vgmstream/src/meta/mpeg.c

74 lines
2.1 KiB
C

#include "meta.h"
#include "../coding/coding.h"
/* MPEG - standard MP1/2/3 audio */
VGMSTREAM* init_vgmstream_mpeg(STREAMFILE* sf) {
#ifdef VGM_USE_MPEG
VGMSTREAM* vgmstream = NULL;
uint32_t start_offset;
int loop_flag = 0;
mpeg_frame_info info = {0};
uint32_t header_id;
/* checks */
header_id = read_u32be(0x00, sf);
if ((header_id & 0xFFF00000) != 0xFFF00000 &&
(header_id & 0xFFFFFF00) != get_id32be("ID3\0") &&
(header_id & 0xFFFFFF00) != get_id32be("TAG\0"))
goto fail;
/* detect base offset, since some tags with images are big
* (init_mpeg only skips tags in a small-ish buffer) */
start_offset = 0x00;
while (start_offset < get_streamfile_size(sf)) {
uint32_t tag_size = mpeg_get_tag_size(sf, start_offset, 0);
if (tag_size == 0)
break;
start_offset += tag_size;
}
if (!mpeg_get_frame_info(sf, start_offset, &info))
goto fail;
/* .mp3/mp2: standard (is .mp1 ever used in games?)
* .lmp1/2/3: for plugins
* .mus: Marc Ecko's Getting Up (PC) */
if (!check_extensions(sf, "mp3,mp2,mp1,mus,lmp3,lmp2,lmp1"))
goto fail;
loop_flag = 0;
/* build VGMSTREAM */
vgmstream = allocate_vgmstream(info.channels, loop_flag);
if (!vgmstream) goto fail;
vgmstream->meta_type = meta_MPEG;
vgmstream->sample_rate = info.sample_rate;
/* more strict, use? */
//mpeg_custom_config cfg = {0};
//cfg.skip_samples = ...
//vgmstream->codec_data = init_mpeg_custom(sf, start_offset, &vgmstream->coding_type, fmt.channels, MPEG_STANDARD, &cfg);
vgmstream->codec_data = init_mpeg(sf, start_offset, &vgmstream->coding_type, info.channels);
if (!vgmstream->codec_data) goto fail;
vgmstream->layout_type = layout_none;
//vgmstream->num_samples = mpeg_bytes_to_samples(data_size, vgmstream->codec_data);
vgmstream->num_samples = mpeg_get_samples(sf, start_offset, get_streamfile_size(sf));
if (!vgmstream_open_stream(vgmstream, sf, start_offset))
goto fail;
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
#else
return NULL;
#endif
}