2 * WMA compatible decoder
3 * Copyright (c) 2002 The FFmpeg Project.
5 * This file is part of FFmpeg.
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.
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.
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
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.
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.
43 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
45 #define HGAINVLCBITS 9
46 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
48 static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
51 static void dump_shorts(WMADecodeContext *s, const char *name, const short *tab, int n)
55 tprintf(s->avctx, "%s[%d]:\n", name, n);
58 tprintf(s->avctx, "%4d: ", i);
59 tprintf(s->avctx, " %5d.0", tab[i]);
61 tprintf(s->avctx, "\n");
65 static void dump_floats(WMADecodeContext *s, const char *name, int prec, const float *tab, int n)
69 tprintf(s->avctx, "%s[%d]:\n", name, n);
72 tprintf(s->avctx, "%4d: ", i);
73 tprintf(s->avctx, " %8.*f", prec, tab[i]);
75 tprintf(s->avctx, "\n");
78 tprintf(s->avctx, "\n");
82 static int wma_decode_init(AVCodecContext * avctx)
84 WMADecodeContext *s = avctx->priv_data;
85 int i, flags1, flags2;
90 /* extract flag infos */
93 extradata = avctx->extradata;
94 if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
95 flags1 = extradata[0] | (extradata[1] << 8);
96 flags2 = extradata[2] | (extradata[3] << 8);
97 } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
98 flags1 = extradata[0] | (extradata[1] << 8) |
99 (extradata[2] << 16) | (extradata[3] << 24);
100 flags2 = extradata[4] | (extradata[5] << 8);
102 // for(i=0; i<avctx->extradata_size; i++)
103 // av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
105 s->use_exp_vlc = flags2 & 0x0001;
106 s->use_bit_reservoir = flags2 & 0x0002;
107 s->use_variable_block_len = flags2 & 0x0004;
109 ff_wma_init(avctx, flags2);
112 for(i = 0; i < s->nb_block_sizes; i++)
113 ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
115 if (s->use_noise_coding) {
116 init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
117 ff_wma_hgain_huffbits, 1, 1,
118 ff_wma_hgain_huffcodes, 2, 2, 0);
121 if (s->use_exp_vlc) {
122 init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_wma_scale_huffbits), //FIXME move out of context
123 ff_wma_scale_huffbits, 1, 1,
124 ff_wma_scale_huffcodes, 4, 4, 0);
126 wma_lsp_to_curve_init(s, s->frame_len);
133 * interpolate values for a bigger or smaller block. The block must
134 * have multiple sizes
136 static void interpolate_array(float *scale, int old_size, int new_size)
141 if (new_size > old_size) {
142 jincr = new_size / old_size;
144 for(i = old_size - 1; i >=0; i--) {
151 } else if (new_size < old_size) {
153 jincr = old_size / new_size;
154 for(i = 0; i < new_size; i++) {
162 * compute x^-0.25 with an exponent and mantissa table. We use linear
163 * interpolation to reduce the mantissa table size at a small speed
164 * expense (linear interpolation approximately doubles the number of
165 * bits of precision).
167 static inline float pow_m1_4(WMADecodeContext *s, float x)
178 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
179 /* build interpolation scale: 1 <= t < 2. */
180 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
181 a = s->lsp_pow_m_table1[m];
182 b = s->lsp_pow_m_table2[m];
183 return s->lsp_pow_e_table[e] * (a + b * t.f);
186 static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
191 wdel = M_PI / frame_len;
192 for(i=0;i<frame_len;i++)
193 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
195 /* tables for x^-0.25 computation */
198 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
201 /* NOTE: these two tables are needed to avoid two operations in
204 for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
205 m = (1 << LSP_POW_BITS) + i;
206 a = (float)m * (0.5 / (1 << LSP_POW_BITS));
208 s->lsp_pow_m_table1[i] = 2 * a - b;
209 s->lsp_pow_m_table2[i] = b - a;
218 printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
224 * NOTE: We use the same code as Vorbis here
225 * @todo optimize it further with SSE/3Dnow
227 static void wma_lsp_to_curve(WMADecodeContext *s,
228 float *out, float *val_max_ptr,
232 float p, q, w, v, val_max;
238 w = s->lsp_cos_table[i];
239 for(j=1;j<NB_LSP_COEFS;j+=2){
251 *val_max_ptr = val_max;
255 * decode exponents coded with LSP coefficients (same idea as Vorbis)
257 static void decode_exp_lsp(WMADecodeContext *s, int ch)
259 float lsp_coefs[NB_LSP_COEFS];
262 for(i = 0; i < NB_LSP_COEFS; i++) {
263 if (i == 0 || i >= 8)
264 val = get_bits(&s->gb, 3);
266 val = get_bits(&s->gb, 4);
267 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
270 wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
271 s->block_len, lsp_coefs);
275 * decode exponents coded with VLC codes
277 static int decode_exp_vlc(WMADecodeContext *s, int ch)
279 int last_exp, n, code;
280 const uint16_t *ptr, *band_ptr;
281 float v, *q, max_scale, *q_end;
283 band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
285 q = s->exponents[ch];
286 q_end = q + s->block_len;
288 if (s->version == 1) {
289 last_exp = get_bits(&s->gb, 5) + 10;
290 /* XXX: use a table */
291 v = pow(10, last_exp * (1.0 / 16.0));
301 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
304 /* NOTE: this offset is the same as MPEG4 AAC ! */
305 last_exp += code - 60;
306 /* XXX: use a table */
307 v = pow(10, last_exp * (1.0 / 16.0));
315 s->max_exponent[ch] = max_scale;
320 * @return 0 if OK. 1 if last block of frame. return -1 if
321 * unrecorrable error.
