aac.c

   1 /*
   2  * Copyright 2006 dnk <dnk@bjum.net>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  17  * 02111-1307, USA.
  18  */
  19
  20 #include "ip.h"
  21 #include "xmalloc.h"
  22 #include "debug.h"
  23 #include "id3.h"
  24 #include "comment.h"
  25 #include "read_wrapper.h"
  26
  27 #include <faad.h>
  28
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <sys/types.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34
  35 /* FAAD_MIN_STREAMSIZE == 768, 6 == # of channels */
  36 #define BUFFER_SIZE     (FAAD_MIN_STREAMSIZE * 6 * 4)
  37
  38 struct aac_private {
  39         char rbuf[BUFFER_SIZE];
  40         int rbuf_len;
  41         int rbuf_pos;
  42
  43         unsigned char channels;
  44         unsigned long sample_rate;
  45
  46         char *overflow_buf;
  47         int overflow_buf_len;
  48
  49         faacDecHandle decoder;  /* typedef void * */
  50 };
  51
  52 static inline int buffer_length(const struct input_plugin_data *ip_data)
  53 {
  54         struct aac_private *priv = ip_data->private;
  55
  56         return priv->rbuf_len - priv->rbuf_pos;
  57 }
  58
  59 static inline void *buffer_data(const struct input_plugin_data *ip_data)
  60 {
  61         struct aac_private *priv = ip_data->private;
  62
  63         return priv->rbuf + priv->rbuf_pos;
  64 }
  65
  66 static int buffer_fill(struct input_plugin_data *ip_data)
  67 {
  68         struct aac_private *priv = ip_data->private;
  69         int32_t n;
  70
  71         if (priv->rbuf_pos > 0) {
  72                 priv->rbuf_len = buffer_length(ip_data);
  73                 memmove(priv->rbuf, priv->rbuf + priv->rbuf_pos, priv->rbuf_len);
  74                 priv->rbuf_pos = 0;
  75         }
  76
  77         if (priv->rbuf_len == BUFFER_SIZE)
  78                 return 1;
  79
  80         n = read_wrapper(ip_data, priv->rbuf + priv->rbuf_len, BUFFER_SIZE - priv->rbuf_len);
  81         if (n == -1)
  82                 return -1;
  83         if (n == 0)
  84                 return 0;
  85
  86         priv->rbuf_len += n;
  87         return 1;
  88 }
  89
  90 static inline void buffer_consume(struct input_plugin_data *ip_data, int n)
  91 {
  92         struct aac_private *priv = ip_data->private;
  93
  94         BUG_ON(n > buffer_length(ip_data));
  95
  96         priv->rbuf_pos += n;
  97 }
  98
  99 static int buffer_fill_min(struct input_plugin_data *ip_data, int len)
 100 {
 101         int rc;
 102
 103         BUG_ON(len > BUFFER_SIZE);
 104
 105         while (buffer_length(ip_data) < len) {
 106                 rc = buffer_fill(ip_data);
 107                 if (rc <= 0)
 108                         return rc;
 109         }
 110         return 1;
 111 }
 112
 113 /* 'data' must point to at least 6 bytes of data */
 114 static inline int parse_frame(const unsigned char data[6])
 115 {
 116         int len;
 117
 118         /* http://www.audiocoding.com/modules/wiki/?page=ADTS */
 119
 120         /* first 12 bits must be set */
 121         if (data[0] != 0xFF)
 122                 return 0;
 123         if ((data[1] & 0xF0) != 0xF0)
 124                 return 0;
 125
 126         /* layer is always '00' */
 127         if ((data[1] & 0x06) != 0x00)
 128                 return 0;
 129
 130         /* frame length is stored in 13 bits */
 131         len  = data[3] << 11;   /* ..1100000000000 */
 132         len |= data[4] << 3;    /* ..xx11111111xxx */
 133         len |= data[5] >> 5;    /* ..xxxxxxxxxx111 */
 134         len &= 0x1FFF;          /* 13 bits */
 135         return len;
 136 }
 137
 138 /* scans forward to the next aac frame and makes sure
 139  * the entire frame is in the buffer.
