2 * WMA compatible decoder
4 * Extracted 2009 from the mplayer source code 2009-02-10.
6 * Copyright (c) 2002 The FFmpeg Project
8 * Licensed under the GNU Lesser General Public License.
9 * For licencing details see COPYING.LIB.
12 /** \file wmadec_filter.c paraslash's WMA decoder. */
15 * This decoder handles Microsoft Windows Media Audio data version 2.
18 #define _XOPEN_SOURCE 600
27 #include <sys/select.h>
36 #include "bitstream.h"
43 #define BLOCK_MIN_BITS 7
44 #define BLOCK_MAX_BITS 11
45 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
47 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
49 /* XXX: find exact max size */
50 #define HIGH_BAND_MAX_SIZE 16
52 /* XXX: is it a suitable value ? */
53 #define MAX_CODED_SUPERFRAME_SIZE 16384
55 #define MAX_CHANNELS 2
57 #define NOISE_TAB_SIZE 8192
59 #define LSP_POW_BITS 7
61 struct private_wmadec_data {
62 struct asf_header_info ahi;
63 struct getbit_context gb;
64 int use_bit_reservoir;
65 int use_variable_block_len;
66 int use_exp_vlc; ///< exponent coding: 0 = lsp, 1 = vlc + delta
67 int use_noise_coding; ///< true if perceptual noise is added
70 int exponent_sizes[BLOCK_NB_SIZES];
71 uint16_t exponent_bands[BLOCK_NB_SIZES][25];
72 int high_band_start[BLOCK_NB_SIZES]; ///< index of first coef in high band
73 int coefs_start; ///< first coded coef
74 int coefs_end[BLOCK_NB_SIZES]; ///< max number of coded coefficients
75 int exponent_high_sizes[BLOCK_NB_SIZES];
76 int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
79 /* coded values in high bands */
80 int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
81 int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
83 /* there are two possible tables for spectral coefficients */
84 struct vlc coef_vlc[2];
85 uint16_t *run_table[2];
86 uint16_t *level_table[2];
87 const struct coef_vlc_table *coef_vlcs[2];
89 int frame_len; ///< frame length in samples
90 int frame_len_bits; ///< frame_len = 1 << frame_len_bits
91 int nb_block_sizes; ///< number of block sizes
93 int reset_block_lengths;
94 int block_len_bits; ///< log2 of current block length
95 int next_block_len_bits; ///< log2 of next block length
96 int prev_block_len_bits; ///< log2 of prev block length
97 int block_len; ///< block length in samples
98 int block_pos; ///< current position in frame
99 uint8_t ms_stereo; ///< true if mid/side stereo mode
100 uint8_t channel_coded[MAX_CHANNELS]; ///< true if channel is coded
101 int exponents_bsize[MAX_CHANNELS]; ///< log2 ratio frame/exp. length
102 float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
103 float max_exponent[MAX_CHANNELS];
104 int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
105 float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
106 float output[BLOCK_MAX_SIZE * 2];
107 struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
108 float *windows[BLOCK_NB_SIZES];
109 /* output buffer for one frame and the last for IMDCT windowing */
110 float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
111 /* last frame info */
112 uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
114 int last_superframe_len;
115 float noise_table[NOISE_TAB_SIZE];
117 float noise_mult; /* XXX: suppress that and integrate it in the noise array */
118 /* lsp_to_curve tables */
119 float lsp_cos_table[BLOCK_MAX_SIZE];
120 float lsp_pow_e_table[256];
121 float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
122 float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
126 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
128 #define HGAINVLCBITS 9
129 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
132 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
134 #define SINE_WINDOW(x) float sine_ ## x[x] __aligned(16)
143 static float *sine_windows[6] = {
144 sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
147 /* Generate a sine window. */
148 static void sine_window_init(float *window, int n)
152 for (i = 0; i < n; i++)
153 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
156 static void wmadec_cleanup(struct private_wmadec_data *pwd)
