/* * WMA compatible decoder * Copyright (c) 2002 The FFmpeg Project. * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file wmadec.c * WMA compatible decoder. * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2. * WMA v1 is identified by audio format 0x160 in Microsoft media files * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161. * * To use this decoder, a calling application must supply the extra data * bytes provided with the WMA data. These are the extra, codec-specific * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes * to the decoder using the extradata[_size] fields in AVCodecContext. There * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data. */ #include "avcodec.h" #include "bitstream.h" #include "dsputil.h" /* size of blocks */ #define BLOCK_MIN_BITS 7 #define BLOCK_MAX_BITS 11 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS) #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1) /* XXX: find exact max size */ #define HIGH_BAND_MAX_SIZE 16 #define NB_LSP_COEFS 10 /* XXX: is it a suitable value ? */ #define MAX_CODED_SUPERFRAME_SIZE 16384 #define MAX_CHANNELS 2 #define NOISE_TAB_SIZE 8192 #define LSP_POW_BITS 7 #define VLCBITS 9 #define VLCMAX ((22+VLCBITS-1)/VLCBITS) #define EXPVLCBITS 8 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS) #define HGAINVLCBITS 9 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS) typedef struct WMADecodeContext { GetBitContext gb; int sample_rate; int nb_channels; int bit_rate; int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */ int block_align; int use_bit_reservoir; int use_variable_block_len; int use_exp_vlc; /* exponent coding: 0 = lsp, 1 = vlc + delta */ int use_noise_coding; /* true if perceptual noise is added */ int byte_offset_bits; VLC exp_vlc; int exponent_sizes[BLOCK_NB_SIZES]; uint16_t exponent_bands[BLOCK_NB_SIZES][25]; int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */ int coefs_start; /* first coded coef */ int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */ int exponent_high_sizes[BLOCK_NB_SIZES]; int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE]; VLC hgain_vlc; /* coded values in high bands */ int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE]; int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE]; /* there are two possible tables for spectral coefficients */ VLC coef_vlc[2]; uint16_t *run_table[2]; uint16_t *level_table[2]; /* frame info */ int frame_len; /* frame length in samples */ int frame_len_bits; /* frame_len = 1 << frame_len_bits */ int nb_block_sizes; /* number of block sizes */ /* block info */ int reset_block_lengths; int block_len_bits; /* log2 of current block length */ int next_block_len_bits; /* log2 of next block length */ int prev_block_len_bits; /* log2 of prev block length */ int block_len; /* block length in samples */ int block_num; /* block number in current frame */ int block_pos; /* current position in frame */ uint8_t ms_stereo; /* true if mid/side stereo mode */ uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */ DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]); float max_exponent[MAX_CHANNELS]; int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE]; DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]); MDCTContext mdct_ctx[BLOCK_NB_SIZES]; float *windows[BLOCK_NB_SIZES]; DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); /* temporary storage for imdct */ /* output buffer for one frame and the last for IMDCT windowing */ DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]); /* last frame info */ uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */ int last_bitoffset; int last_superframe_len; float noise_table[NOISE_TAB_SIZE]; int noise_index; float noise_mult; /* XXX: suppress that and integrate it in the noise array */ /* lsp_to_curve tables */ float lsp_cos_table[BLOCK_MAX_SIZE]; float