 140  */
 141 static int buffer_fill_frame(struct input_plugin_data *ip_data)
 142 {
 143         unsigned char *data;
 144         int rc, n, len;
 145         int max = 32768;
 146
 147         while (1) {
 148                 /* need at least 6 bytes of data */
 149                 rc = buffer_fill_min(ip_data, 6);
 150                 if (rc <= 0)
 151                         return rc;
 152
 153                 len = buffer_length(ip_data);
 154                 data = buffer_data(ip_data);
 155
 156                 /* scan for a frame */
 157                 for (n = 0; n < len - 5; n++) {
 158                         /* give up after 32KB */
 159                         if (max-- == 0) {
 160                                 d_print("no frame found!\n");
 161                                 /* FIXME: set errno? */
 162                                 return -1;
 163                         }
 164
 165                         /* see if there's a frame at this location */
 166                         rc = parse_frame(data + n);
 167                         if (rc == 0)
 168                                 continue;
 169
 170                         /* found a frame, consume all data up to the frame */
 171                         buffer_consume(ip_data, n);
 172
 173                         /* rc == frame length */
 174                         rc = buffer_fill_min(ip_data, rc);
 175                         if (rc <= 0)
 176                                 return rc;
 177
 178                         return 1;
 179                 }
 180
 181                 /* consume what we used */
 182                 buffer_consume(ip_data, n);
 183         }
 184         /* not reached */
 185 }
 186
 187 static int aac_open(struct input_plugin_data *ip_data)
 188 {
 189         struct aac_private *priv;
 190         faacDecConfigurationPtr neaac_cfg;
 191         int ret, n;
 192
 193         /* init private struct */
 194         priv = xnew0(struct aac_private, 1);
 195         priv->decoder = faacDecOpen();
 196         ip_data->private = priv;
 197
 198         /* set decoder config */
 199         neaac_cfg = faacDecGetCurrentConfiguration(priv->decoder);
 200         neaac_cfg->outputFormat = FAAD_FMT_16BIT;       /* force 16 bit audio */
 201         neaac_cfg->downMatrix = 1;                      /* 5.1 -> stereo */
 202         neaac_cfg->dontUpSampleImplicitSBR = 0;         /* upsample, please! */
 203         faacDecSetConfiguration(priv->decoder, neaac_cfg);
 204
 205         /* find a frame */
 206         if (buffer_fill_frame(ip_data) <= 0) {
 207                 ret = -IP_ERROR_FILE_FORMAT;
 208                 goto out;
 209         }
 210
 211         /* in case of a bug, make sure there is at least some data
 212          * in the buffer for faacDecInit() to work with.
 213          */
 214         if (buffer_fill_min(ip_data, 256) <= 0) {
 215                 d_print("not enough data\n");
 216                 ret = -IP_ERROR_FILE_FORMAT;
 217                 goto out;
 218         }
 219
 220         /* init decoder, returns the length of the header (if any) */
 221         n = faacDecInit(priv->decoder, buffer_data(ip_data), buffer_length(ip_data),
 222                 &priv->sample_rate, &priv->channels);
 223         if (n < 0) {
 224                 d_print("faacDecInit failed\n");
 225                 ret = -IP_ERROR_FILE_FORMAT;
 226                 goto out;
 227         }
 228
 229         d_print("sample rate %luhz, channels %u\n", priv->sample_rate, priv->channels);
 230         if (!priv->sample_rate || !priv->channels) {
 231                 ret = -IP_ERROR_FILE_FORMAT;
 232                 goto out;
 233         }
 234
 235         /* skip the header */
 236         d_print("skipping header (%d bytes)\n", n);
 237
 238         buffer_consume(ip_data, n);
 239
 240         /*faacDecInitDRM(priv->decoder, priv->sample_rate, priv->channels);*/
 241
 242         ip_data->sf = sf_rate(priv->sample_rate) | sf_channels(priv->channels) | sf_bits(16) | sf_signed(1);
 243 #if defined(WORDS_BIGENDIAN)
 244         ip_data->sf |= sf_bigendian(1);
 245 #endif
 246         return 0;
 247 out:
 248         faacDecClose(priv->decoder);
 249         free(priv);
 250         return ret;
 251 }
 252
 253 static int aac_close(struct input_plugin_data *ip_data)
 254 {
 255         struct aac_private *priv = ip_data->private;
 256
 257         faacDecClose(priv->decoder);
 258         free(priv);
 259         ip_data->private = NULL;
 260         return 0;
 261 }
 262
 263 /* returns -1 on fatal errors
 264  * returns -2 on non-fatal errors
 265  * 0 on eof
 266  * number of bytes put in 'buffer' on success */
 267 static int decode_one_frame(struct input_plugin_data *ip_data, void *buffer, int count)
 268 {
 269         struct aac_private *priv = ip_data->private;
 270         unsigned char *aac_data;
 271         unsigned int aac_data_size;
 272         faacDecFrameInfo frame_info;
 273         char *sample_buf;
 274         int bytes, rc;
 275
 276         rc = buffer_fill_frame(ip_data);
 277         if (rc <= 0)
 278                 return rc;
 279
 280         aac_data = buffer_data(ip_data);
 281         aac_data_size = buffer_length(ip_data);
 282
 283         /* aac data -> raw pcm */