160 for (i = 0; i < pwd->nb_block_sizes; i++)
161 imdct_end(pwd->mdct_ctx[i]);
162 if (pwd->use_exp_vlc)
163 free_vlc(&pwd->exp_vlc);
164 if (pwd->use_noise_coding)
165 free_vlc(&pwd->hgain_vlc);
166 for (i = 0; i < 2; i++) {
167 free_vlc(&pwd->coef_vlc[i]);
168 free(pwd->run_table[i]);
169 free(pwd->level_table[i]);
173 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
174 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
176 int n = vlc_table->n;
177 const uint8_t *table_bits = vlc_table->huffbits;
178 const uint32_t *table_codes = vlc_table->huffcodes;
179 const uint16_t *levels_table = vlc_table->levels;
180 uint16_t *run_table, *level_table;
181 int i, l, j, k, level;
183 init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
185 run_table = para_malloc(n * sizeof(uint16_t));
186 level_table = para_malloc(n * sizeof(uint16_t));
191 l = levels_table[k++];
192 for (j = 0; j < l; j++) {
194 level_table[i] = level;
199 *prun_table = run_table;
200 *plevel_table = level_table;
203 /* compute the scale factor band sizes for each MDCT block size */
204 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
207 struct asf_header_info *ahi = &pwd->ahi;
208 int a, b, pos, lpos, k, block_len, i, j, n;
209 const uint8_t *table;
211 pwd->coefs_start = 0;
212 for (k = 0; k < pwd->nb_block_sizes; k++) {
213 block_len = pwd->frame_len >> k;
216 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
218 if (ahi->sample_rate >= 44100)
219 table = exponent_band_44100[a];
220 else if (ahi->sample_rate >= 32000)
221 table = exponent_band_32000[a];
222 else if (ahi->sample_rate >= 22050)
223 table = exponent_band_22050[a];
227 for (i = 0; i < n; i++)
228 pwd->exponent_bands[k][i] = table[i];
229 pwd->exponent_sizes[k] = n;
233 for (i = 0; i < 25; i++) {
234 a = wma_critical_freqs[i];
235 b = ahi->sample_rate;
236 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
241 pwd->exponent_bands[k][j++] = pos - lpos;
242 if (pos >= block_len)
246 pwd->exponent_sizes[k] = j;
249 /* max number of coefs */
250 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
251 /* high freq computation */
252 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
253 / ahi->sample_rate + 0.5);
254 n = pwd->exponent_sizes[k];
257 for (i = 0; i < n; i++) {
260 pos += pwd->exponent_bands[k][i];
262 if (start < pwd->high_band_start[k])
263 start = pwd->high_band_start[k];
264 if (end > pwd->coefs_end[k])
265 end = pwd->coefs_end[k];
267 pwd->exponent_high_bands[k][j++] = end - start;
269 pwd->exponent_high_sizes[k] = j;
273 static int wma_init(struct private_wmadec_data *pwd)
276 float bps1, high_freq;
280 struct asf_header_info *ahi = &pwd->ahi;
281 int flags2 = ahi->flags2;
283 if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
284 || ahi->channels <= 0 || ahi->channels > 8
285 || ahi->bit_rate <= 0)
286 return -E_WMA_BAD_PARAMS;
288 /* compute MDCT block size */
289 if (ahi->sample_rate <= 16000) {
290 pwd->frame_len_bits = 9;
291 } else if (ahi->sample_rate <= 22050) {
292 pwd->frame_len_bits = 10;
294 pwd->frame_len_bits = 11;
296 pwd->frame_len = 1 << pwd->frame_len_bits;
297 if (pwd->use_variable_block_len) {
299 nb = ((flags2 >> 3) & 3) + 1;
300 if ((ahi->bit_rate / ahi->channels) >= 32000)
302 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
305 pwd->nb_block_sizes = nb + 1;
307 pwd->nb_block_sizes = 1;
309 /* init rate dependent parameters */
310 pwd->use_noise_coding = 1;
311 high_freq = ahi->sample_rate * 0.5;
313 /* wma2 rates are normalized */
314 sample_rate1 = ahi->sample_rate;
315 if (sample_rate1 >= 44100)
316 sample_rate1 = 44100;
317 else if (sample_rate1 >= 22050)
318 sample_rate1 = 22050;
319 else if (sample_rate1 >= 16000)
320 sample_rate1 = 16000;
321 else if (sample_rate1 >= 11025)
322 sample_rate1 = 11025;
323 else if (sample_rate1 >= 8000)
326 bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
327 pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
329 * Compute high frequency value and choose if noise coding should be
333 if (ahi->channels == 2)
335 if (sample_rate1 == 44100) {
337 pwd->use_noise_coding = 0;
