1/*
2 * WMA compatible decoder
3 * Copyright (c) 2002 The FFmpeg Project
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * WMA compatible decoder.
25 * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
26 * WMA v1 is identified by audio format 0x160 in Microsoft media files
27 * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
28 *
29 * To use this decoder, a calling application must supply the extra data
30 * bytes provided with the WMA data. These are the extra, codec-specific
31 * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
32 * to the decoder using the extradata[_size] fields in AVCodecContext. There
33 * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
34 */
35
36#include "avcodec.h"
37#include "wma.h"
38
39#undef NDEBUG
40#include <assert.h>
41
42#define EXPVLCBITS 8
43#define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
44
45#define HGAINVLCBITS 9
46#define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
47
48static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
49
50#ifdef TRACE
51static void dump_shorts(WMACodecContext *s, const char *name, const short *tab, int n)
52{
53    int i;
54
55    tprintf(s->avctx, "%s[%d]:\n", name, n);
56    for(i=0;i<n;i++) {
57        if ((i & 7) == 0)
58            tprintf(s->avctx, "%4d: ", i);
59        tprintf(s->avctx, " %5d.0", tab[i]);
60        if ((i & 7) == 7)
61            tprintf(s->avctx, "\n");
62    }
63}
64
65static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)
66{
67    int i;
68
69    tprintf(s->avctx, "%s[%d]:\n", name, n);
70    for(i=0;i<n;i++) {
71        if ((i & 7) == 0)
72            tprintf(s->avctx, "%4d: ", i);
73        tprintf(s->avctx, " %8.*f", prec, tab[i]);
74        if ((i & 7) == 7)
75            tprintf(s->avctx, "\n");
76    }
77    if ((i & 7) != 0)
78        tprintf(s->avctx, "\n");
79}
80#endif
81
82static int wma_decode_init(AVCodecContext * avctx)
83{
84    WMACodecContext *s = avctx->priv_data;
85    int i, flags2;
86    uint8_t *extradata;
87
88    s->avctx = avctx;
89
90    /* extract flag infos */
91    flags2 = 0;
92    extradata = avctx->extradata;
93    if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
94        flags2 = AV_RL16(extradata+2);
95    } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
96        flags2 = AV_RL16(extradata+4);
97    }
98// for(i=0; i<avctx->extradata_size; i++)
99//     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
100
101    s->use_exp_vlc = flags2 & 0x0001;
102    s->use_bit_reservoir = flags2 & 0x0002;
103    s->use_variable_block_len = flags2 & 0x0004;
104
105    if(ff_wma_init(avctx, flags2)<0)
106        return -1;
107
108    /* init MDCT */
109    for(i = 0; i < s->nb_block_sizes; i++)
110        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
111
112    if (s->use_noise_coding) {
113        init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
114                 ff_wma_hgain_huffbits, 1, 1,
115                 ff_wma_hgain_huffcodes, 2, 2, 0);
116    }
117
118    if (s->use_exp_vlc) {
119        init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
120                 ff_aac_scalefactor_bits, 1, 1,
121                 ff_aac_scalefactor_code, 4, 4, 0);
122    } else {
123        wma_lsp_to_curve_init(s, s->frame_len);
124    }
125
126    avctx->sample_fmt = SAMPLE_FMT_S16;
127    return 0;
128}
129
130/**
131 * compute x^-0.25 with an exponent and mantissa table. We use linear
132 * interpolation to reduce the mantissa table size at a small speed
133 * expense (linear interpolation approximately doubles the number of
134 * bits of precision).
