xref: /third_party/ffmpeg/libavcodec/atrac3.c (revision cabdff1a)
1/*
2 * ATRAC3 compatible decoder
3 * Copyright (c) 2006-2008 Maxim Poliakovski
4 * Copyright (c) 2006-2008 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 * ATRAC3 compatible decoder.
26 * This decoder handles Sony's ATRAC3 data.
27 *
28 * Container formats used to store ATRAC3 data:
29 * RealMedia (.rm), RIFF WAV (.wav, .at3), Sony OpenMG (.oma, .aa3).
30 *
31 * To use this decoder, a calling application must supply the extradata
32 * bytes provided in the containers above.
33 */
34
35#include <math.h>
36#include <stddef.h>
37#include <stdio.h>
38
39#include "libavutil/attributes.h"
40#include "libavutil/float_dsp.h"
41#include "libavutil/libm.h"
42#include "libavutil/mem_internal.h"
43#include "libavutil/thread.h"
44
45#include "avcodec.h"
46#include "bytestream.h"
47#include "codec_internal.h"
48#include "fft.h"
49#include "get_bits.h"
50#include "internal.h"
51
52#include "atrac.h"
53#include "atrac3data.h"
54
55#define MIN_CHANNELS    1
56#define MAX_CHANNELS    8
57#define MAX_JS_PAIRS    8 / 2
58
59#define JOINT_STEREO    0x12
60#define SINGLE          0x2
61
62#define SAMPLES_PER_FRAME 1024
63#define MDCT_SIZE          512
64
65#define ATRAC3_VLC_BITS 8
66
67typedef struct GainBlock {
68    AtracGainInfo g_block[4];
69} GainBlock;
70
71typedef struct TonalComponent {
72    int pos;
73    int num_coefs;
74    float coef[8];
75} TonalComponent;
76
77typedef struct ChannelUnit {
78    int            bands_coded;
79    int            num_components;
80    float          prev_frame[SAMPLES_PER_FRAME];
81    int            gc_blk_switch;
82    TonalComponent components[64];
83    GainBlock      gain_block[2];
84
85    DECLARE_ALIGNED(32, float, spectrum)[SAMPLES_PER_FRAME];
86    DECLARE_ALIGNED(32, float, imdct_buf)[SAMPLES_PER_FRAME];
87
88    float          delay_buf1[46]; ///<qmf delay buffers
89    float          delay_buf2[46];
90    float          delay_buf3[46];
91} ChannelUnit;
92
93typedef struct ATRAC3Context {
94    GetBitContext gb;
95    //@{
96    /** stream data */
97    int coding_mode;
98
99    ChannelUnit *units;
100    //@}
101    //@{
102    /** joint-stereo related variables */
103    int matrix_coeff_index_prev[MAX_JS_PAIRS][4];
104    int matrix_coeff_index_now[MAX_JS_PAIRS][4];
105    int matrix_coeff_index_next[MAX_JS_PAIRS][4];
106    int weighting_delay[MAX_JS_PAIRS][6];
107    //@}
108    //@{
109    /** data buffers */
110    uint8_t *decoded_bytes_buffer;
111    float temp_buf[1070];
112    //@}
113    //@{
114    /** extradata */
115    int scrambled_stream;
116    //@}
117
118    AtracGCContext    gainc_ctx;
119    FFTContext        mdct_ctx;
120    void (*vector_fmul)(float *dst, const float *src0, const float *src1,
121                        int len);
122} ATRAC3Context;
123
124static DECLARE_ALIGNED(32, float, mdct_window)[MDCT_SIZE];
125static VLCElem atrac3_vlc_table[7 * 1 << ATRAC3_VLC_BITS];
126static VLC   spectral_coeff_tab[7];
127
128/**
129 * Regular 512 points IMDCT without overlapping, with the exception of the
130 * swapping of odd bands caused by the reverse spectra of the QMF.
131 *
132 * @param odd_band  1 if the band is an odd band
133 */
134static void imlt(ATRAC3Context *q, float *input, float *output, int odd_band)
135{
136    int i;
137
138    if (odd_band) {
139        /**
140         * Reverse the odd bands before IMDCT, this is an effect of the QMF
141         * transform or it gives better compression to do it this way.
142         * FIXME: It should be possible to handle this in imdct_calc
143         * for that to happen a modification of the prerotation step of
144         * all SIMD code and C code is needed.
145         * Or fix the functions before so they generate a pre reversed spectrum.