339 high_freq = high_freq * 0.4;
340 } else if (sample_rate1 == 22050) {
342 pwd->use_noise_coding = 0;
343 else if (bps1 >= 0.72)
344 high_freq = high_freq * 0.7;
346 high_freq = high_freq * 0.6;
347 } else if (sample_rate1 == 16000) {
349 high_freq = high_freq * 0.5;
351 high_freq = high_freq * 0.3;
352 } else if (sample_rate1 == 11025) {
353 high_freq = high_freq * 0.7;
354 } else if (sample_rate1 == 8000) {
356 high_freq = high_freq * 0.5;
357 } else if (bps > 0.75) {
358 pwd->use_noise_coding = 0;
360 high_freq = high_freq * 0.65;
364 high_freq = high_freq * 0.75;
365 } else if (bps >= 0.6) {
366 high_freq = high_freq * 0.6;
368 high_freq = high_freq * 0.5;
371 PARA_INFO_LOG("channels=%d sample_rate=%d "
372 "bitrate=%d block_align=%d\n",
373 ahi->channels, ahi->sample_rate,
374 ahi->bit_rate, ahi->block_align);
375 PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
376 "high_freq=%f bitoffset=%d\n",
377 pwd->frame_len, bps, bps1,
378 high_freq, pwd->byte_offset_bits);
379 PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
380 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
382 compute_scale_factor_band_sizes(pwd, high_freq);
383 /* init MDCT windows : simple sinus window */
384 for (i = 0; i < pwd->nb_block_sizes; i++) {
386 n = 1 << (pwd->frame_len_bits - i);
387 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
388 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
391 pwd->reset_block_lengths = 1;
393 if (pwd->use_noise_coding) {
394 /* init the noise generator */
395 if (pwd->use_exp_vlc)
396 pwd->noise_mult = 0.02;
398 pwd->noise_mult = 0.04;
404 norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
405 for (i = 0; i < NOISE_TAB_SIZE; i++) {
406 seed = seed * 314159 + 1;
407 pwd->noise_table[i] = (float) ((int) seed) * norm;
412 /* choose the VLC tables for the coefficients */
414 if (ahi->sample_rate >= 32000) {
417 else if (bps1 < 1.16)
420 pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
421 pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
422 init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
424 init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
429 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
434 wdel = M_PI / frame_len;
435 for (i = 0; i < frame_len; i++)
436 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
438 /* tables for x^-0.25 computation */
439 for (i = 0; i < 256; i++) {
441 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
444 /* These two tables are needed to avoid two operations in pow_m1_4. */
446 for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
447 m = (1 << LSP_POW_BITS) + i;
448 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
450 pwd->lsp_pow_m_table1[i] = 2 * a - b;
451 pwd->lsp_pow_m_table2[i] = b - a;
456 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
458 struct private_wmadec_data *pwd;
461 PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
462 pwd = para_calloc(sizeof(*pwd));
463 ret = read_asf_header(initial_buf, len, &pwd->ahi);
469 pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
470 pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
471 pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
477 for (i = 0; i < pwd->nb_block_sizes; i++) {
478 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
482 if (pwd->use_noise_coding) {
483 PARA_INFO_LOG("using noise coding\n");
484 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
485 sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
486 wma_hgain_huffcodes, 2);
489 if (pwd->use_exp_vlc) {
490 PARA_INFO_LOG("using exp_vlc\n");
491 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
492 sizeof(wma_scale_huffbits), wma_scale_huffbits,
493 wma_scale_huffcodes, 4);
495 PARA_INFO_LOG("using curve\n");
496 wma_lsp_to_curve_init(pwd, pwd->frame_len);
499 return pwd->ahi.header_len;
503 * compute x^-0.25 with an exponent and mantissa table. We use linear
504 * interpolation to reduce the mantissa table size at a small speed
505 * expense (linear interpolation approximately doubles the number of
506 * bits of precision).