135 */
136static inline float pow_m1_4(WMACodecContext *s, float x)
137{
138    union {
139        float f;
140        unsigned int v;
141    } u, t;
142    unsigned int e, m;
143    float a, b;
144
145    u.f = x;
146    e = u.v >> 23;
147    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
148    /* build interpolation scale: 1 <= t < 2. */
149    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
150    a = s->lsp_pow_m_table1[m];
151    b = s->lsp_pow_m_table2[m];
152    return s->lsp_pow_e_table[e] * (a + b * t.f);
153}
154
155static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
156{
157    float wdel, a, b;
158    int i, e, m;
159
160    wdel = M_PI / frame_len;
161    for(i=0;i<frame_len;i++)
162        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
163
164    /* tables for x^-0.25 computation */
165    for(i=0;i<256;i++) {
166        e = i - 126;
167        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
168    }
169
170    /* NOTE: these two tables are needed to avoid two operations in
171       pow_m1_4 */
172    b = 1.0;
173    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
174        m = (1 << LSP_POW_BITS) + i;
175        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
176        a = pow(a, -0.25);
177        s->lsp_pow_m_table1[i] = 2 * a - b;
178        s->lsp_pow_m_table2[i] = b - a;
179        b = a;
180    }
181#if 0
182    for(i=1;i<20;i++) {
183        float v, r1, r2;
184        v = 5.0 / i;
185        r1 = pow_m1_4(s, v);
186        r2 = pow(v,-0.25);
187        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
188    }
189#endif
190}
191
192/**
193 * NOTE: We use the same code as Vorbis here
194 * @todo optimize it further with SSE/3Dnow
195 */
196static void wma_lsp_to_curve(WMACodecContext *s,
197                             float *out, float *val_max_ptr,
198                             int n, float *lsp)
199{
200    int i, j;
201    float p, q, w, v, val_max;
202
203    val_max = 0;
204    for(i=0;i<n;i++) {
205        p = 0.5f;
206        q = 0.5f;
207        w = s->lsp_cos_table[i];
208        for(j=1;j<NB_LSP_COEFS;j+=2){
209            q *= w - lsp[j - 1];
210            p *= w - lsp[j];
211        }
212        p *= p * (2.0f - w);
213        q *= q * (2.0f + w);
214        v = p + q;
215        v = pow_m1_4(s, v);
216        if (v > val_max)
217            val_max = v;
218        out[i] = v;
219    }
220    *val_max_ptr = val_max;
221}
222
223/**
224 * decode exponents coded with LSP coefficients (same idea as Vorbis)
225 */
226static void decode_exp_lsp(WMACodecContext *s, int ch)
227{
228    float lsp_coefs[NB_LSP_COEFS];
229    int val, i;
230
231    for(i = 0; i < NB_LSP_COEFS; i++) {
232        if (i == 0 || i >= 8)
233            val = get_bits(&s->gb, 3);
234        else
235            val = get_bits(&s->gb, 4);
236        lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
237    }
238
239    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
240                     s->block_len, lsp_coefs);
241}
242
243/** pow(10, i / 16.0) for i in -60..95 */
244static const float pow_tab[] = {
245    1.7782794100389e-04, 2.0535250264571e-04,
246    2.3713737056617e-04, 2.7384196342644e-04,
247    3.1622776601684e-04, 3.6517412725484e-04,
248    4.2169650342858e-04, 4.8696752516586e-04,
249    5.6234132519035e-04, 6.4938163157621e-04,
250    7.4989420933246e-04, 8.6596432336006e-04,
251    1.0000000000000e-03, 1.1547819846895e-03,
252    1.3335214321633e-03, 1.5399265260595e-03,
