aac_afh.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 /*
   7  * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
   8  * Ahead Software AG
   9  */
  10
  11 /** \file aac_afh.c para_server's aac audio format handler. */
  12
  13 #include <regex.h>
  14 #include <mp4v2/mp4v2.h>
  15
  16 #include "para.h"
  17 #include "error.h"
  18 #include "afh.h"
  19 #include "string.h"
  20 #include "aac.h"
  21 #include "fd.h"
  22
  23 static int aac_find_stsz(unsigned char *buf, size_t buflen, off_t *skip)
  24 {
  25         int i;
  26
  27         for (i = 0; i + 16 < buflen; i++) {
  28                 unsigned char *p = buf + i;
  29                 unsigned sample_count, sample_size;
  30
  31                 if (p[0] != 's' || p[1] != 't' || p[2] != 's' || p[3] != 'z')
  32                         continue;
  33                 PARA_DEBUG_LOG("found stsz@%d\n", i);
  34                 i += 8;
  35                 sample_size = aac_read_int32(buf + i);
  36                 PARA_DEBUG_LOG("sample size: %d\n", sample_size);
  37                 i += 4;
  38                 sample_count = aac_read_int32(buf + i);
  39                 i += 4;
  40                 PARA_DEBUG_LOG("sample count: %d\n", sample_count);
  41                 *skip = i;
  42                 return sample_count;
  43         }
  44         return -E_STSZ;
  45 }
  46
  47 static int atom_cmp(const unsigned char *buf1, const char *buf2)
  48 {
  49         return memcmp(buf1, buf2, 4)? 1 : 0;
  50 }
  51
  52 static int read_atom_header(unsigned char *buf, uint64_t *subsize, unsigned char type[5])
  53 {
  54         int i;
  55         uint64_t size = aac_read_int32(buf);
  56
  57         memcpy(type, buf + 4, 4);
  58         type[4] = '\0';
  59
  60         PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
  61         if (size != 1) {
  62                 *subsize = size;
  63                 return 8;
  64         }
  65         buf += 4;
  66         size = 0;
  67         for (i = 0; i < 8; i++)
  68                 size |= ((uint64_t)buf[i]) << ((7 - i) * 8);
  69         *subsize = size;
  70         return 16;
  71 }
  72
  73 static char *get_tag(unsigned char *p, int size)
  74 {
  75         char *buf;
  76
  77         assert(size > 0);
  78         buf = para_malloc(size + 1);
  79
  80         memcpy(buf, p, size);
  81         buf[size] = '\0';
  82         PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
  83         return buf;
  84 }
  85
  86 static void read_tags(unsigned char *buf, size_t buflen, struct afh_info *afhi)
  87 {
  88         unsigned char *p = buf;
  89
  90         while (p + 32 < buf + buflen) {
  91                 unsigned char *q, type1[5], type2[5];
  92                 uint64_t size1, size2;
  93                 int ret, ret2;
  94
  95                 ret = read_atom_header(p, &size1, type1);
  96                 ret2 = read_atom_header(p + ret, &size2, type2);
  97
  98                 if (size2 <= 16 || atom_cmp(type2, "data")) {
  99                         p += size1;
 100                         continue;
 101                 }
 102                 size2 -= 16;
 103                 q = p + ret + ret2 + 8;
 104                 if (q + size2 > buf + buflen)
 105                         break;
 106                 if (!atom_cmp(type1, "\xa9" "ART"))
 107                         afhi->tags.artist = get_tag(q, size2);
 108                 else if (!atom_cmp(type1, "\xa9" "alb"))
 109                         afhi->tags.album = get_tag(q, size2);
 110                 else if (!atom_cmp(type1, "\xa9" "nam"))