146         */
147        for (i = 0; i < 128; i++)
148            FFSWAP(float, input[i], input[255 - i]);
149    }
150
151    q->mdct_ctx.imdct_calc(&q->mdct_ctx, output, input);
152
153    /* Perform windowing on the output. */
154    q->vector_fmul(output, output, mdct_window, MDCT_SIZE);
155}
156
157/*
158 * indata descrambling, only used for data coming from the rm container
159 */
160static int decode_bytes(const uint8_t *input, uint8_t *out, int bytes)
161{
162    int i, off;
163    uint32_t c;
164    const uint32_t *buf;
165    uint32_t *output = (uint32_t *)out;
166
167    off = (intptr_t)input & 3;
168    buf = (const uint32_t *)(input - off);
169    if (off)
170        c = av_be2ne32((0x537F6103U >> (off * 8)) | (0x537F6103U << (32 - (off * 8))));
171    else
172        c = av_be2ne32(0x537F6103U);
173    bytes += 3 + off;
174    for (i = 0; i < bytes / 4; i++)
175        output[i] = c ^ buf[i];
176
177    if (off)
178        avpriv_request_sample(NULL, "Offset of %d", off);
179
180    return off;
181}
182
183static av_cold void init_imdct_window(void)
184{
185    int i, j;
186
187    /* generate the mdct window, for details see
188     * http://wiki.multimedia.cx/index.php?title=RealAudio_atrc#Windows */
189    for (i = 0, j = 255; i < 128; i++, j--) {
190        float wi = sin(((i + 0.5) / 256.0 - 0.5) * M_PI) + 1.0;
191        float wj = sin(((j + 0.5) / 256.0 - 0.5) * M_PI) + 1.0;
192        float w  = 0.5 * (wi * wi + wj * wj);
193        mdct_window[i] = mdct_window[511 - i] = wi / w;
194        mdct_window[j] = mdct_window[511 - j] = wj / w;
195    }
196}
197
198static av_cold int atrac3_decode_close(AVCodecContext *avctx)
199{
200    ATRAC3Context *q = avctx->priv_data;
201
202    av_freep(&q->units);
203    av_freep(&q->decoded_bytes_buffer);
204
205    ff_mdct_end(&q->mdct_ctx);
206
207    return 0;
208}
209
210/**
211 * Mantissa decoding
212 *
213 * @param selector     which table the output values are coded with
214 * @param coding_flag  constant length coding or variable length coding
215 * @param mantissas    mantissa output table
216 * @param num_codes    number of values to get
217 */
218static void read_quant_spectral_coeffs(GetBitContext *gb, int selector,
219                                       int coding_flag, int *mantissas,
220                                       int num_codes)
221{
222    int i, code, huff_symb;
223
224    if (selector == 1)
225        num_codes /= 2;
226
227    if (coding_flag != 0) {
228        /* constant length coding (CLC) */
229        int num_bits = clc_length_tab[selector];
230
231        if (selector > 1) {
232            for (i = 0; i < num_codes; i++) {
233                if (num_bits)
234                    code = get_sbits(gb, num_bits);
235                else
236                    code = 0;
237                mantissas[i] = code;
238            }
239        } else {
240            for (i = 0; i < num_codes; i++) {
241                if (num_bits)
242                    code = get_bits(gb, num_bits); // num_bits is always 4 in this case
243                else
244                    code = 0;
245                mantissas[i * 2    ] = mantissa_clc_tab[code >> 2];
246                mantissas[i * 2 + 1] = mantissa_clc_tab[code &  3];
247            }
248        }
249    } else {
250        /* variable length coding (VLC) */
251        if (selector != 1) {
252            for (i = 0; i < num_codes; i++) {
253                mantissas[i] = get_vlc2(gb, spectral_coeff_tab[selector-1].table,
254                                        ATRAC3_VLC_BITS, 1);
255            }
256        } else {
257            for (i = 0; i < num_codes; i++) {
258                huff_symb = get_vlc2(gb, spectral_coeff_tab[selector - 1].table,
259                                     ATRAC3_VLC_BITS, 1);
260                mantissas[i * 2    ] = mantissa_vlc_tab[huff_symb * 2    ];
261                mantissas[i * 2 + 1] = mantissa_vlc_tab[huff_symb * 2 + 1];
262            }
263        }
264    }
265}
266
267/**
268 * Restore the quantized band spectrum coefficients
269 *
270 * @return subband count, fix for broken specification/files
271 */
272static int decode_spectrum(GetBitContext *gb, float *output)
273{
274    int num_subbands, coding_mode, i, j, first, last, subband_size;
275    int subband_vlc_index[32], sf_index[32];
276    int mantissas[128];
277    float scale_factor;
278
279    num_subbands = get_bits(gb, 5);  // number of coded subbands
280    coding_mode  = get_bits1(gb);    // coding Mode: 0 - VLC/ 1-CLC
281
282    /* get the VLC selector table for the subbands, 0 means not coded */
283    for (i = 0; i <= num_subbands; i++)
284        subband_vlc_index[i] = get_bits(gb, 3);
285
286    /* read the scale factor indexes from the stream */
287    for (i = 0; i <= num_subbands; i++) {
