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 "avcodec.h"
43#include "bytestream.h"
44#include "fft.h"
45#include "fmtconvert.h"
46#include "get_bits.h"
47#include "internal.h"
48
49#include "atrac.h"
50#include "atrac3data.h"
51
52#define JOINT_STEREO    0x12
53#define STEREO          0x2
54
55#define SAMPLES_PER_FRAME 1024
56#define MDCT_SIZE          512
57
58typedef struct GainBlock {
59    AtracGainInfo g_block[4];
60} GainBlock;
61
62typedef struct TonalComponent {
63    int pos;
64    int num_coefs;
65    float coef[8];
66} TonalComponent;
67
68typedef struct ChannelUnit {
69    int            bands_coded;
70    int            num_components;
71    float          prev_frame[SAMPLES_PER_FRAME];
72    int            gc_blk_switch;
73    TonalComponent components[64];
74    GainBlock      gain_block[2];
75
76    DECLARE_ALIGNED(32, float, spectrum)[SAMPLES_PER_FRAME];
77    DECLARE_ALIGNED(32, float, imdct_buf)[SAMPLES_PER_FRAME];
78
79    float          delay_buf1[46]; ///<qmf delay buffers
80    float          delay_buf2[46];
81    float          delay_buf3[46];
82} ChannelUnit;
83
84typedef struct ATRAC3Context {
85    GetBitContext gb;
86    //@{
87    /** stream data */
88    int coding_mode;
89
90    ChannelUnit *units;
91    //@}
92    //@{
93    /** joint-stereo related variables */
94    int matrix_coeff_index_prev[4];
95    int matrix_coeff_index_now[4];
96    int matrix_coeff_index_next[4];
97    int weighting_delay[6];
98    //@}
99    //@{
100    /** data buffers */
101    uint8_t *decoded_bytes_buffer;
102    float temp_buf[1070];
103    //@}
104    //@{
105    /** extradata */
106    int scrambled_stream;
107    //@}
108
109    AtracGCContext    gainc_ctx;
110    FFTContext        mdct_ctx;
111    FmtConvertContext fmt_conv;
112    AVFloatDSPContext fdsp;
113} ATRAC3Context;
114
115static DECLARE_ALIGNED(32, float, mdct_window)[MDCT_SIZE];
116static VLC_TYPE atrac3_vlc_table[4096][2];
117static VLC   spectral_coeff_tab[7];
118
119/**
120 * Regular 512 points IMDCT without overlapping, with the exception of the
121 * swapping of odd bands caused by the reverse spectra of the QMF.
122 *
123 * @param odd_band  1 if the band is an odd band
124 */
125static void imlt(ATRAC3Context *q, float *input, float *output, int odd_band)
126{
127    int i;
128
129    if (odd_band) {
130        /**
131         * Reverse the odd bands before IMDCT, this is an effect of the QMF
132         * transform or it gives better compression to do it this way.
133         * FIXME: It should be possible to handle this in imdct_calc
134         * for that to happen a modification of the prerotation step of
135         * all SIMD code and C code is needed.
136         * Or fix the functions before so they generate a pre reversed spectrum.
