aac_afh.c

   1 /* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2 /*
   3  * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
   4  * Ahead Software AG
   5  */
   6
   7 /** \file aac_afh.c para_server's aac audio format handler. */
   8
   9 #include <regex.h>
  10 #include <neaacdec.h>
  11
  12 #include "para.h"
  13
  14 /* To get the mp4ff_tag_t and mp4ff_metadata_t typedefs. */
  15 #define USE_TAGGING
  16 #include <mp4ff.h>
  17
  18 #include "error.h"
  19 #include "portable_io.h"
  20 #include "afh.h"
  21 #include "string.h"
  22 #include "fd.h"
  23
  24
  25 struct aac_afh_context {
  26         const void *map;
  27         size_t mapsize;
  28         size_t fpos;
  29         int32_t track;
  30         mp4ff_t *mp4ff;
  31         mp4AudioSpecificConfig masc;
  32         mp4ff_callback_t cb;
  33 };
  34
  35 static uint32_t aac_afh_read_cb(void *user_data, void *dest, uint32_t want)
  36 {
  37         struct aac_afh_context *c = user_data;
  38         size_t have, rv;
  39
  40         if (want == 0 || c->fpos >= c->mapsize)
  41                 return 0;
  42         have = c->mapsize - c->fpos;
  43         rv = PARA_MIN(have, (size_t)want);
  44         PARA_DEBUG_LOG("reading %zu bytes @%zu\n", rv, c->fpos);
  45         memcpy(dest, c->map + c->fpos, rv);
  46         c->fpos += rv;
  47         return rv;
  48 }
  49
  50 static uint32_t aac_afh_seek_cb(void *user_data, uint64_t pos)
  51 {
  52         struct aac_afh_context *c = user_data;
  53         c->fpos = pos;
  54         return 0;
  55 }
  56
  57 static int32_t aac_afh_get_track(mp4ff_t *mp4ff, mp4AudioSpecificConfig *masc)
  58 {
  59         int32_t i, rc, num_tracks = mp4ff_total_tracks(mp4ff);
  60
  61         assert(num_tracks >= 0);
  62         for (i = 0; i < num_tracks; i++) {
  63                 unsigned char *buf = NULL;
  64                 unsigned buf_size = 0;
  65
  66                 mp4ff_get_decoder_config(mp4ff, i, &buf, &buf_size);
  67                 if (buf) {
  68                         rc = NeAACDecAudioSpecificConfig(buf, buf_size, masc);
  69                         free(buf);
  70                         if (rc < 0)
  71                                 continue;
  72                         return i;
  73                 }
  74         }
  75         return -1; /* no audio track */
  76 }
  77
  78 static int aac_afh_open(const void *map, size_t mapsize, void **afh_context)
  79 {
  80         int ret;
  81         struct aac_afh_context *c = para_malloc(sizeof(*c));
  82
  83         c->map = map;
  84         c->mapsize = mapsize;
  85         c->fpos = 0;
  86         c->cb.read = aac_afh_read_cb;
  87         c->cb.seek = aac_afh_seek_cb;
  88         c->cb.user_data = c;
  89
  90         ret = -E_MP4FF_OPEN;
  91         c->mp4ff = mp4ff_open_read(&c->cb);
  92         if (!c->mp4ff)
  93                 goto free_ctx;
  94         c->track = aac_afh_get_track(c->mp4ff, &c->masc);
  95         ret = -E_MP4FF_TRACK;
  96         if (c->track < 0)
  97                 goto close_mp4ff;
  98         *afh_context = c;
  99         return 0;
 100 close_mp4ff:
 101         mp4ff_close(c->mp4ff);
 102 free_ctx:
 103         free(c);
 104         *afh_context = NULL;
 105         return ret;
 106 }
 107
 108 static void aac_afh_close(void *afh_context)
 109 {
 110         struct aac_afh_context *c = afh_context;
 111         mp4ff_close(c->mp4ff);
 112         free(c);
 113 }
 114
 115 /**
 116  * Libmp4ff function to reposition the file to the given sample.
 117  *
 118  * \param f The opaque handle returned by mp4ff_open_read().
 119  * \param track The number of the (audio) track.
 120  * \param sample Destination.
 121  *
 122  * We need this function to obtain the offset of the sample within the audio
 123  * file. Unfortunately, it is not exposed in the mp4ff header.
 124  *
 125  * \return This function always returns 0.
