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
26 #include <sys/select.h>
34 #include "buffer_tree.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 /** Information contained in the audio file header. */
63 struct asf_header_info ahi;
64 struct getbit_context gb;
65 /** Whether perceptual noise is added. */
67 /** Depends on number of the bits per second and the frame length. */
69 /** Only used if ahi->use_exp_vlc is true. */
71 uint16_t exponent_bands[BLOCK_NB_SIZES][25];
72 /** The index of the first coef in high band. */
73 int high_band_start[BLOCK_NB_SIZES];
74 /** Maximal number of coded coefficients. */
75 int coefs_end[BLOCK_NB_SIZES];
76 int exponent_high_sizes[BLOCK_NB_SIZES];
77 int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
80 /* coded values in high bands */
81 int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
82 int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
84 /* there are two possible tables for spectral coefficients */
85 struct vlc coef_vlc[2];
86 uint16_t *run_table[2];
87 uint16_t *level_table[2];
88 const struct coef_vlc_table *coef_vlcs[2];
89 /** Frame length in samples. */
91 /** log2 of frame_len. */
93 /** Number of block sizes, one if !ahi->use_variable_block_len. */
96 int reset_block_lengths;
97 /** log2 of current block length. */
99 /** log2 of next block length. */
100 int next_block_len_bits;
101 /** log2 of previous block length. */
102 int prev_block_len_bits;
103 /** Block length in samples. */
105 /** Current position in frame. */
107 /** True if mid/side stereo mode. */
109 /** True if channel is coded. */
110 uint8_t channel_coded[MAX_CHANNELS];
111 /** log2 ratio frame/exp. length. */
112 int exponents_bsize[MAX_CHANNELS];
114 float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
115 float max_exponent[MAX_CHANNELS];
116 int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
117 float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
118 float output[BLOCK_MAX_SIZE * 2];
119 struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
120 float *windows[BLOCK_NB_SIZES];
121 /** Output buffer for one frame and the last for IMDCT windowing. */
122 float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
123 /** Last frame info. */
124 uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
126 int last_superframe_len;
127 float noise_table[NOISE_TAB_SIZE];
129 float noise_mult; /* XXX: suppress that and integrate it in the noise array */
130 /* lsp_to_curve tables */
131 float lsp_cos_table[BLOCK_MAX_SIZE];
132 float lsp_pow_e_table[256];
133 float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
134 float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
138 #define EXPMAX DIV_ROUND_UP(19, EXPVLCBITS)
140 #define HGAINVLCBITS 9
141 #define HGAINMAX DIV_ROUND_UP(13, HGAINVLCBITS)
144 #define VLCMAX DIV_ROUND_UP(22, VLCBITS)
146 /** \cond sine_winows */
148 #define SINE_WINDOW(x) static float sine_ ## x[x] __a_aligned(16)
157 static float *sine_windows[6] = {
158 sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
160 /** \endcond sine_windows */
162 /* Generate a sine window. */
163 static void sine_window_init(float *window, int n)
167 for (i = 0; i < n; i++)
168 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
171 static void wmadec_cleanup(struct private_wmadec_data *pwd)
175 for (i = 0; i < pwd->nb_block_sizes; i++)
176 imdct_end(pwd->mdct_ctx[i]);
177 if (pwd->ahi.use_exp_vlc)
178 free_vlc(&pwd->exp_vlc);
179 if (pwd->use_noise_coding)
180 free_vlc(&pwd->hgain_vlc);
181 for (i = 0; i < 2; i++) {
182 free_vlc(&pwd->coef_vlc[i]);
183 free(pwd->run_table[i]);
184 free(pwd->level_table[i]);
188 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