137         */
138        for (i = 0; i < 128; i++)
139            FFSWAP(float, input[i], input[255 - i]);
140    }
141
142    q->mdct_ctx.imdct_calc(&q->mdct_ctx, output, input);
143
144    /* Perform windowing on the output. */
145    q->fdsp.vector_fmul(output, output, mdct_window, MDCT_SIZE);
146}
147
148/*
149 * indata descrambling, only used for data coming from the rm container
150 */
151static int decode_bytes(const uint8_t *input, uint8_t *out, int bytes)
152{
153    int i, off;
154    uint32_t c;
155    const uint32_t *buf;
156    uint32_t *output = (uint32_t *)out;
157
158    off = (intptr_t)input & 3;
159    buf = (const uint32_t *)(input - off);
160    if (off)
161        c = av_be2ne32((0x537F6103U >> (off * 8)) | (0x537F6103U << (32 - (off * 8))));
162    else
163        c = av_be2ne32(0x537F6103U);
164    bytes += 3 + off;
165    for (i = 0; i < bytes / 4; i++)
166        output[i] = c ^ buf[i];
167
168    if (off)
169        avpriv_request_sample(NULL, "Offset of %d", off);
170
171    return off;
172}
173
174static av_cold void init_imdct_window(void)
175{
176    int i, j;
177
178    /* generate the mdct window, for details see
179     * http://wiki.multimedia.cx/index.php?title=RealAudio_atrc#Windows */
180    for (i = 0, j = 255; i < 128; i++, j--) {
181        float wi = sin(((i + 0.5) / 256.0 - 0.5) * M_PI) + 1.0;
182        float wj = sin(((j + 0.5) / 256.0 - 0.5) * M_PI) + 1.0;
183        float w  = 0.5 * (wi * wi + wj * wj);
184        mdct_window[i] = mdct_window[511 - i] = wi / w;
185        mdct_window[j] = mdct_window[511 - j] = wj / w;
186    }
187}
188
189static av_cold int atrac3_decode_close(AVCodecContext *avctx)
190{
191    ATRAC3Context *q = avctx->priv_data;
192
193    av_free(q->units);
194    av_free(q->decoded_bytes_buffer);
195
196    ff_mdct_end(&q->mdct_ctx);
197
198    return 0;
199}
200
201/**
202 * Mantissa decoding
203 *
204 * @param selector     which table the output values are coded with
205 * @param coding_flag  constant length coding or variable length coding
206 * @param mantissas    mantissa output table
207 * @param num_codes    number of values to get
208 */
209static void read_quant_spectral_coeffs(GetBitContext *gb, int selector,
210                                       int coding_flag, int *mantissas,
211                                       int num_codes)
212{
213    int i, code, huff_symb;
214
215    if (selector == 1)
216        num_codes /= 2;
217
218    if (coding_flag != 0) {
219        /* constant length coding (CLC) */
220        int num_bits = clc_length_tab[selector];
221
222        if (selector > 1) {
223            for (i = 0; i < num_codes; i++) {
224                if (num_bits)
225                    code = get_sbits(gb, num_bits);
226                else
227                    code = 0;
228                mantissas[i] = code;
229            }
230        } else {
231            for (i = 0; i < num_codes; i++) {
232                if (num_bits)
233                    code = get_bits(gb, num_bits); // num_bits is always 4 in this case
234                else
235                    code = 0;
236                mantissas[i * 2    ] = mantissa_clc_tab[code >> 2];
237                mantissas[i * 2 + 1] = mantissa_clc_tab[code &  3];
238            }
239        }
240    } else {
241        /* variable length coding (VLC) */
242        if (selector != 1) {
243            for (i = 0; i < num_codes; i++) {
244                huff_symb = get_vlc2(gb, spectral_coeff_tab[selector-1].table,
245                                     spectral_coeff_tab[selector-1].bits, 3);
246                huff_symb += 1;
247                code = huff_symb >> 1;
248                if (huff_symb & 1)
249                    code = -code;
250                mantissas[i] = code;
251            }
252        } else {
253            for (i = 0; i < num_codes; i++) {
254                huff_symb = get_vlc2(gb, spectral_coeff_tab[selector - 1].table,
255                                     spectral_coeff_tab[selector - 1].bits, 3);
256                mantissas[i * 2    ] = mantissa_vlc_tab[huff_symb * 2    ];
257                mantissas[i * 2 + 1] = mantissa_vlc_tab[huff_symb * 2 + 1];
258            }
259        }
260    }
