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(WMACodecContext *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 WMACodecContext *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 if(ff_wma_init(avctx, flags2)<0)
113 for(i = 0; i < s->nb_block_sizes; i++)
114 ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
116 if (s->use_noise_coding) {
117 init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
118 ff_wma_hgain_huffbits, 1, 1,
119 ff_wma_hgain_huffcodes, 2, 2, 0);
122 if (s->use_exp_vlc) {
123 init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_wma_scale_huffbits), //FIXME move out of context
124 ff_wma_scale_huffbits, 1, 1,
125 ff_wma_scale_huffcodes, 4, 4, 0);
127 wma_lsp_to_curve_init(s, s->frame_len);
134 * compute x^-0.25 with an exponent and mantissa table. We use linear
135 * interpolation to reduce the mantissa table size at a small speed
136 * expense (linear interpolation approximately doubles the number of
137 * bits of precision).
139 static inline float pow_m1_4(WMACodecContext *s, float x)
150 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
151 /* build interpolation scale: 1 <= t < 2. */
152 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
153 a = s->lsp_pow_m_table1[m];
154 b = s->lsp_pow_m_table2[m];
155 return s->lsp_pow_e_table[e] * (a + b * t.f);
158 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
163 wdel = M_PI / frame_len;
164 for(i=0;i<frame_len;i++)
165 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
167 /* tables for x^-0.25 computation */
170 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
173 /* NOTE: these two tables are needed to avoid two operations in
176 for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
177 m = (1 << LSP_POW_BITS) + i;
178 a = (float)m * (0.5 / (1 << LSP_POW_BITS));
180 s->lsp_pow_m_table1[i] = 2 * a - b;
181 s->lsp_pow_m_table2[i] = b - a;
190 printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
196 * NOTE: We use the same code as Vorbis here
197 * @todo optimize it further with SSE/3Dnow
199 static void wma_lsp_to_curve(WMACodecContext *s,
200 float *out, float *val_max_ptr,
204 float p, q, w, v, val_max;
210 w = s->lsp_cos_table[i];
211 for(j=1;j<NB_LSP_COEFS;j+=2){
223 *val_max_ptr = val_max;
227 * decode exponents coded with LSP coefficients (same idea as Vorbis)
229 static void decode_exp_lsp(WMACodecContext *s, int ch)
231 float lsp_coefs[NB_LSP_COEFS];
234 for(i = 0; i < NB_LSP_COEFS; i++) {
235 if (i == 0 || i >= 8)
236 val = get_bits(&s->gb, 3);
238 val = get_bits(&s->gb, 4);
239 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
242 wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
243 s->block_len, lsp_coefs);
247 * decode exponents coded with VLC codes
249 static int decode_exp_vlc(WMACodecContext *s, int ch)
251 int last_exp, n, code;
252 const uint16_t *ptr, *band_ptr;
253 float v, *q, max_scale, *q_end;
255 band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
257 q = s->exponents[ch];
258 q_end = q + s->block_len;
260 if (s->version == 1) {
261 last_exp = get_bits(&s->gb, 5) + 10;
262 /* XXX: use a table */
263 v = pow(10, last_exp * (1.0 / 16.0));
273 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
276 /* NOTE: this offset is the same as MPEG4 AAC ! */
277 last_exp += code - 60;
278 /* XXX: use a table */
279 v = pow(10, last_exp * (1.0 / 16.0));
287 s->max_exponent[ch] = max_scale;
293 * Apply MDCT window and add into output.
295 * We ensure that when the windows overlap their squared sum
296 * is always 1 (MDCT reconstruction rule).
298 static void wma_window(WMACodecContext *s, float *out)
300 float *in = s->output;
301 int block_len, bsize, n;
304 if (s->block_len_bits <= s->prev_block_len_bits) {
305 block_len = s->block_len;
306 bsize = s->frame_len_bits - s->block_len_bits;
308 s->dsp.vector_fmul_add_add(out, in, s->windows[bsize],
309 out, 0, block_len, 1);
312 block_len = 1 << s->prev_block_len_bits;
313 n = (s->block_len - block_len) / 2;
314 bsize = s->frame_len_bits - s->prev_block_len_bits;
316 s->dsp.vector_fmul_add_add(out+n, in+n, s->windows[bsize],
317 out+n, 0, block_len, 1);
319 memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
326 if (s->block_len_bits <= s->next_block_len_bits) {
327 block_len = s->block_len;
328 bsize = s->frame_len_bits - s->block_len_bits;
330 s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
333 block_len = 1 << s->next_block_len_bits;
334 n = (s->block_len - block_len) / 2;
335 bsize = s->frame_len_bits - s->next_block_len_bits;
337 memcpy(out, in, n*sizeof(float));
339 s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
341 memset(out+n+block_len, 0, n*sizeof(float));
347 * @return 0 if OK. 1 if last block of frame. return -1 if
348 * unrecorrable error.
