opus_afh.c

   1 /*
   2  * Copyright (C) 2012 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file opus_afh.c Audio format handler for ogg/opus files. */
   8
   9 #include <ogg/ogg.h>
  10 #include <regex.h>
  11
  12 #include "para.h"
  13 #include "afh.h"
  14 #include "error.h"
  15 #include "portable_io.h"
  16 #include "string.h"
  17 #include "opus_common.h"
  18 #include "ogg_afh_common.h"
  19
  20 static const char * const opus_suffixes[] = {"opus", NULL};
  21
  22 #define OPUS_COMMENT_HEADER "OpusTags"
  23
  24 static bool copy_if_tag_type(const char *tag, int taglen, const char *type,
  25                 char **p)
  26 {
  27         char *q = key_value_copy(tag, taglen, type);
  28         if (!q)
  29                 return false;
  30         free(*p);
  31         *p = q;
  32         return true;
  33 }
  34
  35 static int opus_get_comments(char *comments, int length,
  36                 struct taginfo *tags)
  37 {
  38         char *p = comments, *end = comments + length;
  39         int i;
  40         uint32_t val, ntags;
  41
  42         /* min size of a opus header is 16 bytes */
  43         if (length < 16)
  44                 return -E_OPUS_COMMENT;
  45         if (memcmp(p, OPUS_COMMENT_HEADER, strlen(OPUS_COMMENT_HEADER)) != 0)
  46                 return -E_OPUS_COMMENT;
  47         p += 8;
  48         val = read_u32(p);
  49         p += 4;
  50         if (p + val > end)
  51                 return -E_OPUS_COMMENT;
  52         tags->comment = safe_strdup(p, val);
  53         p += val;
  54         ntags = read_u32(p);
  55         p += 4;
  56         if (p + ntags * 4 > end)
  57                 return -E_OPUS_COMMENT;
  58         PARA_INFO_LOG("found %u tag(s)\n", ntags);
  59         for (i = 0; i < ntags; i++, p += val) {
  60                 char *tag;
  61
  62                 if (p + 4 > end)
  63                         return -E_OPUS_COMMENT;
  64                 val = read_u32(p);
  65                 p += 4;
  66                 if (p + val > end)
  67                         return -E_OPUS_COMMENT;
  68                 if (copy_if_tag_type(p, val, "author", &tags->artist))
  69                         continue;
  70                 if (copy_if_tag_type(p, val, "artist", &tags->artist))
  71                         continue;
  72                 if (copy_if_tag_type(p, val, "title", &tags->title))
  73                         continue;
  74                 if (copy_if_tag_type(p, val, "album", &tags->album))
  75                         continue;
  76                 if (copy_if_tag_type(p, val, "year", &tags->year))
  77                         continue;
  78                 if (copy_if_tag_type(p, val, "comment", &tags->comment))
  79                         continue;
  80                 tag = safe_strdup(p, val);
  81                 PARA_NOTICE_LOG("unrecognized tag: %s\n", tag);
  82                 free(tag);
  83         }
  84         return 1;
  85 }
  86
  87 static int opus_packet_callback(ogg_packet *packet, int packet_num,
  88                 __a_unused int serial, struct afh_info *afhi,
  89                 void *private_data)
  90 {
  91         int ret;
  92         struct opus_header *oh = private_data;
  93
  94         if (packet_num == 0) {
  95                 ret = opus_parse_header((char *)packet->packet, packet->bytes, oh);
  96                 if (ret < 0)
  97                         return ret;
  98                 afhi->channels = oh->channels;
  99                 afhi->techinfo = make_message(
 100                         "header version %d, input sample rate: %" PRIu32 "Hz",
 101                         oh->version, oh->input_sample_rate);
 102                 /*
 103                  * The input sample rate is irrelevant for afhi->frequency as
 104                  * we always decode to 48kHz.