189 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
191 int n = vlc_table->n;
192 const uint8_t *table_bits = vlc_table->huffbits;
193 const uint32_t *table_codes = vlc_table->huffcodes;
194 const uint16_t *levels_table = vlc_table->levels;
195 uint16_t *run_table, *level_table;
196 int i, l, j, k, level;
198 init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
200 run_table = para_malloc(n * sizeof(uint16_t));
201 level_table = para_malloc(n * sizeof(uint16_t));
206 l = levels_table[k++];
207 for (j = 0; j < l; j++) {
209 level_table[i] = level;
214 *prun_table = run_table;
215 *plevel_table = level_table;
218 /* compute the scale factor band sizes for each MDCT block size */
219 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
222 struct asf_header_info *ahi = &pwd->ahi;
223 int a, b, pos, lpos, k, block_len, i, j, n;
224 const uint8_t *table;
226 for (k = 0; k < pwd->nb_block_sizes; k++) {
229 block_len = pwd->frame_len >> k;
231 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
233 if (ahi->sample_rate >= 44100)
234 table = exponent_band_44100[a];
235 else if (ahi->sample_rate >= 32000)
236 table = exponent_band_32000[a];
237 else if (ahi->sample_rate >= 22050)
238 table = exponent_band_22050[a];
242 for (i = 0; i < n; i++)
243 pwd->exponent_bands[k][i] = table[i];
248 for (i = 0; i < 25; i++) {
249 a = wma_critical_freqs[i];
250 b = ahi->sample_rate;
251 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
256 pwd->exponent_bands[k][j++] = pos - lpos;
257 if (pos >= block_len)
264 /* max number of coefs */
265 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
266 /* high freq computation */
267 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
268 / ahi->sample_rate + 0.5);
272 for (i = 0; i < n; i++) {
275 pos += pwd->exponent_bands[k][i];
277 if (start < pwd->high_band_start[k])
278 start = pwd->high_band_start[k];
279 if (end > pwd->coefs_end[k])
280 end = pwd->coefs_end[k];
282 pwd->exponent_high_bands[k][j++] = end - start;
284 pwd->exponent_high_sizes[k] = j;
288 static int wma_init(struct private_wmadec_data *pwd)
291 float bps1, high_freq;
295 struct asf_header_info *ahi = &pwd->ahi;
296 int flags2 = ahi->flags2;
298 if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
299 || ahi->channels <= 0 || ahi->channels > 8
300 || ahi->bit_rate <= 0)
301 return -E_WMA_BAD_PARAMS;
303 /* compute MDCT block size */
304 if (ahi->sample_rate <= 16000)
305 pwd->frame_len_bits = 9;
306 else if (ahi->sample_rate <= 22050)
307 pwd->frame_len_bits = 10;
309 pwd->frame_len_bits = 11;
310 pwd->frame_len = 1 << pwd->frame_len_bits;
311 if (pwd->ahi.use_variable_block_len) {
313 nb = ((flags2 >> 3) & 3) + 1;
314 if ((ahi->bit_rate / ahi->channels) >= 32000)
316 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
319 pwd->nb_block_sizes = nb + 1;
321 pwd->nb_block_sizes = 1;
323 /* init rate dependent parameters */
324 pwd->use_noise_coding = 1;
325 high_freq = ahi->sample_rate * 0.5;
327 /* wma2 rates are normalized */
328 sample_rate1 = ahi->sample_rate;
329 if (sample_rate1 >= 44100)
330 sample_rate1 = 44100;
331 else if (sample_rate1 >= 22050)
332 sample_rate1 = 22050;
333 else if (sample_rate1 >= 16000)
334 sample_rate1 = 16000;
335 else if (sample_rate1 >= 11025)
336 sample_rate1 = 11025;
337 else if (sample_rate1 >= 8000)
340 bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
341 pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
343 * Compute high frequency value and choose if noise coding should be
347 if (ahi->channels == 2)
349 if (sample_rate1 == 44100) {
351 pwd->use_noise_coding = 0;
353 high_freq = high_freq * 0.4;
354 } else if (sample_rate1 == 22050) {
356 pwd->use_noise_coding = 0;
357 else if (bps1 >= 0.72)