350 static int wma_decode_block(WMACodecContext *s)
352 int n, v, a, ch, code, bsize;
353 int coef_nb_bits, total_gain;
354 int nb_coefs[MAX_CHANNELS];
358 tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
361 /* compute current block length */
362 if (s->use_variable_block_len) {
363 n = av_log2(s->nb_block_sizes - 1) + 1;
365 if (s->reset_block_lengths) {
366 s->reset_block_lengths = 0;
367 v = get_bits(&s->gb, n);
368 if (v >= s->nb_block_sizes)
370 s->prev_block_len_bits = s->frame_len_bits - v;
371 v = get_bits(&s->gb, n);
372 if (v >= s->nb_block_sizes)
374 s->block_len_bits = s->frame_len_bits - v;
376 /* update block lengths */
377 s->prev_block_len_bits = s->block_len_bits;
378 s->block_len_bits = s->next_block_len_bits;
380 v = get_bits(&s->gb, n);
381 if (v >= s->nb_block_sizes)
383 s->next_block_len_bits = s->frame_len_bits - v;
385 /* fixed block len */
386 s->next_block_len_bits = s->frame_len_bits;
387 s->prev_block_len_bits = s->frame_len_bits;
388 s->block_len_bits = s->frame_len_bits;
391 /* now check if the block length is coherent with the frame length */
392 s->block_len = 1 << s->block_len_bits;
393 if ((s->block_pos + s->block_len) > s->frame_len)
396 if (s->nb_channels == 2) {
397 s->ms_stereo = get_bits(&s->gb, 1);
400 for(ch = 0; ch < s->nb_channels; ch++) {
401 a = get_bits(&s->gb, 1);
402 s->channel_coded[ch] = a;
405 /* if no channel coded, no need to go further */
406 /* XXX: fix potential framing problems */
410 bsize = s->frame_len_bits - s->block_len_bits;
412 /* read total gain and extract corresponding number of bits for
413 coef escape coding */
416 a = get_bits(&s->gb, 7);
422 coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
424 /* compute number of coefficients */
425 n = s->coefs_end[bsize] - s->coefs_start;
426 for(ch = 0; ch < s->nb_channels; ch++)
430 if (s->use_noise_coding) {
432 for(ch = 0; ch < s->nb_channels; ch++) {
433 if (s->channel_coded[ch]) {
435 n = s->exponent_high_sizes[bsize];
437 a = get_bits(&s->gb, 1);
438 s->high_band_coded[ch][i] = a;
439 /* if noise coding, the coefficients are not transmitted */
441 nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
445 for(ch = 0; ch < s->nb_channels; ch++) {
446 if (s->channel_coded[ch]) {
449 n = s->exponent_high_sizes[bsize];
450 val = (int)0x80000000;
452 if (s->high_band_coded[ch][i]) {
453 if (val == (int)0x80000000) {
454 val = get_bits(&s->gb, 7) - 19;
456 code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
461 s->high_band_values[ch][i] = val;
468 /* exponents can be reused in short blocks. */
469 if ((s->block_len_bits == s->frame_len_bits) ||
470 get_bits(&s->gb, 1)) {
471 for(ch = 0; ch < s->nb_channels; ch++) {
472 if (s->channel_coded[ch]) {
473 if (s->use_exp_vlc) {
474 if (decode_exp_vlc(s, ch) < 0)
477 decode_exp_lsp(s, ch);
479 s->exponents_bsize[ch] = bsize;
484 /* parse spectral coefficients : just RLE encoding */
485 for(ch = 0; ch < s->nb_channels; ch++) {
486 if (s->channel_coded[ch]) {
488 int level, run, sign, tindex;
490 const uint16_t *level_table, *run_table;
492 /* special VLC tables are used for ms stereo because
493 there is potentially less energy there */
494 tindex = (ch == 1 && s->ms_stereo);
495 coef_vlc = &s->coef_vlc[tindex];
496 run_table = s->run_table[tindex];
497 level_table = s->level_table[tindex];
499 ptr = &s->coefs1[ch][0];
500 eptr = ptr + nb_coefs[ch];
501 memset(ptr, 0, s->block_len * sizeof(int16_t));
503 code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
509 } else if (code == 0) {
511 level = get_bits(&s->gb, coef_nb_bits);
512 /* NOTE: this is rather suboptimal. reading
513 block_len_bits would be better */
