91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
#define _CRT_NONSTDC_NO_WARNINGS
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#define _CRT_SECURE_NO_WARNINGS
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#include <io.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdbool.h>
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#include <sys/stat.h>
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#define BITS 8
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void main(int argc, const char *argv[])
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{
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if (argc != 2)
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{
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fprintf(stderr, "usage: %s file\n", argv[0]);
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return;
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}
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char name[256];
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sprintf(name, "%s.raw", argv[1]);
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int source = open(name, O_RDONLY | O_BINARY);
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fprintf(stderr, "source: %s\n", name);
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if (source == -1)
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{
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perror("source");
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return;
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}
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sprintf(name, "%s.a2stream", argv[1]);
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int target = open(name, O_WRONLY | O_BINARY | O_CREAT | O_TRUNC, S_IREAD | S_IWRITE);
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fprintf(stderr, "target: %s\n", name);
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if (target == -1)
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{
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close(source);
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perror("target");
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return;
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}
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int samples = 0;
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int size;
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float error = 0.0;
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bool last = false;
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do
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{
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float x[256 * BITS];
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size = read(source, x, sizeof(x)) / sizeof(float);
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if (size == -1)
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{
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perror("source");
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close(source);
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close(target);
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return;
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}
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unsigned char y[256];
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memset(y, 0, sizeof(y));
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// first-order delta-sigma converter
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for (int n = 0; n < size; n++)
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{
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bool next = x[n] >= error;
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error = (next ? 1.0 : -1.0) - x[n] + error;
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if (next != last)
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{
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y[n / BITS] |= 1 << (n % BITS);
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}
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last = next;
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}
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if (write(target, y, size / BITS) != size / BITS)
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{
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perror("target");
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close(source);
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close(target);
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return;
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}
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samples += size;
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int h = (samples / 78670 / 3600);
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int m = (samples / 78670 / 60) % 60;
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int s = (samples / 78670 ) % 60;
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fprintf(stderr, "offset: %02d:%02d:%02d\r", h, m, s);
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}
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while (size);
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close(source);
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close(target);
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}
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