Libav 0.7.1
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00001 /* 00002 * WMA compatible encoder 00003 * Copyright (c) 2007 Michael Niedermayer 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avcodec.h" 00023 #include "wma.h" 00024 00025 #undef NDEBUG 00026 #include <assert.h> 00027 00028 00029 static int encode_init(AVCodecContext * avctx){ 00030 WMACodecContext *s = avctx->priv_data; 00031 int i, flags1, flags2; 00032 uint8_t *extradata; 00033 00034 s->avctx = avctx; 00035 00036 if(avctx->channels > MAX_CHANNELS) { 00037 av_log(avctx, AV_LOG_ERROR, "too many channels: got %i, need %i or fewer", 00038 avctx->channels, MAX_CHANNELS); 00039 return AVERROR(EINVAL); 00040 } 00041 00042 if(avctx->bit_rate < 24*1000) { 00043 av_log(avctx, AV_LOG_ERROR, "bitrate too low: got %i, need 24000 or higher\n", 00044 avctx->bit_rate); 00045 return AVERROR(EINVAL); 00046 } 00047 00048 /* extract flag infos */ 00049 flags1 = 0; 00050 flags2 = 1; 00051 if (avctx->codec->id == CODEC_ID_WMAV1) { 00052 extradata= av_malloc(4); 00053 avctx->extradata_size= 4; 00054 AV_WL16(extradata, flags1); 00055 AV_WL16(extradata+2, flags2); 00056 } else if (avctx->codec->id == CODEC_ID_WMAV2) { 00057 extradata= av_mallocz(10); 00058 avctx->extradata_size= 10; 00059 AV_WL32(extradata, flags1); 00060 AV_WL16(extradata+4, flags2); 00061 }else 00062 assert(0); 00063 avctx->extradata= extradata; 00064 s->use_exp_vlc = flags2 & 0x0001; 00065 s->use_bit_reservoir = flags2 & 0x0002; 00066 s->use_variable_block_len = flags2 & 0x0004; 00067 00068 ff_wma_init(avctx, flags2); 00069 00070 /* init MDCT */ 00071 for(i = 0; i < s->nb_block_sizes; i++) 00072 ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0); 00073 00074 avctx->block_align= 00075 s->block_align= avctx->bit_rate*(int64_t)s->frame_len / (avctx->sample_rate*8); 00076 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d\n", s->block_align, avctx->bit_rate, s->frame_len, avctx->sample_rate); 00077 avctx->frame_size= s->frame_len; 00078 00079 return 0; 00080 } 00081 00082 00083 static void apply_window_and_mdct(AVCodecContext * avctx, const signed short * audio, int len) { 00084 WMACodecContext *s = avctx->priv_data; 00085 int window_index= s->frame_len_bits - s->block_len_bits; 00086 FFTContext *mdct = &s->mdct_ctx[window_index]; 00087 int i, j, channel; 00088 const float * win = s->windows[window_index]; 00089 int window_len = 1 << s->block_len_bits; 00090 float n = window_len/2; 00091 00092 for (channel = 0; channel < avctx->channels; channel++) { 00093 memcpy(s->output, s->frame_out[channel], sizeof(float)*window_len); 00094 j = channel; 00095 for (i = 0; i < len; i++, j += avctx->channels){ 00096 s->output[i+window_len] = audio[j] / n * win[window_len - i - 1]; 00097 s->frame_out[channel][i] = audio[j] / n * win[i]; 00098 } 00099 mdct->mdct_calc(mdct, s->coefs[channel], s->output); 00100 } 00101 } 00102 00103 //FIXME use for decoding too 00104 static void init_exp(WMACodecContext *s, int ch, const int *exp_param){ 00105 int n; 