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         uint32_t have, rv;
  39
  40         if (want == 0 || c->fpos >= c->mapsize) {
  41                 PARA_INFO_LOG("failed attempt to read %u bytes @%zu\n", want,
  42                         c->fpos);
  43                 errno = EAGAIN;
  44                 return -1;
  45         }
  46         have = c->mapsize - c->fpos;
  47         rv = PARA_MIN(have, want);
  48         PARA_DEBUG_LOG("reading %u bytes @%zu\n", rv, c->fpos);
  49         memcpy(dest, c->map + c->fpos, rv);
  50         c->fpos += rv;
  51         return rv;
  52 }
  53
  54 static uint32_t aac_afh_seek_cb(void *user_data, uint64_t pos)
  55 {
  56         struct aac_afh_context *c = user_data;
  57         c->fpos = pos;
  58         return 0;
  59 }
  60
  61 static int32_t aac_afh_get_track(mp4ff_t *mp4ff, mp4AudioSpecificConfig *masc)
  62 {
  63         int32_t i, rc, num_tracks = mp4ff_total_tracks(mp4ff);
  64
  65         assert(num_tracks >= 0);
  66         for (i = 0; i < num_tracks; i++) {
  67                 unsigned char *buf = NULL;
  68                 unsigned buf_size = 0;
  69
  70                 mp4ff_get_decoder_config(mp4ff, i, &buf, &buf_size);
  71                 if (buf) {
  72                         rc = NeAACDecAudioSpecificConfig(buf, buf_size, masc);
  73                         free(buf);
  74                         if (rc < 0)
  75                                 continue;
  76                         return i;
  77                 }
  78         }
  79         return -1; /* no audio track */
  80 }
  81
  82 static int aac_afh_open(const void *map, size_t mapsize, void **afh_context)
  83 {
  84         int ret;
  85         struct aac_afh_context *c = para_malloc(sizeof(*c));
  86
  87         c->map = map;
  88         c->mapsize = mapsize;
  89         c->fpos = 0;
  90         c->cb.read = aac_afh_read_cb;
  91         c->cb.seek = aac_afh_seek_cb;
  92         c->cb.user_data = c;
  93
  94         ret = -E_MP4FF_OPEN;
  95         c->mp4ff = mp4ff_open_read(&c->cb);
  96         if (!c->mp4ff)
  97                 goto free_ctx;
  98         c->track = aac_afh_get_track(c->mp4ff, &c->masc);
  99         ret = -E_MP4FF_TRACK;
 100         if (c->track < 0)
 101                 goto close_mp4ff;
 102         *afh_context = c;
 103         return 0;
 104 close_mp4ff:
 105         mp4ff_close(c->mp4ff);
 106 free_ctx:
 107         free(c);
 108         *afh_context = NULL;
 109         return ret;
 110 }
 111
 112 static void aac_afh_close(void *afh_context)
 113 {
 114         struct aac_afh_context *c = afh_context;
 115         mp4ff_close(c->mp4ff);
 116         free(c);
 117 }
 118
 119 /**
 120  * Libmp4ff function to reposition the file to the given sample.
 121  *
 122  * \param f The opaque handle returned by mp4ff_open_read().
 123  * \param track The number of the (audio) track.
 124  * \param sample Destination.
 125  *
 126  * We need this function to obtain the offset of the sample within the audio
 127  * file. Unfortunately, it is not exposed in the mp4ff header.
 128  *
 129  * \return This function always returns 0.
 130  */
 131 int32_t mp4ff_set_sample_position(mp4ff_t *f, const int32_t track, const int32_t sample);
 132
 133 static int aac_afh_get_chunk(long unsigned chunk_num, void *afh_context,
 134                 const char **buf, size_t *len)
 135 {
 136         struct aac_afh_context *c = afh_context;
 137         int32_t ss;
 138         size_t offset;
 139
 140         assert(chunk_num <= INT_MAX);
 141         /* this function always returns zero */
 142         mp4ff_set_sample_position(c->mp4ff, c->track, chunk_num);
 143         offset = c->fpos;
 144         ss = mp4ff_read_sample_getsize(c->mp4ff, c->track, chunk_num);
 145         if (ss <= 0)
 146                 return -E_MP4FF_BAD_SAMPLE;
 147         assert(ss + offset <= c->mapsize);
 148         *buf = c->map + offset;
 149         *len = ss;
 150         return 1;
 151 }
 152
 153 static void _aac_afh_get_taginfo(const mp4ff_t *mp4ff, struct taginfo *tags)
 154 {
 155         mp4ff_meta_get_artist(mp4ff, &tags->artist);
 156         mp4ff_meta_get_title(mp4ff, &tags->title);
 157         mp4ff_meta_get_date(mp4ff, &tags->year);
 158         mp4ff_meta_get_album(mp4ff, &tags->album);
 159         mp4ff_meta_get_comment(mp4ff, &tags->comment);
 160 }
 161
 162 /*
 163  * Init m4a file and write some tech data to given pointers.