 111                         afhi->tags.title = get_tag(q, size2);
 112                 else if (!atom_cmp(type1, "\xa9" "cmt"))
 113                         afhi->tags.comment = get_tag(q, size2);
 114                 else if (!atom_cmp(type1, "\xa9" "day"))
 115                         afhi->tags.year = get_tag(q, size2);
 116                 p += size1;
 117         }
 118 }
 119
 120 static void read_meta(unsigned char *buf, size_t buflen, struct afh_info *afhi)
 121 {
 122         unsigned char *p = buf;
 123
 124         while (p + 4 < buf + buflen) {
 125
 126                 if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
 127                         p++;
 128                         continue;
 129                 }
 130                 p += 4;
 131                 return read_tags(p, buflen - (p - buf), afhi);
 132         }
 133 }
 134
 135 static void aac_get_taginfo(unsigned char *buf, size_t buflen,
 136                 struct afh_info *afhi)
 137 {
 138         int i;
 139         uint64_t subsize;
 140         unsigned char type[5];
 141
 142         for (i = 0; i + 24 < buflen; i++) {
 143                 unsigned char *p = buf + i;
 144                 if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
 145                         continue;
 146                 PARA_INFO_LOG("found metadata at offset %d\n", i);
 147                 i += 8;
 148                 p = buf + i;
 149                 i += read_atom_header(p, &subsize, type);
 150                 p = buf + i;
 151                 return read_meta(p, buflen - i, afhi);
 152         }
 153         PARA_INFO_LOG("no meta data\n");
 154 }
 155
 156 static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
 157                 unsigned char *map, size_t numbytes)
 158 {
 159         int ret, i;
 160         size_t sum = 0;
 161         off_t skip;
 162
 163         ret = aac_find_stsz(map, numbytes, &skip);
 164         if (ret < 0)
 165                 return ret;
 166         afhi->chunks_total = ret;
 167         PARA_DEBUG_LOG("sz table has %" PRIu32 " entries\n", afhi->chunks_total);
 168         afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * sizeof(size_t));
 169         for (i = 1; i <= afhi->chunks_total; i++) {
 170                 if (skip + 4 > numbytes)
 171                         break;
 172                 sum += aac_read_int32(map + skip);
 173                 afhi->chunk_table[i] = sum;
 174                 skip += 4;
 175 //              if (i < 10 || i + 10 > afhi->chunks_total)
 176 //                      PARA_DEBUG_LOG("offset #%d: %zu\n", i, afhi->chunk_table[i]);
 177         }
 178         return skip;
 179 }
 180
 181 static int aac_set_chunk_tv(struct afh_info *afhi,
 182                 mp4AudioSpecificConfig *mp4ASC, uint32_t *seconds)
 183 {
 184         float tmp = mp4ASC->sbr_present_flag == 1? 2047 : 1023;
 185         struct timeval total;
 186         long unsigned ms;
 187
 188         if (!mp4ASC->samplingFrequency)
 189                 return -E_MP4ASC;
 190         ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
 191         ms2tv(ms, &total);
 192         tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
 193         PARA_INFO_LOG("%luHz, %lus (%" PRIu32 " x %lums)\n",
 194                 mp4ASC->samplingFrequency, ms / 1000,
 195                 afhi->chunks_total, tv2ms(&afhi->chunk_tv));
 196         if (ms < 1000)
 197                 return -E_MP4ASC;
 198         *seconds = ms / 1000;
 199         return 1;
 200 }
 201
 202 /*
 203  * Init m4a file and write some tech data to given pointers.
