI_CHANNEL\n");
1149            if (extradata_size >= 4)
1150                channel_mask |= q->subpacket[s].channel_mask = bytestream_get_be32(&edata_ptr);
1151
1152            if (av_get_channel_layout_nb_channels(q->subpacket[s].channel_mask) > 1) {
1153                q->subpacket[s].total_subbands = q->subpacket[s].subbands +
1154                                                 q->subpacket[s].js_subband_start;
1155                q->subpacket[s].joint_stereo = 1;
1156                q->subpacket[s].num_channels = 2;
1157                q->subpacket[s].samples_per_channel = samples_per_frame >> 1;
1158
1159                if (q->subpacket[s].samples_per_channel > 256) {
1160                    q->subpacket[s].log2_numvector_size = 6;
1161                }
1162                if (q->subpacket[s].samples_per_channel > 512) {
1163                    q->subpacket[s].log2_numvector_size = 7;
1164                }
1165            } else
1166                q->subpacket[s].samples_per_channel = samples_per_frame;
1167
1168            break;
1169        default:
1170            avpriv_request_sample(avctx, "Cook version %d",
1171                                  q->subpacket[s].cookversion);
1172            return AVERROR_PATCHWELCOME;
1173        }
1174
1175        if (s > 1 && q->subpacket[s].samples_per_channel != q->samples_per_channel) {
1176            av_log(avctx, AV_LOG_ERROR, "different number of samples per channel!\n");
1177            return AVERROR_INVALIDDATA;
1178        } else
1179            q->samples_per_channel = q->subpacket[0].samples_per_channel;
1180
1181
1182        /* Initialize variable relations */
1183        q->subpacket[s].numvector_size = (1 << q->subpacket[s].log2_numvector_size);
1184
1185        /* Try to catch some obviously faulty streams, othervise it might be exploitable */
1186        if (q->subpacket[s].total_subbands > 53) {
1187            avpriv_request_sample(avctx, "total_subbands > 53");
1188            return AVERROR_PATCHWELCOME;
1189        }
1190
1191        if ((q->subpacket[s].js_vlc_bits > 6) ||
1192            (q->subpacket[s].js_vlc_bits < 2 * q->subpacket[s].joint_stereo)) {
1193            av_log(avctx, AV_LOG_ERROR, "js_vlc_bits = %d, only >= %d and <= 6 allowed!\n",
1194                   q->subpacket[s].js_vlc_bits, 2 * q->subpacket[s].joint_stereo);
1195            return AVERROR_INVALIDDATA;
1196        }
1197
1198        if (q->subpacket[s].subbands > 50) {
1199            avpriv_request_sample(avctx, "subbands > 50");
1200            return AVERROR_PATCHWELCOME;
1201        }
1202        if (q->subpacket[s].subbands == 0) {
1203            avpriv_request_sample(avctx, "subbands = 0");
1204            return AVERROR_PATCHWELCOME;
1205        }
1206        q->subpacket[s].gains1.now      = q->subpacket[s].gain_1;
1207        q->subpacket[s].gains1.previous = q->subpacket[s].gain_2;
1208        q->subpacket[s].gains2.now      = q->subpacket[s].gain_3;
1209        q->subpacket[s].gains2.previous = q->subpacket[s].gain_4;
1210
1211        if (q->num_subpackets + q->subpacket[s].num_channels > q->avctx->channels) {
1212            av_log(avctx, AV_LOG_ERROR, "Too many subpackets %d for channels %d\n", q->num_subpackets, q->avctx->channels);
1213            return AVERROR_INVALIDDATA;
1214        }
1215
1216        q->num_subpackets++;
1217        s++;
1218        if (s > MAX_SUBPACKETS) {
1219            avpriv_request_sample(avctx, "subpackets > %d", MAX_SUBPACKETS);
1220            return AVERROR_PATCHWELCOME;
1221        }
1222    }
1223    /* Generate tables */
1224    init_pow2table();
1225    init_gain_table(q);
1226    init_cplscales_table(q);
1227
1228    if ((ret = init_cook_vlc_tables(q)))
1229        return ret;
1230
1231
1232    if (avctx->block_align >= UINT_MAX / 2)
1233        return AVERROR(EINVAL);
1234
1235    /* Pad the databuffer with:
1236       DECODE_BYTES_PAD1 or DECODE_BYTES_PAD2 for decode_bytes(),
1237       FF_INPUT_BUFFER_PADDING_SIZE, for the bitstreamreader. */
1238    q->decoded_bytes_buffer =
1239        av_mallocz(avctx->block_align
1240                   + DECODE_BYTES_PAD1(avctx->block_align)
1241                   + FF_INPUT_BUFFER_PADDING_SIZE);
1242    if (q->decoded_bytes_buffer == NULL)
1243        return AVERROR(ENOMEM);
1244
1245    /* Initialize transform. */
1246    if ((ret = init_cook_mlt(q)))
1247        return ret;
1248
1249    /* Initialize COOK signal arithmetic handling */
1250    if (1) {
1251        q->scalar_dequant  = scalar_dequant_float;
1252        q->decouple        = decouple_float;
1253        q->imlt_window     = imlt_window_float;
1254        q->interpolate     = interpolate_float;
1255        q->saturate_output = saturate_output_float;
1256    }
1257
1258    /* Try to catch some obviously faulty streams, othervise it might be exploitable */
1259    if (q->samples_per_channel != 256 && q->samples_per_channel != 512 &&
1260        q->samples_per_channel != 1024) {
1261        avpriv_request_sample(avctx, "samples_per_channel = %d",
1262                              q->samples_per_channel);
1263        return AVERROR_PATCHWELCOME;
1264    }
1265
1266    avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
1267    if (channel_mask)
1268        avctx->channel_layout = channel_mask;
1269    else
1270        avctx->channel_layout = (avctx->channels == 2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
1271
1272#ifdef DEBUG
1273    dump_cook_context(q);
1274#endif
1275    return 0;
1276}
1277
1278AVCodec ff_cook_decoder = {
1279    .name           = "cook",
1280    .long_name      = NULL_IF_CONFIG_SMALL("Cook / Cooker / Gecko (RealAudio G2)"),
1281    .type           = AVMEDIA_TYPE_AUDIO,
1282    .id             = AV_CODEC_ID_COOK,
1283    .priv_data_size = sizeof(COOKContext),
1284    .init           = cook_decode_init,
1285    .close          = cook_decode_close,
1286    .decode         = cook_decode_frame,
1287    .capabilities   = CODEC_CAP_DR1,
1288    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1289                                                      AV_SAMPLE_FMT_NONE },
1290};
1291