323 static int wma_decode_block(WMADecodeContext *s)
325 int n, v, a, ch, code, bsize;
326 int coef_nb_bits, total_gain, parse_exponents;
327 int nb_coefs[MAX_CHANNELS];
331 tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
334 /* compute current block length */
335 if (s->use_variable_block_len) {
336 n = av_log2(s->nb_block_sizes - 1) + 1;
338 if (s->reset_block_lengths) {
339 s->reset_block_lengths = 0;
340 v = get_bits(&s->gb, n);
341 if (v >= s->nb_block_sizes)
343 s->prev_block_len_bits = s->frame_len_bits - v;
344 v = get_bits(&s->gb, n);
345 if (v >= s->nb_block_sizes)
347 s->block_len_bits = s->frame_len_bits - v;
349 /* update block lengths */
350 s->prev_block_len_bits = s->block_len_bits;
351 s->block_len_bits = s->next_block_len_bits;
353 v = get_bits(&s->gb, n);
354 if (v >= s->nb_block_sizes)
356 s->next_block_len_bits = s->frame_len_bits - v;
358 /* fixed block len */
359 s->next_block_len_bits = s->frame_len_bits;
360 s->prev_block_len_bits = s->frame_len_bits;
361 s->block_len_bits = s->frame_len_bits;
364 /* now check if the block length is coherent with the frame length */
365 s->block_len = 1 << s->block_len_bits;
366 if ((s->block_pos + s->block_len) > s->frame_len)
369 if (s->nb_channels == 2) {
370 s->ms_stereo = get_bits(&s->gb, 1);
373 for(ch = 0; ch < s->nb_channels; ch++) {
374 a = get_bits(&s->gb, 1);
375 s->channel_coded[ch] = a;
378 /* if no channel coded, no need to go further */
379 /* XXX: fix potential framing problems */
383 bsize = s->frame_len_bits - s->block_len_bits;
385 /* read total gain and extract corresponding number of bits for
386 coef escape coding */
389 a = get_bits(&s->gb, 7);
395 coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
397 /* compute number of coefficients */
398 n = s->coefs_end[bsize] - s->coefs_start;
399 for(ch = 0; ch < s->nb_channels; ch++)
403 if (s->use_noise_coding) {
405 for(ch = 0; ch < s->nb_channels; ch++) {
406 if (s->channel_coded[ch]) {
408 n = s->exponent_high_sizes[bsize];
410 a = get_bits(&s->gb, 1);
411 s->high_band_coded[ch][i] = a;
412 /* if noise coding, the coefficients are not transmitted */
414 nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
418 for(ch = 0; ch < s->nb_channels; ch++) {
419 if (s->channel_coded[ch]) {
422 n = s->exponent_high_sizes[bsize];
423 val = (int)0x80000000;
425 if (s->high_band_coded[ch][i]) {
426 if (val == (int)0x80000000) {
427 val = get_bits(&s->gb, 7) - 19;
429 code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
434 s->high_band_values[ch][i] = val;
441 /* exposant can be interpolated in short blocks. */
443 if (s->block_len_bits != s->frame_len_bits) {
444 parse_exponents = get_bits(&s->gb, 1);
447 if (parse_exponents) {
448 for(ch = 0; ch < s->nb_channels; ch++) {
449 if (s->channel_coded[ch]) {
450 if (s->use_exp_vlc) {
451 if (decode_exp_vlc(s, ch) < 0)
454 decode_exp_lsp(s, ch);
459 for(ch = 0; ch < s->nb_channels; ch++) {
460 if (s->channel_coded[ch]) {
461 interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
467 /* parse spectral coefficients : just RLE encoding */
468 for(ch = 0; ch < s->nb_channels; ch++) {
469 if (s->channel_coded[ch]) {
471 int level, run, sign, tindex;
473 const uint16_t *level_table, *run_table;
475 /* special VLC tables are used for ms stereo because
476 there is potentially less energy there */
477 tindex = (ch == 1 && s->ms_stereo);
478 coef_vlc = &s->coef_vlc[tindex];
479 run_table = s->run_table[tindex];
480 level_table = s->level_table[tindex];
482 ptr = &s->coefs1[ch][0];
483 eptr = ptr + nb_coefs[ch];
484 memset(ptr, 0, s->block_len * sizeof(int16_t));
486 code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
492 } else if (code == 0) {
494 level = get_bits(&s->gb, coef_nb_bits);
495 /* NOTE: this is rather suboptimal. reading
496 block_len_bits would be better */
497 run = get_bits(&s->gb, s->frame_len_bits);
500 run = run_table[code];
501 level = level_table[code];
503 sign = get_bits(&s->gb, 1);
509 av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
513 /* NOTE: EOB can be omitted */