 164  */
 165 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 166                 struct afh_info *afhi)
 167 {
 168         int ret;
 169         int32_t rv;
 170         struct aac_afh_context *c;
 171         int64_t tmp;
 172         const char *buf;
 173         size_t sz;
 174         uint32_t n;
 175
 176         ret = aac_afh_open(map, numbytes, (void **)&c);
 177         if (ret < 0)
 178                 return ret;
 179
 180         ret = -E_MP4FF_BAD_SAMPLERATE;
 181         rv = mp4ff_get_sample_rate(c->mp4ff, c->track);
 182         if (rv <= 0)
 183                 goto close;
 184         afhi->frequency = rv;
 185
 186         ret = -E_MP4FF_BAD_CHANNEL_COUNT;
 187         rv = mp4ff_get_channel_count(c->mp4ff, c->track);
 188         if (rv <= 0)
 189                 goto close;
 190         afhi->channels = rv;
 191
 192         ret = -E_MP4FF_BAD_SAMPLE_COUNT;
 193         rv = mp4ff_num_samples(c->mp4ff, c->track);
 194         if (rv <= 0)
 195                 goto close;
 196         afhi->chunks_total = rv;
 197         afhi->max_chunk_size = 0;
 198         for (n = 0; n < afhi->chunks_total; n++) {
 199                 if (aac_afh_get_chunk(n, c, &buf, &sz) < 0)
 200                         break;
 201                 afhi->max_chunk_size = PARA_MAX((size_t)afhi->max_chunk_size, sz);
 202         }
 203
 204         tmp = c->masc.sbr_present_flag == 1? 2048 : 1024;
 205         afhi->seconds_total = tmp * afhi->chunks_total / afhi->frequency;
 206         ms2tv(1000 * tmp / afhi->frequency, &afhi->chunk_tv);
 207
 208         if (aac_afh_get_chunk(0, c, &buf, &sz) >= 0)
 209                 numbytes -= buf - map;
 210         afhi->bitrate = 8 * numbytes / afhi->seconds_total / 1000;
 211         _aac_afh_get_taginfo(c->mp4ff, &afhi->tags);
 212         ret = 1;
 213 close:
 214         aac_afh_close(c);
 215         return ret;
 216 }
 217
 218 static uint32_t aac_afh_meta_read_cb(void *user_data, void *dest, uint32_t want)
 219 {
 220         int fd = *(int *)user_data;
 221         return read(fd, dest, want);
 222 }
 223
 224 static uint32_t aac_afh_meta_seek_cb(void *user_data, uint64_t pos)
 225 {
 226         int fd = *(int *)user_data;
 227         return lseek(fd, pos, SEEK_SET);
 228 }
 229
 230 static uint32_t aac_afh_meta_write_cb(void *user_data, void *dest, uint32_t want)
 231 {
 232         int fd = *(int *)user_data;
 233         return write(fd, dest, want);
 234 }
 235
 236 static uint32_t aac_afh_meta_truncate_cb(void *user_data)
 237 {
 238         int fd = *(int *)user_data;
 239         off_t offset = lseek(fd, 0, SEEK_CUR);
 240         return ftruncate(fd, offset);
 241 }
 242
 243 static void replace_tag(mp4ff_tag_t *tag, const char *new_val, bool *found)
 244 {
 245         free(tag->value);
 246         tag->value = para_strdup(new_val);
 247         *found = true;
 248 }
 249
 250 static void add_tag(mp4ff_metadata_t *md, const char *item, const char *value)
 251 {
 252         md->tags[md->count].item = para_strdup(item);
 253         md->tags[md->count].value = para_strdup(value);
 254         md->count++;
 255 }
 256
 257 static int aac_afh_rewrite_tags(const char *map, size_t mapsize,
 258                 struct taginfo *tags, int fd, __a_unused const char *filename)
 259 {
 260         int ret, i;
 261         int32_t rv;
 262         mp4ff_metadata_t metadata;
 263         mp4ff_t *mp4ff;
 264         mp4ff_callback_t cb = {
 265                 .read = aac_afh_meta_read_cb,