261}
262
263/**
264 * Restore the quantized band spectrum coefficients
265 *
266 * @return subband count, fix for broken specification/files
267 */
268static int decode_spectrum(GetBitContext *gb, float *output)
269{
270    int num_subbands, coding_mode, i, j, first, last, subband_size;
271    int subband_vlc_index[32], sf_index[32];
272    int mantissas[128];
273    float scale_factor;
274
275    num_subbands = get_bits(gb, 5);  // number of coded subbands
276    coding_mode  = get_bits1(gb);    // coding Mode: 0 - VLC/ 1-CLC
277
278    /* get the VLC selector table for the subbands, 0 means not coded */
279    for (i = 0; i <= num_subbands; i++)
280        subband_vlc_index[i] = get_bits(gb, 3);
281
282    /* read the scale factor indexes from the stream */
283    for (i = 0; i <= num_subbands; i++) {
284        if (subband_vlc_index[i] != 0)
285            sf_index[i] = get_bits(gb, 6);
286    }
287
288    for (i = 0; i <= num_subbands; i++) {
289        first = subband_tab[i    ];
290        last  = subband_tab[i + 1];
291
292        subband_size = last - first;
293
294        if (subband_vlc_index[i] != 0) {
295            /* decode spectral coefficients for this subband */
296            /* TODO: This can be done faster is several blocks share the
297             * same VLC selector (subband_vlc_index) */
298            read_quant_spectral_coeffs(gb, subband_vlc_index[i], coding_mode,
299                                       mantissas, subband_size);
300
301            /* decode the scale factor for this subband */
302            scale_factor = ff_atrac_sf_table[sf_index[i]] *
303                           inv_max_quant[subband_vlc_index[i]];
304
305            /* inverse quantize the coefficients */
306            for (j = 0; first < last; first++, j++)
307                output[first] = mantissas[j] * scale_factor;
308        } else {
309            /* this subband was not coded, so zero the entire subband */
310            memset(output + first, 0, subband_size * sizeof(*output));
311        }
312    }
313
314    /* clear the subbands that were not coded */
315    first = subband_tab[i];
316    memset(output + first, 0, (SAMPLES_PER_FRAME - first) * sizeof(*output));
317    return num_subbands;
318}
319
320/**
321 * Restore the quantized tonal components
322 *
323 * @param components tonal components
324 * @param num_bands  number of coded bands
325 */
326static int decode_tonal_components(GetBitContext *gb,
327                                   TonalComponent *components, int num_bands)
328{
329    int i, b, c, m;
330    int nb_components, coding_mode_selector, coding_mode;
331    int band_flags[4], mantissa[8];
332    int component_count = 0;
333
334    nb_components = get_bits(gb, 5);
335
336    /* no tonal components */
337    if (nb_components == 0)
338        return 0;
339
340    coding_mode_selector = get_bits(gb, 2);
341    if (coding_mode_selector == 2)
342        return AVERROR_INVALIDDATA;
343
344    coding_mode = coding_mode_selector & 1;
345
346    for (i = 0; i < nb_components; i++) {
347        int coded_values_per_component, quant_step_index;
348
349        for (b = 0; b <= num_bands; b++)
350            band_flags[b] = get_bits1(gb);
351
352        coded_values_per_component = get_bits(gb, 3);
353
354        quant_step_index = get_bits(gb, 3);
355        if (quant_step_index <= 1)
356            return AVERROR_INVALIDDATA;
357
358        if (coding_mode_selector == 3)
359            coding_mode = get_bits1(gb);
360
361        for (b = 0; b < (num_bands + 1) * 4; b++) {
362            int coded_components;
363
364            if (band_flags[b >> 2] == 0)
365                continue;
366
367            coded_components = get_bits(gb, 3);
368
369            for (c = 0; c < coded_components; c++) {
370                TonalComponent *cmp = &components[component_count];
371                int sf_index, coded_values, max_coded_values;
372                float scale_factor;
373
374                sf_index = get_bits(gb, 6);
375                if (component_count >= 64)
376                    return AVERROR_INVALIDDATA;
377
378                cmp->pos = b * 64 + get_bits(gb, 6);
379
380                max_coded_values = SAMPLES_PER_FRAME - cmp->pos;