253    1.7782794100389e-03, 2.0535250264571e-03,
254    2.3713737056617e-03, 2.7384196342644e-03,
255    3.1622776601684e-03, 3.6517412725484e-03,
256    4.2169650342858e-03, 4.8696752516586e-03,
257    5.6234132519035e-03, 6.4938163157621e-03,
258    7.4989420933246e-03, 8.6596432336006e-03,
259    1.0000000000000e-02, 1.1547819846895e-02,
260    1.3335214321633e-02, 1.5399265260595e-02,
261    1.7782794100389e-02, 2.0535250264571e-02,
262    2.3713737056617e-02, 2.7384196342644e-02,
263    3.1622776601684e-02, 3.6517412725484e-02,
264    4.2169650342858e-02, 4.8696752516586e-02,
265    5.6234132519035e-02, 6.4938163157621e-02,
266    7.4989420933246e-02, 8.6596432336007e-02,
267    1.0000000000000e-01, 1.1547819846895e-01,
268    1.3335214321633e-01, 1.5399265260595e-01,
269    1.7782794100389e-01, 2.0535250264571e-01,
270    2.3713737056617e-01, 2.7384196342644e-01,
271    3.1622776601684e-01, 3.6517412725484e-01,
272    4.2169650342858e-01, 4.8696752516586e-01,
273    5.6234132519035e-01, 6.4938163157621e-01,
274    7.4989420933246e-01, 8.6596432336007e-01,
275    1.0000000000000e+00, 1.1547819846895e+00,
276    1.3335214321633e+00, 1.5399265260595e+00,
277    1.7782794100389e+00, 2.0535250264571e+00,
278    2.3713737056617e+00, 2.7384196342644e+00,
279    3.1622776601684e+00, 3.6517412725484e+00,
280    4.2169650342858e+00, 4.8696752516586e+00,
281    5.6234132519035e+00, 6.4938163157621e+00,
282    7.4989420933246e+00, 8.6596432336007e+00,
283    1.0000000000000e+01, 1.1547819846895e+01,
284    1.3335214321633e+01, 1.5399265260595e+01,
285    1.7782794100389e+01, 2.0535250264571e+01,
286    2.3713737056617e+01, 2.7384196342644e+01,
287    3.1622776601684e+01, 3.6517412725484e+01,
288    4.2169650342858e+01, 4.8696752516586e+01,
289    5.6234132519035e+01, 6.4938163157621e+01,
290    7.4989420933246e+01, 8.6596432336007e+01,
291    1.0000000000000e+02, 1.1547819846895e+02,
292    1.3335214321633e+02, 1.5399265260595e+02,
293    1.7782794100389e+02, 2.0535250264571e+02,
294    2.3713737056617e+02, 2.7384196342644e+02,
295    3.1622776601684e+02, 3.6517412725484e+02,
296    4.2169650342858e+02, 4.8696752516586e+02,
297    5.6234132519035e+02, 6.4938163157621e+02,
298    7.4989420933246e+02, 8.6596432336007e+02,
299    1.0000000000000e+03, 1.1547819846895e+03,
300    1.3335214321633e+03, 1.5399265260595e+03,
301    1.7782794100389e+03, 2.0535250264571e+03,
302    2.3713737056617e+03, 2.7384196342644e+03,
303    3.1622776601684e+03, 3.6517412725484e+03,
304    4.2169650342858e+03, 4.8696752516586e+03,
305    5.6234132519035e+03, 6.4938163157621e+03,
306    7.4989420933246e+03, 8.6596432336007e+03,
307    1.0000000000000e+04, 1.1547819846895e+04,
308    1.3335214321633e+04, 1.5399265260595e+04,
309    1.7782794100389e+04, 2.0535250264571e+04,
310    2.3713737056617e+04, 2.7384196342644e+04,
311    3.1622776601684e+04, 3.6517412725484e+04,
312    4.2169650342858e+04, 4.8696752516586e+04,
313    5.6234132519035e+04, 6.4938163157621e+04,
314    7.4989420933246e+04, 8.6596432336007e+04,
315    1.0000000000000e+05, 1.1547819846895e+05,
316    1.3335214321633e+05, 1.5399265260595e+05,
317    1.7782794100389e+05, 2.0535250264571e+05,
318    2.3713737056617e+05, 2.7384196342644e+05,
319    3.1622776601684e+05, 3.6517412725484e+05,
320    4.2169650342858e+05, 4.8696752516586e+05,
321    5.6234132519035e+05, 6.4938163157621e+05,
322    7.4989420933246e+05, 8.6596432336007e+05,
323};
324
325/**
326 * decode exponents coded with VLC codes
327 */
328static int decode_exp_vlc(WMACodecContext *s, int ch)