288        if (subband_vlc_index[i] != 0)
289            sf_index[i] = get_bits(gb, 6);
290    }
291
292    for (i = 0; i <= num_subbands; i++) {
293        first = subband_tab[i    ];
294        last  = subband_tab[i + 1];
295
296        subband_size = last - first;
297
298        if (subband_vlc_index[i] != 0) {
299            /* decode spectral coefficients for this subband */
300            /* TODO: This can be done faster is several blocks share the
301             * same VLC selector (subband_vlc_index) */
302            read_quant_spectral_coeffs(gb, subband_vlc_index[i], coding_mode,
303                                       mantissas, subband_size);
304
305            /* decode the scale factor for this subband */
306            scale_factor = ff_atrac_sf_table[sf_index[i]] *
307                           inv_max_quant[subband_vlc_index[i]];
308
309            /* inverse quantize the coefficients */
310            for (j = 0; first < last; first++, j++)
311                output[first] = mantissas[j] * scale_factor;
312        } else {
313            /* this subband was not coded, so zero the entire subband */
314            memset(output + first, 0, subband_size * sizeof(*output));
315        }
316    }
317
318    /* clear the subbands that were not coded */
319    first = subband_tab[i];
320    memset(output + first, 0, (SAMPLES_PER_FRAME - first) * sizeof(*output));
321    return num_subbands;
322}
323
324/**
325 * Restore the quantized tonal components
326 *
327 * @param components tonal components
328 * @param num_bands  number of coded bands
329 */
330static int decode_tonal_components(GetBitContext *gb,
331                                   TonalComponent *components, int num_bands)
332{
333    int i, b, c, m;
334    int nb_components, coding_mode_selector, coding_mode;
335    int band_flags[4], mantissa[8];
336    int component_count = 0;
337
338    nb_components = get_bits(gb, 5);
339
340    /* no tonal components */
341    if (nb_components == 0)
342        return 0;
343
344    coding_mode_selector = get_bits(gb, 2);
345    if (coding_mode_selector == 2)
346        return AVERROR_INVALIDDATA;
347
348    coding_mode = coding_mode_selector & 1;
349
350    for (i = 0; i < nb_components; i++) {
351        int coded_values_per_component, quant_step_index;
352
353        for (b = 0; b <= num_bands; b++)
354            band_flags[b] = get_bits1(gb);
355
356        coded_values_per_component = get_bits(gb, 3);
357
358        quant_step_index = get_bits(gb, 3);
359        if (quant_step_index <= 1)
360            return AVERROR_INVALIDDATA;
361
362        if (coding_mode_selector == 3)
363            coding_mode = get_bits1(gb);
364
365        for (b = 0; b < (num_bands + 1) * 4; b++) {
366            int coded_components;
367
368            if (band_flags[b >> 2] == 0)
369                continue;
370
371            coded_components = get_bits(gb, 3);
372
373            for (c = 0; c < coded_components; c++) {
374                TonalComponent *cmp = &components[component_count];
375                int sf_index, coded_values, max_coded_values;
376                float scale_factor;
377
378                sf_index = get_bits(gb, 6);
379                if (component_count >= 64)
380                    return AVERROR_INVALIDDATA;
381
382                cmp->pos = b * 64 + get_bits(gb, 6);
383
384                max_coded_values = SAMPLES_PER_FRAME - cmp->pos;
385                coded_values     = coded_values_per_component + 1;
386                coded_values     = FFMIN(max_coded_values, coded_values);
387
388                scale_factor = ff_atrac_sf_table[sf_index] *
389                               inv_max_quant[quant_step_index];
390
391                read_quant_spectral_coeffs(gb, quant_step_index, coding_mode,
392                                           mantissa, coded_values);
393
394                cmp->num_coefs = coded_values;
395
396                /* inverse quant */
397                for (m = 0; m < coded_values; m++)
398                    cmp->coef[m] = mantissa[m] * scale_factor;
399
400                component_count++;
401            }
402        }
403    }
404
405    return component_count;
406}
407
408/**
409 * Decode gain parameters for the coded bands
410 *
411 * @param block      the gainblock for the current band
412 * @param num_bands  amount of coded bands
413 */
414static int decode_gain_control(GetBitContext *gb, GainBlock *block,
415                               int num_bands)
416{
417    int b, j;
418    int *level, *loc;
419
420    AtracGainInfo *gain = block->g_block;
421
422    for (b = 0; b <= num_bands; b++) {
423        gain[b].num_points = get_bits(gb, 3);
424        level              = gain[b].lev_code;
425        loc                = gain[b].loc_code;
426
427        for (j = 0; j < gain[b].num_points; j++) {
