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 #include "mp4.h"
  14 #include "error.h"
  15 #include "portable_io.h"
  16 #include "afh.h"
  17 #include "string.h"
  18 #include "fd.h"
  19
  20
  21 struct aac_afh_context {
  22         const void *map;
  23         size_t mapsize;
  24         size_t fpos;
  25         struct mp4 *mp4;
  26         struct mp4_callback cb;
  27 };
  28
  29 static ssize_t aac_afh_read_cb(void *user_data, void *dest, size_t want)
  30 {
  31         struct aac_afh_context *c = user_data;
  32         size_t have, rv;
  33
  34         if (want == 0 || c->fpos >= c->mapsize)
  35                 return 0;
  36         have = c->mapsize - c->fpos;
  37         rv = PARA_MIN(have, want);
  38         PARA_DEBUG_LOG("reading %zu bytes @%zu\n", rv, c->fpos);
  39         memcpy(dest, c->map + c->fpos, rv);
  40         c->fpos += rv;
  41         return rv;
  42 }
  43
  44 static off_t aac_afh_seek_cb(void *user_data, off_t offset, int whence)
  45 {
  46         struct aac_afh_context *c = user_data;
  47
  48         if (whence == SEEK_SET)
  49                 c->fpos = offset;
  50         else if (whence == SEEK_CUR)
  51                 c->fpos += offset;
  52         else if (whence == SEEK_END)
  53                 c->fpos = c->mapsize + offset;
  54         else
  55                 assert(false);
  56         return c->fpos;
  57 }
  58
  59 static int aac_afh_open(const void *map, size_t mapsize, void **afh_context)
  60 {
  61         int ret;
  62         struct aac_afh_context *c = alloc(sizeof(*c));
  63
  64         c->map = map;
  65         c->mapsize = mapsize;
  66         c->fpos = 0;
  67         c->cb.read = aac_afh_read_cb;
  68         c->cb.seek = aac_afh_seek_cb;
  69         c->cb.user_data = c;
  70
  71         ret = mp4_open(&c->cb, &c->mp4);
  72         if (ret < 0)
  73                 goto free_ctx;
  74         *afh_context = c;
  75         return 0;
  76 free_ctx:
  77         free(c);
  78         *afh_context = NULL;
  79         return ret;
  80 }
  81
  82 static void aac_afh_close(void *afh_context)
  83 {
  84         struct aac_afh_context *c = afh_context;
  85         mp4_close(c->mp4);
  86         free(c);
  87 }
  88
  89 static int aac_afh_get_chunk(uint32_t chunk_num, void *afh_context,
  90                 const char **buf, uint32_t *len)
  91 {
  92         struct aac_afh_context *c = afh_context;
  93         uint32_t ss;
  94         size_t offset;
  95         int ret;
  96
  97         ret = mp4_set_sample_position(c->mp4, chunk_num);
  98         if (ret < 0)
  99                 return ret;
 100         offset = c->fpos;
 101         ret = mp4_get_sample_size(c->mp4, chunk_num, &ss);
 102         if (ret < 0)
 103                 return ret;
 104         if (ss + offset > c->mapsize) /* file got truncated?! */
 105                 return -E_MP4_CORRUPT;
 106         *buf = c->map + offset;
 107         *len = ss;
 108         return 1;
 109 }
 110
 111 static void aac_afh_get_taginfo(const struct mp4 *mp4, struct taginfo *tags)
 112 {
 113         tags->artist = mp4_get_tag_value(mp4, "artist");
 114         tags->title = mp4_get_tag_value(mp4, "title");
 115         tags->year = mp4_get_tag_value(mp4, "date");
 116         tags->album = mp4_get_tag_value(mp4, "album");
 117         tags->comment = mp4_get_tag_value(mp4, "comment");
 118 }
 119
 120 /*
 121  * Init m4a file and write some tech data to given pointers.