508 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
519 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
520 /* build interpolation scale: 1 <= t < 2. */
521 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
522 a = pwd->lsp_pow_m_table1[m];
523 b = pwd->lsp_pow_m_table2[m];
524 return pwd->lsp_pow_e_table[e] * (a + b * t.f);
527 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
528 float *out, float *val_max_ptr, int n, float *lsp)
531 float p, q, w, v, val_max;
534 for (i = 0; i < n; i++) {
537 w = pwd->lsp_cos_table[i];
538 for (j = 1; j < NB_LSP_COEFS; j += 2) {
545 v = pow_m1_4(pwd, v);
550 *val_max_ptr = val_max;
553 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
554 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
556 float lsp_coefs[NB_LSP_COEFS];
559 for (i = 0; i < NB_LSP_COEFS; i++) {
560 if (i == 0 || i >= 8)
561 val = get_bits(&pwd->gb, 3);
563 val = get_bits(&pwd->gb, 4);
564 lsp_coefs[i] = wma_lsp_codebook[i][val];
567 wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
568 pwd->block_len, lsp_coefs);
571 /* Decode exponents coded with VLC codes. */
572 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
574 int last_exp, n, code;
575 const uint16_t *ptr, *band_ptr;
576 float v, *q, max_scale, *q_end;
578 band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
580 q = pwd->exponents[ch];
581 q_end = q + pwd->block_len;
586 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
589 /* NOTE: this offset is the same as MPEG4 AAC ! */
590 last_exp += code - 60;
591 /* XXX: use a table */
592 v = pow(10, last_exp * (1.0 / 16.0));
600 pwd->max_exponent[ch] = max_scale;
604 /* compute src0 * src1 + src2 */
605 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
606 const float *src2, int len)
610 for (i = 0; i < len; i++)
611 dst[i] = src0[i] * src1[i] + src2[i];
614 static inline void vector_mult_reverse(float *dst, const float *src0,
615 const float *src1, int len)
620 for (i = 0; i < len; i++)
621 dst[i] = src0[i] * src1[-i];
625 * Apply MDCT window and add into output.
627 * We ensure that when the windows overlap their squared sum
628 * is always 1 (MDCT reconstruction rule).
630 static void wma_window(struct private_wmadec_data *pwd, float *out)
632 float *in = pwd->output;
633 int block_len, bsize, n;
636 if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
637 block_len = pwd->block_len;
638 bsize = pwd->frame_len_bits - pwd->block_len_bits;
639 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
641 block_len = 1 << pwd->prev_block_len_bits;
642 n = (pwd->block_len - block_len) / 2;
643 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
644 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
646 memcpy(out + n + block_len, in + n + block_len,
649 out += pwd->block_len;
650 in += pwd->block_len;
652 if (pwd->block_len_bits <= pwd->next_block_len_bits) {
653 block_len = pwd->block_len;
654 bsize = pwd->frame_len_bits - pwd->block_len_bits;
655 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
657 block_len = 1 << pwd->next_block_len_bits;
658 n = (pwd->block_len - block_len) / 2;
659 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
660 memcpy(out, in, n * sizeof(float));
661 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
663 memset(out + n + block_len, 0, n * sizeof(float));
667 static int wma_total_gain_to_bits(int total_gain)
671 else if (total_gain < 32)
673 else if (total_gain < 40)
675 else if (total_gain < 45)
681 static int compute_high_band_values(struct private_wmadec_data *pwd,
682 int bsize, int nb_coefs[MAX_CHANNELS])
686 if (!pwd->use_noise_coding)
688 for (ch = 0; ch < pwd->ahi.channels; ch++) {
690 if (!pwd->channel_coded[ch])