428            level[j] = get_bits(gb, 4);
429            loc[j]   = get_bits(gb, 5);
430            if (j && loc[j] <= loc[j - 1])
431                return AVERROR_INVALIDDATA;
432        }
433    }
434
435    /* Clear the unused blocks. */
436    for (; b < 4 ; b++)
437        gain[b].num_points = 0;
438
439    return 0;
440}
441
442/**
443 * Combine the tonal band spectrum and regular band spectrum
444 *
445 * @param spectrum        output spectrum buffer
446 * @param num_components  number of tonal components
447 * @param components      tonal components for this band
448 * @return                position of the last tonal coefficient
449 */
450static int add_tonal_components(float *spectrum, int num_components,
451                                TonalComponent *components)
452{
453    int i, j, last_pos = -1;
454    float *input, *output;
455
456    for (i = 0; i < num_components; i++) {
457        last_pos = FFMAX(components[i].pos + components[i].num_coefs, last_pos);
458        input    = components[i].coef;
459        output   = &spectrum[components[i].pos];
460
461        for (j = 0; j < components[i].num_coefs; j++)
462            output[j] += input[j];
463    }
464
465    return last_pos;
466}
467
468#define INTERPOLATE(old, new, nsample) \
469    ((old) + (nsample) * 0.125 * ((new) - (old)))
470
471static void reverse_matrixing(float *su1, float *su2, int *prev_code,
472                              int *curr_code)
473{
474    int i, nsample, band;
475    float mc1_l, mc1_r, mc2_l, mc2_r;
476
477    for (i = 0, band = 0; band < 4 * 256; band += 256, i++) {
478        int s1 = prev_code[i];
479        int s2 = curr_code[i];
480        nsample = band;
481
482        if (s1 != s2) {
483            /* Selector value changed, interpolation needed. */
484            mc1_l = matrix_coeffs[s1 * 2    ];
485            mc1_r = matrix_coeffs[s1 * 2 + 1];
486            mc2_l = matrix_coeffs[s2 * 2    ];
487            mc2_r = matrix_coeffs[s2 * 2 + 1];
488
489            /* Interpolation is done over the first eight samples. */
490            for (; nsample < band + 8; nsample++) {
491                float c1 = su1[nsample];
492                float c2 = su2[nsample];
493                c2 = c1 * INTERPOLATE(mc1_l, mc2_l, nsample - band) +
494                     c2 * INTERPOLATE(mc1_r, mc2_r, nsample - band);
495                su1[nsample] = c2;
496                su2[nsample] = c1 * 2.0 - c2;
497            }
498        }
499
500        /* Apply the matrix without interpolation. */
501        switch (s2) {
502        case 0:     /* M/S decoding */
503            for (; nsample < band + 256; nsample++) {
504                float c1 = su1[nsample];
505                float c2 = su2[nsample];
506                su1[nsample] =  c2       * 2.0;
507                su2[nsample] = (c1 - c2) * 2.0;
508            }
509            break;
510        case 1:
511            for (; nsample < band + 256; nsample++) {
512                float c1 = su1[nsample];
513                float c2 = su2[nsample];
514                su1[nsample] = (c1 + c2) *  2.0;
515                su2[nsample] =  c2       * -2.0;
516            }
517            break;
518        case 2:
519        case 3:
520            for (; nsample < band + 256; nsample++) {
521                float c1 = su1[nsample];
522                float c2 = su2[nsample];
523                su1[nsample] = c1 + c2;
524                su2[nsample] = c1 - c2;
525            }
526            break;
527        default:
528            av_assert1(0);
529        }
530    }
531}
532
533static void get_channel_weights(int index, int flag, float ch[2])
534{
535    if (index == 7) {
536        ch[0] = 1.0;
537        ch[1] = 1.0;
538    } else {
539        ch[0] = (index & 7) / 7.0;
540        ch[1] = sqrt(2 - ch[0] * ch[0]);
541        if (flag)
542            FFSWAP(float, ch[0], ch[1]);
543    }
544}
545
546static void channel_weighting(float *su1, float *su2, int *p3)
547{
548    int band, nsample;
549    /* w[x][y] y=0 is left y=1 is right */
550    float w[2][2];
551
552    if (p3[1] != 7 || p3[3] != 7) {
553        get_channel_weights(p3[1], p3[0], w[0]);
554        get_channel_weights(p3[3], p3[2], w[1]);
555
556        for (band = 256; band < 4 * 256; band += 256) {
557            for (nsample = band; nsample < band + 8; nsample++) {
558                su1[nsample] *= INTERPOLATE(w[0][0], w[0][1], nsample - band);
559                su2[nsample] *= INTERPOLATE(w[1][0], w[1][1], nsample - band);
560            }
561            for(; nsample < band + 256; nsample++) {
562                su1[nsample] *= w[1][0];
563                su2[nsample] *= w[1][1];
564            }
565        }
566    }
567}
568
569/**
570 * Decode a Sound Unit
571 *
572 * @param snd           the channel unit to be used
