/* * WMA compatible codec * Copyright (c) 2002-2007 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 */ #include "avcodec.h" #include "wma.h" #include "wmadata.h" #undef NDEBUG #include <assert.h> /* XXX: use same run/length optimization as mpeg decoders */ //FIXME maybe split decode / encode or pass flag static void init_coef_vlc(VLC *vlc, uint16_t **prun_table, uint16_t **plevel_table, uint16_t **pint_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, *int_table; int i, l, j, k, 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)); int_table = av_malloc(n * sizeof(uint16_t)); i = 2; level = 1; k = 0; while (i < n) { int_table[k]= i; l = levels_table[k++]; for(j=0;j<l;j++) { run_table[i] = j; level_table[i] = level; i++; } level++; } *prun_table = run_table; *plevel_table = level_table; *pint_table= int_table; } int ff_wma_init(AVCodecContext * avctx, int flags2) { WMACodecContext *s = avctx->priv_data; int i; float bps1, high_freq; volatile float bps; int sample_rate1; int coef_vlc_table; if( avctx->sample_rate<=0 || avctx->sample_rate>50000 || avctx->channels<=0 || avctx->channels>8 || avctx->bit_rate<=0) return -1; 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; } /* 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 dependent 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(s->avctx, "flags2=0x%x\n", flags2); dprintf(s->avctx, "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(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n", bps, bps1, high_freq, s->byte_offset_bits); dprintf(s->avctx, "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(s->avctx, "%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(s->avctx, " %d", s->exponent_high_bands[k][j]); tprintf(s->avctx, "\n"); #endif } } #ifdef TRACE { int i, j; for(i = 0; i < s->nb_block_sizes; i++) { tprintf(s->avctx, "%5d: n=%2d:", s->frame_len >> i, s->exponent_sizes[i]); for(j=0;j<s->exponent_sizes[i];j++) tprintf(s->avctx, " %d", s->exponent_bands[i][j]); tprintf(s->avctx, "\n"); } } #endif /* init MDCT windows : simple sinus window */ for(i = 0; i < s->nb_block_sizes; i++) { int n; n = 1 << (s->frame_len_bits - i); ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n); s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7]; } 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 } /* 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; } s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ]; s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1]; init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0], s->coef_vlcs[0]); init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1], s->coef_vlcs[1]); return 0; } int ff_wma_total_gain_to_bits(int total_gain){ if (total_gain < 15) return 13; else if (total_gain < 32) return 12; else if (total_gain < 40) return 11; else if (total_gain < 45) return 10; else return 9; } int ff_wma_end(AVCodecContext *avctx) { WMACodecContext *s = avctx->priv_data; int i; for(i = 0; i < s->nb_block_sizes; i++) ff_mdct_end(&s->mdct_ctx[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]); av_free(s->int_table[i]); } return 0; }