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* 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 %d 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("header version %d, input sample rate: %dHz",
 100                         oh->version, oh->input_sample_rate);
 101                 /*
 102                  * The input sample rate is irrelevant for afhi->frequency as
 103                  * we always decode to 48kHz.
 104                  */
 105                 afhi->frequency = 48000;
 106                 return 1;
 107         }
 108         if (packet_num == 1) {
 109                 ret = opus_get_comments((char *)packet->packet, packet->bytes,
 110                         &afhi->tags);
 111                 if (ret < 0)
 112                         return ret;
 113                 return 0; /* header complete */
 114         }
 115         /* never reached */
 116         assert(0);
 117 }
 118
 119 static int opus_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 120                 struct afh_info *afhi)
 121 {
 122         int ret, ms;
 123         struct opus_header oh = {.version = 0};
 124
 125         struct ogg_afh_callback_info opus_callback_info = {
 126                 .packet_callback = opus_packet_callback,
 127                 .private_data = &oh,
 128         };
 129         ret = ogg_get_file_info(map, numbytes, afhi, &opus_callback_info);
 130         if (ret < 0)
 131                 return ret;
 132         ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
 133         ms = tv2ms(&afhi->chunk_tv) * afhi->chunks_total;
 134         afhi->bitrate = ret / ms;
 135         return 1;
 136 }
 137
 138 static size_t opus_make_meta_packet(struct taginfo *tags, char **result)
 139 {
 140         size_t sz;
 141         char *buf, *p;
 142         size_t comment_len = strlen(tags->comment),
 143                 artist_len = strlen(tags->artist),
 144                 title_len = strlen(tags->title),
 145                 album_len = strlen(tags->album),
 146                 year_len = strlen(tags->year);
 147         uint32_t comment_sz = comment_len,
 148                 artist_sz = artist_len + strlen("artist="),
 149                 title_sz = title_len + strlen("title="),
 150                 album_sz = album_len + strlen("album="),
 151                 year_sz = year_len + strlen("year=");
 152         uint32_t num_tags;
 153
 154         sz = strlen(OPUS_COMMENT_HEADER)
 155                 + 4 /* comment length (always present) */
 156                 + comment_sz
 157                 + 4; /* number of tags */
 158         num_tags = 0;
 159         if (artist_len) {
 160                 num_tags++;
 161                 sz += 4 + artist_sz;
 162         }
 163         if (title_len) {
 164                 num_tags++;
 165                 sz += 4 + title_sz;
 166         }
 167         if (album_len) {
 168                 num_tags++;
 169                 sz += 4 + album_sz;
 170         }
 171         if (year_len) {
 172                 num_tags++;
 173                 sz += 4 + year_sz;
 174         }
 175         PARA_DEBUG_LOG("meta packet size: %zu bytes\n", sz);
 176         /* terminating zero byte for the last sprintf() */
 177         buf = p = para_malloc(sz + 1);
 178         memcpy(p, OPUS_COMMENT_HEADER, strlen(OPUS_COMMENT_HEADER));
 179         p += strlen(OPUS_COMMENT_HEADER);
 180         write_u32(p, comment_sz);
 181         p += 4;
 182         strcpy(p, tags->comment);
 183         p += comment_sz;
 184         write_u32(p, num_tags);
 185         p += 4;
 186         if (artist_len) {
 187                 write_u32(p, artist_sz);
 188                 p += 4;
 189                 sprintf(p, "artist=%s", tags->artist);
 190                 p += artist_sz;
 191         }
 192         if (title_len) {
 193                 write_u32(p, title_sz);
 194                 p += 4;
 195                 sprintf(p, "title=%s", tags->title);
 196                 p += title_sz;
 197         }
 198         if (album_len) {
 199                 write_u32(p, album_sz);
 200                 p += 4;
 201                 sprintf(p, "album=%s", tags->album);
 202                 p += album_sz;
 203         }
 204         if (year_len) {
 205                 write_u32(p, year_sz);
 206                 p += 4;
 207                 sprintf(p, "year=%s", tags->year);
 208                 p += year_sz;
 209         }
 210         assert(p == buf + sz);
 211         *result = buf;
 212         return sz;
 213 }
 214
 215 static int opus_rewrite_tags(const char *map, size_t mapsize,
 216                 struct taginfo *tags, int output_fd,
 217                 __a_unused const char *filename)
 218 {
 219         char *meta_packet;
 220         size_t meta_sz;
 221         int ret;
 222
 223         meta_sz = opus_make_meta_packet(tags, &meta_packet);
 224         ret = ogg_rewrite_tags(map, mapsize, output_fd, meta_packet, meta_sz);
 225         free(meta_packet);
 226         return ret;
 227 }
 228
 229 /**
 230  * The init function of the ogg/opus audio format handler.
 231  *
 232  * \param afh Pointer to the struct to initialize.
 233  */
 234 void opus_afh_init(struct audio_format_handler *afh)
 235 {
 236         afh->get_file_info = opus_get_file_info,
 237         afh->suffixes = opus_suffixes;
 238         afh->rewrite_tags = opus_rewrite_tags;
 239 }