 105                  */
 106                 afhi->frequency = 48000;
 107                 return 1;
 108         }
 109         if (packet_num == 1) {
 110                 ret = opus_get_comments((char *)packet->packet, packet->bytes,
 111                         &afhi->tags);
 112                 if (ret < 0)
 113                         return ret;
 114                 return 0; /* header complete */
 115         }
 116         /* never reached */
 117         assert(0);
 118 }
 119
 120 static int opus_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 121                 struct afh_info *afhi)
 122 {
 123         int ret, ms;
 124         struct opus_header oh = {.version = 0};
 125
 126         struct ogg_afh_callback_info opus_callback_info = {
 127                 .packet_callback = opus_packet_callback,
 128                 .private_data = &oh,
 129         };
 130         ret = ogg_get_file_info(map, numbytes, afhi, &opus_callback_info);
 131         if (ret < 0)
 132                 return ret;
 133         ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
 134         ms = tv2ms(&afhi->chunk_tv) * afhi->chunks_total;
 135         afhi->bitrate = ret / ms;
 136         return 1;
 137 }
 138
 139 static size_t opus_make_meta_packet(struct taginfo *tags, char **result)
 140 {
 141         size_t sz;
 142         char *buf, *p;
 143         size_t comment_len = strlen(tags->comment),
 144                 artist_len = strlen(tags->artist),
 145                 title_len = strlen(tags->title),
 146                 album_len = strlen(tags->album),
 147                 year_len = strlen(tags->year);
 148         uint32_t comment_sz = comment_len,
 149                 artist_sz = artist_len + strlen("artist="),
 150                 title_sz = title_len + strlen("title="),
 151                 album_sz = album_len + strlen("album="),
 152                 year_sz = year_len + strlen("year=");
 153         uint32_t num_tags;
 154
 155         sz = strlen(OPUS_COMMENT_HEADER)
 156                 + 4 /* comment length (always present) */
 157                 + comment_sz
 158                 + 4; /* number of tags */
 159         num_tags = 0;
 160         if (artist_len) {
 161                 num_tags++;
 162                 sz += 4 + artist_sz;
 163         }
 164         if (title_len) {
 165                 num_tags++;
 166                 sz += 4 + title_sz;
 167         }
 168         if (album_len) {
 169                 num_tags++;
 170                 sz += 4 + album_sz;
 171         }
 172         if (year_len) {
 173                 num_tags++;
 174                 sz += 4 + year_sz;
 175         }
 176         PARA_DEBUG_LOG("meta packet size: %zu bytes\n", sz);
 177         /* terminating zero byte for the last sprintf() */
 178         buf = p = para_malloc(sz + 1);
 179         memcpy(p, OPUS_COMMENT_HEADER, strlen(OPUS_COMMENT_HEADER));
 180         p += strlen(OPUS_COMMENT_HEADER);
 181         write_u32(p, comment_sz);
 182         p += 4;
 183         strcpy(p, tags->comment);
 184         p += comment_sz;
 185         write_u32(p, num_tags);
 186         p += 4;
 187         if (artist_len) {
 188                 write_u32(p, artist_sz);
 189                 p += 4;
 190                 sprintf(p, "artist=%s", tags->artist);
 191                 p += artist_sz;
 192         }
 193         if (title_len) {
 194                 write_u32(p, title_sz);
 195                 p += 4;
 196                 sprintf(p, "title=%s", tags->title);
 197                 p += title_sz;
 198         }
 199         if (album_len) {
 200                 write_u32(p, album_sz);
 201                 p += 4;
 202                 sprintf(p, "album=%s", tags->album);
 203                 p += album_sz;
 204         }
 205         if (year_len) {
 206                 write_u32(p, year_sz);
 207                 p += 4;
 208                 sprintf(p, "year=%s", tags->year);
 209                 p += year_sz;
 210         }
 211         assert(p == buf + sz);
 212         *result = buf;
 213         return sz;
 214 }
 215
 216 static int opus_rewrite_tags(const char *map, size_t mapsize,
 217                 struct taginfo *tags, int output_fd,
 218                 __a_unused const char *filename)
 219 {
 220         char *meta_packet;
 221         size_t meta_sz;
 222         int ret;
 223
 224         meta_sz = opus_make_meta_packet(tags, &meta_packet);
 225         ret = ogg_rewrite_tags(map, mapsize, output_fd, meta_packet, meta_sz);
 226         free(meta_packet);
 227         return ret;
 228 }
 229
 230 /**
 231  * The init function of the ogg/opus audio format handler.
 232  *
 233  * \param afh Pointer to the struct to initialize.
 234  */
 235 void opus_afh_init(struct audio_format_handler *afh)
 236 {
 237         afh->get_file_info = opus_get_file_info,
 238         afh->suffixes = opus_suffixes;
 239         afh->rewrite_tags = opus_rewrite_tags;
 240 }