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(const char *name, const short *tab, int n)
55 tprintf("%s[%d]:\n", name, n);
59 tprintf(" %5d.0", tab[i]);
65 static void dump_floats(const char *name, int prec, const float *tab, int n)
69 tprintf("%s[%d]:\n", name, n);
73 tprintf(" %8.*f", prec, tab[i]);
82 static int wma_decode_init(AVCodecContext * avctx)
84 WMADecodeContext *s = avctx->priv_data;
85 int i, flags1, flags2;
88 /* extract flag infos */
91 extradata = avctx->extradata;
92 if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
93 flags1 = extradata[0] | (extradata[1] << 8);
94 flags2 = extradata[2] | (extradata[3] << 8);
95 } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
96 flags1 = extradata[0] | (extradata[1] << 8) |
97 (extradata[2] << 16) | (extradata[3] << 24);
98 flags2 = extradata[4] | (extradata[5] << 8);
100 // for(i=0; i<avctx->extradata_size; i++)
101 // av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
103 s->use_exp_vlc = flags2 & 0x0001;
104 s->use_bit_reservoir = flags2 & 0x0002;
105 s->use_variable_block_len = flags2 & 0x0004;
107 ff_wma_init(avctx, flags2);
110 for(i = 0; i < s->nb_block_sizes; i++)
111 ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
113 if (s->use_noise_coding) {
114 init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
115 ff_wma_hgain_huffbits, 1, 1,
116 ff_wma_hgain_huffcodes, 2, 2, 0);
119 if (s->use_exp_vlc) {
120 init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_wma_scale_huffbits), //FIXME move out of context
121 ff_wma_scale_huffbits, 1, 1,
122 ff_wma_scale_huffcodes, 4, 4, 0);
124 wma_lsp_to_curve_init(s, s->frame_len);
131 * interpolate values for a bigger or smaller block. The block must
132 * have multiple sizes
134 static void interpolate_array(float *scale, int old_size, int new_size)
139 if (new_size > old_size) {
140 jincr = new_size / old_size;
142 for(i = old_size - 1; i >=0; i--) {
149 } else if (new_size < old_size) {
151 jincr = old_size / new_size;
152 for(i = 0; i < new_size; i++) {
160 * compute x^-0.25 with an exponent and mantissa table. We use linear
161 * interpolation to reduce the mantissa table size at a small speed
162 * expense (linear interpolation approximately doubles the number of
163 * bits of precision).
165 static inline float pow_m1_4(WMADecodeContext *s, float x)
176 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
177 /* build interpolation scale: 1 <= t < 2. */
178 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
179 a = s->lsp_pow_m_table1[m];
180 b = s->lsp_pow_m_table2[m];
181 return s->lsp_pow_e_table[e] * (a + b * t.f);
184 static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
189 wdel = M_PI / frame_len;
190 for(i=0;i<frame_len;i++)
191 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
193 /* tables for x^-0.25 computation */
196 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
199 /* NOTE: these two tables are needed to avoid two operations in
202 for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
203 m = (1 << LSP_POW_BITS) + i;
204 a = (float)m * (0.5 / (1 << LSP_POW_BITS));
206 s->lsp_pow_m_table1[i] = 2 * a - b;
207 s->lsp_pow_m_table2[i] = b - a;
216 printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
222 * NOTE: We use the same code as Vorbis here
223 * @todo optimize it further with SSE/3Dnow
225 static void wma_lsp_to_curve(WMADecodeContext *s,
226 float *out, float *val_max_ptr,
230 float p, q, w, v, val_max;
236 w = s->lsp_cos_table[i];
237 for(j=1;j<NB_LSP_COEFS;j+=2){
249 *val_max_ptr = val_max;
253 * decode exponents coded with LSP coefficients (same idea as Vorbis)
255 static void decode_exp_lsp(WMADecodeContext *s, int ch)
257 float lsp_coefs[NB_LSP_COEFS];
260 for(i = 0; i < NB_LSP_COEFS; i++) {
261 if (i == 0 || i >= 8)
262 val = get_bits(&s->gb, 3);
264 val = get_bits(&s->gb, 4);
265 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
268 wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
269 s->block_len, lsp_coefs);
273 * decode exponents coded with VLC codes
275 static int decode_exp_vlc(WMADecodeContext *s, int ch)
277 int last_exp, n, code;
278 const uint16_t *ptr, *band_ptr;
279 float v, *q, max_scale, *q_end;
281 band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
283 q = s->exponents[ch];
284 q_end = q + s->block_len;
286 if (s->version == 1) {
287 last_exp = get_bits(&s->gb, 5) + 10;
288 /* XXX: use a table */
289 v = pow(10, last_exp * (1.0 / 16.0));
299 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
302 /* NOTE: this offset is the same as MPEG4 AAC ! */
303 last_exp += code - 60;
304 /* XXX: use a table */
305 v = pow(10, last_exp * (1.0 / 16.0));
313 s->max_exponent[ch] = max_scale;
318 * @return 0 if OK. 1 if last block of frame. return -1 if
319 * unrecorrable error.