00106 const uint16_t *ptr; 00107 float v, *q, max_scale, *q_end; 00108 00109 ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits]; 00110 q = s->exponents[ch]; 00111 q_end = q + s->block_len; 00112 max_scale = 0; 00113 while (q < q_end) { 00114 /* XXX: use a table */ 00115 v = pow(10, *exp_param++ * (1.0 / 16.0)); 00116 max_scale= FFMAX(max_scale, v); 00117 n = *ptr++; 00118 do { 00119 *q++ = v; 00120 } while (--n); 00121 } 00122 s->max_exponent[ch] = max_scale; 00123 } 00124 00125 static void encode_exp_vlc(WMACodecContext *s, int ch, const int *exp_param){ 00126 int last_exp; 00127 const uint16_t *ptr; 00128 float *q, *q_end; 00129 00130 ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits]; 00131 q = s->exponents[ch]; 00132 q_end = q + s->block_len; 00133 if (s->version == 1) { 00134 last_exp= *exp_param++; 00135 assert(last_exp-10 >= 0 && last_exp-10 < 32); 00136 put_bits(&s->pb, 5, last_exp - 10); 00137 q+= *ptr++; 00138 }else 00139 last_exp = 36; 00140 while (q < q_end) { 00141 int exp = *exp_param++; 00142 int code = exp - last_exp + 60; 00143 assert(code >= 0 && code < 120); 00144 put_bits(&s->pb, ff_aac_scalefactor_bits[code], ff_aac_scalefactor_code[code]); 00145 /* XXX: use a table */ 00146 q+= *ptr++; 00147 last_exp= exp; 00148 } 00149 } 00150 00151 static int encode_block(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], int total_gain){ 00152 int v, bsize, ch, coef_nb_bits, parse_exponents; 00153 float mdct_norm; 00154 int nb_coefs[MAX_CHANNELS]; 00155 static const int fixed_exp[25]={20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20}; 00156 00157 //FIXME remove duplication relative to decoder 00158 if (s->use_variable_block_len) { 00159 assert(0); //FIXME not implemented 00160 }else{ 00161 /* fixed block len */ 00162 s->next_block_len_bits = s->frame_len_bits; 00163 s->prev_block_len_bits = s->frame_len_bits; 00164 s->block_len_bits = s->frame_len_bits; 00165 } 00166 00167 s->block_len = 1 << s->block_len_bits; 00168 // assert((s->block_pos + s->block_len) <= s->frame_len); 00169 bsize = s->frame_len_bits - s->block_len_bits; 00170 00171 //FIXME factor 00172 v = s->coefs_end[bsize] - s->coefs_start; 00173 for(ch = 0; ch < s->nb_channels; ch++) 00174 nb_coefs[ch] = v; 00175 { 00176 int n4 = s->block_len / 2; 00177 mdct_norm = 1.0 / (float)n4; 00178 if (s->version == 1) { 00179 mdct_norm *= sqrt(n4); 00180 } 00181 } 00182 00183 if (s->nb_channels == 2) { 00184 put_bits(&s->pb, 1, s->ms_stereo= 1); 00185 } 00186 00187 for(ch = 0; ch < s->nb_channels; ch++) { 00188 s->channel_coded[ch] = 1; //FIXME only set channel_coded when needed, instead of always 00189 if (s->channel_coded[ch]) { 00190 init_exp(s, ch, fixed_exp); 00191 } 00192 } 00193 00194 for(ch = 0; ch < s->nb_channels; ch++) { 00195 if (s->channel_coded[ch]) { 00196 WMACoef *coefs1; 00197 float *coefs, *exponents, mult; 00198 int i, n; 00199 00200 coefs1 = s->coefs1[ch]; 00201 exponents = s->exponents[ch]; 00202 mult = pow(10, total_gain * 0.05) / s->max_exponent[ch]; 00203 mult *= mdct_norm; 00204 coefs = src_coefs[ch]; 00205 if (s->use_noise_coding && 0) { 00206 assert(0); //FIXME not implemented 00207 } else { 00208 coefs += s->coefs_start; 00209 n = nb_coefs[ch]; 00210 for(i = 0;i < n; i++){ 00211 double t= *coefs++ / (exponents[i] * mult); 00212 if(t<-32768 || t>32767) 00213 return -1; 00214 00215 coefs1[i] = lrint(t); 00216 } 00217 } 00218 } 00219 } 00220 00221 v = 0; 00222 for(ch = 0; ch < s->nb_channels; ch++) { 00223 int a = s->channel_coded[ch]; 00224 put_bits(&s->pb, 1, a); 00225 v |= a; 00226 } 00227 00228 if (!v) 00229 return 1; 00230 00231 for(v= total_gain-1; v>=127; v-= 127) 00232 put_bits(&s->pb, 7, 127); 00233 put_bits(&s->pb, 7, v); 00234 00235 coef_nb_bits= ff_wma_total_gain_to_bits(total_gain); 00236 00237 if (s->use_noise_coding) { 00238 for(ch = 0; ch < s->nb_channels; ch++) { 00239 if (s->channel_coded[ch]) { 00240 int i, n; 00241 n = s->exponent_high_sizes[bsize]; 00242 for(i=0;i<n;i++) { 00243 put_bits(&s->pb, 1, s->high_band_coded[ch][i]= 0); 00244 if (0) 00245 nb_coefs[ch] -= s->exponent_high_bands[bsize][i]; 00246 } 00247 } 00248 } 00249 } 00250 00251 parse_exponents = 1; 00252 if (s->block_len_bits != s->frame_len_bits) { 00253 put_bits(&s->pb, 1, parse_exponents); 00254 } 00255 00256 if (parse_exponents) { 00257 for(ch = 0; ch < s->nb_channels; ch++) { 00258 if (s->channel_coded[ch]) { 00259 if (s->use_exp_vlc) { 00260 encode_exp_vlc(s, ch, fixed_exp); 00261 } else { 00262 assert(0); //FIXME not implemented 00263 // encode_exp_lsp(s, ch); 00264 } 00265 } 00266 } 00267 } else { 00268 assert(0); //FIXME not implemented 00269 } 00270 00271 for(ch = 0; ch < s->nb_channels; ch++) { 00272 if (s->channel_coded[ch]) { 00273 int run, tindex; 00274 WMACoef *ptr, *eptr; 00275 tindex = (ch == 1 && s->ms_stereo); 00276 ptr = &s->coefs1[ch][0]; 00277 eptr = ptr + nb_coefs[ch]; 00278 00279 run=0; 00280 for(;ptr < eptr; ptr++){ 00281 if(*ptr){ 00282 int level= *ptr; 00283 int abs_level= FFABS(level); 00284 int code= 0; 00285 if(abs_level <= s->coef_vlcs[tindex]->max_level){ 00286 if(run < s->coef_vlcs[tindex]->levels[abs_level-1]) 00287 code= run + s->int_table[tindex][abs_level-1]; 00288 } 00289 00290 assert(code < s->coef_vlcs[tindex]->n); 00291 put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[code], s->coef_vlcs[tindex]->huffcodes[code]); 00292 00293 if(code == 0){ 00294 if(1<<coef_nb_bits <= abs_level) 00295 return -1; 00296 00297 00298 //Workaround minor rounding differences for the regression tests, FIXME we should find and replace the problematic float by fixpoint for reg tests 00299 if(abs_level == 0x71B && (s->avctx->flags & CODEC_FLAG_BITEXACT)) abs_level=0x71A; 00300 00301 put_bits(&s->pb, coef_nb_bits, abs_level); 00302 put_bits(&s->pb, s->frame_len_bits, run); 00303 } 00304 put_bits(&s->pb, 1, level < 0); //FIXME the sign is fliped somewhere 00305 run=0; 00306 }else{ 00307 run++; 00308 } 00309 } 00310 if(run) 00311 put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[1], s->coef_vlcs[tindex]->huffcodes[1]); 