358 high_freq = high_freq * 0.7;
360 high_freq = high_freq * 0.6;
361 } else if (sample_rate1 == 16000) {
363 high_freq = high_freq * 0.5;
365 high_freq = high_freq * 0.3;
366 } else if (sample_rate1 == 11025)
367 high_freq = high_freq * 0.7;
368 else if (sample_rate1 == 8000) {
370 high_freq = high_freq * 0.5;
372 pwd->use_noise_coding = 0;
374 high_freq = high_freq * 0.65;
377 high_freq = high_freq * 0.75;
379 high_freq = high_freq * 0.6;
381 high_freq = high_freq * 0.5;
383 PARA_INFO_LOG("channels=%d sample_rate=%d "
384 "bitrate=%d block_align=%d\n",
385 ahi->channels, ahi->sample_rate,
386 ahi->bit_rate, ahi->block_align);
387 PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
388 "high_freq=%f bitoffset=%d\n",
389 pwd->frame_len, bps, bps1,
390 high_freq, pwd->byte_offset_bits);
391 PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
392 pwd->use_noise_coding, pwd->ahi.use_exp_vlc, pwd->nb_block_sizes);
394 compute_scale_factor_band_sizes(pwd, high_freq);
395 /* init MDCT windows : simple sinus window */
396 for (i = 0; i < pwd->nb_block_sizes; i++) {
398 n = 1 << (pwd->frame_len_bits - i);
399 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
400 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
403 pwd->reset_block_lengths = 1;
405 if (pwd->use_noise_coding) {
406 /* init the noise generator */
407 if (pwd->ahi.use_exp_vlc)
408 pwd->noise_mult = 0.02;
410 pwd->noise_mult = 0.04;
416 norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
417 for (i = 0; i < NOISE_TAB_SIZE; i++) {
418 seed = seed * 314159 + 1;
419 pwd->noise_table[i] = (float) ((int) seed) * norm;
424 /* choose the VLC tables for the coefficients */
426 if (ahi->sample_rate >= 32000) {
429 else if (bps1 < 1.16)
432 pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
433 pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
434 init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
436 init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
441 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
446 wdel = M_PI / frame_len;
447 for (i = 0; i < frame_len; i++)
448 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
450 /* tables for x^-0.25 computation */
451 for (i = 0; i < 256; i++) {
453 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
456 /* These two tables are needed to avoid two operations in pow_m1_4. */
458 for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
459 m = (1 << LSP_POW_BITS) + i;
460 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
462 pwd->lsp_pow_m_table1[i] = 2 * a - b;
463 pwd->lsp_pow_m_table2[i] = b - a;
468 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
470 struct private_wmadec_data *pwd;
473 PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
474 pwd = para_calloc(sizeof(*pwd));
475 ret = read_asf_header(initial_buf, len, &pwd->ahi);
485 for (i = 0; i < pwd->nb_block_sizes; i++) {
486 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
490 if (pwd->use_noise_coding) {
491 PARA_INFO_LOG("using noise coding\n");
492 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
493 sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
494 wma_hgain_huffcodes, 2);
497 if (pwd->ahi.use_exp_vlc) {
498 PARA_INFO_LOG("using exp_vlc\n");
499 init_vlc(&pwd->exp_vlc, EXPVLCBITS, sizeof(wma_scale_huffbits),
500 wma_scale_huffbits, wma_scale_huffcodes, 4);
502 PARA_INFO_LOG("using curve\n");
503 wma_lsp_to_curve_init(pwd, pwd->frame_len);
506 return pwd->ahi.header_len;
510 * compute x^-0.25 with an exponent and mantissa table. We use linear
511 * interpolation to reduce the mantissa table size at a small speed
512 * expense (linear interpolation approximately doubles the number of
513 * bits of precision).
