mdw@git.distorted.org.uk Git - disorder/blob - server/decode.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2007, 2008 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file server/decode.c
  19  * @brief General-purpose decoder for use by speaker process
  20  */
  21
  22 #include "disorder-server.h"
  23
  24 #include <mad.h>
  25 #include <vorbis/vorbisfile.h>
  26
  27 /* libFLAC has had an API change and stupidly taken away the old API */
  28 #if HAVE_FLAC_FILE_DECODER_H
  29 # include <FLAC/file_decoder.h>
  30 #else
  31 # include <FLAC/stream_decoder.h>
  32 #define FLAC__FileDecoder FLAC__StreamDecoder
  33 #define FLAC__FileDecoderState FLAC__StreamDecoderState
  34 #endif
  35
  36 #include "wav.h"
  37 #include "speaker-protocol.h"
  38
  39
  40 /** @brief Encoding lookup table type */
  41 struct decoder {
  42   /** @brief Glob pattern matching file */
  43   const char *pattern;
  44   /** @brief Decoder function */
  45   void (*decode)(void);
  46 };
  47
  48 /** @brief Input file */
  49 static int inputfd;
  50
  51 /** @brief Output file */
  52 static FILE *outputfp;
  53
  54 /** @brief Filename */
  55 static const char *path;
  56
  57 /** @brief Input buffer */
  58 static char input_buffer[1048576];
  59
  60 /** @brief Number of bytes read into buffer */
  61 static int input_count;
  62
  63 /** @brief Write an 8-bit word */
  64 static inline void output_8(int n) {
  65   if(putc(n, outputfp) < 0)
  66     fatal(errno, "decoding %s: output error", path);
  67 }
  68
  69 /** @brief Write a 16-bit word in bigendian format */
  70 static inline void output_16(uint16_t n) {
  71   if(putc(n >> 8, outputfp) < 0
  72      || putc(n, outputfp) < 0)
  73     fatal(errno, "decoding %s: output error", path);
  74 }
  75
  76 /** @brief Write a 24-bit word in bigendian format */
  77 static inline void output_24(uint32_t n) {
  78   if(putc(n >> 16, outputfp) < 0
  79      || putc(n >> 8, outputfp) < 0
  80      || putc(n, outputfp) < 0)
  81     fatal(errno, "decoding %s: output error", path);
  82 }
  83
  84 /** @brief Write a 32-bit word in bigendian format */
  85 static inline void output_32(uint32_t n) {
  86   if(putc(n >> 24, outputfp) < 0
  87      || putc(n >> 16, outputfp) < 0
  88      || putc(n >> 8, outputfp) < 0
  89      || putc(n, outputfp) < 0)
  90     fatal(errno, "decoding %s: output error", path);
  91 }
  92
  93 /** @brief Write a block header
  94  * @param rate Sample rate in Hz
  95  * @param channels Channel count (currently only 1 or 2 supported)
  96  * @param bits Bits per sample (must be a multiple of 8, no more than 64)
  97  * @param nbytes Total number of data bytes
  98  * @param endian @ref ENDIAN_BIG or @ref ENDIAN_LITTLE
  99  *
 100  * Checks that the sample format is a supported one (so other calls do not have
 101  * to) and calls fatal() on error.