 126  */
 127 int32_t mp4ff_set_sample_position(mp4ff_t *f, const int32_t track, const int32_t sample);
 128
 129 static int aac_afh_get_chunk(uint32_t chunk_num, void *afh_context,
 130                 const char **buf, uint32_t *len)
 131 {
 132         struct aac_afh_context *c = afh_context;
 133         int32_t ss;
 134         size_t offset;
 135
 136         assert(chunk_num <= INT_MAX);
 137         /* this function always returns zero */
 138         mp4ff_set_sample_position(c->mp4ff, c->track, chunk_num);
 139         offset = c->fpos;
 140         ss = mp4ff_read_sample_getsize(c->mp4ff, c->track, chunk_num);
 141         if (ss <= 0)
 142                 return -E_MP4FF_BAD_SAMPLE;
 143         assert(ss + offset <= c->mapsize);
 144         *buf = c->map + offset;
 145         *len = ss;
 146         return 1;
 147 }
 148
 149 static void _aac_afh_get_taginfo(const mp4ff_t *mp4ff, struct taginfo *tags)
 150 {
 151         mp4ff_meta_get_artist(mp4ff, &tags->artist);
 152         mp4ff_meta_get_title(mp4ff, &tags->title);
 153         mp4ff_meta_get_date(mp4ff, &tags->year);
 154         mp4ff_meta_get_album(mp4ff, &tags->album);
 155         mp4ff_meta_get_comment(mp4ff, &tags->comment);
 156 }
 157
 158 /*
 159  * Init m4a file and write some tech data to given pointers.
 160  */
 161 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 162                 struct afh_info *afhi)
 163 {
 164         int ret;
 165         int32_t rv;
 166         struct aac_afh_context *c;
 167         int64_t tmp;
 168         const char *buf;
 169         uint32_t n, len;
 170
 171         ret = aac_afh_open(map, numbytes, (void **)&c);
 172         if (ret < 0)
 173                 return ret;
 174
 175         ret = -E_MP4FF_BAD_SAMPLERATE;
 176         rv = mp4ff_get_sample_rate(c->mp4ff, c->track);
 177         if (rv <= 0)
 178                 goto close;
 179         afhi->frequency = rv;
 180
 181         ret = -E_MP4FF_BAD_CHANNEL_COUNT;
 182         rv = mp4ff_get_channel_count(c->mp4ff, c->track);
 183         if (rv <= 0)
 184                 goto close;
 185         afhi->channels = rv;
 186
 187         ret = -E_MP4FF_BAD_SAMPLE_COUNT;
 188         rv = mp4ff_num_samples(c->mp4ff, c->track);
 189         if (rv <= 0)
 190                 goto close;
 191         afhi->chunks_total = rv;
 192         afhi->max_chunk_size = 0;
 193         for (n = 0; n < afhi->chunks_total; n++) {
 194                 if (aac_afh_get_chunk(n, c, &buf, &len) < 0)
 195                         break;
 196                 afhi->max_chunk_size = PARA_MAX(afhi->max_chunk_size, len);
 197         }
 198
 199         tmp = c->masc.sbr_present_flag == 1? 2048 : 1024;
 200         afhi->seconds_total = tmp * afhi->chunks_total / afhi->frequency;
 201         ms2tv(1000 * tmp / afhi->frequency, &afhi->chunk_tv);
 202
 203         if (aac_afh_get_chunk(0, c, &buf, &len) >= 0)
 204                 numbytes -= buf - map;
 205         afhi->bitrate = 8 * numbytes / afhi->seconds_total / 1000;
 206         _aac_afh_get_taginfo(c->mp4ff, &afhi->tags);
 207         ret = 1;
 208 close:
 209         aac_afh_close(c);
 210         return ret;
 211 }
 212
 213 static uint32_t aac_afh_meta_read_cb(void *user_data, void *dest, uint32_t want)
 214 {
 215         int fd = *(int *)user_data;
 216         return read(fd, dest, want);
 217 }
 218
 219 static uint32_t aac_afh_meta_seek_cb(void *user_data, uint64_t pos)
 220 {
 221         int fd = *(int *)user_data;
 222         return lseek(fd, pos, SEEK_SET);
 223 }
 224
 225 static uint32_t aac_afh_meta_write_cb(void *user_data, void *dest, uint32_t want)
 226 {
 227         int fd = *(int *)user_data;
 228         return write(fd, dest, want);
 229 }
 230
 231 static uint32_t aac_afh_meta_truncate_cb(void *user_data)
 232 {
 233         int fd = *(int *)user_data;
 234         off_t offset = lseek(fd, 0, SEEK_CUR);
 235         return ftruncate(fd, offset);
 236 }
 237
 238 static void replace_tag(mp4ff_tag_t *tag, const char *new_val, bool *found)
 239 {
 240         free(tag->value);
 241         tag->value = para_strdup(new_val);