329{
330    int last_exp, n, code;
331    const uint16_t *ptr;
332    float v, max_scale;
333    uint32_t *q, *q_end, iv;
334    const float *ptab = pow_tab + 60;
335    const uint32_t *iptab = (const uint32_t*)ptab;
336
337    ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
338    q = (uint32_t *)s->exponents[ch];
339    q_end = q + s->block_len;
340    max_scale = 0;
341    if (s->version == 1) {
342        last_exp = get_bits(&s->gb, 5) + 10;
343        v = ptab[last_exp];
344        iv = iptab[last_exp];
345        max_scale = v;
346        n = *ptr++;
347        switch (n & 3) do {
348        case 0: *q++ = iv;
349        case 3: *q++ = iv;
350        case 2: *q++ = iv;
351        case 1: *q++ = iv;
352        } while ((n -= 4) > 0);
353    }else
354        last_exp = 36;
355
356    while (q < q_end) {
357        code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
358        if (code < 0){
359            av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
360            return -1;
361        }
362        /* NOTE: this offset is the same as MPEG4 AAC ! */
363        last_exp += code - 60;
364        if ((unsigned)last_exp + 60 > FF_ARRAY_ELEMS(pow_tab)) {
365            av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
366                   last_exp);
367            return -1;
368        }
369        v = ptab[last_exp];
370        iv = iptab[last_exp];
371        if (v > max_scale)
372            max_scale = v;
373        n = *ptr++;
374        switch (n & 3) do {
375        case 0: *q++ = iv;
376        case 3: *q++ = iv;
377        case 2: *q++ = iv;
378        case 1: *q++ = iv;
379        } while ((n -= 4) > 0);
380    }
381    s->max_exponent[ch] = max_scale;
382    return 0;
383}
384
385
386/**
387 * Apply MDCT window and add into output.
388 *
389 * We ensure that when the windows overlap their squared sum
390 * is always 1 (MDCT reconstruction rule).
391 */
392static void wma_window(WMACodecContext *s, float *out)
393{
394    float *in = s->output;
395    int block_len, bsize, n;
396
397    /* left part */
398    if (s->block_len_bits <= s->prev_block_len_bits) {
399        block_len = s->block_len;
400        bsize = s->frame_len_bits - s->block_len_bits;
401
402        s->dsp.vector_fmul_add(out, in, s->windows[bsize],
403                               out, block_len);
404
405    } else {
406        block_len = 1 << s->prev_block_len_bits;
407        n = (s->block_len - block_len) / 2;
408        bsize = s->frame_len_bits - s->prev_block_len_bits;
409
410        s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
411                               out+n, block_len);
412
413        memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
414    }
415
416    out += s->block_len;
417    in += s->block_len;
418
419    /* right part */
420    if (s->block_len_bits <= s->next_block_len_bits) {
421        block_len = s->block_len;
422        bsize = s->frame_len_bits - s->block_len_bits;
423
424        s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
425
426    } else {
427        block_len = 1 << s->next_block_len_bits;
428        n = (s->block_len - block_len) / 2;
429        bsize = s->frame_len_bits - s->next_block_len_bits;
430
431        memcpy(out, in, n*sizeof(float));
432
433        s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
434
435        memset(out+n+block_len, 0, n*sizeof(float));
436    }
437}
438
439
440/**
441 * @return 0 if OK. 1 if last block of frame. return -1 if
442 * unrecorrable error.