 102  */
 103 static void output_header(int rate,
 104                           int channels,
 105                           int bits,
 106                           int nbytes,
 107                           int endian) {
 108   struct stream_header header;
 109
 110   if(bits <= 0 || bits % 8 || bits > 64)
 111     fatal(0, "decoding %s: unsupported sample size %d bits", path, bits);
 112   if(channels <= 0 || channels > 2)
 113     fatal(0, "decoding %s: unsupported channel count %d", path, channels);
 114   if(rate <= 0)
 115     fatal(0, "decoding %s: nonsensical sample rate %dHz", path, rate);
 116   header.rate = rate;
 117   header.bits = bits;
 118   header.channels = channels;
 119   header.endian = endian;
 120   header.nbytes = nbytes;
 121   if(fwrite(&header, sizeof header, 1, outputfp) < 1)
 122     fatal(errno, "decoding %s: writing format header", path);
 123 }
 124
 125 /** @brief Dithering state
 126  * Filched from mpg321, which credits it to Robert Leslie */
 127 struct audio_dither {
 128   mad_fixed_t error[3];
 129   mad_fixed_t random;
 130 };
 131
 132 /** @brief 32-bit PRNG
 133  * Filched from mpg321, which credits it to Robert Leslie */
 134 static inline unsigned long prng(unsigned long state)
 135 {
 136   return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
 137 }
 138
 139 /** @brief Generic linear sample quantize and dither routine
 140  * Filched from mpg321, which credits it to Robert Leslie */
 141 static long audio_linear_dither(mad_fixed_t sample,
 142                                 struct audio_dither *dither) {
 143   unsigned int scalebits;
 144   mad_fixed_t output, mask, rnd;
 145   const int bits = 16;
 146
 147   enum {
 148     MIN = -MAD_F_ONE,
 149     MAX =  MAD_F_ONE - 1
 150   };
 151
 152   /* noise shape */
 153   sample += dither->error[0] - dither->error[1] + dither->error[2];
 154
 155   dither->error[2] = dither->error[1];
 156   dither->error[1] = dither->error[0] / 2;
 157
 158   /* bias */
 159   output = sample + (1L << (MAD_F_FRACBITS + 1 - bits - 1));
 160
 161   scalebits = MAD_F_FRACBITS + 1 - bits;
 162   mask = (1L << scalebits) - 1;
 163
 164   /* dither */
 165   rnd  = prng(dither->random);
 166   output += (rnd & mask) - (dither->random & mask);
 167
 168   dither->random = rnd;
 169
 170   /* clip */
 171   if (output > MAX) {
 172     output = MAX;
 173
 174     if (sample > MAX)
 175       sample = MAX;
 176   }
 177   else if (output < MIN) {
 178     output = MIN;
 179
 180     if (sample < MIN)
 181       sample = MIN;
 182   }
 183
 184   /* quantize */
 185   output &= ~mask;
 186
 187   /* error feedback */
 188   dither->error[0] = sample - output;
 189
 190   /* scale */
 191   return output >> scalebits;
 192 }
 193
 194 /** @brief MP3 output callback */
 195 static enum mad_flow mp3_output(void attribute((unused)) *data,
 196                                 struct mad_header const *header,
 197                                 struct mad_pcm *pcm) {
 198   size_t n = pcm->length;
 199   const mad_fixed_t *l = pcm->samples[0], *r = pcm->samples[1];
 200   static struct audio_dither ld[1], rd[1];
 201
 202   output_header(header->samplerate,
 203                 pcm->channels,
 204                 16,
 205                 2 * pcm->channels * pcm->length,
 206                 ENDIAN_BIG);
 207   switch(pcm->channels) {
 208   case 1:
 209     while(n--)
 210       output_16(audio_linear_dither(*l++, ld));
 211     break;
 212   case 2:
 213     while(n--) {
 214       output_16(audio_linear_dither(*l++, ld));
 215       output_16(audio_linear_dither(*r++, rd));
 216     }
 217     break;
 218   }
 219   return MAD_FLOW_CONTINUE;
 220 }
 221
 222 /** @brief MP3 input callback */
 223 static enum mad_flow mp3_input(void attribute((unused)) *data,
 224                                struct mad_stream *stream) {
 225   int used, remain, n;
 226
 227   /* libmad requires its caller to do ALL the buffering work, including coping
 228    * with partial frames.  Given that it appears to be completely undocumented
 229    * you could perhaps be forgiven for not discovering this...  */
 230   if(input_count) {
 231     /* Compute total number of bytes consumed */
 232     used = (char *)stream->next_frame - input_buffer;
 233     /* Compute number of bytes left to consume */
 234     remain = input_count - used;
 235     memmove(input_buffer, input_buffer + used, remain);
 236   } else {
