commit: 6962a6a68324dab4f0b8d2c400e8f08f7a4b3f3e
parent 21c8c3e4cbd5fa58439f1bbea09c338448c36fa8
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date: Mon, 26 Oct 2020 12:08:10 +0100
C/au.h: New header
Diffstat:
2 files changed, 66 insertions(+), 9 deletions(-)
diff --git a/C/AU 8-bit 8kHz.c b/C/AU 8-bit 8kHz.c
@@ -1,15 +1,23 @@
#define _POSIX_C_SOURCE 200809L
-// 16k Because 8kHz × 8-bit
#include <stdio.h>
-#include <unistd.h>
#include <inttypes.h> // uint32_t
-int main(void){
-write(1, "\x2e\x73\x6e\x64", 4); // AU magic header (big-endian ".snd")
-write(1, "\x00\x00\x00\x18", 4); // 24 = byte offset, no annotation
-write(1, "\xFF\xFF\xFF\xFF", 4); // 0xffffffff = unknown data size
-write(1, "\x00\x00\x00\x02", 4); // 10 = (unsigned) 8-bit fixed-point
-write(1, "\x00\x00\x1F\x40", 4); // 8000 = Hz
-write(1, "\x00\x00\x00\x01", 4); // mono
+
+#include "au.h"
+
+int
+main(void)
+{
+ struct au_header header = {
+ .offset = 24, // no-annotation, in octets
+ .lenght = 0xFFFFFFFF, // unknown data size
+ .encoding = 02, // unsigned 8-bit linear PCM
+ .samplerate = 8000, // Hz
+ .channels = 1
+ };
+
+ // fd 1 is stdout
+ write_au_header(1, &header);
+
for(int t = 0;;t++)putchar(
// 8kHz
//t*(((t>>12)|(t>>8))&(63&(t>>4)))
diff --git a/C/au.h b/C/au.h
@@ -0,0 +1,49 @@
+#include <unistd.h> // write()
+#include <inttypes.h> // uint32_t
+#include <stdio.h> // perror()
+
+struct au_header {
+ uint32_t offset;
+ uint32_t lenght;
+ uint32_t encoding;
+ uint32_t samplerate;
+ uint32_t channels;
+};
+
+static void
+be32enc(void *buf, uint32_t in)
+{
+ char *out = (char *)buf;
+
+ out[0] = (in >> 24) & 0xff;
+ out[1] = (in >> 16) & 0xff;
+ out[2] = (in >> 8) & 0xff;
+ out[3] = (in >> 0) & 0xff;
+}
+
+static int
+write_au_header(int fd, struct au_header *header)
+{
+ char buf[4];
+ uint32_t *value = (uint32_t*)header;
+
+ if(4 != write(fd, "\x2E\x73\x6E\x64", 4))
+ {
+ perror("write(fd, signature, 4)");
+ return -1;
+ }
+
+ // 5: number of params in struct au_header
+ for(int i = 0;i<5; i++)
+ {
+ // 32 bits = 4 octets
+ be32enc(buf, *(value+i));
+ if(4 != write(fd, buf, 4))
+ {
+ perror("write(fd, au_header, 4)");
+ return -1;
+ }
+ }
+
+ return 0;
+}