692 m = pwd->exponent_high_sizes[bsize];
693 for (i = 0; i < m; i++) {
694 a = get_bit(&pwd->gb);
695 pwd->high_band_coded[ch][i] = a;
698 nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
701 for (ch = 0; ch < pwd->ahi.channels; ch++) {
703 if (!pwd->channel_coded[ch])
705 n = pwd->exponent_high_sizes[bsize];
706 val = (int)0x80000000;
707 for (i = 0; i < n; i++) {
708 if (!pwd->high_band_coded[ch][i])
710 if (val == (int)0x80000000)
711 val = get_bits(&pwd->gb, 7) - 19;
713 int code = get_vlc(&pwd->gb,
714 pwd->hgain_vlc.table, HGAINVLCBITS,
720 pwd->high_band_values[ch][i] = val;
726 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
727 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
730 float mdct_norm = 1.0 / (pwd->block_len / 2);
732 for (ch = 0; ch < pwd->ahi.channels; ch++) {
734 float *coefs, *exponents, mult, mult1, noise;
735 int i, j, n, n1, last_high_band, esize;
736 float exp_power[HIGH_BAND_MAX_SIZE];
738 if (!pwd->channel_coded[ch])
740 coefs1 = pwd->coefs1[ch];
741 exponents = pwd->exponents[ch];
742 esize = pwd->exponents_bsize[ch];
743 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
745 coefs = pwd->coefs[ch];
746 if (!pwd->use_noise_coding) {
747 /* XXX: optimize more */
748 for (i = 0; i < pwd->coefs_start; i++)
751 for (i = 0; i < n; i++)
752 *coefs++ = coefs1[i] *
753 exponents[i << bsize >> esize] * mult;
754 n = pwd->block_len - pwd->coefs_end[bsize];
755 for (i = 0; i < n; i++)
760 /* very low freqs: noise */
761 for (i = 0; i < pwd->coefs_start; i++) {
762 *coefs++ = pwd->noise_table[pwd->noise_index] *
763 exponents[i << bsize >> esize] * mult1;
764 pwd->noise_index = (pwd->noise_index + 1) &
765 (NOISE_TAB_SIZE - 1);
767 n1 = pwd->exponent_high_sizes[bsize];
768 /* compute power of high bands */
769 exponents = pwd->exponents[ch] +
770 (pwd->high_band_start[bsize] << bsize);
771 last_high_band = 0; /* avoid warning */
772 for (j = 0; j < n1; j++) {
773 n = pwd->exponent_high_bands[
774 pwd->frame_len_bits - pwd->block_len_bits][j];
775 if (pwd->high_band_coded[ch][j]) {
778 for (i = 0; i < n; i++) {
779 val = exponents[i << bsize >> esize];
782 exp_power[j] = e2 / n;
785 exponents += n << bsize;
787 /* main freqs and high freqs */
788 exponents = pwd->exponents[ch] + (pwd->coefs_start << bsize);
789 for (j = -1; j < n1; j++) {
791 n = pwd->high_band_start[bsize]
794 n = pwd->exponent_high_bands[pwd->frame_len_bits
795 - pwd->block_len_bits][j];
796 if (j >= 0 && pwd->high_band_coded[ch][j]) {
797 /* use noise with specified power */
798 mult1 = sqrt(exp_power[j]
799 / exp_power[last_high_band]);
800 /* XXX: use a table */
801 mult1 = mult1 * pow(10,
802 pwd->high_band_values[ch][j] * 0.05);
803 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
805 for (i = 0; i < n; i++) {
806 noise = pwd->noise_table[pwd->noise_index];
807 pwd->noise_index = (pwd->noise_index + 1)
808 & (NOISE_TAB_SIZE - 1);
809 *coefs++ = noise * exponents[
810 i << bsize >> esize] * mult1;
812 exponents += n << bsize;
814 /* coded values + small noise */
815 for (i = 0; i < n; i++) {
816 noise = pwd->noise_table[pwd->noise_index];
817 pwd->noise_index = (pwd->noise_index + 1)
818 & (NOISE_TAB_SIZE - 1);
819 *coefs++ = ((*coefs1++) + noise) *
820 exponents[i << bsize >> esize]
823 exponents += n << bsize;
826 /* very high freqs: noise */
827 n = pwd->block_len - pwd->coefs_end[bsize];
828 mult1 = mult * exponents[((-1 << bsize)) >> esize];
829 for (i = 0; i < n; i++) {
830 *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
831 pwd->noise_index = (pwd->noise_index + 1)
832 & (NOISE_TAB_SIZE - 1);
838 * @return 0 if OK. 1 if last block of frame. return -1 if
839 * unrecorrable error.