 237     remain = 0;
 238   }
 239   /* Read new data */
 240   n = read(inputfd, input_buffer + remain, (sizeof input_buffer) - remain);
 241   if(n < 0)
 242     fatal(errno, "reading from %s", path);
 243   /* Compute total number of bytes available */
 244   input_count = remain + n;
 245   if(input_count)
 246     mad_stream_buffer(stream, (unsigned char *)input_buffer, input_count);
 247   if(n)
 248     return MAD_FLOW_CONTINUE;
 249   else
 250     return MAD_FLOW_STOP;
 251 }
 252
 253 /** @brief MP3 error callback */
 254 static enum mad_flow mp3_error(void attribute((unused)) *data,
 255                                struct mad_stream *stream,
 256                                struct mad_frame attribute((unused)) *frame) {
 257   if(0)
 258     /* Just generates pointless verbosity l-( */
 259     error(0, "decoding %s: %s (%#04x)",
 260           path, mad_stream_errorstr(stream), stream->error);
 261   return MAD_FLOW_CONTINUE;
 262 }
 263
 264 /** @brief MP3 decoder */
 265 static void decode_mp3(void) {
 266   struct mad_decoder mad[1];
 267
 268   if((inputfd = open(path, O_RDONLY)) < 0)
 269     fatal(errno, "opening %s", path);
 270   mad_decoder_init(mad, 0/*data*/, mp3_input, 0/*header*/, 0/*filter*/,
 271                    mp3_output, mp3_error, 0/*message*/);
 272   if(mad_decoder_run(mad, MAD_DECODER_MODE_SYNC))
 273     exit(1);
 274   mad_decoder_finish(mad);
 275 }
 276
 277 /** @brief OGG decoder */
 278 static void decode_ogg(void) {
 279   FILE *fp;
 280   OggVorbis_File vf[1];
 281   int err;
 282   long n;
 283   int bitstream;
 284   vorbis_info *vi;
 285
 286   if(!(fp = fopen(path, "rb")))
 287     fatal(errno, "cannot open %s", path);
 288   /* There doesn't seem to be any standard function for mapping the error codes
 289    * to strings l-( */
 290   if((err = ov_open(fp, vf, 0/*initial*/, 0/*ibytes*/)))
 291     fatal(0, "ov_fopen %s: %d", path, err);
 292   if(!(vi = ov_info(vf, 0/*link*/)))
 293     fatal(0, "ov_info %s: failed", path);
 294   while((n = ov_read(vf, input_buffer, sizeof input_buffer, 1/*bigendianp*/,
 295                      2/*bytes/word*/, 1/*signed*/, &bitstream))) {
 296     if(n < 0)
 297       fatal(0, "ov_read %s: %ld", path, n);
 298     if(bitstream > 0)
 299       fatal(0, "only single-bitstream ogg files are supported");
 300     output_header(vi->rate, vi->channels, 16/*bits*/, n, ENDIAN_BIG);
 301     if(fwrite(input_buffer, 1, n, outputfp) < (size_t)n)
 302       fatal(errno, "decoding %s: writing sample data", path);
 303   }
 304 }
 305
 306 /** @brief Sample data callback used by decode_wav() */
 307 static int wav_write(struct wavfile attribute((unused)) *f,
 308                      const char *data,
 309                      size_t nbytes,
 310                      void attribute((unused)) *u) {
 311   if(fwrite(data, 1, nbytes, outputfp) < nbytes)
 312     fatal(errno, "decoding %s: writing sample data", path);
 313   return 0;
 314 }
 315
 316 /** @brief WAV file decoder */
 317 static void decode_wav(void) {
 318   struct wavfile f[1];
 319   int err;
 320
 321   if((err = wav_init(f, path)))
 322     fatal(err, "opening %s", path);
 323   output_header(f->rate, f->channels, f->bits, f->datasize, ENDIAN_LITTLE);
 324   if((err = wav_data(f, wav_write, 0)))
 325     fatal(err, "error decoding %s", path);
 326 }
 327
 328 /** @brief Metadata callback for FLAC decoder
 329  *
 330  * This is a no-op here.
 331  */
 332 static void flac_metadata(const FLAC__FileDecoder attribute((unused)) *decoder,
 333                           const FLAC__StreamMetadata attribute((unused)) *metadata,
 334                           void attribute((unused)) *client_data) {
 335 }
 336
 337 /** @brief Error callback for FLAC decoder */
 338 static void flac_error(const FLAC__FileDecoder attribute((unused)) *decoder,
 339                        FLAC__StreamDecoderErrorStatus status,
 340                        void attribute((unused)) *client_data) {
 341   fatal(0, "error decoding %s: %s", path,
 342         FLAC__StreamDecoderErrorStatusString[status]);
 343 }
 344
 345 /** @brief Write callback for FLAC decoder */
 346 static FLAC__StreamDecoderWriteStatus flac_write
 347     (const FLAC__FileDecoder attribute((unused)) *decoder,
 348      const FLAC__Frame *frame,
 349      const FLAC__int32 *const buffer[],
 350      void attribute((unused)) *client_data) {
 351   size_t n, c;
 352