515 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
526 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
527 /* build interpolation scale: 1 <= t < 2. */
528 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
529 a = pwd->lsp_pow_m_table1[m];
530 b = pwd->lsp_pow_m_table2[m];
531 return pwd->lsp_pow_e_table[e] * (a + b * t.f);
534 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
535 float *out, float *val_max_ptr, int n, float *lsp)
538 float p, q, w, v, val_max;
541 for (i = 0; i < n; i++) {
544 w = pwd->lsp_cos_table[i];
545 for (j = 1; j < NB_LSP_COEFS; j += 2) {
552 v = pow_m1_4(pwd, v);
557 *val_max_ptr = val_max;
560 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
561 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
563 float lsp_coefs[NB_LSP_COEFS];
566 for (i = 0; i < NB_LSP_COEFS; i++) {
567 if (i == 0 || i >= 8)
568 val = get_bits(&pwd->gb, 3);
570 val = get_bits(&pwd->gb, 4);
571 lsp_coefs[i] = wma_lsp_codebook[i][val];
574 wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
575 pwd->block_len, lsp_coefs);
578 /* Decode exponents coded with VLC codes. */
579 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
581 int last_exp, n, code;
582 const uint16_t *ptr, *band_ptr;
583 float v, *q, max_scale, *q_end;
585 band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
587 q = pwd->exponents[ch];
588 q_end = q + pwd->block_len;
593 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
596 /* NOTE: this offset is the same as MPEG4 AAC ! */
597 last_exp += code - 60;
598 /* XXX: use a table */
599 v = pow(10, last_exp * (1.0 / 16.0));
607 pwd->max_exponent[ch] = max_scale;
611 /* compute src0 * src1 + src2 */
612 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
613 const float *src2, int len)
617 for (i = 0; i < len; i++)
618 dst[i] = src0[i] * src1[i] + src2[i];
621 static inline void vector_mult_reverse(float *dst, const float *src0,
622 const float *src1, int len)
627 for (i = 0; i < len; i++)
628 dst[i] = src0[i] * src1[-i];
632 * Apply MDCT window and add into output.
634 * We ensure that when the windows overlap their squared sum
635 * is always 1 (MDCT reconstruction rule).
637 static void wma_window(struct private_wmadec_data *pwd, float *out)
639 float *in = pwd->output;
640 int block_len, bsize, n;
643 if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
644 block_len = pwd->block_len;
645 bsize = pwd->frame_len_bits - pwd->block_len_bits;
646 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
648 block_len = 1 << pwd->prev_block_len_bits;
649 n = (pwd->block_len - block_len) / 2;
650 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
651 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
653 memcpy(out + n + block_len, in + n + block_len,
656 out += pwd->block_len;
657 in += pwd->block_len;
659 if (pwd->block_len_bits <= pwd->next_block_len_bits) {
660 block_len = pwd->block_len;
661 bsize = pwd->frame_len_bits - pwd->block_len_bits;
662 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
664 block_len = 1 << pwd->next_block_len_bits;
665 n = (pwd->block_len - block_len) / 2;
666 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
667 memcpy(out, in, n * sizeof(float));
668 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
670 memset(out + n + block_len, 0, n * sizeof(float));
674 static int wma_total_gain_to_bits(int total_gain)
678 else if (total_gain < 32)
680 else if (total_gain < 40)
682 else if (total_gain < 45)
688 static int compute_high_band_values(struct private_wmadec_data *pwd,