518 if (s->version == 1 && s->nb_channels >= 2) {
519 align_get_bits(&s->gb);
525 int n4 = s->block_len / 2;
526 mdct_norm = 1.0 / (float)n4;
527 if (s->version == 1) {
528 mdct_norm *= sqrt(n4);
532 /* finally compute the MDCT coefficients */
533 for(ch = 0; ch < s->nb_channels; ch++) {
534 if (s->channel_coded[ch]) {
536 float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
537 int i, j, n, n1, last_high_band;
538 float exp_power[HIGH_BAND_MAX_SIZE];
540 coefs1 = s->coefs1[ch];
541 exponents = s->exponents[ch];
542 mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
544 coefs = s->coefs[ch];
545 if (s->use_noise_coding) {
547 /* very low freqs : noise */
548 for(i = 0;i < s->coefs_start; i++) {
549 *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
550 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
553 n1 = s->exponent_high_sizes[bsize];
555 /* compute power of high bands */
556 exp_ptr = exponents +
557 s->high_band_start[bsize] -
559 last_high_band = 0; /* avoid warning */
561 n = s->exponent_high_bands[s->frame_len_bits -
562 s->block_len_bits][j];
563 if (s->high_band_coded[ch][j]) {
566 for(i = 0;i < n; i++) {
570 exp_power[j] = e2 / n;
572 tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
577 /* main freqs and high freqs */
580 n = s->high_band_start[bsize] -
583 n = s->exponent_high_bands[s->frame_len_bits -
584 s->block_len_bits][j];
586 if (j >= 0 && s->high_band_coded[ch][j]) {
587 /* use noise with specified power */
588 mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
589 /* XXX: use a table */
590 mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
591 mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
593 for(i = 0;i < n; i++) {
594 noise = s->noise_table[s->noise_index];
595 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
596 *coefs++ = (*exponents++) * noise * mult1;
599 /* coded values + small noise */
600 for(i = 0;i < n; i++) {
601 noise = s->noise_table[s->noise_index];
602 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
603 *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
608 /* very high freqs : noise */
609 n = s->block_len - s->coefs_end[bsize];
610 mult1 = mult * exponents[-1];
611 for(i = 0; i < n; i++) {
612 *coefs++ = s->noise_table[s->noise_index] * mult1;
613 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
616 /* XXX: optimize more */
617 for(i = 0;i < s->coefs_start; i++)
620 for(i = 0;i < n; i++) {
621 *coefs++ = coefs1[i] * exponents[i] * mult;
623 n = s->block_len - s->coefs_end[bsize];
624 for(i = 0;i < n; i++)
631 for(ch = 0; ch < s->nb_channels; ch++) {
632 if (s->channel_coded[ch]) {
633 dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
634 dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
639 if (s->ms_stereo && s->channel_coded[1]) {
643 /* nominal case for ms stereo: we do it before mdct */
644 /* no need to optimize this case because it should almost
646 if (!s->channel_coded[0]) {
647 tprintf(s->avctx, "rare ms-stereo case happened\n");
648 memset(s->coefs[0], 0, sizeof(float) * s->block_len);
649 s->channel_coded[0] = 1;
652 for(i = 0; i < s->block_len; i++) {
655 s->coefs[0][i] = a + b;
656 s->coefs[1][i] = a - b;
660 /* build the window : we ensure that when the windows overlap
661 their squared sum is always 1 (MDCT reconstruction rule) */
662 /* XXX: merge with output */
664 int i, next_block_len, block_len, prev_block_len, n;
667 block_len = s->block_len;
668 prev_block_len = 1 << s->prev_block_len_bits;
669 next_block_len = 1 << s->next_block_len_bits;
672 wptr = s->window + block_len;
673 if (block_len <= next_block_len) {
674 for(i=0;i<block_len;i++)
675 *wptr++ = s->windows[bsize][i];
678 n = (block_len / 2) - (next_block_len / 2);
681 for(i=0;i<next_block_len;i++)
682 *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
688 wptr = s->window + block_len;
689 if (block_len <= prev_block_len) {
690 for(i=0;i<block_len;i++)
691 *--wptr = s->windows[bsize][i];
694 n = (block_len / 2) - (prev_block_len / 2);
697 for(i=0;i<prev_block_len;i++)