841 static int wma_decode_block(struct private_wmadec_data *pwd)
843 int n, v, ch, code, bsize;
844 int coef_nb_bits, total_gain;
845 int nb_coefs[MAX_CHANNELS];
847 /* compute current block length */
848 if (pwd->use_variable_block_len) {
849 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
851 if (pwd->reset_block_lengths) {
852 pwd->reset_block_lengths = 0;
853 v = get_bits(&pwd->gb, n);
854 if (v >= pwd->nb_block_sizes)
856 pwd->prev_block_len_bits = pwd->frame_len_bits - v;
857 v = get_bits(&pwd->gb, n);
858 if (v >= pwd->nb_block_sizes)
860 pwd->block_len_bits = pwd->frame_len_bits - v;
862 /* update block lengths */
863 pwd->prev_block_len_bits = pwd->block_len_bits;
864 pwd->block_len_bits = pwd->next_block_len_bits;
866 v = get_bits(&pwd->gb, n);
867 if (v >= pwd->nb_block_sizes)
869 pwd->next_block_len_bits = pwd->frame_len_bits - v;
871 /* fixed block len */
872 pwd->next_block_len_bits = pwd->frame_len_bits;
873 pwd->prev_block_len_bits = pwd->frame_len_bits;
874 pwd->block_len_bits = pwd->frame_len_bits;
877 /* now check if the block length is coherent with the frame length */
878 pwd->block_len = 1 << pwd->block_len_bits;
879 if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
880 return -E_INCOHERENT_BLOCK_LEN;
882 if (pwd->ahi.channels == 2)
883 pwd->ms_stereo = get_bit(&pwd->gb);
885 for (ch = 0; ch < pwd->ahi.channels; ch++) {
886 int a = get_bit(&pwd->gb);
887 pwd->channel_coded[ch] = a;
891 bsize = pwd->frame_len_bits - pwd->block_len_bits;
893 /* if no channel coded, no need to go further */
894 /* XXX: fix potential framing problems */
898 /* read total gain and extract corresponding number of bits for
899 coef escape coding */
902 int a = get_bits(&pwd->gb, 7);
908 coef_nb_bits = wma_total_gain_to_bits(total_gain);
910 /* compute number of coefficients */
911 n = pwd->coefs_end[bsize] - pwd->coefs_start;
912 for (ch = 0; ch < pwd->ahi.channels; ch++)
915 if (compute_high_band_values(pwd, bsize, nb_coefs) < 0)
918 /* exponents can be reused in short blocks. */
919 if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
920 for (ch = 0; ch < pwd->ahi.channels; ch++) {
921 if (pwd->channel_coded[ch]) {
922 if (pwd->use_exp_vlc) {
923 if (decode_exp_vlc(pwd, ch) < 0)
926 decode_exp_lsp(pwd, ch);
928 pwd->exponents_bsize[ch] = bsize;
933 /* parse spectral coefficients : just RLE encoding */
934 for (ch = 0; ch < pwd->ahi.channels; ch++) {
935 struct vlc *coef_vlc;
936 int level, run, tindex;
938 const uint16_t *level_table, *run_table;
940 if (!pwd->channel_coded[ch])
943 * special VLC tables are used for ms stereo because there is
944 * potentially less energy there
946 tindex = (ch == 1 && pwd->ms_stereo);
947 coef_vlc = &pwd->coef_vlc[tindex];
948 run_table = pwd->run_table[tindex];
949 level_table = pwd->level_table[tindex];
951 ptr = &pwd->coefs1[ch][0];
952 eptr = ptr + nb_coefs[ch];
953 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
955 code = get_vlc(&pwd->gb, coef_vlc->table,
959 if (code == 1) /* EOB */
961 if (code == 0) { /* escape */
962 level = get_bits(&pwd->gb, coef_nb_bits);
963 /* reading block_len_bits would be better */
964 run = get_bits(&pwd->gb, pwd->frame_len_bits);
965 } else { /* normal code */
966 run = run_table[code];
967 level = level_table[code];
969 if (!get_bit(&pwd->gb))
973 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
977 if (ptr >= eptr) /* EOB can be omitted */
982 compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
984 if (pwd->ms_stereo && pwd->channel_coded[1]) {
989 * Nominal case for ms stereo: we do it before mdct.