381                coded_values     = coded_values_per_component + 1;
382                coded_values     = FFMIN(max_coded_values, coded_values);
383
384                scale_factor = ff_atrac_sf_table[sf_index] *
385                               inv_max_quant[quant_step_index];
386
387                read_quant_spectral_coeffs(gb, quant_step_index, coding_mode,
388                                           mantissa, coded_values);
389
390                cmp->num_coefs = coded_values;
391
392                /* inverse quant */
393                for (m = 0; m < coded_values; m++)
394                    cmp->coef[m] = mantissa[m] * scale_factor;
395
396                component_count++;
397            }
398        }
399    }
400
401    return component_count;
402}
403
404/**
405 * Decode gain parameters for the coded bands
406 *
407 * @param block      the gainblock for the current band
408 * @param num_bands  amount of coded bands
409 */
410static int decode_gain_control(GetBitContext *gb, GainBlock *block,
411                               int num_bands)
412{
413    int b, j;
414    int *level, *loc;
415
416    AtracGainInfo *gain = block->g_block;
417
418    for (b = 0; b <= num_bands; b++) {
419        gain[b].num_points = get_bits(gb, 3);
420        level              = gain[b].lev_code;
421        loc                = gain[b].loc_code;
422
423        for (j = 0; j < gain[b].num_points; j++) {
424            level[j] = get_bits(gb, 4);
425            loc[j]   = get_bits(gb, 5);
426            if (j && loc[j] <= loc[j - 1])
427                return AVERROR_INVALIDDATA;
428        }
429    }
430
431    /* Clear the unused blocks. */
432    for (; b < 4 ; b++)
433        gain[b].num_points = 0;
434
435    return 0;
436}
437
438/**
439 * Combine the tonal band spectrum and regular band spectrum
440 *
441 * @param spectrum        output spectrum buffer
442 * @param num_components  number of tonal components
443 * @param components      tonal components for this band
444 * @return                position of the last tonal coefficient
445 */
446static int add_tonal_components(float *spectrum, int num_components,
447                                TonalComponent *components)
448{
449    int i, j, last_pos = -1;
450    float *input, *output;
451
452    for (i = 0; i < num_components; i++) {
453        last_pos = FFMAX(components[i].pos + components[i].num_coefs, last_pos);
454        input    = components[i].coef;
455        output   = &spectrum[components[i].pos];
456
457        for (j = 0; j < components[i].num_coefs; j++)
458            output[j] += input[j];
459    }
460
461    return last_pos;
462}
463
464#define INTERPOLATE(old, new, nsample) \
465    ((old) + (nsample) * 0.125 * ((new) - (old)))
466
467static void reverse_matrixing(float *su1, float *su2, int *prev_code,
468                              int *curr_code)
469{
470    int i, nsample, band;
471    float mc1_l, mc1_r, mc2_l, mc2_r;
472
473    for (i = 0, band = 0; band < 4 * 256; band += 256, i++) {
474        int s1 = prev_code[i];
475        int s2 = curr_code[i];
476        nsample = band;
477
478        if (s1 != s2) {
479            /* Selector value changed, interpolation needed. */
480            mc1_l = matrix_coeffs[s1 * 2    ];
481            mc1_r = matrix_coeffs[s1 * 2 + 1];
482            mc2_l = matrix_coeffs[s2 * 2    ];
483            mc2_r = matrix_coeffs[s2 * 2 + 1];
484
485            /* Interpolation is done over the first eight samples. */
486            for (; nsample < band + 8; nsample++) {
487                float c1 = su1[nsample];
488                float c2 = su2[nsample];
489                c2 = c1 * INTERPOLATE(mc1_l, mc2_l, nsample - band) +
490                     c2 * INTERPOLATE(mc1_r, mc2_r, nsample - band);
491                su1[nsample] = c2;
492                su2[nsample] = c1 * 2.0 - c2;
493            }
494        }
495
496        /* Apply the matrix without interpolation. */
497        switch (s2) {
498        case 0:     /* M/S decoding */
499            for (; nsample < band + 256; nsample++) {
500                float c1 = su1[nsample];
501                float c2 = su2[nsample];
502                su1[nsample] =  c2       * 2.0;
