vgmstream/src/meta/ogl.c

73 lines
2.6 KiB
C

#include "meta.h"
#include "../util.h"
#include "../coding/coding.h"
/* OGL - Shin'en custom Vorbis [Jett Rocket (Wii), FAST Racing NEO (WiiU)] */
VGMSTREAM * init_vgmstream_ogl(STREAMFILE *streamFile) {
VGMSTREAM * vgmstream = NULL;
off_t start_offset;
size_t partial_file_size;
int loop_flag, channel_count, sample_rate;
uint32_t num_samples, loop_start_sample, loop_end_sample;
/* check extension, case insensitive */
if (!check_extensions(streamFile,"ogl"))
goto fail;
/* OGL headers are very basic with no ID but libvorbis should reject garbage data anyway */
loop_flag = read_32bitLE(0x00,streamFile) > 0; /* absolute loop offset */
loop_start_sample = read_32bitLE(0x04,streamFile);
//loop_start_block = read_32bitLE(0x08,streamFile);
num_samples = read_32bitLE(0x0c,streamFile);
partial_file_size = read_32bitLE(0x10,streamFile); /* header + data not counting end padding */
if (partial_file_size > get_streamfile_size(streamFile)) goto fail;
loop_end_sample = num_samples; /* there is no data after num_samples (ie.- it's really num_samples) */
/* actually peeking into the Vorbis id packet */
channel_count = read_8bit (0x21,streamFile);
sample_rate = read_32bitLE(0x22,streamFile);
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channel_count,loop_flag);
if (!vgmstream) goto fail;
vgmstream->sample_rate = sample_rate;
vgmstream->num_samples = num_samples;
vgmstream->loop_start_sample = loop_start_sample;
vgmstream->loop_end_sample = loop_end_sample;
vgmstream->meta_type = meta_OGL;
#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, 0x14, VORBIS_OGL, &cfg);
if (!vgmstream->codec_data) goto fail;
start_offset = cfg.data_start_offset;
}
#else
goto fail;
#endif
/* non-looping files do this */
if (!num_samples) {
uint32_t avg_bitrate = read_32bitLE(0x2a,streamFile); /* inside id packet */
/* approximate as we don't know the sizes of all packet headers */ //todo this is wrong... but somehow works?
vgmstream->num_samples = (partial_file_size - start_offset) * ((sample_rate*10/avg_bitrate)+1);
}
/* open the file for reading */
if ( !vgmstream_open_stream(vgmstream, streamFile, start_offset) )
goto fail;
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
}