321 static int wma_decode_block(WMADecodeContext *s)
323 int n, v, a, ch, code, bsize;
324 int coef_nb_bits, total_gain, parse_exponents;
325 int nb_coefs[MAX_CHANNELS];
329 tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
332 /* compute current block length */
333 if (s->use_variable_block_len) {
334 n = av_log2(s->nb_block_sizes - 1) + 1;
336 if (s->reset_block_lengths) {
337 s->reset_block_lengths = 0;
338 v = get_bits(&s->gb, n);
339 if (v >= s->nb_block_sizes)
341 s->prev_block_len_bits = s->frame_len_bits - v;
342 v = get_bits(&s->gb, n);
343 if (v >= s->nb_block_sizes)
345 s->block_len_bits = s->frame_len_bits - v;
347 /* update block lengths */
348 s->prev_block_len_bits = s->block_len_bits;
349 s->block_len_bits = s->next_block_len_bits;
351 v = get_bits(&s->gb, n);
352 if (v >= s->nb_block_sizes)
354 s->next_block_len_bits = s->frame_len_bits - v;
356 /* fixed block len */
357 s->next_block_len_bits = s->frame_len_bits;
358 s->prev_block_len_bits = s->frame_len_bits;
359 s->block_len_bits = s->frame_len_bits;
362 /* now check if the block length is coherent with the frame length */
363 s->block_len = 1 << s->block_len_bits;
364 if ((s->block_pos + s->block_len) > s->frame_len)
367 if (s->nb_channels == 2) {
368 s->ms_stereo = get_bits(&s->gb, 1);
371 for(ch = 0; ch < s->nb_channels; ch++) {
372 a = get_bits(&s->gb, 1);
373 s->channel_coded[ch] = a;
376 /* if no channel coded, no need to go further */
377 /* XXX: fix potential framing problems */
381 bsize = s->frame_len_bits - s->block_len_bits;
383 /* read total gain and extract corresponding number of bits for
384 coef escape coding */
387 a = get_bits(&s->gb, 7);
393 coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
395 /* compute number of coefficients */
396 n = s->coefs_end[bsize] - s->coefs_start;
397 for(ch = 0; ch < s->nb_channels; ch++)
401 if (s->use_noise_coding) {
403 for(ch = 0; ch < s->nb_channels; ch++) {
404 if (s->channel_coded[ch]) {
406 n = s->exponent_high_sizes[bsize];
408 a = get_bits(&s->gb, 1);
409 s->high_band_coded[ch][i] = a;
410 /* if noise coding, the coefficients are not transmitted */
412 nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
416 for(ch = 0; ch < s->nb_channels; ch++) {
417 if (s->channel_coded[ch]) {
420 n = s->exponent_high_sizes[bsize];
421 val = (int)0x80000000;
423 if (s->high_band_coded[ch][i]) {
424 if (val == (int)0x80000000) {
425 val = get_bits(&s->gb, 7) - 19;
427 code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
432 s->high_band_values[ch][i] = val;
439 /* exposant can be interpolated in short blocks. */
441 if (s->block_len_bits != s->frame_len_bits) {
442 parse_exponents = get_bits(&s->gb, 1);
445 if (parse_exponents) {
446 for(ch = 0; ch < s->nb_channels; ch++) {
447 if (s->channel_coded[ch]) {
448 if (s->use_exp_vlc) {
449 if (decode_exp_vlc(s, ch) < 0)
452 decode_exp_lsp(s, ch);
457 for(ch = 0; ch < s->nb_channels; ch++) {
458 if (s->channel_coded[ch]) {
459 interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
465 /* parse spectral coefficients : just RLE encoding */
466 for(ch = 0; ch < s->nb_channels; ch++) {
467 if (s->channel_coded[ch]) {
469 int level, run, sign, tindex;
471 const uint16_t *level_table, *run_table;
473 /* special VLC tables are used for ms stereo because
474 there is potentially less energy there */
475 tindex = (ch == 1 && s->ms_stereo);
476 coef_vlc = &s->coef_vlc[tindex];
477 run_table = s->run_table[tindex];
478 level_table = s->level_table[tindex];
480 ptr = &s->coefs1[ch][0];
481 eptr = ptr + nb_coefs[ch];
482 memset(ptr, 0, s->block_len * sizeof(int16_t));
484 code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
490 } else if (code == 0) {
492 level = get_bits(&s->gb, coef_nb_bits);
493 /* NOTE: this is rather suboptimal. reading
494 block_len_bits would be better */
495 run = get_bits(&s->gb, s->frame_len_bits);
498 run = run_table[code];
499 level = level_table[code];
501 sign = get_bits(&s->gb, 1);
507 av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
511 /* NOTE: EOB can be omitted */