 284         sample_buf = faacDecDecode(priv->decoder, &frame_info, aac_data, aac_data_size);
 285
 286         buffer_consume(ip_data, frame_info.bytesconsumed);
 287
 288         if (!sample_buf || frame_info.bytesconsumed <= 0) {
 289                 d_print("fatal error: %s\n", faacDecGetErrorMessage(frame_info.error));
 290                 errno = EINVAL;
 291                 return -1;
 292         }
 293
 294         if (frame_info.error != 0) {
 295                 d_print("frame error: %s\n", faacDecGetErrorMessage(frame_info.error));
 296                 return -2;
 297         }
 298
 299         if (frame_info.samples <= 0)
 300                 return -2;
 301
 302         if (frame_info.channels != priv->channels || frame_info.samplerate != priv->sample_rate) {
 303                 d_print("invalid channel or sample_rate count\n");
 304                 return -2;
 305         }
 306
 307         /* 16-bit samples */
 308         bytes = frame_info.samples * 2;
 309
 310         if (bytes > count) {
 311                 /* decoded too much, keep overflow */
 312                 priv->overflow_buf = sample_buf + count;
 313                 priv->overflow_buf_len = bytes - count;
 314                 memcpy(buffer, sample_buf, count);
 315                 return count;
 316         } else {
 317                 memcpy(buffer, sample_buf, bytes);
 318         }
 319         return bytes;
 320 }
 321
 322 static int aac_read(struct input_plugin_data *ip_data, char *buffer, int count)
 323 {
 324         struct aac_private *priv = ip_data->private;
 325         int rc;
 326
 327         /* use overflow from previous call (if any) */
 328         if (priv->overflow_buf_len) {
 329                 int len = priv->overflow_buf_len;
 330
 331                 if (len > count)
 332                         len = count;
 333
 334                 memcpy(buffer, priv->overflow_buf, len);
 335                 priv->overflow_buf += len;
 336                 priv->overflow_buf_len -= len;
 337                 return len;
 338         }
 339
 340         do {
 341                 rc = decode_one_frame(ip_data, buffer, count);
 342         } while (rc == -2);
 343         return rc;
 344 }
 345
 346 static int aac_seek(struct input_plugin_data *ip_data, double offset)
 347 {
 348         return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 349 }
 350
 351 static int aac_read_comments(struct input_plugin_data *ip_data,
 352                 struct keyval **comments)
 353 {
 354         GROWING_KEYVALS(c);
 355         struct id3tag id3;
 356         int rc, fd, i;
 357
 358         fd = open(ip_data->filename, O_RDONLY);
 359         if (fd == -1)
 360                 return -1;
 361
 362         id3_init(&id3);
 363         rc = id3_read_tags(&id3, fd, ID3_V1 | ID3_V2);
 364         if (rc == -1) {
 365                 d_print("error: %s\n", strerror(errno));
 366                 goto out;
 367         }
 368
 369         for (i = 0; i < NUM_ID3_KEYS; i++) {
 370                 char *val = id3_get_comment(&id3, i);
 371
 372                 if (val)
 373                         comments_add(&c, id3_key_names[i], val);
 374         }
 375 out:
 376         close(fd);
 377         id3_free(&id3);
 378         keyvals_terminate(&c);
 379         *comments = c.keyvals;
 380         return 0;
 381 }
 382
 383 static int aac_duration(struct input_plugin_data *ip_data)
 384 {
 385         struct aac_private *priv = ip_data->private;
 386         faacDecFrameInfo frame_info;
 387         int samples = 0, bytes = 0, frames = 0;
 388         off_t file_size;
 389         char *sample_buf;
 390
 391         file_size = lseek(ip_data->fd, 0, SEEK_END);
 392         if (file_size == -1)
 393                 return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 394
 395         /* guess track length by decoding the first 10 frames */
 396         while (frames < 10) {
 397                 if (buffer_fill_frame(ip_data) <= 0)
 398                         break;
 399
 400                 sample_buf = faacDecDecode(priv->decoder, &frame_info,
 401                         buffer_data(ip_data), buffer_length(ip_data));
 402                 if (frame_info.error == 0 && frame_info.samples > 0) {
 403                         samples += frame_info.samples;
 404                         bytes += frame_info.bytesconsumed;
 405                         frames++;
 406                 }
 407                 if (frame_info.bytesconsumed == 0)
 408                         break;
 409
 410                 buffer_consume(ip_data, frame_info.bytesconsumed);
 411         }
 412
 413         if (frames == 0)
 414                 return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 415
 416         samples /= frames;
 417         samples /= priv->channels;
 418         bytes /= frames;
 419
 420         return ((file_size / bytes) * samples) / priv->sample_rate;
 421 }
 422
 423 const struct input_plugin_ops ip_ops = {
 424         .open = aac_open,
 425         .close = aac_close,
 426         .read = aac_read,
 427         .seek = aac_seek,
 428         .read_comments = aac_read_comments,
 429         .duration = aac_duration
 430 };
 431
 432 const char * const ip_extensions[] = { "aac", NULL };
 433 const char * const ip_mime_types[] = { "audio/aac", "audio/aacp", NULL };