573 * @param output        the decoded samples before IQMF in float representation
574 * @param channel_num   channel number
575 * @param coding_mode   the coding mode (JOINT_STEREO or single channels)
576 */
577static int decode_channel_sound_unit(ATRAC3Context *q, GetBitContext *gb,
578                                     ChannelUnit *snd, float *output,
579                                     int channel_num, int coding_mode)
580{
581    int band, ret, num_subbands, last_tonal, num_bands;
582    GainBlock *gain1 = &snd->gain_block[    snd->gc_blk_switch];
583    GainBlock *gain2 = &snd->gain_block[1 - snd->gc_blk_switch];
584
585    if (coding_mode == JOINT_STEREO && (channel_num % 2) == 1) {
586        if (get_bits(gb, 2) != 3) {
587            av_log(NULL,AV_LOG_ERROR,"JS mono Sound Unit id != 3.\n");
588            return AVERROR_INVALIDDATA;
589        }
590    } else {
591        if (get_bits(gb, 6) != 0x28) {
592            av_log(NULL,AV_LOG_ERROR,"Sound Unit id != 0x28.\n");
593            return AVERROR_INVALIDDATA;
594        }
595    }
596
597    /* number of coded QMF bands */
598    snd->bands_coded = get_bits(gb, 2);
599
600    ret = decode_gain_control(gb, gain2, snd->bands_coded);
601    if (ret)
602        return ret;
603
604    snd->num_components = decode_tonal_components(gb, snd->components,
605                                                  snd->bands_coded);
606    if (snd->num_components < 0)
607        return snd->num_components;
608
609    num_subbands = decode_spectrum(gb, snd->spectrum);
610
611    /* Merge the decoded spectrum and tonal components. */
612    last_tonal = add_tonal_components(snd->spectrum, snd->num_components,
613                                      snd->components);
614
615
616    /* calculate number of used MLT/QMF bands according to the amount of coded
617       spectral lines */
618    num_bands = (subband_tab[num_subbands] - 1) >> 8;
619    if (last_tonal >= 0)
620        num_bands = FFMAX((last_tonal + 256) >> 8, num_bands);
621
622
623    /* Reconstruct time domain samples. */
624    for (band = 0; band < 4; band++) {
625        /* Perform the IMDCT step without overlapping. */
626        if (band <= num_bands)
627            imlt(q, &snd->spectrum[band * 256], snd->imdct_buf, band & 1);
628        else
629            memset(snd->imdct_buf, 0, 512 * sizeof(*snd->imdct_buf));
630
631        /* gain compensation and overlapping */
632        ff_atrac_gain_compensation(&q->gainc_ctx, snd->imdct_buf,
633                                   &snd->prev_frame[band * 256],
634                                   &gain1->g_block[band], &gain2->g_block[band],
635                                   256, &output[band * 256]);
636    }
637
638    /* Swap the gain control buffers for the next frame. */
639    snd->gc_blk_switch ^= 1;
640
641    return 0;
642}
643
644static int decode_frame(AVCodecContext *avctx, const uint8_t *databuf,
645                        float **out_samples)
646{
647    ATRAC3Context *q = avctx->priv_data;
648    int ret, i, ch;
649    uint8_t *ptr1;
650    int channels = avctx->ch_layout.nb_channels;
651
652    if (q->coding_mode == JOINT_STEREO) {
653        /* channel coupling mode */
654
655        /* Decode sound unit pairs (channels are expected to be even).
656         * Multichannel joint stereo interleaves pairs (6ch: 2ch + 2ch + 2ch) */
657        const uint8_t *js_databuf;
658        int js_pair, js_block_align;
659
660        js_block_align = (avctx->block_align / channels) * 2; /* block pair */
661
662        for (ch = 0; ch < channels; ch = ch + 2) {
663            js_pair = ch/2;
664            js_databuf = databuf + js_pair * js_block_align; /* align to current pair */
665
666            /* Set the bitstream reader at the start of first channel sound unit. */
667            init_get_bits(&q->gb,
668                          js_databuf, js_block_align * 8);
669
670            /* decode Sound Unit 1 */
671            ret = decode_channel_sound_unit(q, &q->gb, &q->units[ch],
672                                            out_samples[ch], ch, JOINT_STEREO);
673            if (ret != 0)
674                return ret;
675
676            /* Framedata of the su2 in the joint-stereo mode is encoded in
677             * reverse byte order so we need to swap it first. */
678            if (js_databuf == q->decoded_bytes_buffer) {
679                uint8_t *ptr2 = q->decoded_bytes_buffer + js_block_align - 1;
680                ptr1          = q->decoded_bytes_buffer;
681                for (i = 0; i < js_block_align / 2; i++, ptr1++, ptr2--)
682                    FFSWAP(uint8_t, *ptr1, *ptr2);
683            } else {
684                const uint8_t *ptr2 = js_databuf + js_block_align - 1;
685                for (i = 0; i < js_block_align; i++)
686                    q->decoded_bytes_buffer[i] = *ptr2--;
687            }