991 * No need to optimize this case because it should almost never
994 if (!pwd->channel_coded[0]) {
995 PARA_NOTICE_LOG("rare ms-stereo\n");
996 memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
997 pwd->channel_coded[0] = 1;
999 for (i = 0; i < pwd->block_len; i++) {
1000 a = pwd->coefs[0][i];
1001 b = pwd->coefs[1][i];
1002 pwd->coefs[0][i] = a + b;
1003 pwd->coefs[1][i] = a - b;
1008 for (ch = 0; ch < pwd->ahi.channels; ch++) {
1012 n4 = pwd->block_len / 2;
1013 if (pwd->channel_coded[ch])
1014 imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1015 else if (!(pwd->ms_stereo && ch == 1))
1016 memset(pwd->output, 0, sizeof(pwd->output));
1018 /* multiply by the window and add in the frame */
1019 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1020 wma_window(pwd, &pwd->frame_out[ch][index]);
1023 /* update block number */
1024 pwd->block_pos += pwd->block_len;
1025 if (pwd->block_pos >= pwd->frame_len)
1032 * Clip a signed integer value into the -32768,32767 range.
1034 * \param a The value to clip.
1036 * \return The clipped value.
1038 static inline int16_t av_clip_int16(int a)
1040 if ((a + 32768) & ~65535)
1041 return (a >> 31) ^ 32767;
1046 /* Decode a frame of frame_len samples. */
1047 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1049 int ret, i, n, ch, incr;
1053 /* read each block */
1056 ret = wma_decode_block(pwd);
1063 /* convert frame to integer */
1065 incr = pwd->ahi.channels;
1066 for (ch = 0; ch < pwd->ahi.channels; ch++) {
1068 iptr = pwd->frame_out[ch];
1070 for (i = 0; i < n; i++) {
1071 *ptr = av_clip_int16(lrintf(*iptr++));
1074 /* prepare for next block */
1075 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1076 pwd->frame_len * sizeof(float));
1081 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1082 int *data_size, const uint8_t *buf, int buf_size)
1086 static int frame_count;
1088 if (buf_size == 0) {
1089 pwd->last_superframe_len = 0;
1092 if (buf_size < pwd->ahi.block_align)
1094 buf_size = pwd->ahi.block_align;
1096 init_get_bits(&pwd->gb, buf, buf_size);
1097 if (pwd->use_bit_reservoir) {
1098 int i, nb_frames, bit_offset, pos, len;
1101 /* read super frame header */
1102 skip_bits(&pwd->gb, 4); /* super frame index */
1103 nb_frames = get_bits(&pwd->gb, 4) - 1;
1104 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1105 ret = -E_WMA_OUTPUT_SPACE;
1106 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1107 * sizeof(int16_t) > *data_size)
1110 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1112 if (pwd->last_superframe_len > 0) {
1113 /* add bit_offset bits to last frame */
1114 ret = -E_WMA_BAD_SUPERFRAME;
1115 if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1116 MAX_CODED_SUPERFRAME_SIZE)
1118 q = pwd->last_superframe + pwd->last_superframe_len;
1121 *q++ = get_bits(&pwd->gb, 8);
1125 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1127 /* XXX: bit_offset bits into last frame */
1128 init_get_bits(&pwd->gb, pwd->last_superframe,
1129 MAX_CODED_SUPERFRAME_SIZE);
1130 /* skip unused bits */
1131 if (pwd->last_bitoffset > 0)