443 */
444static int wma_decode_block(WMACodecContext *s)
445{
446    int n, v, a, ch, bsize;
447    int coef_nb_bits, total_gain;
448    int nb_coefs[MAX_CHANNELS];
449    float mdct_norm;
450
451#ifdef TRACE
452    tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
453#endif
454
455    /* compute current block length */
456    if (s->use_variable_block_len) {
457        n = av_log2(s->nb_block_sizes - 1) + 1;
458
459        if (s->reset_block_lengths) {
460            s->reset_block_lengths = 0;
461            v = get_bits(&s->gb, n);
462            if (v >= s->nb_block_sizes){
463                av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
464                return -1;
465            }
466            s->prev_block_len_bits = s->frame_len_bits - v;
467            v = get_bits(&s->gb, n);
468            if (v >= s->nb_block_sizes){
469                av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
470                return -1;
471            }
472            s->block_len_bits = s->frame_len_bits - v;
473        } else {
474            /* update block lengths */
475            s->prev_block_len_bits = s->block_len_bits;
476            s->block_len_bits = s->next_block_len_bits;
477        }
478        v = get_bits(&s->gb, n);
479        if (v >= s->nb_block_sizes){
480            av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
481            return -1;
482        }
483        s->next_block_len_bits = s->frame_len_bits - v;
484    } else {
485        /* fixed block len */
486        s->next_block_len_bits = s->frame_len_bits;
487        s->prev_block_len_bits = s->frame_len_bits;
488        s->block_len_bits = s->frame_len_bits;
489    }
490
491    /* now check if the block length is coherent with the frame length */
492    s->block_len = 1 << s->block_len_bits;
493    if ((s->block_pos + s->block_len) > s->frame_len){
494        av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
495        return -1;
496    }
497
498    if (s->nb_channels == 2) {
499        s->ms_stereo = get_bits1(&s->gb);
500    }
501    v = 0;
502    for(ch = 0; ch < s->nb_channels; ch++) {
503        a = get_bits1(&s->gb);
504        s->channel_coded[ch] = a;
505        v |= a;
506    }
507
508    bsize = s->frame_len_bits - s->block_len_bits;
509
510    /* if no channel coded, no need to go further */
511    /* XXX: fix potential framing problems */
512    if (!v)
513        goto next;
514
515    /* read total gain and extract corresponding number of bits for
516       coef escape coding */
517    total_gain = 1;
518    for(;;) {
519        a = get_bits(&s->gb, 7);
520        total_gain += a;
521        if (a != 127)
522            break;
523    }
524
525    coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
526
527    /* compute number of coefficients */
528    n = s->coefs_end[bsize] - s->coefs_start;
529    for(ch = 0; ch < s->nb_channels; ch++)
530        nb_coefs[ch] = n;
531
532    /* complex coding */
533    if (s->use_noise_coding) {
534
535        for(ch = 0; ch < s->nb_channels; ch++) {
536            if (s->channel_coded[ch]) {
537                int i, n, a;
538                n = s->exponent_high_sizes[bsize];
539                for(i=0;i<n;i++) {
540                    a = get_bits1(&s->gb);
541                    s->high_band_coded[ch][i] = a;
542                    /* if noise coding, the coefficients are not transmitted */
543                    if (a)
544                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
545                }
546            }
547        }
548        for(ch = 0; ch < s->nb_channels; ch++) {
549            if (s->channel_coded[ch]) {
550                int i, n, val, code;
551
552                n = s->exponent_high_sizes[bsize];
553                val = (int)0x80000000;
554                for(i=0;i<n;i++) {
555                    if (s->high_band_coded[ch][i]) {
556                        if (val == (int)0x80000000) {
557                            val = get_bits(&s->gb, 7) - 19;
558                        } else {
559                            code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
560                            if (code < 0){
561                                av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
562                                return -1;
563                            }
564                            val += code - 18;
565                        }
566                        s->high_band_values[ch][i] = val;
567                    }
568                }
569            }
570        }
571    }
572
573    /* exponents can be reused in short blocks. */
574    if ((s->block_len_bits == s->frame_len_bits) ||
575        get_bits1(&s->gb)) {
576        for(ch = 0; ch < s->nb_channels; ch++) {
577            if (s->channel_coded[ch]) {