689 int bsize, int nb_coefs[MAX_CHANNELS])
693 if (!pwd->use_noise_coding)
695 for (ch = 0; ch < pwd->ahi.channels; ch++) {
697 if (!pwd->channel_coded[ch])
699 m = pwd->exponent_high_sizes[bsize];
700 for (i = 0; i < m; i++) {
701 a = get_bit(&pwd->gb);
702 pwd->high_band_coded[ch][i] = a;
705 nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
708 for (ch = 0; ch < pwd->ahi.channels; ch++) {
710 if (!pwd->channel_coded[ch])
712 n = pwd->exponent_high_sizes[bsize];
713 val = (int)0x80000000;
714 for (i = 0; i < n; i++) {
715 if (!pwd->high_band_coded[ch][i])
717 if (val == (int)0x80000000)
718 val = get_bits(&pwd->gb, 7) - 19;
720 int code = get_vlc(&pwd->gb,
721 pwd->hgain_vlc.table, HGAINVLCBITS,
727 pwd->high_band_values[ch][i] = val;
733 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
734 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
737 float mdct_norm = 1.0 / (pwd->block_len / 2);
739 for (ch = 0; ch < pwd->ahi.channels; ch++) {
741 float *coefs, *exponents, mult, mult1, noise;
742 int i, j, n, n1, last_high_band, esize;
743 float exp_power[HIGH_BAND_MAX_SIZE];
745 if (!pwd->channel_coded[ch])
747 coefs1 = pwd->coefs1[ch];
748 exponents = pwd->exponents[ch];
749 esize = pwd->exponents_bsize[ch];
750 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
752 coefs = pwd->coefs[ch];
753 if (!pwd->use_noise_coding) {
754 /* XXX: optimize more */
756 for (i = 0; i < n; i++)
757 *coefs++ = coefs1[i] *
758 exponents[i << bsize >> esize] * mult;
759 n = pwd->block_len - pwd->coefs_end[bsize];
760 for (i = 0; i < n; i++)
764 n1 = pwd->exponent_high_sizes[bsize];
765 /* compute power of high bands */
766 exponents = pwd->exponents[ch] +
767 (pwd->high_band_start[bsize] << bsize);
768 last_high_band = 0; /* avoid warning */
769 for (j = 0; j < n1; j++) {
770 n = pwd->exponent_high_bands[
771 pwd->frame_len_bits - pwd->block_len_bits][j];
772 if (pwd->high_band_coded[ch][j]) {
775 for (i = 0; i < n; i++) {
776 val = exponents[i << bsize >> esize];
779 exp_power[j] = e2 / n;
782 exponents += n << bsize;
784 /* main freqs and high freqs */
785 exponents = pwd->exponents[ch];
786 for (j = -1; j < n1; j++) {
788 n = pwd->high_band_start[bsize];
790 n = pwd->exponent_high_bands[pwd->frame_len_bits
791 - pwd->block_len_bits][j];
792 if (j >= 0 && pwd->high_band_coded[ch][j]) {
793 /* use noise with specified power */
794 mult1 = sqrt(exp_power[j]
795 / exp_power[last_high_band]);
796 /* XXX: use a table */
797 mult1 *= pow(10, pwd->high_band_values[ch][j] * 0.05);
798 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
800 for (i = 0; i < n; i++) {
801 noise = pwd->noise_table[pwd->noise_index];
802 pwd->noise_index = (pwd->noise_index + 1)
803 & (NOISE_TAB_SIZE - 1);
804 *coefs++ = noise * exponents[
805 i << bsize >> esize] * mult1;
807 exponents += n << bsize;
809 /* coded values + small noise */
810 for (i = 0; i < n; i++) {
811 noise = pwd->noise_table[pwd->noise_index];
812 pwd->noise_index = (pwd->noise_index + 1)
813 & (NOISE_TAB_SIZE - 1);
814 *coefs++ = ((*coefs1++) + noise) *
815 exponents[i << bsize >> esize]
818 exponents += n << bsize;
821 /* very high freqs: noise */
822 n = pwd->block_len - pwd->coefs_end[bsize];
823 mult1 = mult * exponents[((-1 << bsize)) >> esize];
824 for (i = 0; i < n; i++) {
825 *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
826 pwd->noise_index = (pwd->noise_index + 1)
827 & (NOISE_TAB_SIZE - 1);
833 * Returns 0 if OK, 1 if last block of frame, negative on uncorrectable
836 static int wma_decode_block(struct private_wmadec_data *pwd)