688
689            /* Skip the sync codes (0xF8). */
690            ptr1 = q->decoded_bytes_buffer;
691            for (i = 4; *ptr1 == 0xF8; i++, ptr1++) {
692                if (i >= js_block_align)
693                    return AVERROR_INVALIDDATA;
694            }
695
696
697            /* set the bitstream reader at the start of the second Sound Unit */
698            ret = init_get_bits8(&q->gb,
699                           ptr1, q->decoded_bytes_buffer + js_block_align - ptr1);
700            if (ret < 0)
701                return ret;
702
703            /* Fill the Weighting coeffs delay buffer */
704            memmove(q->weighting_delay[js_pair], &q->weighting_delay[js_pair][2],
705                    4 * sizeof(*q->weighting_delay[js_pair]));
706            q->weighting_delay[js_pair][4] = get_bits1(&q->gb);
707            q->weighting_delay[js_pair][5] = get_bits(&q->gb, 3);
708
709            for (i = 0; i < 4; i++) {
710                q->matrix_coeff_index_prev[js_pair][i] = q->matrix_coeff_index_now[js_pair][i];
711                q->matrix_coeff_index_now[js_pair][i]  = q->matrix_coeff_index_next[js_pair][i];
712                q->matrix_coeff_index_next[js_pair][i] = get_bits(&q->gb, 2);
713            }
714
715            /* Decode Sound Unit 2. */
716            ret = decode_channel_sound_unit(q, &q->gb, &q->units[ch+1],
717                                            out_samples[ch+1], ch+1, JOINT_STEREO);
718            if (ret != 0)
719                return ret;
720
721            /* Reconstruct the channel coefficients. */
722            reverse_matrixing(out_samples[ch], out_samples[ch+1],
723                              q->matrix_coeff_index_prev[js_pair],
724                              q->matrix_coeff_index_now[js_pair]);
725
726            channel_weighting(out_samples[ch], out_samples[ch+1], q->weighting_delay[js_pair]);
727        }
728    } else {
729        /* single channels */
730        /* Decode the channel sound units. */
731        for (i = 0; i < channels; i++) {
732            /* Set the bitstream reader at the start of a channel sound unit. */
733            init_get_bits(&q->gb,
734                          databuf + i * avctx->block_align / channels,
735                          avctx->block_align * 8 / channels);
736
737            ret = decode_channel_sound_unit(q, &q->gb, &q->units[i],
738                                            out_samples[i], i, q->coding_mode);
739            if (ret != 0)
740                return ret;
741        }
742    }
743
744    /* Apply the iQMF synthesis filter. */
745    for (i = 0; i < channels; i++) {
746        float *p1 = out_samples[i];
747        float *p2 = p1 + 256;
748        float *p3 = p2 + 256;
749        float *p4 = p3 + 256;
750        ff_atrac_iqmf(p1, p2, 256, p1, q->units[i].delay_buf1, q->temp_buf);
751        ff_atrac_iqmf(p4, p3, 256, p3, q->units[i].delay_buf2, q->temp_buf);
752        ff_atrac_iqmf(p1, p3, 512, p1, q->units[i].delay_buf3, q->temp_buf);
753    }
754
755    return 0;
756}
757
758static int al_decode_frame(AVCodecContext *avctx, const uint8_t *databuf,
759                           int size, float **out_samples)
760{
761    ATRAC3Context *q = avctx->priv_data;
762    int channels = avctx->ch_layout.nb_channels;
763    int ret, i;
764
765    /* Set the bitstream reader at the start of a channel sound unit. */
766    init_get_bits(&q->gb, databuf, size * 8);
767    /* single channels */
768    /* Decode the channel sound units. */
769    for (i = 0; i < channels; i++) {
770        ret = decode_channel_sound_unit(q, &q->gb, &q->units[i],
771                                        out_samples[i], i, q->coding_mode);
772        if (ret != 0)
773            return ret;
774        while (i < channels && get_bits_left(&q->gb) > 6 && show_bits(&q->gb, 6) != 0x28) {
775            skip_bits(&q->gb, 1);
776        }
777    }
778
779    /* Apply the iQMF synthesis filter. */
780    for (i = 0; i < channels; i++) {
781        float *p1 = out_samples[i];
782        float *p2 = p1 + 256;
783        float *p3 = p2 + 256;
784        float *p4 = p3 + 256;
785        ff_atrac_iqmf(p1, p2, 256, p1, q->units[i].delay_buf1, q->temp_buf);
786        ff_atrac_iqmf(p4, p3, 256, p3, q->units[i].delay_buf2, q->temp_buf);
787        ff_atrac_iqmf(p1, p3, 512, p1, q->units[i].delay_buf3, q->temp_buf);
788    }
789
790    return 0;
791}
792
793static int atrac3_decode_frame(AVCodecContext *avctx, AVFrame *frame,
794                               int *got_frame_ptr, AVPacket *avpkt)
795{
796    const uint8_t *buf = avpkt->data;
797    int buf_size = avpkt->size;
798    ATRAC3Context *q = avctx->priv_data;
799    int ret;
800    const uint8_t *databuf;
801
802    if (buf_size < avctx->block_align) {
803        av_log(avctx, AV_LOG_ERROR,