503                su2[nsample] = (c1 - c2) * 2.0;
504            }
505            break;
506        case 1:
507            for (; nsample < band + 256; nsample++) {
508                float c1 = su1[nsample];
509                float c2 = su2[nsample];
510                su1[nsample] = (c1 + c2) *  2.0;
511                su2[nsample] =  c2       * -2.0;
512            }
513            break;
514        case 2:
515        case 3:
516            for (; nsample < band + 256; nsample++) {
517                float c1 = su1[nsample];
518                float c2 = su2[nsample];
519                su1[nsample] = c1 + c2;
520                su2[nsample] = c1 - c2;
521            }
522            break;
523        default:
524            av_assert1(0);
525        }
526    }
527}
528
529static void get_channel_weights(int index, int flag, float ch[2])
530{
531    if (index == 7) {
532        ch[0] = 1.0;
533        ch[1] = 1.0;
534    } else {
535        ch[0] = (index & 7) / 7.0;
536        ch[1] = sqrt(2 - ch[0] * ch[0]);
537        if (flag)
538            FFSWAP(float, ch[0], ch[1]);
539    }
540}
541
542static void channel_weighting(float *su1, float *su2, int *p3)
543{
544    int band, nsample;
545    /* w[x][y] y=0 is left y=1 is right */
546    float w[2][2];
547
548    if (p3[1] != 7 || p3[3] != 7) {
549        get_channel_weights(p3[1], p3[0], w[0]);
550        get_channel_weights(p3[3], p3[2], w[1]);
551
552        for (band = 256; band < 4 * 256; band += 256) {
553            for (nsample = band; nsample < band + 8; nsample++) {
554                su1[nsample] *= INTERPOLATE(w[0][0], w[0][1], nsample - band);
555                su2[nsample] *= INTERPOLATE(w[1][0], w[1][1], nsample - band);
556            }
557            for(; nsample < band + 256; nsample++) {
558                su1[nsample] *= w[1][0];
559                su2[nsample] *= w[1][1];
560            }
561        }
562    }
563}
564
565/**
566 * Decode a Sound Unit
567 *
568 * @param snd           the channel unit to be used
569 * @param output        the decoded samples before IQMF in float representation
570 * @param channel_num   channel number
571 * @param coding_mode   the coding mode (JOINT_STEREO or regular stereo/mono)
572 */
573static int decode_channel_sound_unit(ATRAC3Context *q, GetBitContext *gb,
574                                     ChannelUnit *snd, float *output,
575                                     int channel_num, int coding_mode)
576{
577    int band, ret, num_subbands, last_tonal, num_bands;
578    GainBlock *gain1 = &snd->gain_block[    snd->gc_blk_switch];
579    GainBlock *gain2 = &snd->gain_block[1 - snd->gc_blk_switch];
580
581    if (coding_mode == JOINT_STEREO && channel_num == 1) {
582        if (get_bits(gb, 2) != 3) {
583            av_log(NULL,AV_LOG_ERROR,"JS mono Sound Unit id != 3.\n");
584            return AVERROR_INVALIDDATA;
585        }
586    } else {
587        if (get_bits(gb, 6) != 0x28) {
588            av_log(NULL,AV_LOG_ERROR,"Sound Unit id != 0x28.\n");
589            return AVERROR_INVALIDDATA;
590        }
591    }
592
593    /* number of coded QMF bands */
594    snd->bands_coded = get_bits(gb, 2);
595
596    ret = decode_gain_control(gb, gain2, snd->bands_coded);
597    if (ret)
598        return ret;
599
600    snd->num_components = decode_tonal_components(gb, snd->components,
601                                                  snd->bands_coded);
602    if (snd->num_components < 0)
603        return snd->num_components;
604
605    num_subbands = decode_spectrum(gb, snd->spectrum);
606
607    /* Merge the decoded spectrum and tonal components. */
608    last_tonal = add_tonal_components(snd->spectrum, snd->num_components,
609                                      snd->components);
610
611
612    /* calculate number of used MLT/QMF bands according to the amount of coded
613       spectral lines */
614    num_bands = (subband_tab[num_subbands] - 1) >> 8;
615    if (last_tonal >= 0)
616        num_bands = FFMAX((last_tonal + 256) >> 8, num_bands);
617
618
619    /* Reconstruct time domain samples. */
620    for (band = 0; band < 4; band++) {
621        /* Perform the IMDCT step without overlapping. */
622        if (band <= num_bands)