lsp_pow_e_table[256]; float lsp_pow_m_table1[(1 << LSP_POW_BITS)]; float lsp_pow_m_table2[(1 << LSP_POW_BITS)]; DSPContext dsp; #ifdef TRACE int frame_count; #endif } WMADecodeContext; typedef struct CoefVLCTable { int n; /* total number of codes */ const uint32_t *huffcodes; /* VLC bit values */ const uint8_t *huffbits; /* VLC bit size */ const uint16_t *levels; /* table to build run/level tables */ } CoefVLCTable; static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len); #include "wmadata.h" #ifdef TRACE static void dump_shorts(const char *name, const short *tab, int n) { int i; tprintf("%s[%d]:\n", name, n); for(i=0;i<n;i++) { if ((i & 7) == 0) tprintf("%4d: ", i); tprintf(" %5d.0", tab[i]); if ((i & 7) == 7) tprintf("\n"); } } static void dump_floats(const char *name, int prec, const float *tab, int n) { int i; tprintf("%s[%d]:\n", name, n); for(i=0;i<n;i++) { if ((i & 7) == 0) tprintf("%4d: ", i); tprintf(" %8.*f", prec, tab[i]); if ((i & 7) == 7) tprintf("\n"); } if ((i & 7) != 0) tprintf("\n"); } #endif /* XXX: use same run/length optimization as mpeg decoders */ static void init_coef_vlc(VLC *vlc, uint16_t **prun_table, uint16_t **plevel_table, const CoefVLCTable *vlc_table) { int n = vlc_table->n; const uint8_t *table_bits = vlc_table->huffbits; const uint32_t *table_codes = vlc_table->huffcodes; const uint16_t *levels_table = vlc_table->levels; uint16_t *run_table, *level_table; const uint16_t *p; int i, l, j, level; init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0); run_table = av_malloc(n * sizeof(uint16_t)); level_table = av_malloc(n * sizeof(uint16_t)); p = levels_table; i = 2; level = 1; while (i < n) { l = *p++; for(j=0;j<l;j++) { run_table[i] = j; level_table[i] = level; i++; } level++; } *prun_table = run_table; *plevel_table = level_table; } static int wma_decode_init(AVCodecContext * avctx) { WMADecodeContext *s = avctx->priv_data; int i, flags1, flags2; float *window; uint8_t *extradata; float bps1, high_freq; volatile float bps; int sample_rate1; int coef_vlc_table; s->sample_rate = avctx->sample_rate; s->nb_channels = avctx->channels; s->bit_rate = avctx->bit_rate; s->block_align = avctx->block_align; dsputil_init(&s->dsp, avctx); if (avctx->codec->id == CODEC_ID_WMAV1) { s->version = 1; } else { s->version = 2; } /* extract flag infos */ flags1 = 0; flags2 = 0; extradata = avctx->extradata; if (s->version == 1 && avctx->extradata_size >= 4) { flags1 = extradata[0] | (extradata[1] << 8); flags2 = extradata[2] | (extradata[3] << 8); } else if (s->version == 2 && avctx->extradata_size >= 6) { flags1 = extradata[0] | (extradata[1] << 8) | (extradata[2] << 16) | (extradata[3] << 24); flags2 = extradata[4] | (extradata[5] << 8); } s->use_exp_vlc = flags2 & 0x0001; s->use_bit_reservoir = flags2 & 0x0002; s->use_variable_block_len = flags2 & 0x0004; /* compute MDCT block size */ if (s->sample_rate <= 16000) { s->frame_len_bits = 9; } else if (s->sample_rate <= 22050 || (s->sample_rate <= 32000 && s->version == 1)) { s->frame_len_bits = 10; } else { s->frame_len_bits = 11; } s->frame_len = 1 << s->frame_len_bits; if (s->use_variable_block_len) { int nb_max, nb; nb = ((flags2 >> 3) & 3) + 1; if ((s->bit_rate / s->nb_channels) >= 32000) nb += 2; nb_max = s->frame_len_bits - BLOCK_MIN_BITS; if (nb > nb_max) nb = nb_max; s->nb_block_sizes = nb + 1; } else { s->nb_block_sizes = 1; } /* init rate dependant parameters */ s->use_noise_coding = 1; high_freq = s->sample_rate * 0.5; /* if version 2, then the rates are normalized */ sample_rate1 = s->sample_rate; if (s->version == 2) { if (sample_rate1 >= 44100) sample_rate1 = 44100; else if (sample_rate1 >= 22050) sample_rate1 = 22050; else if (sample_rate1 >= 16000) sample_rate1 = 16000; else if (sample_rate1 >= 11025) sample_rate1 = 11025; else if (sample_rate1 >= 8000) sample_rate1 = 