vgmstream/src/meta/sfh_streamfile.h
2019-03-11 14:49:29 +01:00

134 lines
4.3 KiB
C

#ifndef _SFH_STREAMFILE_H_
#define _SFH_STREAMFILE_H_
#include "../streamfile.h"
typedef struct {
/* config */
off_t stream_offset;
size_t stream_size;
/* state */
off_t logical_offset; /* fake offset */
off_t physical_offset; /* actual offset */
size_t block_size; /* current size */
size_t skip_size; /* size from block start to reach data */
size_t data_size; /* usable size in a block */
size_t logical_size;
} sfh_io_data;
static size_t sfh_io_read(STREAMFILE *streamfile, uint8_t *dest, off_t offset, size_t length, sfh_io_data* data) {
size_t total_read = 0;
/* re-start when previous offset (can't map logical<>physical offsets) */
if (data->logical_offset < 0 || offset < data->logical_offset) {
data->physical_offset = data->stream_offset;
data->logical_offset = 0x00;
data->data_size = 0;
}
/* read blocks */
while (length > 0) {
/* ignore EOF */
if (offset < 0 || data->physical_offset >= data->stream_offset + data->stream_size) {
break;
}
/* process new block */
if (data->data_size == 0) {
data->skip_size = 0x10; /* skip 0x10 garbage on every block */
data->data_size = data->block_size - 0x10;
}
/* move to next block */
if (data->data_size == 0 || offset >= data->logical_offset + data->data_size) {
data->physical_offset += data->block_size;
data->logical_offset += data->data_size;
data->data_size = 0;
continue;
}
/* read data */
{
size_t bytes_consumed, bytes_done, to_read;
bytes_consumed = offset - data->logical_offset;
to_read = data->data_size - bytes_consumed;
if (to_read > length)
to_read = length;
bytes_done = read_streamfile(dest, data->physical_offset + data->skip_size + bytes_consumed, to_read, streamfile);
total_read += bytes_done;
dest += bytes_done;
offset += bytes_done;
length -= bytes_done;
if (bytes_done != to_read || bytes_done == 0) {
break; /* error/EOF */
}
}
}
return total_read;
}
static size_t sfh_io_size(STREAMFILE *streamfile, sfh_io_data* data) {
uint8_t buf[1];
if (data->logical_size)
return data->logical_size;
/* force a fake read at max offset, to get max logical_offset (will be reset next read) */
sfh_io_read(streamfile, buf, 0x7FFFFFFF, 1, data);
data->logical_size = data->logical_offset;
return data->logical_size;
}
/* Handles deinterleaving of SFH blocked streams */
static STREAMFILE* setup_sfh_streamfile(STREAMFILE *streamFile, off_t stream_offset, size_t block_size, size_t clean_size, const char* extension) {
STREAMFILE *temp_streamFile = NULL, *new_streamFile = NULL;
sfh_io_data io_data = {0};
size_t io_data_size = sizeof(sfh_io_data);
io_data.stream_offset = stream_offset;
io_data.stream_size = get_streamfile_size(streamFile) - stream_offset;
io_data.block_size = block_size;
io_data.logical_offset = -1; /* force phys offset reset */
/* setup subfile */
new_streamFile = open_wrap_streamfile(streamFile);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
new_streamFile = open_io_streamfile(new_streamFile, &io_data,io_data_size, sfh_io_read,sfh_io_size);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
new_streamFile = open_buffer_streamfile(new_streamFile,0);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
new_streamFile = open_clamp_streamfile(new_streamFile,0x00, clean_size);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
if (extension) {
new_streamFile = open_fakename_streamfile(temp_streamFile, NULL,extension);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
}
return temp_streamFile;
fail:
close_streamfile(temp_streamFile);
return NULL;
}
#endif /* _SFH_STREAMFILE_H_ */