 204  */
 205 static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 206                 struct afh_info *afhi)
 207 {
 208         int i;
 209         size_t skip;
 210         ssize_t ret;
 211         unsigned long rate = 0, decoder_len;
 212         unsigned char channels = 0;
 213         mp4AudioSpecificConfig mp4ASC;
 214         NeAACDecHandle handle = NULL;
 215         unsigned char *umap = (unsigned char *) map;
 216
 217         ret = aac_find_esds(umap, numbytes, &skip, &decoder_len);
 218         if (ret < 0)
 219                 goto out;
 220         aac_get_taginfo(umap, numbytes, afhi);
 221         handle = aac_open();
 222         ret = -E_AAC_AFH_INIT;
 223         if (NeAACDecInit(handle, umap + skip, decoder_len, &rate, &channels))
 224                 goto out;
 225         if (!channels)
 226                 goto out;
 227         PARA_DEBUG_LOG("rate: %lu, channels: %d\n", rate, channels);
 228         ret = -E_MP4ASC;
 229         if (NeAACDecAudioSpecificConfig(umap + skip, numbytes - skip, &mp4ASC))
 230                 goto out;
 231         if (!mp4ASC.samplingFrequency)
 232                 goto out;
 233         ret = aac_compute_chunk_table(afhi, umap, numbytes);
 234         if (ret < 0)
 235                 goto out;
 236         skip = ret;
 237         ret = aac_set_chunk_tv(afhi, &mp4ASC, &afhi->seconds_total);
 238         if (ret < 0)
 239                 goto out;
 240         ret = aac_find_entry_point(umap + skip, numbytes - skip, &skip);
 241         if (ret < 0)
 242                 goto out;
 243         afhi->chunk_table[0] = ret;
 244         for (i = 1; i<= afhi->chunks_total; i++)
 245                 afhi->chunk_table[i] += ret;
 246         afhi->channels = channels;
 247         afhi->frequency = rate;
 248         ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
 249         ret += (channels * afhi->seconds_total * 500); /* avoid rounding error */
 250         afhi->bitrate = ret / (channels * afhi->seconds_total * 1000);
 251         ret = 1;
 252 out:
 253         if (handle)
 254                 NeAACDecClose(handle);
 255         return ret;
 256 }
 257
 258 static int aac_rewrite_tags(const char *map, size_t mapsize,
 259                 struct taginfo *tags, int fd, const char *filename)
 260 {
 261         MP4FileHandle h;
 262         const MP4Tags *mdata;
 263         int ret = write_all(fd, map, mapsize);
 264
 265         if (ret < 0)
 266                 return ret;
 267         lseek(fd, 0, SEEK_SET);
 268         h = MP4Modify(filename, 0);
 269         if (!h) {
 270                 PARA_ERROR_LOG("MP4Modify() failed, fd = %d\n", fd);
 271                 return -E_MP4V2;
 272         }
 273         mdata = MP4TagsAlloc();
 274         assert(mdata);
 275         if (!MP4TagsFetch(mdata, h)) {
 276                 PARA_ERROR_LOG("MP4Tags_Fetch() failed\n");
 277                 ret = -E_MP4V2;
 278                 goto close;
 279         }
 280
 281         if (!MP4TagsSetAlbum(mdata, tags->album)) {
 282                 PARA_ERROR_LOG("Could not set album\n");
 283                 ret = -E_MP4V2;
 284                 goto tags_free;
 285         }
 286         if (!MP4TagsSetArtist(mdata, tags->artist)) {
 287                 PARA_ERROR_LOG("Could not set album\n");
 288                 ret = -E_MP4V2;
 289                 goto tags_free;
 290         }
 291         if (!MP4TagsSetComments(mdata, tags->comment)) {
 292                 PARA_ERROR_LOG("Could not set comment\n");
 293                 ret = -E_MP4V2;
 294                 goto tags_free;
 295         }
 296         if (!MP4TagsSetName(mdata, tags->title)) {
 297                 PARA_ERROR_LOG("Could not set title\n");
 298                 ret = -E_MP4V2;
 299                 goto tags_free;
 300         }
 301         if (!MP4TagsSetReleaseDate(mdata, tags->year)) {
 302                 PARA_ERROR_LOG("Could not set release date\n");
 303                 ret = -E_MP4V2;
 304                 goto tags_free;
 305         }
 306
 307         if (!MP4TagsStore(mdata, h)) {
 308                 PARA_ERROR_LOG("Could not store tags\n");
 309                 ret = -E_MP4V2;
 310                 goto tags_free;
 311         }
 312         ret = 1;
 313 tags_free:
 314         MP4TagsFree(mdata);
 315 close:
 316         MP4Close(h, 0);
 317         return ret;
 318 }
 319
 320 static const char* aac_suffixes[] = {"m4a", "mp4", NULL};
 321 /**
 322  * the init function of the aac audio format handler
 323  *
 324  * \param afh pointer to the struct to initialize
 325  */
 326 void aac_afh_init(struct audio_format_handler *afh)
 327 {
 328         afh->get_file_info = aac_get_file_info,
 329         afh->suffixes = aac_suffixes;
 330         afh->rewrite_tags = aac_rewrite_tags;
 331 }