623            imlt(q, &snd->spectrum[band * 256], snd->imdct_buf, band & 1);
624        else
625            memset(snd->imdct_buf, 0, 512 * sizeof(*snd->imdct_buf));
626
627        /* gain compensation and overlapping */
628        ff_atrac_gain_compensation(&q->gainc_ctx, snd->imdct_buf,
629                                   &snd->prev_frame[band * 256],
630                                   &gain1->g_block[band], &gain2->g_block[band],
631                                   256, &output[band * 256]);
632    }
633
634    /* Swap the gain control buffers for the next frame. */
635    snd->gc_blk_switch ^= 1;
636
637    return 0;
638}
639
640static int decode_frame(AVCodecContext *avctx, const uint8_t *databuf,
641                        float **out_samples)
642{
643    ATRAC3Context *q = avctx->priv_data;
644    int ret, i;
645    uint8_t *ptr1;
646
647    if (q->coding_mode == JOINT_STEREO) {
648        /* channel coupling mode */
649        /* decode Sound Unit 1 */
650        init_get_bits(&q->gb, databuf, avctx->block_align * 8);
651
652        ret = decode_channel_sound_unit(q, &q->gb, q->units, out_samples[0], 0,
653                                        JOINT_STEREO);
654        if (ret != 0)
655            return ret;
656
657        /* Framedata of the su2 in the joint-stereo mode is encoded in
658         * reverse byte order so we need to swap it first. */
659        if (databuf == q->decoded_bytes_buffer) {
660            uint8_t *ptr2 = q->decoded_bytes_buffer + avctx->block_align - 1;
661            ptr1          = q->decoded_bytes_buffer;
662            for (i = 0; i < avctx->block_align / 2; i++, ptr1++, ptr2--)
663                FFSWAP(uint8_t, *ptr1, *ptr2);
664        } else {
665            const uint8_t *ptr2 = databuf + avctx->block_align - 1;
666            for (i = 0; i < avctx->block_align; i++)
667                q->decoded_bytes_buffer[i] = *ptr2--;
668        }
669
670        /* Skip the sync codes (0xF8). */
671        ptr1 = q->decoded_bytes_buffer;
672        for (i = 4; *ptr1 == 0xF8; i++, ptr1++) {
673            if (i >= avctx->block_align)
674                return AVERROR_INVALIDDATA;
675        }
676
677
678        /* set the bitstream reader at the start of the second Sound Unit*/
679        init_get_bits8(&q->gb, ptr1, q->decoded_bytes_buffer + avctx->block_align - ptr1);
680
681        /* Fill the Weighting coeffs delay buffer */
682        memmove(q->weighting_delay, &q->weighting_delay[2],
683                4 * sizeof(*q->weighting_delay));
684        q->weighting_delay[4] = get_bits1(&q->gb);
685        q->weighting_delay[5] = get_bits(&q->gb, 3);
686
687        for (i = 0; i < 4; i++) {
688            q->matrix_coeff_index_prev[i] = q->matrix_coeff_index_now[i];
689            q->matrix_coeff_index_now[i]  = q->matrix_coeff_index_next[i];
690            q->matrix_coeff_index_next[i] = get_bits(&q->gb, 2);
691        }
692
693        /* Decode Sound Unit 2. */
694        ret = decode_channel_sound_unit(q, &q->gb, &q->units[1],
695                                        out_samples[1], 1, JOINT_STEREO);
696        if (ret != 0)
697            return ret;
698
699        /* Reconstruct the channel coefficients. */
700        reverse_matrixing(out_samples[0], out_samples[1],
701                          q->matrix_coeff_index_prev,
702                          q->matrix_coeff_index_now);
703
704        channel_weighting(out_samples[0], out_samples[1], q->weighting_delay);
705    } else {
706        /* normal stereo mode or mono */
707        /* Decode the channel sound units. */
708        for (i = 0; i < avctx->channels; i++) {
709            /* Set the bitstream reader at the start of a channel sound unit. */
710            init_get_bits(&q->gb,
711                          databuf + i * avctx->block_align / avctx->channels,
712                          avctx->block_align * 8 / avctx->channels);
713
714            ret = decode_channel_sound_unit(q, &q->gb, &q->units[i],
715                                            out_samples[i], i, q->coding_mode);
716            if (ret != 0)
717                return ret;
718        }
719    }
720
721    /* Apply the iQMF synthesis filter. */
722    for (i = 0; i < avctx->channels; i++) {