804               "Frame too small (%d bytes). Truncated file?\n", buf_size);
805        return AVERROR_INVALIDDATA;
806    }
807
808    /* get output buffer */
809    frame->nb_samples = SAMPLES_PER_FRAME;
810    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
811        return ret;
812
813    /* Check if we need to descramble and what buffer to pass on. */
814    if (q->scrambled_stream) {
815        decode_bytes(buf, q->decoded_bytes_buffer, avctx->block_align);
816        databuf = q->decoded_bytes_buffer;
817    } else {
818        databuf = buf;
819    }
820
821    ret = decode_frame(avctx, databuf, (float **)frame->extended_data);
822    if (ret) {
823        av_log(avctx, AV_LOG_ERROR, "Frame decoding error!\n");
824        return ret;
825    }
826
827    *got_frame_ptr = 1;
828
829    return avctx->block_align;
830}
831
832static int atrac3al_decode_frame(AVCodecContext *avctx, AVFrame *frame,
833                                 int *got_frame_ptr, AVPacket *avpkt)
834{
835    int ret;
836
837    frame->nb_samples = SAMPLES_PER_FRAME;
838    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
839        return ret;
840
841    ret = al_decode_frame(avctx, avpkt->data, avpkt->size,
842                          (float **)frame->extended_data);
843    if (ret) {
844        av_log(avctx, AV_LOG_ERROR, "Frame decoding error!\n");
845        return ret;
846    }
847
848    *got_frame_ptr = 1;
849
850    return avpkt->size;
851}
852
853static av_cold void atrac3_init_static_data(void)
854{
855    VLCElem *table = atrac3_vlc_table;
856    const uint8_t (*hufftabs)[2] = atrac3_hufftabs;
857    int i;
858
859    init_imdct_window();
860    ff_atrac_generate_tables();
861
862    /* Initialize the VLC tables. */
863    for (i = 0; i < 7; i++) {
864        spectral_coeff_tab[i].table           = table;
865        spectral_coeff_tab[i].table_allocated = 256;
866        ff_init_vlc_from_lengths(&spectral_coeff_tab[i], ATRAC3_VLC_BITS, huff_tab_sizes[i],
867                                 &hufftabs[0][1], 2,
868                                 &hufftabs[0][0], 2, 1,
869                                 -31, INIT_VLC_USE_NEW_STATIC, NULL);
870        hufftabs += huff_tab_sizes[i];
871        table += 256;
872    }
873}
874
875static av_cold int atrac3_decode_init(AVCodecContext *avctx)
876{
877    static AVOnce init_static_once = AV_ONCE_INIT;
878    int i, js_pair, ret;
879    int version, delay, samples_per_frame, frame_factor;
880    const uint8_t *edata_ptr = avctx->extradata;
881    ATRAC3Context *q = avctx->priv_data;
882    AVFloatDSPContext *fdsp;
883    int channels = avctx->ch_layout.nb_channels;
884
885    if (channels < MIN_CHANNELS || channels > MAX_CHANNELS) {
886        av_log(avctx, AV_LOG_ERROR, "Channel configuration error!\n");
887        return AVERROR(EINVAL);
888    }
889
890    /* Take care of the codec-specific extradata. */
891    if (avctx->codec_id == AV_CODEC_ID_ATRAC3AL) {
892        version           = 4;
893        samples_per_frame = SAMPLES_PER_FRAME * channels;
894        delay             = 0x88E;
895        q->coding_mode    = SINGLE;
896    } else if (avctx->extradata_size == 14) {
897        /* Parse the extradata, WAV format */
898        av_log(avctx, AV_LOG_DEBUG, "[0-1] %d\n",
899               bytestream_get_le16(&edata_ptr));  // Unknown value always 1
900        edata_ptr += 4;                             // samples per channel
901        q->coding_mode = bytestream_get_le16(&edata_ptr);
902        av_log(avctx, AV_LOG_DEBUG,"[8-9] %d\n",
903               bytestream_get_le16(&edata_ptr));  //Dupe of coding mode
904        frame_factor = bytestream_get_le16(&edata_ptr);  // Unknown always 1
905        av_log(avctx, AV_LOG_DEBUG,"[12-13] %d\n",
906               bytestream_get_le16(&edata_ptr));  // Unknown always 0
907
908        /* setup */
909        samples_per_frame    = SAMPLES_PER_FRAME * channels;
910        version              = 4;
911        delay                = 0x88E;
912        q->coding_mode       = q->coding_mode ? JOINT_STEREO : SINGLE;
913        q->scrambled_stream  = 0;
914
915        if (avctx->block_align !=  96 * channels * frame_factor &&
916            avctx->block_align != 152 * channels * frame_factor &&
917            avctx->block_align != 192 * channels * frame_factor) {
918            av_log(avctx, AV_LOG_ERROR, "Unknown frame/channel/frame_factor "
919                   "configuration %d/%d/%d\n", avctx->block_align,
920                   channels, frame_factor);
921            return AVERROR_INVALIDDATA;
922        }
923    } else if (avctx->extradata_size == 12 || avctx->extradata_size == 10) {
924        /* Parse the extradata, RM format. */
925        version                = bytestream_get_be32(&edata_ptr);
926        samples_per_frame      = bytestream_get_be16(&edata_ptr);
927        delay                  = bytestream_get_be16(&edata_ptr);