516 if (s->version == 1 && s->nb_channels >= 2) {
517 align_get_bits(&s->gb);
523 int n4 = s->block_len / 2;
524 mdct_norm = 1.0 / (float)n4;
525 if (s->version == 1) {
526 mdct_norm *= sqrt(n4);
530 /* finally compute the MDCT coefficients */
531 for(ch = 0; ch < s->nb_channels; ch++) {
532 if (s->channel_coded[ch]) {
534 float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
535 int i, j, n, n1, last_high_band;
536 float exp_power[HIGH_BAND_MAX_SIZE];
538 coefs1 = s->coefs1[ch];
539 exponents = s->exponents[ch];
540 mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
542 coefs = s->coefs[ch];
543 if (s->use_noise_coding) {
545 /* very low freqs : noise */
546 for(i = 0;i < s->coefs_start; i++) {
547 *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
548 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
551 n1 = s->exponent_high_sizes[bsize];
553 /* compute power of high bands */
554 exp_ptr = exponents +
555 s->high_band_start[bsize] -
557 last_high_band = 0; /* avoid warning */
559 n = s->exponent_high_bands[s->frame_len_bits -
560 s->block_len_bits][j];
561 if (s->high_band_coded[ch][j]) {
564 for(i = 0;i < n; i++) {
568 exp_power[j] = e2 / n;
570 tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
575 /* main freqs and high freqs */
578 n = s->high_band_start[bsize] -
581 n = s->exponent_high_bands[s->frame_len_bits -
582 s->block_len_bits][j];
584 if (j >= 0 && s->high_band_coded[ch][j]) {
585 /* use noise with specified power */
586 mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
587 /* XXX: use a table */
588 mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
589 mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
591 for(i = 0;i < n; i++) {
592 noise = s->noise_table[s->noise_index];
593 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
594 *coefs++ = (*exponents++) * noise * mult1;
597 /* coded values + small noise */
598 for(i = 0;i < n; i++) {
599 noise = s->noise_table[s->noise_index];
600 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
601 *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
606 /* very high freqs : noise */
607 n = s->block_len - s->coefs_end[bsize];
608 mult1 = mult * exponents[-1];
609 for(i = 0; i < n; i++) {
610 *coefs++ = s->noise_table[s->noise_index] * mult1;
611 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
614 /* XXX: optimize more */
615 for(i = 0;i < s->coefs_start; i++)
618 for(i = 0;i < n; i++) {
619 *coefs++ = coefs1[i] * exponents[i] * mult;
621 n = s->block_len - s->coefs_end[bsize];
622 for(i = 0;i < n; i++)
629 for(ch = 0; ch < s->nb_channels; ch++) {
630 if (s->channel_coded[ch]) {
631 dump_floats("exponents", 3, s->exponents[ch], s->block_len);
632 dump_floats("coefs", 1, s->coefs[ch], s->block_len);
637 if (s->ms_stereo && s->channel_coded[1]) {
641 /* nominal case for ms stereo: we do it before mdct */
642 /* no need to optimize this case because it should almost
644 if (!s->channel_coded[0]) {
645 tprintf("rare ms-stereo case happened\n");
646 memset(s->coefs[0], 0, sizeof(float) * s->block_len);
647 s->channel_coded[0] = 1;
650 for(i = 0; i < s->block_len; i++) {
653 s->coefs[0][i] = a + b;
654 s->coefs[1][i] = a - b;
658 /* build the window : we ensure that when the windows overlap
659 their squared sum is always 1 (MDCT reconstruction rule) */
660 /* XXX: merge with output */
662 int i, next_block_len, block_len, prev_block_len, n;
665 block_len = s->block_len;
666 prev_block_len = 1 << s->prev_block_len_bits;
667 next_block_len = 1 << s->next_block_len_bits;
670 wptr = s->window + block_len;
671 if (block_len <= next_block_len) {
672 for(i=0;i<block_len;i++)
673 *wptr++ = s->windows[bsize][i];
676 n = (block_len / 2) - (next_block_len / 2);
679 for(i=0;i<next_block_len;i++)
680 *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
686 wptr = s->window + block_len;
687 if (block_len <= prev_block_len) {
688 for(i=0;i<block_len;i++)
689 *--wptr = s->windows[bsize][i];
692 n = (block_len / 2) - (prev_block_len / 2);
695 for(i=0;i<prev_block_len;i++)