578                if (s->use_exp_vlc) {
579                    if (decode_exp_vlc(s, ch) < 0)
580                        return -1;
581                } else {
582                    decode_exp_lsp(s, ch);
583                }
584                s->exponents_bsize[ch] = bsize;
585            }
586        }
587    }
588
589    /* parse spectral coefficients : just RLE encoding */
590    for(ch = 0; ch < s->nb_channels; ch++) {
591        if (s->channel_coded[ch]) {
592            int tindex;
593            WMACoef* ptr = &s->coefs1[ch][0];
594
595            /* special VLC tables are used for ms stereo because
596               there is potentially less energy there */
597            tindex = (ch == 1 && s->ms_stereo);
598            memset(ptr, 0, s->block_len * sizeof(WMACoef));
599            ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
600                  s->level_table[tindex], s->run_table[tindex],
601                  0, ptr, 0, nb_coefs[ch],
602                  s->block_len, s->frame_len_bits, coef_nb_bits);
603        }
604        if (s->version == 1 && s->nb_channels >= 2) {
605            align_get_bits(&s->gb);
606        }
607    }
608
609    /* normalize */
610    {
611        int n4 = s->block_len / 2;
612        mdct_norm = 1.0 / (float)n4;
613        if (s->version == 1) {
614            mdct_norm *= sqrt(n4);
615        }
616    }
617
618    /* finally compute the MDCT coefficients */
619    for(ch = 0; ch < s->nb_channels; ch++) {
620        if (s->channel_coded[ch]) {
621            WMACoef *coefs1;
622            float *coefs, *exponents, mult, mult1, noise;
623            int i, j, n, n1, last_high_band, esize;
624            float exp_power[HIGH_BAND_MAX_SIZE];
625
626            coefs1 = s->coefs1[ch];
627            exponents = s->exponents[ch];
628            esize = s->exponents_bsize[ch];
629            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
630            mult *= mdct_norm;
631            coefs = s->coefs[ch];
632            if (s->use_noise_coding) {
633                mult1 = mult;
634                /* very low freqs : noise */
635                for(i = 0;i < s->coefs_start; i++) {
636                    *coefs++ = s->noise_table[s->noise_index] *
637                      exponents[i<<bsize>>esize] * mult1;
638                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
639                }
640
641                n1 = s->exponent_high_sizes[bsize];
642
643                /* compute power of high bands */
644                exponents = s->exponents[ch] +
645                    (s->high_band_start[bsize]<<bsize>>esize);
646                last_high_band = 0; /* avoid warning */
647                for(j=0;j<n1;j++) {
648                    n = s->exponent_high_bands[s->frame_len_bits -
649                                              s->block_len_bits][j];
650                    if (s->high_band_coded[ch][j]) {
651                        float e2, v;
652                        e2 = 0;
653                        for(i = 0;i < n; i++) {
654                            v = exponents[i<<bsize>>esize];
655                            e2 += v * v;
656                        }
657                        exp_power[j] = e2 / n;
658                        last_high_band = j;
659                        tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
660                    }
661                    exponents += n<<bsize>>esize;
662                }
663
664                /* main freqs and high freqs */
665                exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
666                for(j=-1;j<n1;j++) {
667                    if (j < 0) {
668                        n = s->high_band_start[bsize] -
669                            s->coefs_start;
670                    } else {
671                        n = s->exponent_high_bands[s->frame_len_bits -
672                                                  s->block_len_bits][j];
673                    }
674                    if (j >= 0 && s->high_band_coded[ch][j]) {
675                        /* use noise with specified power */
676                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
677                        /* XXX: use a table */
678                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
679                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
680                        mult1 *= mdct_norm;
681                        for(i = 0;i < n; i++) {
682                            noise = s->noise_table[s->noise_index];
683                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
684                            *coefs++ =  noise *
685                                exponents[i<<bsize>>esize] * mult1;
686                        }
