mqbgen: allow single-channel input

mqbgen.c

@@ -144,7 +144,8 @@ int main(int argc, char **argv)
 	SNDFILE *ofile;
 	SF_INFO ifmt;
 	SF_INFO ofmt;
-	int32_t *buf;
+	int32_t *ibuf;
+	int32_t *obuf;
 	uint8_t mqb[32];
 	uint8_t *mqb_end;
 	int mqb_len;
@@ -203,7 +204,7 @@ int main(int argc, char **argv)
 	if (!ifile)
 		error("%s: %s\n", argv[0], sf_strerror(NULL));
 
-	if (ifmt.channels != 2)
+	if (ifmt.channels > 2)
 		error("unsupported channel count %d\n", ifmt.channels);
 
 	if (rate < 8) {
@@ -248,15 +249,19 @@ int main(int argc, char **argv)
 		break;
 	}
 
-	buf = malloc(BUF_SIZE * ifmt.channels * sizeof(*buf));
-	if (!buf)
+	ibuf = malloc(BUF_SIZE * ifmt.channels * sizeof(*ibuf));
+	if (!ibuf)
 		error("malloc: %s\n", strerror(errno));
 
 	memset(&ofmt, 0, sizeof(ofmt));
 	ofmt.samplerate = ifmt.samplerate;
-	ofmt.channels = ifmt.channels;
+	ofmt.channels = 2;
 	ofmt.format = SF_FORMAT_WAV | SF_FORMAT_PCM_24;
 
+	obuf = malloc(BUF_SIZE * ofmt.channels * sizeof(*obuf));
+	if (!obuf)
+		error("malloc: %s\n", strerror(errno));
+
 	ofile = sf_open(argv[1], SFM_WRITE, &ofmt);
 	if (!ofile)
 		error("%s: %s\n", argv[1], sf_strerror(NULL));
@@ -270,16 +275,22 @@ int main(int argc, char **argv)
 	mqb_bit = 7;
 
 	for (;;) {
-		int frames = sf_readf_int(ifile, buf, BUF_SIZE);
+		int frames = sf_readf_int(ifile, ibuf, BUF_SIZE);
 		int i;
 
 		if (!frames)
 			break;
 
 		for (i = 0; i < frames; i++) {
-			int32_t l = buf[2 * i] >> 8;
-			int32_t r = buf[2 * i + 1] >> 8;
 			int bit = mqb[mqb_pos] >> mqb_bit & 1;
+			int32_t l, r;
+
+			if (ifmt.channels == 1) {
+				l = r = ibuf[i] >> 8;
+			} else {
+				l = ibuf[2 * i] >> 8;
+				r = ibuf[2 * i + 1] >> 8;
+			}
 
 			if (mqb_bit-- == 0) {
 				if (++mqb_pos == mqb_len)
@@ -294,18 +305,19 @@ int main(int argc, char **argv)
 
 			mqb_write_bit(&l, &r, bit);
 
-			buf[2 * i] = l << 8;
-			buf[2 * i + 1] = r << 8;
+			obuf[2 * i] = l << 8;
+			obuf[2 * i + 1] = r << 8;
 
 		}
 
-		sf_writef_int(ofile, buf, frames);
+		sf_writef_int(ofile, obuf, frames);
 	}
 
 	sf_close(ifile);
 	sf_close(ofile);
 
-	free(buf);
+	free(ibuf);
+	free(obuf);
 
 	return 0;
 }