723        float *p1 = out_samples[i];
724        float *p2 = p1 + 256;
725        float *p3 = p2 + 256;
726        float *p4 = p3 + 256;
727        ff_atrac_iqmf(p1, p2, 256, p1, q->units[i].delay_buf1, q->temp_buf);
728        ff_atrac_iqmf(p4, p3, 256, p3, q->units[i].delay_buf2, q->temp_buf);
729        ff_atrac_iqmf(p1, p3, 512, p1, q->units[i].delay_buf3, q->temp_buf);
730    }
731
732    return 0;
733}
734
735static int atrac3_decode_frame(AVCodecContext *avctx, void *data,
736                               int *got_frame_ptr, AVPacket *avpkt)
737{
738    AVFrame *frame     = data;
739    const uint8_t *buf = avpkt->data;
740    int buf_size = avpkt->size;
741    ATRAC3Context *q = avctx->priv_data;
742    int ret;
743    const uint8_t *databuf;
744
745    if (buf_size < avctx->block_align) {
746        av_log(avctx, AV_LOG_ERROR,
747               "Frame too small (%d bytes). Truncated file?\n", buf_size);
748        return AVERROR_INVALIDDATA;
749    }
750
751    /* get output buffer */
752    frame->nb_samples = SAMPLES_PER_FRAME;
753    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
754        return ret;
755
756    /* Check if we need to descramble and what buffer to pass on. */
757    if (q->scrambled_stream) {
758        decode_bytes(buf, q->decoded_bytes_buffer, avctx->block_align);
759        databuf = q->decoded_bytes_buffer;
760    } else {
761        databuf = buf;
762    }
763
764    ret = decode_frame(avctx, databuf, (float **)frame->extended_data);
765    if (ret) {
766        av_log(NULL, AV_LOG_ERROR, "Frame decoding error!\n");
767        return ret;
768    }
769
770    *got_frame_ptr = 1;
771
772    return avctx->block_align;
773}
774
775static av_cold void atrac3_init_static_data(void)
776{
777    int i;
778
779    init_imdct_window();
780    ff_atrac_generate_tables();
781
782    /* Initialize the VLC tables. */
783    for (i = 0; i < 7; i++) {
784        spectral_coeff_tab[i].table = &atrac3_vlc_table[atrac3_vlc_offs[i]];
785        spectral_coeff_tab[i].table_allocated = atrac3_vlc_offs[i + 1] -
786                                                atrac3_vlc_offs[i    ];
787        init_vlc(&spectral_coeff_tab[i], 9, huff_tab_sizes[i],
788                 huff_bits[i],  1, 1,
789                 huff_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
790    }
791}
792
793static av_cold int atrac3_decode_init(AVCodecContext *avctx)
794{
795    static int static_init_done;
796    int i, ret;
797    int version, delay, samples_per_frame, frame_factor;
798    const uint8_t *edata_ptr = avctx->extradata;
799    ATRAC3Context *q = avctx->priv_data;
800
801    if (avctx->channels <= 0 || avctx->channels > 2) {
802        av_log(avctx, AV_LOG_ERROR, "Channel configuration error!\n");
803        return AVERROR(EINVAL);
804    }
805
806    if (!static_init_done)
807        atrac3_init_static_data();
808    static_init_done = 1;
809
810    /* Take care of the codec-specific extradata. */
811    if (avctx->extradata_size == 14) {
812        /* Parse the extradata, WAV format */
813        av_log(avctx, AV_LOG_DEBUG, "[0-1] %d\n",
814               bytestream_get_le16(&edata_ptr));  // Unknown value always 1
815        edata_ptr += 4;                             // samples per channel
816        q->coding_mode = bytestream_get_le16(&edata_ptr);
817        av_log(avctx, AV_LOG_DEBUG,"[8-9] %d\n",
818               bytestream_get_le16(&edata_ptr));  //Dupe of coding mode
819        frame_factor = bytestream_get_le16(&edata_ptr);  // Unknown always 1
820        av_log(avctx, AV_LOG_DEBUG,"[12-13] %d\n",
821               bytestream_get_le16(&edata_ptr));  // Unknown always 0
822
823        /* setup */
824        samples_per_frame    = SAMPLES_PER_FRAME * avctx->channels;
825        version              = 4;
826        delay                = 0x88E;
827        q->coding_mode       = q->coding_mode ? JOINT_STEREO : STEREO;
828        q->scrambled_stream  = 0;
829
830        if (avctx->block_align !=  96 * avctx->channels * frame_factor &&
831            avctx->block_align != 152 * avctx->channels * frame_factor &&
832            avctx->block_align != 192 * avctx->channels * frame_factor) {
833            av_log(avctx, AV_LOG_ERROR, "Unknown frame/channel/frame_factor "