 122  */
 123 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 124                 struct afh_info *afhi)
 125 {
 126         int ret;
 127         struct aac_afh_context *c;
 128         uint64_t milliseconds;
 129         const char *buf;
 130         uint32_t n, len;
 131
 132         ret = aac_afh_open(map, numbytes, (void **)&c);
 133         if (ret < 0)
 134                 return ret;
 135
 136         afhi->frequency = mp4_get_sample_rate(c->mp4);
 137         assert(afhi->frequency > 0);
 138         afhi->channels = mp4_get_channel_count(c->mp4);
 139         assert(afhi->channels > 0);
 140         afhi->chunks_total = mp4_num_samples(c->mp4);
 141         assert(afhi->chunks_total > 0);
 142
 143         afhi->max_chunk_size = 0;
 144         for (n = 0; n < afhi->chunks_total; n++) {
 145                 ret = aac_afh_get_chunk(n, c, &buf, &len);
 146                 if (ret < 0)
 147                         goto out;
 148                 afhi->max_chunk_size = PARA_MAX(afhi->max_chunk_size, len);
 149         }
 150         milliseconds = mp4_get_duration(c->mp4);
 151         afhi->seconds_total = milliseconds / 1000;
 152         ms2tv(milliseconds / afhi->chunks_total, &afhi->chunk_tv);
 153         if (aac_afh_get_chunk(0, c, &buf, &len) < 0)
 154                 goto out;
 155         numbytes -= buf - map;
 156         afhi->bitrate = 8 * numbytes / afhi->seconds_total / 1000;
 157         aac_afh_get_taginfo(c->mp4, &afhi->tags);
 158         ret = 1;
 159 out:
 160         aac_afh_close(c);
 161         return ret;
 162 }
 163
 164 static ssize_t aac_afh_meta_read_cb(void *user_data, void *dest, size_t want)
 165 {
 166         int fd = *(int *)user_data;
 167         return read(fd, dest, want);
 168 }
 169
 170 static off_t aac_afh_meta_seek_cb(void *user_data, off_t offset, int whence)
 171 {
 172         int fd = *(int *)user_data;
 173         off_t ret = lseek(fd, offset, whence);
 174
 175         assert(ret != (off_t)-1);
 176         return ret;
 177 }
 178
 179 static ssize_t aac_afh_meta_write_cb(void *user_data, void *dest, size_t count)
 180 {
 181         int fd = *(int *)user_data;
 182         return write(fd, dest, count);
 183 }
 184
 185 static int aac_afh_meta_truncate_cb(void *user_data)
 186 {
 187         int fd = *(int *)user_data;
 188         off_t offset = lseek(fd, 0, SEEK_CUR);
 189         return ftruncate(fd, offset);
 190 }
 191
 192 static void replace_or_add_tag(const char *item, const char *value,
 193                 struct mp4_metadata *meta)
 194 {
 195         uint32_t n;
 196         struct mp4_tag *t;
 197
 198         for (n = 0; n < meta->count; n++) {
 199                 t = meta->tags + n;
 200                 if (strcasecmp(t->item, item))
 201                         continue;
 202                 free(t->value);
 203                 t->value = para_strdup(value);
 204                 return;
 205         }
 206         /* item not found, add new tag */
 207         meta->tags = para_realloc(meta->tags, (meta->count + 1)
 208                 * sizeof(struct mp4_tag));
 209         t = meta->tags + meta->count;
 210         t->item = para_strdup(item);
 211         t->value = para_strdup(value);
 212         meta->count++;
 213 }
 214
 215 static int aac_afh_rewrite_tags(const char *map, size_t mapsize,
 216                 struct taginfo *tags, int fd, __a_unused const char *filename)
 217 {
 218         int ret;
 219         struct mp4_metadata *metadata;
 220         struct mp4 *mp4;
 221         struct mp4_callback cb = {
 222                 .read = aac_afh_meta_read_cb,
 223                 .seek = aac_afh_meta_seek_cb,
 224                 .write = aac_afh_meta_write_cb,
 225                 .truncate = aac_afh_meta_truncate_cb,
 226                 .user_data = &fd
 227         };
 228
 229         ret = write_all(fd, map, mapsize);
 230         if (ret < 0)
 231                 return ret;
 232         lseek(fd, 0, SEEK_SET);
 233
 234         ret = mp4_open_meta(&cb, &mp4);
 235         if (ret < 0)
 236                 return ret;
 237         metadata = mp4_get_meta(mp4);
 238         PARA_NOTICE_LOG("%u metadata item(s) found\n", metadata->count);
 239         replace_or_add_tag("artist", tags->artist, metadata);
 240         replace_or_add_tag("title", tags->title, metadata);
 241         replace_or_add_tag("album", tags->album, metadata);
 242         replace_or_add_tag("date", tags->year, metadata);
 243         replace_or_add_tag("comment", tags->comment, metadata);
 244         ret = mp4_update_meta(mp4);
 245         mp4_close(mp4);
 246         return ret;
 247 }
 248
 249 static const char * const aac_suffixes[] = {"m4a", "mp4", NULL};
 250
 251 /**
 252  * The audio format handler for the Advanced Audio Codec.
 253  *
 254  * This is only compiled in if the faad library is installed.
 255  */
 256 const struct audio_format_handler aac_afh = {
 257         .get_file_info = aac_get_file_info,
 258         .suffixes = aac_suffixes,
 259         .rewrite_tags = aac_afh_rewrite_tags,
 260         .open = aac_afh_open,
 261         .get_chunk = aac_afh_get_chunk,
 262         .close = aac_afh_close,
 263 };