838 int ret, n, v, ch, code, bsize;
839 int coef_nb_bits, total_gain;
840 int nb_coefs[MAX_CHANNELS];
842 /* compute current block length */
843 if (pwd->ahi.use_variable_block_len) {
844 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
846 if (pwd->reset_block_lengths) {
847 pwd->reset_block_lengths = 0;
848 v = get_bits(&pwd->gb, n);
849 if (v >= pwd->nb_block_sizes)
850 return -E_WMA_BLOCK_SIZE;
851 pwd->prev_block_len_bits = pwd->frame_len_bits - v;
852 v = get_bits(&pwd->gb, n);
853 if (v >= pwd->nb_block_sizes)
854 return -E_WMA_BLOCK_SIZE;
855 pwd->block_len_bits = pwd->frame_len_bits - v;
857 /* update block lengths */
858 pwd->prev_block_len_bits = pwd->block_len_bits;
859 pwd->block_len_bits = pwd->next_block_len_bits;
861 v = get_bits(&pwd->gb, n);
862 if (v >= pwd->nb_block_sizes)
863 return -E_WMA_BLOCK_SIZE;
864 pwd->next_block_len_bits = pwd->frame_len_bits - v;
866 /* fixed block len */
867 pwd->next_block_len_bits = pwd->frame_len_bits;
868 pwd->prev_block_len_bits = pwd->frame_len_bits;
869 pwd->block_len_bits = pwd->frame_len_bits;
872 /* now check if the block length is coherent with the frame length */
873 pwd->block_len = 1 << pwd->block_len_bits;
874 if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
875 return -E_INCOHERENT_BLOCK_LEN;
877 if (pwd->ahi.channels == 2)
878 pwd->ms_stereo = get_bit(&pwd->gb);
880 for (ch = 0; ch < pwd->ahi.channels; ch++) {
881 int a = get_bit(&pwd->gb);
882 pwd->channel_coded[ch] = a;
886 bsize = pwd->frame_len_bits - pwd->block_len_bits;
888 /* if no channel coded, no need to go further */
889 /* XXX: fix potential framing problems */
894 * Read total gain and extract corresponding number of bits for coef
899 int a = get_bits(&pwd->gb, 7);
905 coef_nb_bits = wma_total_gain_to_bits(total_gain);
907 /* compute number of coefficients */
908 n = pwd->coefs_end[bsize];
909 for (ch = 0; ch < pwd->ahi.channels; ch++)
912 ret = compute_high_band_values(pwd, bsize, nb_coefs);
916 /* exponents can be reused in short blocks. */
917 if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
918 for (ch = 0; ch < pwd->ahi.channels; ch++) {
919 if (pwd->channel_coded[ch]) {
920 if (pwd->ahi.use_exp_vlc) {
921 ret = decode_exp_vlc(pwd, ch);
925 decode_exp_lsp(pwd, ch);
926 pwd->exponents_bsize[ch] = bsize;
931 /* parse spectral coefficients : just RLE encoding */
932 for (ch = 0; ch < pwd->ahi.channels; ch++) {
933 struct vlc *coef_vlc;
934 int level, run, tindex;
936 const uint16_t *level_table, *run_table;
938 if (!pwd->channel_coded[ch])
941 * special VLC tables are used for ms stereo because there is
942 * potentially less energy there
944 tindex = (ch == 1 && pwd->ms_stereo);
945 coef_vlc = &pwd->coef_vlc[tindex];
946 run_table = pwd->run_table[tindex];
947 level_table = pwd->level_table[tindex];
949 ptr = &pwd->coefs1[ch][0];
950 eptr = ptr + nb_coefs[ch];
951 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
953 code = get_vlc(&pwd->gb, coef_vlc->table,
957 if (code == 1) /* EOB */
959 if (code == 0) { /* escape */
960 level = get_bits(&pwd->gb, coef_nb_bits);
961 /* reading block_len_bits would be better */
962 run = get_bits(&pwd->gb, pwd->frame_len_bits);
963 } else { /* normal code */
964 run = run_table[code];
965 level = level_table[code];
967 if (!get_bit(&pwd->gb))
971 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
975 if (ptr >= eptr) /* EOB can be omitted */
979 compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
980 if (pwd->ms_stereo && pwd->channel_coded[1]) {
984 * Nominal case for ms stereo: we do it before mdct.