 242         *found = true;
 243 }
 244
 245 static void add_tag(mp4ff_metadata_t *md, const char *item, const char *value)
 246 {
 247         md->tags[md->count].item = para_strdup(item);
 248         md->tags[md->count].value = para_strdup(value);
 249         md->count++;
 250 }
 251
 252 static int aac_afh_rewrite_tags(const char *map, size_t mapsize,
 253                 struct taginfo *tags, int fd, __a_unused const char *filename)
 254 {
 255         int ret, i;
 256         int32_t rv;
 257         mp4ff_metadata_t metadata;
 258         mp4ff_t *mp4ff;
 259         mp4ff_callback_t cb = {
 260                 .read = aac_afh_meta_read_cb,
 261                 .seek = aac_afh_meta_seek_cb,
 262                 .write = aac_afh_meta_write_cb,
 263                 .truncate = aac_afh_meta_truncate_cb,
 264                 .user_data = &fd
 265         };
 266         bool found_artist = false, found_title = false, found_album = false,
 267                 found_year = false, found_comment = false;
 268
 269         ret = write_all(fd, map, mapsize);
 270         if (ret < 0)
 271                 return ret;
 272         lseek(fd, 0, SEEK_SET);
 273
 274         mp4ff = mp4ff_open_read_metaonly(&cb);
 275         if (!mp4ff)
 276                 return -E_MP4FF_OPEN;
 277
 278         ret = -E_MP4FF_META_READ;
 279         rv = mp4ff_meta_get_num_items(mp4ff);
 280         if (rv < 0)
 281                 goto close;
 282         metadata.count = rv;
 283         PARA_NOTICE_LOG("%d metadata item(s) found\n", rv);
 284
 285         metadata.tags = para_malloc((metadata.count + 5) * sizeof(mp4ff_tag_t));
 286         for (i = 0; i < metadata.count; i++) {
 287                 mp4ff_tag_t *tag = metadata.tags + i;
 288
 289                 ret = -E_MP4FF_META_READ;
 290                 if (!mp4ff_meta_get_by_index(mp4ff, i, &tag->item, &tag->value))
 291                         goto free_tags;
 292                 PARA_INFO_LOG("found: %s: %s\n", tag->item, tag->value);
 293                 if (!strcmp(tag->item, "artist"))
 294                         replace_tag(tag, tags->artist, &found_artist);
 295                 else if (!strcmp(tag->item, "title"))
 296                         replace_tag(tag, tags->title, &found_title);
 297                 else if (!strcmp(tag->item, "album"))
 298                         replace_tag(tag, tags->album, &found_album);
 299                 else if (!strcmp(tag->item, "date"))
 300                         replace_tag(tag, tags->year, &found_year);
 301                 else if (!strcmp(tag->item, "comment"))
 302                         replace_tag(tag, tags->comment, &found_comment);
 303         }
 304         if (!found_artist)
 305                 add_tag(&metadata, "artist", tags->artist);
 306         if (!found_title)
 307                 add_tag(&metadata, "title", tags->title);
 308         if (!found_album)
 309                 add_tag(&metadata, "album", tags->album);
 310         if (!found_year)
 311                 add_tag(&metadata, "date", tags->year);
 312         if (!found_comment)
 313                 add_tag(&metadata, "comment", tags->comment);
 314         ret = -E_MP4FF_META_WRITE;
 315         if (!mp4ff_meta_update(&cb, &metadata))
 316                 goto free_tags;
 317         ret = 1;
 318 free_tags:
 319         for (; i > 0; i--) {
 320                 free(metadata.tags[i - 1].item);
 321                 free(metadata.tags[i - 1].value);
 322         }
 323         free(metadata.tags);
 324 close:
 325         mp4ff_close(mp4ff);
 326         return ret;
 327 }
 328
 329 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
 330
 331 /**
 332  * The audio format handler for the Advanced Audio Codec.
 333  *
 334  * This is only compiled in if the faad library is installed.
 335  */
 336 const struct audio_format_handler aac_afh = {
 337         .get_file_info = aac_get_file_info,
 338         .suffixes = aac_suffixes,
 339         .rewrite_tags = aac_afh_rewrite_tags,
 340         .open = aac_afh_open,
 341         .get_chunk = aac_afh_get_chunk,
 342         .close = aac_afh_close,
 343 };