 353   output_header(frame->header.sample_rate,
 354                 frame->header.channels,
 355                 frame->header.bits_per_sample,
 356                 (frame->header.channels * frame->header.blocksize
 357                  * frame->header.bits_per_sample) / 8,
 358                 ENDIAN_BIG);
 359   for(n = 0; n < frame->header.blocksize; ++n) {
 360     for(c = 0; c < frame->header.channels; ++c) {
 361       switch(frame->header.bits_per_sample) {
 362       case 8: output_8(buffer[c][n]); break;
 363       case 16: output_16(buffer[c][n]); break;
 364       case 24: output_24(buffer[c][n]); break;
 365       case 32: output_32(buffer[c][n]); break;
 366       }
 367     }
 368   }
 369   return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
 370 }
 371
 372
 373 /** @brief FLAC file decoder */
 374 static void decode_flac(void) {
 375 #if HAVE_FLAC_FILE_DECODER_H
 376   FLAC__FileDecoder *fd = 0;
 377   FLAC__FileDecoderState fs;
 378
 379   if(!(fd = FLAC__file_decoder_new()))
 380     fatal(0, "FLAC__file_decoder_new failed");
 381   if(!(FLAC__file_decoder_set_filename(fd, path)))
 382     fatal(0, "FLAC__file_set_filename failed");
 383   FLAC__file_decoder_set_metadata_callback(fd, flac_metadata);
 384   FLAC__file_decoder_set_error_callback(fd, flac_error);
 385   FLAC__file_decoder_set_write_callback(fd, flac_write);
 386   if((fs = FLAC__file_decoder_init(fd)))
 387     fatal(0, "FLAC__file_decoder_init: %s", FLAC__FileDecoderStateString[fs]);
 388   FLAC__file_decoder_process_until_end_of_file(fd);
 389 #else
 390   FLAC__StreamDecoder *sd = FLAC__stream_decoder_new();
 391   FLAC__StreamDecoderInitStatus is;
 392
 393   if (!sd)
 394         fatal(0, "FLAC__stream_decoder_new failed");
 395
 396   if((is = FLAC__stream_decoder_init_file(sd, path, flac_write, flac_metadata,
 397                                           flac_error, 0)))
 398     fatal(0, "FLAC__stream_decoder_init_file %s: %s",
 399           path, FLAC__StreamDecoderInitStatusString[is]);
 400
 401   FLAC__stream_decoder_process_until_end_of_stream(sd);
 402   FLAC__stream_decoder_finish(sd);
 403   FLAC__stream_decoder_delete(sd);
 404 #endif
 405 }
 406
 407 /** @brief Lookup table of decoders */
 408 static const struct decoder decoders[] = {
 409   { "*.mp3", decode_mp3 },
 410   { "*.MP3", decode_mp3 },
 411   { "*.ogg", decode_ogg },
 412   { "*.OGG", decode_ogg },
 413   { "*.flac", decode_flac },
 414   { "*.FLAC", decode_flac },
 415   { "*.wav", decode_wav },
 416   { "*.WAV", decode_wav },
 417   { 0, 0 }
 418 };
 419
 420 static const struct option options[] = {
 421   { "help", no_argument, 0, 'h' },
 422   { "version", no_argument, 0, 'V' },
 423   { 0, 0, 0, 0 }
 424 };
 425
 426 /* Display usage message and terminate. */
 427 static void help(void) {
 428   xprintf("Usage:\n"
 429           "  disorder-decode [OPTIONS] PATH\n"
 430           "Options:\n"
 431           "  --help, -h              Display usage message\n"
 432           "  --version, -V           Display version number\n"
 433           "\n"
 434           "Audio decoder for DisOrder.  Only intended to be used by speaker\n"
 435           "process, not for normal users.\n");
 436   xfclose(stdout);
 437   exit(0);
 438 }
 439
 440 int main(int argc, char **argv) {
 441   int n;
 442   const char *e;
 443
 444   set_progname(argv);
 445   if(!setlocale(LC_CTYPE, "")) fatal(errno, "calling setlocale");
 446   while((n = getopt_long(argc, argv, "hV", options, 0)) >= 0) {
 447     switch(n) {
 448     case 'h': help();
 449     case 'V': version("disorder-decode");
 450     default: fatal(0, "invalid option");
 451     }
 452   }
 453   if(optind >= argc)
 454     fatal(0, "missing filename");
 455   if(optind + 1 < argc)
 456     fatal(0, "excess arguments");
 457   if((e = getenv("DISORDER_RAW_FD"))) {
 458     if(!(outputfp = fdopen(atoi(e), "wb")))
 459       fatal(errno, "fdopen");
 460   } else
 461     outputfp = stdout;
 462   path = argv[optind];
 463   for(n = 0;
 464       decoders[n].pattern
 465         && fnmatch(decoders[n].pattern, path, 0) != 0;
 466       ++n)
 467     ;
 468   if(!decoders[n].pattern)
 469     fatal(0, "cannot determine file type for %s", path);
 470   decoders[n].decode();
 471   xfclose(outputfp);
 472   return 0;
 473 }
 474
 475 /*
 476 Local Variables:
 477 c-basic-offset:2
 478 comment-column:40
 479 fill-column:79
 480 indent-tabs-mode:nil
 481 End:
 482 */