514 run = get_bits(&s->gb, s->frame_len_bits);
517 run = run_table[code];
518 level = level_table[code];
520 sign = get_bits(&s->gb, 1);
526 av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
530 /* NOTE: EOB can be omitted */
535 if (s->version == 1 && s->nb_channels >= 2) {
536 align_get_bits(&s->gb);
542 int n4 = s->block_len / 2;
543 mdct_norm = 1.0 / (float)n4;
544 if (s->version == 1) {
545 mdct_norm *= sqrt(n4);
549 /* finally compute the MDCT coefficients */
550 for(ch = 0; ch < s->nb_channels; ch++) {
551 if (s->channel_coded[ch]) {
553 float *coefs, *exponents, mult, mult1, noise;
554 int i, j, n, n1, last_high_band, esize;
555 float exp_power[HIGH_BAND_MAX_SIZE];
557 coefs1 = s->coefs1[ch];
558 exponents = s->exponents[ch];
559 esize = s->exponents_bsize[ch];
560 mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
562 coefs = s->coefs[ch];
563 if (s->use_noise_coding) {
565 /* very low freqs : noise */
566 for(i = 0;i < s->coefs_start; i++) {
567 *coefs++ = s->noise_table[s->noise_index] *
568 exponents[i<<bsize>>esize] * mult1;
569 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
572 n1 = s->exponent_high_sizes[bsize];
574 /* compute power of high bands */
575 exponents = s->exponents[ch] +
576 (s->high_band_start[bsize]<<bsize);
577 last_high_band = 0; /* avoid warning */
579 n = s->exponent_high_bands[s->frame_len_bits -
580 s->block_len_bits][j];
581 if (s->high_band_coded[ch][j]) {
584 for(i = 0;i < n; i++) {
585 v = exponents[i<<bsize>>esize];
588 exp_power[j] = e2 / n;
590 tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
592 exponents += n<<bsize;
595 /* main freqs and high freqs */
596 exponents = s->exponents[ch] + (s->coefs_start<<bsize);
599 n = s->high_band_start[bsize] -
602 n = s->exponent_high_bands[s->frame_len_bits -
603 s->block_len_bits][j];
605 if (j >= 0 && s->high_band_coded[ch][j]) {
606 /* use noise with specified power */
607 mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
608 /* XXX: use a table */
609 mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
610 mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
612 for(i = 0;i < n; i++) {
613 noise = s->noise_table[s->noise_index];
614 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
616 exponents[i<<bsize>>esize] * mult1;
618 exponents += n<<bsize;
620 /* coded values + small noise */
621 for(i = 0;i < n; i++) {
622 noise = s->noise_table[s->noise_index];
623 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
624 *coefs++ = ((*coefs1++) + noise) *
625 exponents[i<<bsize>>esize] * mult;
627 exponents += n<<bsize;
631 /* very high freqs : noise */
632 n = s->block_len - s->coefs_end[bsize];
633 mult1 = mult * exponents[((-1<<bsize))>>esize];
634 for(i = 0; i < n; i++) {
635 *coefs++ = s->noise_table[s->noise_index] * mult1;
636 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
639 /* XXX: optimize more */
640 for(i = 0;i < s->coefs_start; i++)
643 for(i = 0;i < n; i++) {
644 *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
646 n = s->block_len - s->coefs_end[bsize];
647 for(i = 0;i < n; i++)
654 for(ch = 0; ch < s->nb_channels; ch++) {
655 if (s->channel_coded[ch]) {
656 dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
657 dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
662 if (s->ms_stereo && s->channel_coded[1]) {
666 /* nominal case for ms stereo: we do it before mdct */
667 /* no need to optimize this case because it should almost
669 if (!s->channel_coded[0]) {
670 tprintf(s->avctx, "rare ms-stereo case happened\n");
671 memset(s->coefs[0], 0, sizeof(float) * s->block_len);
672 s->channel_coded[0] = 1;
675 for(i = 0; i < s->block_len; i++) {
678 s->coefs[0][i] = a + b;