696 *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
703 for(ch = 0; ch < s->nb_channels; ch++) {
704 if (s->channel_coded[ch]) {
709 n4 = s->block_len / 2;
710 s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
711 s->output, s->coefs[ch], s->mdct_tmp);
713 /* XXX: optimize all that by build the window and
714 multipying/adding at the same time */
716 /* multiply by the window and add in the frame */
717 index = (s->frame_len / 2) + s->block_pos - n4;
718 ptr = &s->frame_out[ch][index];
719 s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
721 /* specific fast case for ms-stereo : add to second
722 channel if it is not coded */
723 if (s->ms_stereo && !s->channel_coded[1]) {
724 ptr = &s->frame_out[1][index];
725 s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
730 /* update block number */
732 s->block_pos += s->block_len;
733 if (s->block_pos >= s->frame_len)
739 /* decode a frame of frame_len samples */
740 static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
742 int ret, i, n, a, ch, incr;
747 tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
750 /* read each block */
754 ret = wma_decode_block(s);
761 /* convert frame to integer */
763 incr = s->nb_channels;
764 for(ch = 0; ch < s->nb_channels; ch++) {
766 iptr = s->frame_out[ch];
777 /* prepare for next block */
778 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
779 s->frame_len * sizeof(float));
780 /* XXX: suppress this */
781 memset(&s->frame_out[ch][s->frame_len], 0,
782 s->frame_len * sizeof(float));
786 dump_shorts("samples", samples, n * s->nb_channels);
791 static int wma_decode_superframe(AVCodecContext *avctx,
792 void *data, int *data_size,
793 uint8_t *buf, int buf_size)
795 WMADecodeContext *s = avctx->priv_data;
796 int nb_frames, bit_offset, i, pos, len;
800 tprintf("***decode_superframe:\n");
803 s->last_superframe_len = 0;
809 init_get_bits(&s->gb, buf, buf_size*8);
811 if (s->use_bit_reservoir) {
812 /* read super frame header */
813 get_bits(&s->gb, 4); /* super frame index */
814 nb_frames = get_bits(&s->gb, 4) - 1;
816 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
818 if (s->last_superframe_len > 0) {
819 // printf("skip=%d\n", s->last_bitoffset);
820 /* add bit_offset bits to last frame */
821 if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
822 MAX_CODED_SUPERFRAME_SIZE)
824 q = s->last_superframe + s->last_superframe_len;
827 *q++ = (get_bits)(&s->gb, 8);
831 *q++ = (get_bits)(&s->gb, len) << (8 - len);
834 /* XXX: bit_offset bits into last frame */
835 init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
836 /* skip unused bits */
837 if (s->last_bitoffset > 0)
838 skip_bits(&s->gb, s->last_bitoffset);
839 /* this frame is stored in the last superframe and in the
841 if (wma_decode_frame(s, samples) < 0)
843 samples += s->nb_channels * s->frame_len;
846 /* read each frame starting from bit_offset */
847 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
848 init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
851 skip_bits(&s->gb, len);
853 s->reset_block_lengths = 1;
854 for(i=0;i<nb_frames;i++) {
855 if (wma_decode_frame(s, samples) < 0)
857 samples += s->nb_channels * s->frame_len;
860 /* we copy the end of the frame in the last frame buffer */
861 pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
862 s->last_bitoffset = pos & 7;
864 len = buf_size - pos;
865 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
868 s->last_superframe_len = len;
869 memcpy(s->last_superframe, buf + pos, len);
871 /* single frame decode */
872 if (wma_decode_frame(s, samples) < 0)
874 samples += s->nb_channels * s->frame_len;
877 //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);
879 *data_size = (int8_t *)samples - (int8_t *)data;
880 return s->block_align;
882 /* when error, we reset the bit reservoir */
883 s->last_superframe_len = 0;
887 AVCodec wmav1_decoder =
892 sizeof(WMADecodeContext),
896 wma_decode_superframe,
899 AVCodec wmav2_decoder =
904 sizeof(WMADecodeContext),
908 wma_decode_superframe,