Add 16-bit signed option

- Include an argument to set 16-bit output to signed. Default behavior is unsigned
- Utilizes a new (third) argument in the "hsdaoh_open" function to set a dev variable
- format_convert uses intermediate value to unpack 12-bit data, then ternary operator to store signed/unsigned

include/hsdaoh.h

@@ -84,7 +84,7 @@ HSDAOH_API int hsdaoh_get_device_usb_strings(uint32_t index,
  */
 HSDAOH_API int hsdaoh_get_index_by_serial(const char *serial);
 
-HSDAOH_API int hsdaoh_open(hsdaoh_dev_t **dev, uint32_t index);
+HSDAOH_API int hsdaoh_open(hsdaoh_dev_t **dev, uint32_t index, bool out_signed);
 
 HSDAOH_API int hsdaoh_close(hsdaoh_dev_t *dev);
 

include/hsdaoh_private.h

@@ -44,6 +44,7 @@ struct hsdaoh_dev {
 	unsigned int width, height, fps;
 
 	bool output_float;
+	bool output_signed;
 	iqconverter_float_t *cnv_f;
 
 	/* status */

src/format_convert.c

@@ -69,10 +69,15 @@ void hsdaoh_unpack_pio_12bit(hsdaoh_dev_t *dev, hsdaoh_data_info_t *data_info)
 	unsigned int j = 0;
 
 	for (unsigned int i = 0; i < inlen; i += 3) {
-		out[j++] = (in[i+2] & 0xf000) >> 4 | (in[i+1] & 0xf000) >> 8 | (in[i] >> 12);
-		out[j++] = in[i  ] & 0x0fff;
-		out[j++] = in[i+1] & 0x0fff;
-		out[j++] = in[i+2] & 0x0fff;
+		uint16_t sample1 = (in[i+2] & 0xf000) >> 4 | (in[i+1] & 0xf000) >> 8 | (in[i] >> 12);
+		uint16_t sample2 = in[i  ] & 0x0fff;
+		uint16_t sample3 = in[i+1] & 0x0fff;
+		uint16_t sample4 = in[i+2] & 0x0fff;
+
+		out[j++] = dev->output_signed ? (int16_t)((sample1 - 2048) << 4) : sample1;
+		out[j++] = dev->output_signed ? (int16_t)((sample2 - 2048) << 4) : sample2;
+		out[j++] = dev->output_signed ? (int16_t)((sample3 - 2048) << 4) : sample3;
+		out[j++] = dev->output_signed ? (int16_t)((sample4 - 2048) << 4) : sample4;
 	}
 
 	if (dev->output_float) {
@@ -107,8 +112,11 @@ void hsdaoh_unpack_pio_12bit_dual(hsdaoh_dev_t *dev, hsdaoh_data_info_t *data_in
 	}
 
 	for (i = 0; i < j; i++) {
-		out16_1[i] = (out[i] >> 12) & 0x0fff;
-		out16_2[i] = out[i] & 0x0fff;
+		uint16_t sample1 = (out[i] >> 12) & 0x0fff;
+		uint16_t sample2 = out[i] & 0x0fff;
+
+		out16_1[i] = dev->output_signed ? (int16_t)((sample1 - 2048) << 4) : sample1;
+		out16_2[i] = dev->output_signed ? (int16_t)((sample2 - 2048) << 4) : sample2;
 	}
 
 	if (dev->output_float) {
@@ -238,10 +246,16 @@ void hsdaoh_unpack_fpga_12bit_dual(hsdaoh_dev_t *dev, hsdaoh_data_info_t *data_i
 	/* extract packed 2x12 bit samples */
 	for (int i = 0; i < inlen; i += 3) {
 		uint16_t lsbs = in[i+2];
-		out16_1[j]   = ((in[i+0] & 0xff00) >> 4) | ((lsbs >>  0) & 0xf);
-		out16_2[j++] = ((in[i+0] & 0x00ff) << 4) | ((lsbs >>  4) & 0xf);
-		out16_1[j]   = ((in[i+1] & 0xff00) >> 4) | ((lsbs >>  8) & 0xf);
-		out16_2[j++] = ((in[i+1] & 0x00ff) << 4) | ((lsbs >> 12) & 0xf);
+
+		uint16_t sample1 = ((in[i+0] & 0xff00) >> 4) | ((lsbs >>  0) & 0xf);
+		uint16_t sample2 = ((in[i+0] & 0x00ff) << 4) | ((lsbs >>  4) & 0xf);
+		uint16_t sample3 = ((in[i+1] & 0xff00) >> 4) | ((lsbs >>  8) & 0xf);
+		uint16_t sample4 = ((in[i+1] & 0x00ff) << 4) | ((lsbs >> 12) & 0xf);
+
+		out16_1[j]   = dev->output_signed ? (int16_t)((sample1 - 2048) << 4) : sample1;
+		out16_2[j++] = dev->output_signed ? (int16_t)((sample2 - 2048) << 4) : sample2;
+		out16_1[j]   = dev->output_signed ? (int16_t)((sample3 - 2048) << 4) : sample3;
+		out16_2[j++] = dev->output_signed ? (int16_t)((sample4 - 2048) << 4) : sample4;
 	}
 