8000; } bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate); s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2; /* compute high frequency value and choose if noise coding should be activated */ bps1 = bps; if (s->nb_channels == 2) bps1 = bps * 1.6; if (sample_rate1 == 44100) { if (bps1 >= 0.61) s->use_noise_coding = 0; else high_freq = high_freq * 0.4; } else if (sample_rate1 == 22050) { if (bps1 >= 1.16) s->use_noise_coding = 0; else if (bps1 >= 0.72) high_freq = high_freq * 0.7; else high_freq = high_freq * 0.6; } else if (sample_rate1 == 16000) { if (bps > 0.5) high_freq = high_freq * 0.5; else high_freq = high_freq * 0.3; } else if (sample_rate1 == 11025) { high_freq = high_freq * 0.7; } else if (sample_rate1 == 8000) { if (bps <= 0.625) { high_freq = high_freq * 0.5; } else if (bps > 0.75) { s->use_noise_coding = 0; } else { high_freq = high_freq * 0.65; } } else { if (bps >= 0.8) { high_freq = high_freq * 0.75; } else if (bps >= 0.6) { high_freq = high_freq * 0.6; } else { high_freq = high_freq * 0.5; } } dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2); dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n", s->version, s->nb_channels, s->sample_rate, s->bit_rate, s->block_align); dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n", bps, bps1, high_freq, s->byte_offset_bits); dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n", s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes); /* compute the scale factor band sizes for each MDCT block size */ { int a, b, pos, lpos, k, block_len, i, j, n; const uint8_t *table; if (s->version == 1) { s->coefs_start = 3; } else { s->coefs_start = 0; } for(k = 0; k < s->nb_block_sizes; k++) { block_len = s->frame_len >> k; if (s->version == 1) { lpos = 0; for(i=0;i<25;i++) { a = wma_critical_freqs[i]; b = s->sample_rate; pos = ((block_len * 2 * a) + (b >> 1)) / b; if (pos > block_len) pos = block_len; s->exponent_bands[0][i] = pos - lpos; if (pos >= block_len) { i++; break; } lpos = pos; } s->exponent_sizes[0] = i; } else { /* hardcoded tables */ table = NULL; a = s->frame_len_bits - BLOCK_MIN_BITS - k; if (a < 3) { if (s->sample_rate >= 44100) table = exponent_band_44100[a]; else if (s->sample_rate >= 32000) table = exponent_band_32000[a]; else if (s->sample_rate >= 22050) table = exponent_band_22050[a]; } if (table) { n = *table++; for(i=0;i<n;i++) s->exponent_bands[k][i] = table[i]; s->exponent_sizes[k] = n; } else { j = 0; lpos = 0; for(i=0;i<25;i++) { a = wma_critical_freqs[i]; b = s->sample_rate; pos = ((block_len * 2 * a) + (b << 1)) / (4 * b); pos <<= 2; if (pos > block_len) pos = block_len; if (pos > lpos) s->exponent_bands[k][j++] = pos - lpos; if (pos >= block_len) break; lpos = pos; } s->exponent_sizes[k] = j; } } /* max number of coefs */ s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k; /* high freq computation */ s->high_band_start[k] = (int)((block_len * 2 * high_freq) / s->sample_rate + 0.5); n = s->exponent_sizes[k]; j = 0; pos = 0; for(i=0;i<n;i++) { int start, end; start = pos; pos += s->exponent_bands[k][i]; end = pos; if (start < s->high_band_start[k]) start = s->high_band_start[k]; if (end > s->coefs_end[k]) end = s->coefs_end[k]; if (end > start) s->exponent_high_bands[k][j++] = end - start; } s->exponent_high_sizes[k] = j; #if 0 tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ", s->frame_len >> k, s->coefs_end[k], s->high_band_start[k], s->exponent_high_sizes[k]); for(j=0;j<s->exponent_high_sizes[k];j++) tprintf(" %d", s->exponent_high_bands[k][j]); tprintf("\n"); #endif } } #ifdef TRACE { int i, j; for(i = 0; i < s->nb_block_sizes; i++) { tprintf("%5d: n=%2d:", s->frame_len >> i, s->exponent_sizes[i]); for(j=0;j<s->exponent_sizes[i];j++) tprintf(" %d", s->exponent_bands[i][j]); tprintf("\n"); } } #endif /* init MDCT */ for(i = 0; i < s->nb_block_sizes; i++) ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1); /* init MDCT windows : simple sinus window */ for(i = 0; i < s->nb_block_sizes; i++) { int n, j; float alpha; n = 1 << (s->frame_len_bits - i); window = av_malloc(sizeof(float) * n); alpha = M_PI / (2.0 * n); for(j=0;j<n;j++) { window[n - j - 1] = sin((j + 0.5) * alpha); } s->windows[i] = window; } s->reset_block_lengths = 1; if (s->use_noise_coding) { /* init the noise generator */ if (s->use_exp_vlc) s->noise_mult = 0.02; else s->noise_mult = 0.04; #ifdef TRACE for(i=0;i<NOISE_TAB_SIZE;i++) s->noise_table[i] = 1.0 * s->noise_mult; #else { unsigned int seed; float norm; seed = 1; norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult; for(i=0;i<NOISE_TAB_SIZE;i++) { seed = seed * 314159 + 1; s->noise_table[i] = (float)((int)seed) * norm; } } #endif init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(hgain_huffbits), hgain_huffbits, 1, 1, hgain_huffcodes, 2, 2, 0); } if (s->use_exp_vlc) { init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(scale_huffbits), scale_huffbits, 1, 1, scale_huffcodes, 4, 4, 0); } else { wma_lsp_to_curve_init(s, s->frame_len); } /* choose the VLC tables for the coefficients */ coef_vlc_table = 2; if (s->sample_rate >= 32000) { if (bps1 < 0.72) coef_vlc_table = 0; else if (bps1 < 1.16) coef_vlc_table = 1; } init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &coef_vlcs[coef_vlc_table * 2]); init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &coef_vlcs[coef_vlc_table * 2 + 1]); return 0; } /* interpolate values for a bigger or smaller block. The block must have multiple sizes */ static void interpolate_array(float *scale, int old_size, int new_size) { int i, j, jincr, k; float v; if (new_size > old_size) { jincr = new_size / old_size; j = new_size; for(i = old_size - 1; i >=0; i--) { v = scale[i]; k = jincr; do { scale[--j] = v; } while (--k); } } else if (new_size < old_size) { j = 0; jincr = old_size / new_size; for(i = 0; i < new_size; i++) { scale[i] = scale[j]; j += jincr; } } } /* compute x^-0.25 with an exponent and mantissa table. We use linear interpolation to reduce the mantissa table size at a small speed expense (linear interpolation approximately doubles the number of bits of precision). */ static inline float pow_m1_4(WMADecodeContext *s, float x) { union { float f; unsigned int v; } u, t; unsigned int e, m; float a, b; u.f = x; e = u.v >> 23; m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1); /* build interpolation scale: 1 <= t < 2. */ t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23); a = s->lsp_pow_m_table1[m]; b = s->lsp_pow_m_table2[m]; return s->lsp_pow_e_table[e] * (a + b * t.f); } static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len) { float wdel, a, b; int i, e, m; wdel = M_PI / frame_len; for(i=0;i<frame_len;i++) s->lsp_cos_table[i] = 2.0f * cos(wdel * i); /* tables for x^-0.25 computation */ for(i=0;i<256;i++) { e = i - 126; s->lsp_pow_e_table[i] = pow(2.0, e * -0.25); } /* NOTE: these two tables are needed to avoid two operations in pow_m1_4 */ b = 1.0; for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) { m = (1 << LSP_POW_BITS) + i; a = (float)m * (0.5 / (1 << LSP_POW_BITS)); a = pow(a, -0.25); s->lsp_pow_m_table1[i] = 2 * a - b; s->lsp_pow_m_table2[i] = b - a; b = a; } #if 0 for(i=1;i<20;i++) { float v, r1, r2; v = 5.0 / i; r1 = pow_m1_4(s, v); r2 = pow(v,-0.25); printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1); } #endif } /* NOTE: We use the same code as Vorbis here */ /* XXX: optimize it further with SSE/3Dnow */ static void wma_lsp_to_curve(WMADecodeContext *s, float *out, float *val_max_ptr, int n, float *lsp) { int i, j; float p, q, w, v, val_max; val_max = 0; for(i=0;i<n;i++) { p = 0.5f; q = 0.5f; w = s->lsp_cos_table[i]; for(j=1;j<NB_LSP_COEFS;j+=2){ q *= w - lsp[j - 1]; p *= w - lsp[j]; } p *= p * (2.0f - w); q *= q * (2.0f + w); v = p + q; v = pow_m1_4(s, v); if (v > val_max) val_max = v; out[i] = v; } *val_max_ptr = val_max; } /* decode exponents coded with LSP coefficients (same idea as Vorbis) */ static void decode_exp_lsp(WMADecodeContext *s, int ch) { float lsp_coefs[NB_LSP_COEFS]; int val, i; for(i = 0; i < NB_LSP_COEFS; i++) { if (i == 0 || i >= 8) val = get_bits(&s->gb, 3); else val = get_bits(&s->gb, 4); lsp_coefs[i] = lsp_codebook[i][val]; } wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch], s->block_len, lsp_coefs); } /* decode exponents coded with VLC codes */ static int decode_exp_vlc(WMADecodeContext *s, int ch) { int last_exp, n, code; const uint16_t *ptr, *band_ptr; float v, *q, max_scale, *q_end; band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits]; ptr = band_ptr; q = s->exponents[ch]; q_end = q + s->block_len; max_scale = 0; if (s->version == 1) { last_exp = get_bits(&s->gb, 5) + 10; /* XXX: use a table */ v = pow(10, last_exp * (1.0 / 16.0)); max_scale = v; n = *ptr++; do { *q++ = v; } while (--n); } last_exp = 36; while (q < q_end) { code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX); if (code < 0) return -1; /* NOTE: this offset is the same as MPEG4 AAC ! */ last_exp += code - 60; /* XXX: use a table */ v = pow(10, last_exp * (1.0 / 16.0)); if (v > max_scale) max_scale = v; n = *ptr++; do { *q++ = v; } while (--n); } s->max_exponent[ch] = max_scale; return 0; } /* return 0 if OK. return 1 if last block of frame. return -1 if unrecorrable error. */ static int wma_decode_block(WMADecodeContext *s) { int n, v, a, ch, code, bsize; int coef_nb_bits, total_gain, parse_exponents; DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]); int nb_coefs[MAX_CHANNELS]; float mdct_norm; #ifdef TRACE tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num); #endif /* compute current block length */ if (s->use_variable_block_len) { n = av_log2(s->nb_block_sizes - 1) + 1; if (s->reset_block_lengths) { s->reset_block_lengths = 0; v = get_bits(&s->gb, n); if (v >= s->nb_block_sizes) return -1; s->prev_block_len_bits = s->frame_len_bits - v; v = get_bits(&s->gb, n); if (v >= s->nb_block_sizes) return -1; s->block_len_bits = s->frame_len_bits - v; } else { /* update block lengths */ s->prev_block_len_bits = s->block_len_bits; s->block_len_bits = s->next_block_len_bits; } v = get_bits(&s->gb, n); if (v >= s->nb_block_sizes) return -1; s->next_block_len_bits = s->frame_len_bits - v; } else { /* fixed block len */ s->next_block_len_bits = s->frame_len_bits; s->prev_block_len_bits = s->frame_len_bits; s->block_len_bits = s->frame_len_bits; } /* now check if the block length is coherent with the frame length */ s->block_len = 1 << s->block_len_bits; if ((s->block_pos + s->block_len) > s->frame_len) return -1; if (s->nb_channels == 2) { s->ms_stereo = get_bits(&s->gb, 1); } v = 0; for(ch = 0; ch < s->nb_channels; ch++) { a = get_bits(&s->gb, 1); s->channel_coded[ch] = a; v |= a; } /* if no channel coded, no need to go further */ /* XXX: fix potential framing problems */ if (!v) goto next; bsize = s->frame_len_bits - s->block_len_bits; /* read total gain and extract corresponding number of bits for coef escape coding */ total_gain = 1; for(;;) { a = get_bits(&s->gb, 7); total_gain += a; if (a != 127) break; } if (total_gain < 15) coef_nb_bits = 13; else if (total_gain < 32) coef_nb_bits = 12; else if (total_gain < 40) coef_nb_bits = 11; else if (total_gain < 45) coef_nb_bits = 10; else coef_nb_bits = 9; /* compute number of coefficients */ n = s->coefs_end[bsize] - s->coefs_start; for(ch = 0; ch < s->nb_channels; ch++) nb_coefs[ch] = n; /* complex coding */ if (s->use_noise_coding) { for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { int i, n, a; n = s->exponent_high_sizes[bsize]; for(i=0;i<n;i++) { a = get_bits(&s->gb, 1); s->high_band_coded[ch][i] = a; /* if