vgmstream/src/meta/sk_aud.c

75 lines
2.4 KiB
C

#include "meta.h"
#include "../util.h"
#include "../coding/coding.h"
static int get_sk_num_samples(STREAMFILE *streamFile, off_t start_offset);
/* AUD/SK - Silicon Knights obfuscated Ogg (cutscene/voices) [Eternal Darkness (GC)] */
VGMSTREAM * init_vgmstream_sk_aud(STREAMFILE *streamFile) {
VGMSTREAM * vgmstream = NULL;
off_t start_offset;
int loop_flag = 0, channel_count, sample_rate;
/* check extension, case insensitive */
if (!check_extensions(streamFile,"aud"))
goto fail;
if (read_32bitBE(0x00,streamFile) != 0x11534B10) /* \11"SK"\10 */
goto fail;
/* the format is just mutant Ogg so actually peeking into the Vorbis id packet here */
channel_count = read_8bit (0x23,streamFile);
sample_rate = read_32bitLE(0x24,streamFile);
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channel_count,loop_flag);
if (!vgmstream) goto fail;
vgmstream->sample_rate = sample_rate;
vgmstream->num_samples = get_sk_num_samples(streamFile, 0);
vgmstream->meta_type = meta_SK_AUD;
#ifdef VGM_USE_VORBIS
{
vorbis_custom_config cfg = {0};
vgmstream->layout_type = layout_none;
vgmstream->coding_type = coding_VORBIS_custom;
vgmstream->codec_data = init_vorbis_custom(streamFile, 0x00, VORBIS_SK, &cfg);
if (!vgmstream->codec_data) goto fail;
start_offset = cfg.data_start_offset;
}
#else
goto fail;
#endif
/* open the file for reading */
if ( !vgmstream_open_stream(vgmstream, streamFile, start_offset) )
goto fail;
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
}
/* SK/Ogg doesn't have num_samples info, manually read total samples */
static int get_sk_num_samples(STREAMFILE *streamFile, off_t start_offset) {
uint32_t expected_id = 0x11534B10; /* \11"SK"\10 (would read "OggS" by changing the ID) */
off_t off = get_streamfile_size(streamFile) - 4-1-1-8-4-4-4;
/* simplest way is to find last OggS/SK page from stream end */
while (off >= start_offset) {
uint32_t current_id = read_32bitBE(off, streamFile);
if (current_id == expected_id) { /* last packet starts with 0x0004, if more checks are needed */
return read_32bitLE(off+4+1+1, streamFile); /* get last granule = total samples (64b but whatevs) */
}
off--;
}
return 0;
}