 	if (dev->output_float) {

src/hsdaoh_file.c

@@ -53,6 +53,7 @@ void usage(void)
 		"Usage:\n"
 		"\t[-d device_index (default: 0)]\n"
 		"\t[-b maximum number of buffers (default: 16)]\n"
+		"\t[-s save 16-bit streams as signed integer]\n"
 		"\t[-0 to -3 filename of steam 0 to stream 3 (a '-' dumps samples to stdout)]\n"
 		"\tfilename (of stream 0) (a '-' dumps samples to stdout)\n\n");
 	exit(1);
@@ -121,8 +122,9 @@ int main(int argc, char **argv)
 	unsigned int num_bufs = 0;
 	bool fname0_used = false;
 	bool have_file = false;
+	bool set_signed = false;
 
-	while ((opt = getopt(argc, argv, "0:1:2:3:d:b:")) != -1) {
+	while ((opt = getopt(argc, argv, "0:1:2:3:d:b:s:")) != -1) {
 		switch (opt) {
 		case 'd':
 			dev_index = (uint32_t)atoi(optarg);
@@ -130,6 +132,9 @@ int main(int argc, char **argv)
 		case 'b':
 			num_bufs = (unsigned int)atoi(optarg);
 			break;
+		case 's':
+		    set_signed = true;
+			break;
 		case '0':
 			fname0_used = true;
 			have_file = true;
@@ -165,7 +170,7 @@ int main(int argc, char **argv)
 	if (dev_index < 0)
 		exit(1);
 
-	r = hsdaoh_open(&dev, (uint32_t)dev_index);
+	r = hsdaoh_open(&dev, (uint32_t)dev_index, set_signed);
 	if (r < 0) {
 		fprintf(stderr, "Failed to open hsdaoh device #%d.\n", dev_index);
 		exit(1);

src/hsdaoh_tcp.c

@@ -325,6 +325,7 @@ int main(int argc, char **argv)
 	fd_set readfds;
 	u_long blockmode = 1;
 	dongle_info_t dongle_info;
+	int set_signed = 0;
 
 #ifdef _WIN32
 	WSADATA wsd;
@@ -333,7 +334,7 @@ int main(int argc, char **argv)
 	struct sigaction sigact, sigign;
 #endif
 
-	while ((opt = getopt(argc, argv, "a:p:b:n:d")) != -1) {
+	while ((opt = getopt(argc, argv, "a:p:b:n:d:s")) != -1) {
 		switch (opt) {
 		case 'd':
 			dev_index = (uint32_t)atoi(optarg);
@@ -350,6 +351,9 @@ int main(int argc, char **argv)
 		case 'n':
 			llbuf_num = atoi(optarg);
 			break;
+		case 's':
+			set_signed = 1;
+			break;
 		default:
 			usage();
 			break;
@@ -363,7 +367,7 @@ int main(int argc, char **argv)
 		exit(1);
 	}
 
-	hsdaoh_open(&dev, (uint32_t)dev_index);
+	hsdaoh_open(&dev, (uint32_t)dev_index, set_signed);
 	if (NULL == dev) {
 	fprintf(stderr, "Failed to open hsdaoh device #%d.\n", dev_index);
 		exit(1);

src/hsdaoh_test.c

@@ -274,7 +274,7 @@ int main(int argc, char **argv)
 	if (dev_index < 0)
 		exit(1);
 
-	r = hsdaoh_open(&dev, (uint32_t)dev_index);
+	r = hsdaoh_open(&dev, (uint32_t)dev_index, 0);
 	if (r < 0) {
 		fprintf(stderr, "Failed to open hsdaoh device #%d.\n", dev_index);
 		exit(1);

src/libhsdaoh.c

@@ -405,7 +405,7 @@ int _hsdaoh_open_uvc_device(hsdaoh_dev_t *dev)
 	return (int)r;
 }
 
-int hsdaoh_open(hsdaoh_dev_t **out_dev, uint32_t index)
+int hsdaoh_open(hsdaoh_dev_t **out_dev, uint32_t index, bool out_signed)
 {
 	int r;
 	int i;
@@ -423,6 +423,10 @@ int hsdaoh_open(hsdaoh_dev_t **out_dev, uint32_t index)
 
 	memset(dev, 0, sizeof(hsdaoh_dev_t));
 
+	if (out_signed) {
+	   dev->output_signed = 1;
+	}
+
 	r = libusb_init(&dev->ctx);
 	if(r < 0){
 		free(dev);