834                   "configuration %d/%d/%d\n", avctx->block_align,
835                   avctx->channels, frame_factor);
836            return AVERROR_INVALIDDATA;
837        }
838    } else if (avctx->extradata_size == 12 || avctx->extradata_size == 10) {
839        /* Parse the extradata, RM format. */
840        version                = bytestream_get_be32(&edata_ptr);
841        samples_per_frame      = bytestream_get_be16(&edata_ptr);
842        delay                  = bytestream_get_be16(&edata_ptr);
843        q->coding_mode         = bytestream_get_be16(&edata_ptr);
844        q->scrambled_stream    = 1;
845
846    } else {
847        av_log(NULL, AV_LOG_ERROR, "Unknown extradata size %d.\n",
848               avctx->extradata_size);
849        return AVERROR(EINVAL);
850    }
851
852    /* Check the extradata */
853
854    if (version != 4) {
855        av_log(avctx, AV_LOG_ERROR, "Version %d != 4.\n", version);
856        return AVERROR_INVALIDDATA;
857    }
858
859    if (samples_per_frame != SAMPLES_PER_FRAME &&
860        samples_per_frame != SAMPLES_PER_FRAME * 2) {
861        av_log(avctx, AV_LOG_ERROR, "Unknown amount of samples per frame %d.\n",
862               samples_per_frame);
863        return AVERROR_INVALIDDATA;
864    }
865
866    if (delay != 0x88E) {
867        av_log(avctx, AV_LOG_ERROR, "Unknown amount of delay %x != 0x88E.\n",
868               delay);
869        return AVERROR_INVALIDDATA;
870    }
871
872    if (q->coding_mode == STEREO)
873        av_log(avctx, AV_LOG_DEBUG, "Normal stereo detected.\n");
874    else if (q->coding_mode == JOINT_STEREO) {
875        if (avctx->channels != 2) {
876            av_log(avctx, AV_LOG_ERROR, "Invalid coding mode\n");
877            return AVERROR_INVALIDDATA;
878        }
879        av_log(avctx, AV_LOG_DEBUG, "Joint stereo detected.\n");
880    } else {
881        av_log(avctx, AV_LOG_ERROR, "Unknown channel coding mode %x!\n",
882               q->coding_mode);
883        return AVERROR_INVALIDDATA;
884    }
885
886    if (avctx->block_align >= UINT_MAX / 2)
887        return AVERROR(EINVAL);
888
889    q->decoded_bytes_buffer = av_mallocz(FFALIGN(avctx->block_align, 4) +
890                                         FF_INPUT_BUFFER_PADDING_SIZE);
891    if (q->decoded_bytes_buffer == NULL)
892        return AVERROR(ENOMEM);
893
894    avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
895
896    /* initialize the MDCT transform */
897    if ((ret = ff_mdct_init(&q->mdct_ctx, 9, 1, 1.0 / 32768)) < 0) {
898        av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n");
899        av_freep(&q->decoded_bytes_buffer);
900        return ret;
901    }
902
903    /* init the joint-stereo decoding data */
904    q->weighting_delay[0] = 0;
905    q->weighting_delay[1] = 7;
906    q->weighting_delay[2] = 0;
907    q->weighting_delay[3] = 7;
908    q->weighting_delay[4] = 0;
909    q->weighting_delay[5] = 7;
910
911    for (i = 0; i < 4; i++) {
912        q->matrix_coeff_index_prev[i] = 3;
913        q->matrix_coeff_index_now[i]  = 3;
914        q->matrix_coeff_index_next[i] = 3;
915    }
916
917    ff_atrac_init_gain_compensation(&q->gainc_ctx, 4, 3);
918    avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
919    ff_fmt_convert_init(&q->fmt_conv, avctx);
920
921    q->units = av_mallocz_array(avctx->channels, sizeof(*q->units));
922    if (!q->units) {
923        atrac3_decode_close(avctx);
924        return AVERROR(ENOMEM);
925    }
926
927    return 0;
928}
929
930AVCodec ff_atrac3_decoder = {
931    .name             = "atrac3",
932    .long_name        = NULL_IF_CONFIG_SMALL("ATRAC3 (Adaptive TRansform Acoustic Coding 3)"),
933    .type             = AVMEDIA_TYPE_AUDIO,
934    .id               = AV_CODEC_ID_ATRAC3,
935    .priv_data_size   = sizeof(ATRAC3Context),
936    .init             = atrac3_decode_init,
937    .close            = atrac3_decode_close,
938    .decode           = atrac3_decode_frame,
939    .capabilities     = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
940    .sample_fmts      = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
941                                                        AV_SAMPLE_FMT_NONE },
942};
943