noise coding, the coefficients are not transmitted */ if (a) nb_coefs[ch] -= s->exponent_high_bands[bsize][i]; } } } for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { int i, n, val, code; n = s->exponent_high_sizes[bsize]; val = (int)0x80000000; for(i=0;i<n;i++) { if (s->high_band_coded[ch][i]) { if (val == (int)0x80000000) { val = get_bits(&s->gb, 7) - 19; } else { code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX); if (code < 0) return -1; val += code - 18; } s->high_band_values[ch][i] = val; } } } } } /* exposant can be interpolated in short blocks. */ parse_exponents = 1; if (s->block_len_bits != s->frame_len_bits) { parse_exponents = get_bits(&s->gb, 1); } if (parse_exponents) { for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { if (s->use_exp_vlc) { if (decode_exp_vlc(s, ch) < 0) return -1; } else { decode_exp_lsp(s, ch); } } } } else { for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits, s->block_len); } } } /* parse spectral coefficients : just RLE encoding */ for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { VLC *coef_vlc; int level, run, sign, tindex; int16_t *ptr, *eptr; const uint16_t *level_table, *run_table; /* special VLC tables are used for ms stereo because there is potentially less energy there */ tindex = (ch == 1 && s->ms_stereo); coef_vlc = &s->coef_vlc[tindex]; run_table = s->run_table[tindex]; level_table = s->level_table[tindex]; /* XXX: optimize */ ptr = &s->coefs1[ch][0]; eptr = ptr + nb_coefs[ch]; memset(ptr, 0, s->block_len * sizeof(int16_t)); for(;;) { code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX); if (code < 0) return -1; if (code == 1) { /* EOB */ break; } else if (code == 0) { /* escape */ level = get_bits(&s->gb, coef_nb_bits); /* NOTE: this is rather suboptimal. reading block_len_bits would be better */ run = get_bits(&s->gb, s->frame_len_bits); } else { /* normal code */ run = run_table[code]; level = level_table[code]; } sign = get_bits(&s->gb, 1); if (!sign) level = -level; ptr += run; if (ptr >= eptr) { av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n"); break; } *ptr++ = level; /* NOTE: EOB can be omitted */ if (ptr >= eptr) break; } } if (s->version == 1 && s->nb_channels >= 2) { align_get_bits(&s->gb); } } /* normalize */ { int n4 = s->block_len / 2; mdct_norm = 1.0 / (float)n4; if (s->version == 1) { mdct_norm *= sqrt(n4); } } /* finally compute the MDCT coefficients */ for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { int16_t *coefs1; float *coefs, *exponents, mult, mult1, noise, *exp_ptr; int i, j, n, n1, last_high_band; float exp_power[HIGH_BAND_MAX_SIZE]; coefs1 = s->coefs1[ch]; exponents = s->exponents[ch]; mult = pow(10, total_gain * 0.05) / s->max_exponent[ch]; mult *= mdct_norm; coefs = s->coefs[ch]; if (s->use_noise_coding) { mult1 = mult; /* very low freqs : noise */ for(i = 0;i < s->coefs_start; i++) { *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1; s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1); } n1 = s->exponent_high_sizes[bsize]; /* compute power of high bands */ exp_ptr = exponents + s->high_band_start[bsize] - s->coefs_start; last_high_band = 0; /* avoid warning */ for(j=0;j<n1;j++) { n = s->exponent_high_bands[s->frame_len_bits - s->block_len_bits][j]; if (s->high_band_coded[ch][j]) { float e2, v; e2 = 0; for(i = 0;i < n; i++) { v = exp_ptr[i]; e2 += v * v; } exp_power[j] = e2 / n; last_high_band = j; tprintf("%d: power=%f (%d)\n", j, exp_power[j], n); } exp_ptr += n; } /* main freqs and high freqs */ for(j=-1;j<n1;j++) { if (j < 0) { n = s->high_band_start[bsize] - s->coefs_start; } else { n = s->exponent_high_bands[s->frame_len_bits - s->block_len_bits][j]; } if (j >= 0 && s->high_band_coded[ch][j]) { /* use noise with specified power */ mult1 = sqrt(exp_power[j] / exp_power[last_high_band]); /* XXX: use a table */ mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05); mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult); mult1 *= mdct_norm; for(i = 0;i < n; i++) { noise = s->noise_table[s->noise_index]; s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1); *coefs++ = (*exponents++) * noise * mult1; } } else { /* coded values + small noise */ for(i = 0;i < n; i++) { noise = s->noise_table[s->noise_index]; s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1); *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult; } } } /* very high freqs : noise */ n = s->block_len - s->coefs_end[bsize]; mult1 = mult * exponents[-1]; for(i = 0; i < n; i++) { *coefs++ = s->noise_table[s->noise_index] * mult1; s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1); } } else { /* XXX: optimize more */ for(i = 0;i < s->coefs_start; i++) *coefs++ = 0.0; n = nb_coefs[ch]; for(i = 0;i < n; i++) { *coefs++ = coefs1[i] * exponents[i] * mult; } n = s->block_len - s->coefs_end[bsize]; for(i = 0;i < n; i++) *coefs++ = 0.0; } } } #ifdef TRACE for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { dump_floats("exponents", 3, s->exponents[ch], s->block_len); dump_floats("coefs", 1, s->coefs[ch], s->block_len); } } #endif if (s->ms_stereo && s->channel_coded[1]) { float a, b; int i; /* nominal case for ms stereo: we do it before mdct */ /* no need to optimize this case because it should almost never happen */ if (!s->channel_coded[0]) { tprintf("rare ms-stereo case happened\n"); memset(s->coefs[0], 0, sizeof(float) * s->block_len); s->channel_coded[0] = 1; } for(i = 0; i < s->block_len; i++) { a = s->coefs[0][i]; b = s->coefs[1][i]; s->coefs[0][i] = a + b; s->coefs[1][i] = a - b; } } /* build the window : we ensure that when the windows overlap their squared sum is always 1 (MDCT reconstruction rule) */ /* XXX: merge with output */ { int i, next_block_len, block_len, prev_block_len, n; float *wptr; block_len = s->block_len; prev_block_len = 1 << s->prev_block_len_bits; next_block_len = 1 << s->next_block_len_bits; /* right part */ wptr = window + block_len; if (block_len <= next_block_len) { for(i=0;i<block_len;i++) *wptr++ = s->windows[bsize][i]; } else { /* overlap */ n = (block_len / 2) - (next_block_len / 2); for(i=0;i<n;i++) *wptr++ = 1.0; for(i=0;i<next_block_len;i++) *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i]; for(i=0;i<n;i++) *wptr++ = 0.0; } /* left part */ wptr = window + block_len; if (block_len <= prev_block_len) { for(i=0;i<block_len;i++) *--wptr = s->windows[bsize][i]; } else { /* overlap */ n = (block_len / 2) - (prev_block_len / 2); for(i=0;i<n;i++) *--wptr = 1.0; for(i=0;i<prev_block_len;i++) *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i]; for(i=0;i<n;i++) *--wptr = 0.0; } } for(ch = 0; ch < s->nb_channels; ch++) { if (s->channel_coded[ch]) { DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]); float *ptr; int n4, index, n; n = s->block_len; n4 = s->block_len / 2; s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize], output, s->coefs[ch], s->mdct_tmp); /* XXX: optimize all that by build the window and multipying/adding at the same time */ /* multiply by the window and add in the frame */ index = (s->frame_len / 2) + s->block_pos - n4; ptr = &s->frame_out[ch][index]; s->dsp.vector_fmul_add_add(ptr,window,output,ptr,0,2*n,1); /* specific fast case for ms-stereo : add to second channel if it is not coded */ if (s->ms_stereo && !s->channel_coded[1]) { ptr = &s->frame_out[1][index]; s->dsp.vector_fmul_add_add(ptr,window,output,ptr,0,2*n,1); } } } next: /* update block number */ s->block_num++; s->block_pos += s->block_len; if (s->block_pos >= s->frame_len) return 1; else return 0; } /* decode a frame of frame_len samples */ static int wma_decode_frame(WMADecodeContext *s, int16_t *samples) { int ret, i, n, a, ch, incr; int16_t *ptr; float *iptr; #ifdef TRACE tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len); #endif /* read each block */ s->block_num = 0; s->block_pos = 0; for(;;) { ret = wma_decode_block(s); if (ret < 0) return -1; if (ret) break; } /* convert frame to integer */ n = s->frame_len; incr = s->nb_channels; for(ch = 0; ch < s->nb_channels; ch++) { ptr = samples + ch; iptr = s->frame_out[ch]; for(i=0;i<n;i++) { a = lrintf(*iptr++); if (a > 32767) a = 32767; else if (a < -32768) a = -32768; *ptr = a; ptr += incr; } /* prepare for next block */ memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len], s->frame_len * sizeof(float)); /* XXX: suppress this */ memset(&s->frame_out[ch][s->frame_len], 0, s->frame_len * sizeof(float)); } #ifdef TRACE dump_shorts("samples", samples, n * s->nb_channels); #endif return 0; } static int wma_decode_superframe(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size) { WMADecodeContext *s = avctx->priv_data; int nb_frames, bit_offset, i, pos, len; uint8_t *q; int16_t *samples; tprintf("***decode_superframe:\n"); if(buf_size==0){ s->last_superframe_len = 0; return 0; } samples = data; init_get_bits(&s->gb, buf, buf_size*8); if (s->use_bit_reservoir) { /* read super frame header */ get_bits(&s->gb, 4); /* super frame index */ nb_frames = get_bits(&s->gb, 4) - 1; bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3); if (s->last_superframe_len > 0) { // printf("skip=%d\n", s->last_bitoffset); /* add bit_offset bits to last frame */ if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) > MAX_CODED_SUPERFRAME_SIZE) goto fail; q = s->last_superframe + s->last_superframe_len; len = bit_offset; while (len > 7) { *q++ = (get_bits)(&s->gb, 8); len -= 8; } if (len > 0) { *q++ = (get_bits)(&s->gb, len) << (8 - len); } /* XXX: bit_offset bits into last frame */ init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8); /* skip unused bits */ if (s->last_bitoffset > 0) skip_bits(&s->gb, s->last_bitoffset); /* this frame is stored in the last superframe and in the current one */ if (wma_decode_frame(s, samples) < 0) goto fail; samples += s->nb_channels * s->frame_len; } /* read each frame starting from bit_offset */ pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3; init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8); len = pos & 7; if (len > 0) skip_bits(&s->gb, len); s->reset_block_lengths = 1; for(i=0;i<nb_frames;i++) { if (wma_decode_frame(s, samples) < 0) goto fail; samples += s->nb_channels * s->frame_len; } /* we copy the end of the frame in the last frame buffer */ pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7); s->last_bitoffset = pos & 7; pos >>= 3; len = buf_size - pos; if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) { goto fail; } s->last_superframe_len = len; memcpy(s->last_superframe, buf + pos, len); } else { /* single frame decode */ if (wma_decode_frame(s, samples) < 0) goto fail; samples += s->nb_channels * s->frame_len; } *data_size = (int8_t *)samples - (int8_t *)data; return s->block_align; fail: /* when error, we reset the bit reservoir */ s->last_superframe_len = 0; return -1; } static int wma_decode_end(AVCodecContext *avctx) { WMADecodeContext *s = avctx->priv_data; int i; for(i = 0; i < s->nb_block_sizes; i++) ff_mdct_end(&s->mdct_ctx[i]); for(i = 0; i < s->nb_block_sizes; i++) av_free(s->windows[i]); if (s->use_exp_vlc) { free_vlc(&s->exp_vlc); } if (s->use_noise_coding) { free_vlc(&s->hgain_vlc); } for(i = 0;i < 2; i++) { free_vlc(&s->coef_vlc[i]); av_free(s->run_table[i]); av_free(s->level_table[i]); } return 0; } AVCodec wmav1_decoder = { "wmav1", CODEC_TYPE_AUDIO, CODEC_ID_WMAV1, sizeof(WMADecodeContext), wma_decode_init, NULL, wma_decode_end, wma_decode_superframe, }; AVCodec wmav2_decoder = { "wmav2", CODEC_TYPE_AUDIO, CODEC_ID_WMAV2, sizeof(WMADecodeContext), wma_decode_init, NULL, wma_decode_end, wma_decode_superframe, };