687                        exponents += n<<bsize>>esize;
688                    } else {
689                        /* coded values + small noise */
690                        for(i = 0;i < n; i++) {
691                            noise = s->noise_table[s->noise_index];
692                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
693                            *coefs++ = ((*coefs1++) + noise) *
694                                exponents[i<<bsize>>esize] * mult;
695                        }
696                        exponents += n<<bsize>>esize;
697                    }
698                }
699
700                /* very high freqs : noise */
701                n = s->block_len - s->coefs_end[bsize];
702                mult1 = mult * exponents[((-1<<bsize))>>esize];
703                for(i = 0; i < n; i++) {
704                    *coefs++ = s->noise_table[s->noise_index] * mult1;
705                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
706                }
707            } else {
708                /* XXX: optimize more */
709                for(i = 0;i < s->coefs_start; i++)
710                    *coefs++ = 0.0;
711                n = nb_coefs[ch];
712                for(i = 0;i < n; i++) {
713                    *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
714                }
715                n = s->block_len - s->coefs_end[bsize];
716                for(i = 0;i < n; i++)
717                    *coefs++ = 0.0;
718            }
719        }
720    }
721
722#ifdef TRACE
723    for(ch = 0; ch < s->nb_channels; ch++) {
724        if (s->channel_coded[ch]) {
725            dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
726            dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
727        }
728    }
729#endif
730
731    if (s->ms_stereo && s->channel_coded[1]) {
732        /* nominal case for ms stereo: we do it before mdct */
733        /* no need to optimize this case because it should almost
734           never happen */
735        if (!s->channel_coded[0]) {
736            tprintf(s->avctx, "rare ms-stereo case happened\n");
737            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
738            s->channel_coded[0] = 1;
739        }
740
741        s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
742    }
743
744next:
745    for(ch = 0; ch < s->nb_channels; ch++) {
746        int n4, index;
747
748        n4 = s->block_len / 2;
749        if(s->channel_coded[ch]){
750            ff_imdct_calc(&s->mdct_ctx[bsize], s->output, s->coefs[ch]);
751        }else if(!(s->ms_stereo && ch==1))
752            memset(s->output, 0, sizeof(s->output));
753
754        /* multiply by the window and add in the frame */
755        index = (s->frame_len / 2) + s->block_pos - n4;
756        wma_window(s, &s->frame_out[ch][index]);
757    }
758
759    /* update block number */
760    s->block_num++;
761    s->block_pos += s->block_len;
762    if (s->block_pos >= s->frame_len)
763        return 1;
764    else
765        return 0;
766}
767
768/* decode a frame of frame_len samples */
769static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
770{
771    int ret, i, n, ch, incr;
772    int16_t *ptr;
773    float *iptr;
774
775#ifdef TRACE
776    tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
777#endif
778
779    /* read each block */
780    s->block_num = 0;
781    s->block_pos = 0;
782    for(;;) {
783        ret = wma_decode_block(s);
784        if (ret < 0)
785            return -1;
786        if (ret)
787            break;
788    }
789
790    /* convert frame to integer */
791    n = s->frame_len;
792    incr = s->nb_channels;
793    if (s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
794        for(ch = 0; ch < s->nb_channels; ch++) {
795            ptr = samples + ch;
796            iptr = s->frame_out[ch];
797
798            for(i=0;i<n;i++) {
799                *ptr = av_clip_int16(lrintf(*iptr++));
800                ptr += incr;
801            }
802            /* prepare for next block */
803            memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
804                    s->frame_len * sizeof(float));
805        }
806    } else {
807        float *output[MAX_CHANNELS];
808        for (ch = 0; ch < MAX_CHANNELS; ch++)
809            output[ch] = s->frame_out[ch];
810        s->dsp.float_to_int16_interleave(samples, (const float **)output, n, incr);
811        for(ch = 0; ch < incr; ch++) {
812            /* prepare for next block */
813            memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
814        }
815    }
816
817#ifdef TRACE
818    dump_shorts(s, "samples", samples, n * s->nb_channels);
819#endif
820    return 0;
821}
822
823static int wma_decode_superframe(AVCodecContext *avctx,
824                                 void *data, int *data_size,