1132 skip_bits(&pwd->gb, pwd->last_bitoffset);
1134 * This frame is stored in the last superframe and in
1137 ret = -E_WMA_DECODE;
1138 if (wma_decode_frame(pwd, samples) < 0)
1141 samples += pwd->ahi.channels * pwd->frame_len;
1144 /* read each frame starting from bit_offset */
1145 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1146 init_get_bits(&pwd->gb, buf + (pos >> 3),
1147 (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1150 skip_bits(&pwd->gb, len);
1152 pwd->reset_block_lengths = 1;
1153 for (i = 0; i < nb_frames; i++) {
1154 ret = -E_WMA_DECODE;
1155 if (wma_decode_frame(pwd, samples) < 0)
1158 samples += pwd->ahi.channels * pwd->frame_len;
1161 /* we copy the end of the frame in the last frame buffer */
1162 pos = get_bits_count(&pwd->gb) +
1163 ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1164 pwd->last_bitoffset = pos & 7;
1166 len = buf_size - pos;
1167 ret = -E_WMA_BAD_SUPERFRAME;
1168 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1170 pwd->last_superframe_len = len;
1171 memcpy(pwd->last_superframe, buf + pos, len);
1173 PARA_DEBUG_LOG("not using bit reservoir\n");
1174 ret = -E_WMA_OUTPUT_SPACE;
1175 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1177 /* single frame decode */
1178 ret = -E_WMA_DECODE;
1179 if (wma_decode_frame(pwd, samples) < 0)
1182 samples += pwd->ahi.channels * pwd->frame_len;
1184 PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1185 "outbytes: %zd, eaten: %d\n",
1186 frame_count, pwd->frame_len, pwd->block_len,
1187 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1188 *data_size = (int8_t *)samples - (int8_t *)data;
1189 return pwd->ahi.block_align;
1191 /* reset the bit reservoir on errors */
1192 pwd->last_superframe_len = 0;
1196 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1197 struct filter_node *fn)
1199 int ret, out_size = fn->bufsize - fn->loaded;
1200 struct private_wmadec_data *pwd = fn->private_data;
1202 if (out_size < 128 * 1024)
1204 if (len <= WMA_FRAME_SKIP)
1207 ret = wma_decode_init(inbuffer, len, &pwd);
1210 fn->private_data = pwd;
1211 fn->fc->channels = pwd->ahi.channels;
1212 fn->fc->samplerate = pwd->ahi.sample_rate;
1213 return pwd->ahi.header_len;
1216 if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1218 ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1219 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1220 len - WMA_FRAME_SKIP);
1223 fn->loaded += out_size;
1224 return ret + WMA_FRAME_SKIP;
1227 static void wmadec_close(struct filter_node *fn)
1229 struct private_wmadec_data *pwd = fn->private_data;
1233 wmadec_cleanup(pwd);
1236 free(fn->private_data);
1237 fn->private_data = NULL;
1240 static void wmadec_open(struct filter_node *fn)
1242 fn->bufsize = 1024 * 1024;
1243 fn->buf = para_malloc(fn->bufsize);
1244 fn->private_data = NULL;
1249 * The init function of the wma decoder.
1251 * \param f Its fields are filled in by the function.
1253 void wmadec_filter_init(struct filter *f)
1255 f->open = wmadec_open;
1256 f->close = wmadec_close;
1257 f->convert = wmadec_convert;