00312 } 00313 if (s->version == 1 && s->nb_channels >= 2) { 00314 align_put_bits(&s->pb); 00315 } 00316 } 00317 return 0; 00318 } 00319 00320 static int encode_frame(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], uint8_t *buf, int buf_size, int total_gain){ 00321 init_put_bits(&s->pb, buf, buf_size); 00322 00323 if (s->use_bit_reservoir) { 00324 assert(0);//FIXME not implemented 00325 }else{ 00326 if(encode_block(s, src_coefs, total_gain) < 0) 00327 return INT_MAX; 00328 } 00329 00330 align_put_bits(&s->pb); 00331 00332 return put_bits_count(&s->pb)/8 - s->block_align; 00333 } 00334 00335 static int encode_superframe(AVCodecContext *avctx, 00336 unsigned char *buf, int buf_size, void *data){ 00337 WMACodecContext *s = avctx->priv_data; 00338 const short *samples = data; 00339 int i, total_gain; 00340 00341 s->block_len_bits= s->frame_len_bits; //required by non variable block len 00342 s->block_len = 1 << s->block_len_bits; 00343 00344 apply_window_and_mdct(avctx, samples, avctx->frame_size); 00345 00346 if (s->ms_stereo) { 00347 float a, b; 00348 int i; 00349 00350 for(i = 0; i < s->block_len; i++) { 00351 a = s->coefs[0][i]*0.5; 00352 b = s->coefs[1][i]*0.5; 00353 s->coefs[0][i] = a + b; 00354 s->coefs[1][i] = a - b; 00355 } 00356 } 00357 00358 #if 1 00359 total_gain= 128; 00360 for(i=64; i; i>>=1){ 00361 int error= encode_frame(s, s->coefs, buf, buf_size, total_gain-i); 00362 if(error<0) 00363 total_gain-= i; 00364 } 00365 #else 00366 total_gain= 90; 00367 best= encode_frame(s, s->coefs, buf, buf_size, total_gain); 00368 for(i=32; i; i>>=1){ 00369 int scoreL= encode_frame(s, s->coefs, buf, buf_size, total_gain-i); 00370 int scoreR= encode_frame(s, s->coefs, buf, buf_size, total_gain+i); 00371 av_log(NULL, AV_LOG_ERROR, "%d %d %d (%d)\n", scoreL, best, scoreR, total_gain); 00372 if(scoreL < FFMIN(best, scoreR)){ 00373 best = scoreL; 00374 total_gain -= i; 00375 }else if(scoreR < best){ 00376 best = scoreR; 00377 total_gain += i; 00378 } 00379 } 00380 #endif 00381 00382 encode_frame(s, s->coefs, buf, buf_size, total_gain); 00383 assert((put_bits_count(&s->pb) & 7) == 0); 00384 i= s->block_align - (put_bits_count(&s->pb)+7)/8; 00385 assert(i>=0); 00386 while(i--) 00387 put_bits(&s->pb, 8, 'N'); 00388 00389 flush_put_bits(&s->pb); 00390 return put_bits_ptr(&s->pb) - s->pb.buf; 00391 } 00392 00393 AVCodec ff_wmav1_encoder = 00394 { 00395 "wmav1", 00396 AVMEDIA_TYPE_AUDIO, 00397 CODEC_ID_WMAV1, 00398 sizeof(WMACodecContext), 00399 encode_init, 00400 encode_superframe, 00401 ff_wma_end, 00402 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE}, 00403 .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"), 00404 }; 00405 00406 AVCodec ff_wmav2_encoder = 00407 { 00408 "wmav2", 00409 AVMEDIA_TYPE_AUDIO, 00410 CODEC_ID_WMAV2, 00411 sizeof(WMACodecContext), 00412 encode_init, 00413 encode_superframe, 00414 ff_wma_end, 00415 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE}, 00416 .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"), 00417 };