825                                 AVPacket *avpkt)
826{
827    const uint8_t *buf = avpkt->data;
828    int buf_size = avpkt->size;
829    WMACodecContext *s = avctx->priv_data;
830    int nb_frames, bit_offset, i, pos, len;
831    uint8_t *q;
832    int16_t *samples;
833
834    tprintf(avctx, "***decode_superframe:\n");
835
836    if(buf_size==0){
837        s->last_superframe_len = 0;
838        return 0;
839    }
840    if (buf_size < s->block_align)
841        return 0;
842    buf_size = s->block_align;
843
844    samples = data;
845
846    init_get_bits(&s->gb, buf, buf_size*8);
847
848    if (s->use_bit_reservoir) {
849        /* read super frame header */
850        skip_bits(&s->gb, 4); /* super frame index */
851        nb_frames = get_bits(&s->gb, 4) - 1;
852
853        if((nb_frames+1) * s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
854            av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
855            goto fail;
856        }
857
858        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
859
860        if (s->last_superframe_len > 0) {
861            //        printf("skip=%d\n", s->last_bitoffset);
862            /* add bit_offset bits to last frame */
863            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
864                MAX_CODED_SUPERFRAME_SIZE)
865                goto fail;
866            q = s->last_superframe + s->last_superframe_len;
867            len = bit_offset;
868            while (len > 7) {
869                *q++ = (get_bits)(&s->gb, 8);
870                len -= 8;
871            }
872            if (len > 0) {
873                *q++ = (get_bits)(&s->gb, len) << (8 - len);
874            }
875
876            /* XXX: bit_offset bits into last frame */
877            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
878            /* skip unused bits */
879            if (s->last_bitoffset > 0)
880                skip_bits(&s->gb, s->last_bitoffset);
881            /* this frame is stored in the last superframe and in the
882               current one */
883            if (wma_decode_frame(s, samples) < 0)
884                goto fail;
885            samples += s->nb_channels * s->frame_len;
886        }
887
888        /* read each frame starting from bit_offset */
889        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
890        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
891        len = pos & 7;
892        if (len > 0)
893            skip_bits(&s->gb, len);
894
895        s->reset_block_lengths = 1;
896        for(i=0;i<nb_frames;i++) {
897            if (wma_decode_frame(s, samples) < 0)
898                goto fail;
899            samples += s->nb_channels * s->frame_len;
900        }
901
902        /* we copy the end of the frame in the last frame buffer */
903        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
904        s->last_bitoffset = pos & 7;
905        pos >>= 3;
906        len = buf_size - pos;
907        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
908            av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
909            goto fail;
910        }
911        s->last_superframe_len = len;
912        memcpy(s->last_superframe, buf + pos, len);
913    } else {
914        if(s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
915            av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
916            goto fail;
917        }
918        /* single frame decode */
919        if (wma_decode_frame(s, samples) < 0)
920            goto fail;
921        samples += s->nb_channels * s->frame_len;
922    }
923
924//av_log(NULL, AV_LOG_ERROR, "%d %d %d %d outbytes:%d eaten:%d\n", s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,        (int8_t *)samples - (int8_t *)data, s->block_align);
925
926    *data_size = (int8_t *)samples - (int8_t *)data;
927    return s->block_align;
928 fail:
929    /* when error, we reset the bit reservoir */
930    s->last_superframe_len = 0;
931    return -1;
932}
933
934static av_cold void flush(AVCodecContext *avctx)
935{
936    WMACodecContext *s = avctx->priv_data;
937
938    s->last_bitoffset=
939    s->last_superframe_len= 0;
940}
941
942AVCodec wmav1_decoder =
943{
944    "wmav1",
945    AVMEDIA_TYPE_AUDIO,
946    CODEC_ID_WMAV1,
947    sizeof(WMACodecContext),
948    wma_decode_init,
949    NULL,
950    ff_wma_end,
951    wma_decode_superframe,
952    .flush=flush,
953    .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
954};
955
956AVCodec wmav2_decoder =
957{
958    "wmav2",
959    AVMEDIA_TYPE_AUDIO,
960    CODEC_ID_WMAV2,
961    sizeof(WMACodecContext),
962    wma_decode_init,
963    NULL,
964    ff_wma_end,
965    wma_decode_superframe,
966    .flush=flush,
967    .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
968};
969