928        q->coding_mode         = bytestream_get_be16(&edata_ptr);
929        q->scrambled_stream    = 1;
930
931    } else {
932        av_log(avctx, AV_LOG_ERROR, "Unknown extradata size %d.\n",
933               avctx->extradata_size);
934        return AVERROR(EINVAL);
935    }
936
937    /* Check the extradata */
938
939    if (version != 4) {
940        av_log(avctx, AV_LOG_ERROR, "Version %d != 4.\n", version);
941        return AVERROR_INVALIDDATA;
942    }
943
944    if (samples_per_frame != SAMPLES_PER_FRAME * channels) {
945        av_log(avctx, AV_LOG_ERROR, "Unknown amount of samples per frame %d.\n",
946               samples_per_frame);
947        return AVERROR_INVALIDDATA;
948    }
949
950    if (delay != 0x88E) {
951        av_log(avctx, AV_LOG_ERROR, "Unknown amount of delay %x != 0x88E.\n",
952               delay);
953        return AVERROR_INVALIDDATA;
954    }
955
956    if (q->coding_mode == SINGLE)
957        av_log(avctx, AV_LOG_DEBUG, "Single channels detected.\n");
958    else if (q->coding_mode == JOINT_STEREO) {
959        if (channels % 2 == 1) { /* Joint stereo channels must be even */
960            av_log(avctx, AV_LOG_ERROR, "Invalid joint stereo channel configuration.\n");
961            return AVERROR_INVALIDDATA;
962        }
963        av_log(avctx, AV_LOG_DEBUG, "Joint stereo detected.\n");
964    } else {
965        av_log(avctx, AV_LOG_ERROR, "Unknown channel coding mode %x!\n",
966               q->coding_mode);
967        return AVERROR_INVALIDDATA;
968    }
969
970    if (avctx->block_align > 4096 || avctx->block_align <= 0)
971        return AVERROR(EINVAL);
972
973    q->decoded_bytes_buffer = av_mallocz(FFALIGN(avctx->block_align, 4) +
974                                         AV_INPUT_BUFFER_PADDING_SIZE);
975    if (!q->decoded_bytes_buffer)
976        return AVERROR(ENOMEM);
977
978    avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
979
980    /* initialize the MDCT transform */
981    if ((ret = ff_mdct_init(&q->mdct_ctx, 9, 1, 1.0 / 32768)) < 0) {
982        av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n");
983        return ret;
984    }
985
986    /* init the joint-stereo decoding data */
987    for (js_pair = 0; js_pair < MAX_JS_PAIRS; js_pair++) {
988        q->weighting_delay[js_pair][0] = 0;
989        q->weighting_delay[js_pair][1] = 7;
990        q->weighting_delay[js_pair][2] = 0;
991        q->weighting_delay[js_pair][3] = 7;
992        q->weighting_delay[js_pair][4] = 0;
993        q->weighting_delay[js_pair][5] = 7;
994
995        for (i = 0; i < 4; i++) {
996            q->matrix_coeff_index_prev[js_pair][i] = 3;
997            q->matrix_coeff_index_now[js_pair][i]  = 3;
998            q->matrix_coeff_index_next[js_pair][i] = 3;
999        }
1000    }
1001
1002    ff_atrac_init_gain_compensation(&q->gainc_ctx, 4, 3);
1003    fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
1004    if (!fdsp)
1005        return AVERROR(ENOMEM);
1006    q->vector_fmul = fdsp->vector_fmul;
1007    av_free(fdsp);
1008
1009    q->units = av_calloc(channels, sizeof(*q->units));
1010    if (!q->units)
1011        return AVERROR(ENOMEM);
1012
1013    ff_thread_once(&init_static_once, atrac3_init_static_data);
1014
1015    return 0;
1016}
1017
1018const FFCodec ff_atrac3_decoder = {
1019    .p.name           = "atrac3",
1020    .p.long_name      = NULL_IF_CONFIG_SMALL("ATRAC3 (Adaptive TRansform Acoustic Coding 3)"),
1021    .p.type           = AVMEDIA_TYPE_AUDIO,
1022    .p.id             = AV_CODEC_ID_ATRAC3,
1023    .priv_data_size   = sizeof(ATRAC3Context),
1024    .init             = atrac3_decode_init,
1025    .close            = atrac3_decode_close,
1026    FF_CODEC_DECODE_CB(atrac3_decode_frame),
1027    .p.capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
1028    .p.sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1029                                                        AV_SAMPLE_FMT_NONE },
1030    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1031};
1032
1033const FFCodec ff_atrac3al_decoder = {
1034    .p.name           = "atrac3al",
1035    .p.long_name      = NULL_IF_CONFIG_SMALL("ATRAC3 AL (Adaptive TRansform Acoustic Coding 3 Advanced Lossless)"),
1036    .p.type           = AVMEDIA_TYPE_AUDIO,
1037    .p.id             = AV_CODEC_ID_ATRAC3AL,
1038    .priv_data_size   = sizeof(ATRAC3Context),
1039    .init             = atrac3_decode_init,
1040    .close            = atrac3_decode_close,
1041    FF_CODEC_DECODE_CB(atrac3al_decode_frame),
1042    .p.capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
1043    .p.sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1044                                                        AV_SAMPLE_FMT_NONE },
1045    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1046};
1047