679 s->coefs[1][i] = a - b;
683 for(ch = 0; ch < s->nb_channels; ch++) {
684 if (s->channel_coded[ch]) {
688 n4 = s->block_len / 2;
689 s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
690 s->output, s->coefs[ch], s->mdct_tmp);
692 /* multiply by the window and add in the frame */
693 index = (s->frame_len / 2) + s->block_pos - n4;
694 wma_window(s, &s->frame_out[ch][index]);
696 /* specific fast case for ms-stereo : add to second
697 channel if it is not coded */
698 if (s->ms_stereo && !s->channel_coded[1]) {
699 wma_window(s, &s->frame_out[1][index]);
704 /* update block number */
706 s->block_pos += s->block_len;
707 if (s->block_pos >= s->frame_len)
713 /* decode a frame of frame_len samples */
714 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
716 int ret, i, n, a, ch, incr;
721 tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
724 /* read each block */
728 ret = wma_decode_block(s);
735 /* convert frame to integer */
737 incr = s->nb_channels;
738 for(ch = 0; ch < s->nb_channels; ch++) {
740 iptr = s->frame_out[ch];
751 /* prepare for next block */
752 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
753 s->frame_len * sizeof(float));
757 dump_shorts(s, "samples", samples, n * s->nb_channels);
762 static int wma_decode_superframe(AVCodecContext *avctx,
763 void *data, int *data_size,
764 uint8_t *buf, int buf_size)
766 WMACodecContext *s = avctx->priv_data;
767 int nb_frames, bit_offset, i, pos, len;
771 tprintf(avctx, "***decode_superframe:\n");
774 s->last_superframe_len = 0;
780 init_get_bits(&s->gb, buf, buf_size*8);
782 if (s->use_bit_reservoir) {
783 /* read super frame header */
784 get_bits(&s->gb, 4); /* super frame index */
785 nb_frames = get_bits(&s->gb, 4) - 1;
787 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
789 if (s->last_superframe_len > 0) {
790 // printf("skip=%d\n", s->last_bitoffset);
791 /* add bit_offset bits to last frame */
792 if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
793 MAX_CODED_SUPERFRAME_SIZE)
795 q = s->last_superframe + s->last_superframe_len;
798 *q++ = (get_bits)(&s->gb, 8);
802 *q++ = (get_bits)(&s->gb, len) << (8 - len);
805 /* XXX: bit_offset bits into last frame */
806 init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
807 /* skip unused bits */
808 if (s->last_bitoffset > 0)
809 skip_bits(&s->gb, s->last_bitoffset);
810 /* this frame is stored in the last superframe and in the
812 if (wma_decode_frame(s, samples) < 0)
814 samples += s->nb_channels * s->frame_len;
817 /* read each frame starting from bit_offset */
818 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
819 init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
822 skip_bits(&s->gb, len);
824 s->reset_block_lengths = 1;
825 for(i=0;i<nb_frames;i++) {
826 if (wma_decode_frame(s, samples) < 0)
828 samples += s->nb_channels * s->frame_len;
831 /* we copy the end of the frame in the last frame buffer */
832 pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
833 s->last_bitoffset = pos & 7;
835 len = buf_size - pos;
836 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
839 s->last_superframe_len = len;
840 memcpy(s->last_superframe, buf + pos, len);
842 /* single frame decode */
843 if (wma_decode_frame(s, samples) < 0)
845 samples += s->nb_channels * s->frame_len;
848 //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);
850 *data_size = (int8_t *)samples - (int8_t *)data;
851 return s->block_align;
853 /* when error, we reset the bit reservoir */
854 s->last_superframe_len = 0;
858 AVCodec wmav1_decoder =
863 sizeof(WMACodecContext),
867 wma_decode_superframe,
870 AVCodec wmav2_decoder =
875 sizeof(WMACodecContext),
879 wma_decode_superframe,