 266                 .seek = aac_afh_meta_seek_cb,
 267                 .write = aac_afh_meta_write_cb,
 268                 .truncate = aac_afh_meta_truncate_cb,
 269                 .user_data = &fd
 270         };
 271         bool found_artist = false, found_title = false, found_album = false,
 272                 found_year = false, found_comment = false;
 273
 274         ret = write_all(fd, map, mapsize);
 275         if (ret < 0)
 276                 return ret;
 277         lseek(fd, 0, SEEK_SET);
 278
 279         mp4ff = mp4ff_open_read_metaonly(&cb);
 280         if (!mp4ff)
 281                 return -E_MP4FF_OPEN;
 282
 283         ret = -E_MP4FF_META_READ;
 284         rv = mp4ff_meta_get_num_items(mp4ff);
 285         if (rv < 0)
 286                 goto close;
 287         metadata.count = rv;
 288         PARA_NOTICE_LOG("%d metadata item(s) found\n", rv);
 289
 290         metadata.tags = para_malloc((metadata.count + 5) * sizeof(mp4ff_tag_t));
 291         for (i = 0; i < metadata.count; i++) {
 292                 mp4ff_tag_t *tag = metadata.tags + i;
 293
 294                 ret = -E_MP4FF_META_READ;
 295                 if (mp4ff_meta_get_by_index(mp4ff, i,
 296                                 &tag->item, &tag->value) < 0)
 297                         goto free_tags;
 298                 PARA_INFO_LOG("found: %s: %s\n", tag->item, tag->value);
 299                 if (!strcmp(tag->item, "artist"))
 300                         replace_tag(tag, tags->artist, &found_artist);
 301                 else if (!strcmp(tag->item, "title"))
 302                         replace_tag(tag, tags->title, &found_title);
 303                 else if (!strcmp(tag->item, "album"))
 304                         replace_tag(tag, tags->album, &found_album);
 305                 else if (!strcmp(tag->item, "date"))
 306                         replace_tag(tag, tags->year, &found_year);
 307                 else if (!strcmp(tag->item, "comment"))
 308                         replace_tag(tag, tags->comment, &found_comment);
 309         }
 310         if (!found_artist)
 311                 add_tag(&metadata, "artist", tags->artist);
 312         if (!found_title)
 313                 add_tag(&metadata, "title", tags->title);
 314         if (!found_album)
 315                 add_tag(&metadata, "album", tags->album);
 316         if (!found_year)
 317                 add_tag(&metadata, "date", tags->year);
 318         if (!found_comment)
 319                 add_tag(&metadata, "comment", tags->comment);
 320         ret = -E_MP4FF_META_WRITE;
 321         if (mp4ff_meta_update(&cb, &metadata) < 0)
 322                 goto free_tags;
 323         ret = 1;
 324 free_tags:
 325         for (; i > 0; i--) {
 326                 free(metadata.tags[i - 1].item);
 327                 free(metadata.tags[i - 1].value);
 328         }
 329         free(metadata.tags);
 330 close:
 331         mp4ff_close(mp4ff);
 332         return ret;
 333 }
 334
 335 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
 336
 337 /**
 338  * The audio format handler for the Advanced Audio Codec.
 339  *
 340  * This is only compiled in if the faad library is installed.
 341  */
 342 const struct audio_format_handler aac_afh = {
 343         .get_file_info = aac_get_file_info,
 344         .suffixes = aac_suffixes,
 345         .rewrite_tags = aac_afh_rewrite_tags,
 346         .open = aac_afh_open,
 347         .get_chunk = aac_afh_get_chunk,
 348         .close = aac_afh_close,
 349 };