static void init_audio(nestegg *ctx, int track, audio_context *audio_ctx, int volume)
{
// read vorbis header and initialize vorbis decoding
unsigned chunk, chunks;
vorbis_init(&(audio_ctx->vorbis_ctx));
nestegg_track_codec_data_count(ctx, track, &chunks);
assert(chunks == 3);
for (chunk=0; chunk<chunks; chunk++)
{
unsigned char *data;
size_t data_size;
nestegg_track_codec_data(ctx, track, chunk, &data, &data_size);
vorbis_headerpacket(&(audio_ctx->vorbis_ctx), data, data_size, chunk);
}
// initialize audio decoding context
vorbis_prepare(&(audio_ctx->vorbis_ctx));
nestegg_audio_params audioParams;
nestegg_track_audio_params(ctx, track, &audioParams);
audio_ctx->vorbis_ctx.channels = audioParams.channels;
audio_ctx->frequency = (int)audioParams.rate;
audio_ctx->avail_samples = audio_ctx->last_samples = 0;
audio_ctx->packet_queue = queue_init(PACKET_QUEUE_SIZE);
printf("Audio track: %f Hz, %d channels, %d bits/sample\n",
audioParams.rate, audioParams.channels, audioParams.depth / audioParams.channels);
if(audio_ctx->frequency % 11025)
{
printf("Warning: the audio frequency (%i Hz) is suboptimal; resample to 44100 Hz for best quality\n",
audio_ctx->frequency);
}
// initialize soundmix music channel
sound_close_music();
memset(&musicchannel, 0, sizeof(musicchannel));
musicchannel.fp_period = INT_TO_FIX(audio_ctx->frequency) / playfrequency;
musicchannel.volume[0] = volume;
musicchannel.volume[1] = volume;
musicchannel.channels = audioParams.channels;
musicchannel.active = 1;
int i;
for(i = 0; i < MUSIC_NUM_BUFFERS; i++)
{
musicchannel.buf[i] = malloc(MUSIC_BUF_SIZE * sizeof(short));
memset(musicchannel.buf[i], 0, MUSIC_BUF_SIZE * sizeof(short));
}
}
static gint vorbis_open(void)
{
ogg_packet header;
ogg_packet header_comm;
ogg_packet header_code;
vorbis_init(NULL);
vorbis_info_init(&vi);
vorbis_comment_init(&vc);
if (tuple)
{
gchar tmpstr[32];
gint scrint;
add_string_from_tuple (& vc, "title", tuple, FIELD_TITLE);
add_string_from_tuple (& vc, "artist", tuple, FIELD_ARTIST);
add_string_from_tuple (& vc, "album", tuple, FIELD_ALBUM);
add_string_from_tuple (& vc, "genre", tuple, FIELD_GENRE);
add_string_from_tuple (& vc, "date", tuple, FIELD_DATE);
add_string_from_tuple (& vc, "comment", tuple, FIELD_COMMENT);
if ((scrint = tuple_get_int(tuple, FIELD_TRACK_NUMBER, NULL)))
{
g_snprintf(tmpstr, sizeof(tmpstr), "%d", scrint);
vorbis_comment_add_tag(&vc, "tracknumber", tmpstr);
}
if ((scrint = tuple_get_int(tuple, FIELD_YEAR, NULL)))
{
g_snprintf(tmpstr, sizeof(tmpstr), "%d", scrint);
vorbis_comment_add_tag(&vc, "year", tmpstr);
}
}
if (vorbis_encode_init_vbr (& vi, input.channels, input.frequency,
v_base_quality))
{
vorbis_info_clear(&vi);
return 0;
}
vorbis_analysis_init(&vd, &vi);
vorbis_block_init(&vd, &vb);
srand(time(NULL));
ogg_stream_init(&os, rand());
vorbis_analysis_headerout(&vd, &vc, &header, &header_comm, &header_code);
ogg_stream_packetin(&os, &header);
ogg_stream_packetin(&os, &header_comm);
ogg_stream_packetin(&os, &header_code);
while (ogg_stream_flush (& os, & og))
{
write_output(og.header, og.header_len);
write_output(og.body, og.body_len);
}
return 1;
}