986 * No need to optimize this case because it should almost never
989 if (!pwd->channel_coded[0]) {
990 PARA_NOTICE_LOG("rare ms-stereo\n");
991 memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
992 pwd->channel_coded[0] = 1;
994 for (i = 0; i < pwd->block_len; i++) {
995 a = pwd->coefs[0][i];
996 b = pwd->coefs[1][i];
997 pwd->coefs[0][i] = a + b;
998 pwd->coefs[1][i] = a - b;
1002 for (ch = 0; ch < pwd->ahi.channels; ch++) {
1005 n4 = pwd->block_len / 2;
1006 if (pwd->channel_coded[ch])
1007 imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1008 else if (!(pwd->ms_stereo && ch == 1))
1009 memset(pwd->output, 0, sizeof(pwd->output));
1011 /* multiply by the window and add in the frame */
1012 idx = (pwd->frame_len / 2) + pwd->block_pos - n4;
1013 wma_window(pwd, &pwd->frame_out[ch][idx]);
1016 /* update block number */
1017 pwd->block_pos += pwd->block_len;
1018 if (pwd->block_pos >= pwd->frame_len)
1025 * Clip a signed integer value into the -32768,32767 range.
1027 * \param a The value to clip.
1029 * \return The clipped value.
1031 static inline int16_t av_clip_int16(int a)
1033 if ((a + 32768) & ~65535)
1034 return (a >> 31) ^ 32767;
1039 /* Decode a frame of frame_len samples. */
1040 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1042 int ret, i, n, ch, incr;
1046 /* read each block */
1049 ret = wma_decode_block(pwd);
1056 /* convert frame to integer */
1058 incr = pwd->ahi.channels;
1059 for (ch = 0; ch < pwd->ahi.channels; ch++) {
1061 iptr = pwd->frame_out[ch];
1063 for (i = 0; i < n; i++) {
1064 *ptr = av_clip_int16(lrintf(*iptr++));
1067 /* prepare for next block */
1068 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1069 pwd->frame_len * sizeof(float));
1074 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1075 int *data_size, const uint8_t *buf, int buf_size)
1080 if (buf_size == 0) {
1081 pwd->last_superframe_len = 0;
1084 if (buf_size < pwd->ahi.block_align)
1086 buf_size = pwd->ahi.block_align;
1088 init_get_bits(&pwd->gb, buf, buf_size);
1089 if (pwd->ahi.use_bit_reservoir) {
1090 int i, nb_frames, bit_offset, pos, len;
1093 /* read super frame header */
1094 skip_bits(&pwd->gb, 4); /* super frame index */
1095 nb_frames = get_bits(&pwd->gb, 4) - 1;
1096 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1097 ret = -E_WMA_OUTPUT_SPACE;
1098 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1099 * sizeof(int16_t) > *data_size)
1102 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1104 if (pwd->last_superframe_len > 0) {
1105 /* add bit_offset bits to last frame */
1106 ret = -E_WMA_BAD_SUPERFRAME;
1107 if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1108 MAX_CODED_SUPERFRAME_SIZE)
1110 q = pwd->last_superframe + pwd->last_superframe_len;
1113 *q++ = get_bits(&pwd->gb, 8);
1117 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1119 /* XXX: bit_offset bits into last frame */
1120 init_get_bits(&pwd->gb, pwd->last_superframe,
1121 MAX_CODED_SUPERFRAME_SIZE);
1122 /* skip unused bits */
1123 if (pwd->last_bitoffset > 0)
1124 skip_bits(&pwd->gb, pwd->last_bitoffset);
1126 * This frame is stored in the last superframe and in
1129 ret = wma_decode_frame(pwd, samples);
1132 samples += pwd->ahi.channels * pwd->frame_len;
1135 /* read each frame starting from bit_offset */
1136 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1137 init_get_bits(&pwd->gb, buf + (pos >> 3),