698 *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
705 for(ch = 0; ch < s->nb_channels; ch++) {
706 if (s->channel_coded[ch]) {
711 n4 = s->block_len / 2;
712 s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
713 s->output, s->coefs[ch], s->mdct_tmp);
715 /* XXX: optimize all that by build the window and
716 multipying/adding at the same time */
718 /* multiply by the window and add in the frame */
719 index = (s->frame_len / 2) + s->block_pos - n4;
720 ptr = &s->frame_out[ch][index];
721 s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
723 /* specific fast case for ms-stereo : add to second
724 channel if it is not coded */
725 if (s->ms_stereo && !s->channel_coded[1]) {
726 ptr = &s->frame_out[1][index];
727 s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
732 /* update block number */
734 s->block_pos += s->block_len;
735 if (s->block_pos >= s->frame_len)
741 /* decode a frame of frame_len samples */
742 static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
744 int ret, i, n, a, ch, incr;
749 tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
752 /* read each block */
756 ret = wma_decode_block(s);
763 /* convert frame to integer */
765 incr = s->nb_channels;
766 for(ch = 0; ch < s->nb_channels; ch++) {
768 iptr = s->frame_out[ch];
779 /* prepare for next block */
780 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
781 s->frame_len * sizeof(float));
782 /* XXX: suppress this */
783 memset(&s->frame_out[ch][s->frame_len], 0,
784 s->frame_len * sizeof(float));
788 dump_shorts(s, "samples", samples, n * s->nb_channels);
793 static int wma_decode_superframe(AVCodecContext *avctx,
794 void *data, int *data_size,
795 uint8_t *buf, int buf_size)
797 WMADecodeContext *s = avctx->priv_data;
798 int nb_frames, bit_offset, i, pos, len;
802 tprintf(avctx, "***decode_superframe:\n");
805 s->last_superframe_len = 0;
811 init_get_bits(&s->gb, buf, buf_size*8);
813 if (s->use_bit_reservoir) {
814 /* read super frame header */
815 get_bits(&s->gb, 4); /* super frame index */
816 nb_frames = get_bits(&s->gb, 4) - 1;
818 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
820 if (s->last_superframe_len > 0) {
821 // printf("skip=%d\n", s->last_bitoffset);
822 /* add bit_offset bits to last frame */
823 if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
824 MAX_CODED_SUPERFRAME_SIZE)
826 q = s->last_superframe + s->last_superframe_len;
829 *q++ = (get_bits)(&s->gb, 8);
833 *q++ = (get_bits)(&s->gb, len) << (8 - len);
836 /* XXX: bit_offset bits into last frame */
837 init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
838 /* skip unused bits */
839 if (s->last_bitoffset > 0)
840 skip_bits(&s->gb, s->last_bitoffset);
841 /* this frame is stored in the last superframe and in the
843 if (wma_decode_frame(s, samples) < 0)
845 samples += s->nb_channels * s->frame_len;
848 /* read each frame starting from bit_offset */
849 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
850 init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
853 skip_bits(&s->gb, len);
855 s->reset_block_lengths = 1;
856 for(i=0;i<nb_frames;i++) {
857 if (wma_decode_frame(s, samples) < 0)
859 samples += s->nb_channels * s->frame_len;
862 /* we copy the end of the frame in the last frame buffer */
863 pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
864 s->last_bitoffset = pos & 7;
866 len = buf_size - pos;
867 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
870 s->last_superframe_len = len;
871 memcpy(s->last_superframe, buf + pos, len);
873 /* single frame decode */
874 if (wma_decode_frame(s, samples) < 0)
876 samples += s->nb_channels * s->frame_len;
879 //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);
881 *data_size = (int8_t *)samples - (int8_t *)data;
882 return s->block_align;
884 /* when error, we reset the bit reservoir */
885 s->last_superframe_len = 0;
889 AVCodec wmav1_decoder =
894 sizeof(WMADecodeContext),
898 wma_decode_superframe,
901 AVCodec wmav2_decoder =
906 sizeof(WMADecodeContext),
910 wma_decode_superframe,