1138 (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1141 skip_bits(&pwd->gb, len);
1143 pwd->reset_block_lengths = 1;
1144 for (i = 0; i < nb_frames; i++) {
1145 ret = wma_decode_frame(pwd, samples);
1148 samples += pwd->ahi.channels * pwd->frame_len;
1151 /* we copy the end of the frame in the last frame buffer */
1152 pos = get_bits_count(&pwd->gb) +
1153 ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1154 pwd->last_bitoffset = pos & 7;
1156 len = buf_size - pos;
1157 ret = -E_WMA_BAD_SUPERFRAME;
1158 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1160 pwd->last_superframe_len = len;
1161 memcpy(pwd->last_superframe, buf + pos, len);
1163 PARA_DEBUG_LOG("not using bit reservoir\n");
1164 ret = -E_WMA_OUTPUT_SPACE;
1165 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1167 /* single frame decode */
1168 ret = wma_decode_frame(pwd, samples);
1171 samples += pwd->ahi.channels * pwd->frame_len;
1173 PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %d, eaten: %d\n",
1174 pwd->frame_len, pwd->block_len,
1175 (int)((int8_t *)samples - (int8_t *)data), pwd->ahi.block_align);
1176 *data_size = (int8_t *)samples - (int8_t *)data;
1177 return pwd->ahi.block_align;
1179 /* reset the bit reservoir on errors */
1180 pwd->last_superframe_len = 0;
1184 static void wmadec_close(struct filter_node *fn)
1186 struct private_wmadec_data *pwd = fn->private_data;
1190 wmadec_cleanup(pwd);
1191 free(fn->private_data);
1192 fn->private_data = NULL;
1195 static int wmadec_execute(struct btr_node *btrn, const char *cmd, char **result)
1197 struct filter_node *fn = btr_context(btrn);
1198 struct private_wmadec_data *pwd = fn->private_data;
1200 return decoder_execute(cmd, pwd->ahi.sample_rate, pwd->ahi.channels,
1204 #define WMA_OUTPUT_BUFFER_SIZE (128 * 1024)
1206 static int wmadec_post_select(__a_unused struct sched *s, void *context)
1208 struct filter_node *fn = context;
1209 int ret, converted, out_size;
1210 struct private_wmadec_data *pwd = fn->private_data;
1211 struct btr_node *btrn = fn->btrn;
1217 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
1222 btr_merge(btrn, fn->min_iqs);
1223 len = btr_next_buffer(btrn, (char **)&in);
1224 ret = -E_WMADEC_EOF;
1225 if (len < fn->min_iqs)
1228 ret = wma_decode_init(in, len, &pwd);
1232 fn->min_iqs += 4096;
1235 fn->min_iqs = 2 * (WMA_FRAME_SKIP + pwd->ahi.block_align);
1236 fn->private_data = pwd;
1237 converted = pwd->ahi.header_len;
1240 fn->min_iqs = WMA_FRAME_SKIP + pwd->ahi.block_align;
1241 if (fn->min_iqs > len)
1243 out_size = WMA_OUTPUT_BUFFER_SIZE;
1244 out = para_malloc(out_size);
1245 ret = wma_decode_superframe(pwd, out, &out_size,
1246 (uint8_t *)in + WMA_FRAME_SKIP, len - WMA_FRAME_SKIP);
1251 out = para_realloc(out, out_size);
1253 btr_add_output(out, out_size, btrn);
1254 converted += ret + WMA_FRAME_SKIP;
1256 btr_consume(btrn, converted);
1260 btr_remove_node(&fn->btrn);
1264 static void wmadec_open(struct filter_node *fn)
1266 fn->private_data = NULL;
1271 * The init function of the wma decoder.
1273 * \param f Its fields are filled in by the function.
1275 void wmadec_filter_init(struct filter *f)
1277 f->open = wmadec_open;
1278 f->close = wmadec_close;
1279 f->execute = wmadec_execute;
1280 f->pre_select = generic_filter_pre_select;
1281 f->post_select = wmadec_post_select;