/*
* sstvtx - Martin 1 mode SSTV generator
*
* $Id: sstvtx.c 82 2008-07-30 12:13:59Z dj1yfk $
*
* Copyright (c) 2008 Fabian Kurz, DJ1YFK
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/*
* Compile with: gcc sstvtx.c -lsndfile -ljpeg -lm -o sstvtx
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sndfile.h>
#include "jpeglib.h"
#include "jerror.h"
#include <setjmp.h>
#include <unistd.h>
#define PIXEL 1
#define SYNC 0
/* JPEG input image will be read into this array; picture size 320x256,
* RGB components in separate rows */
static unsigned char pic[320][3*256];
typedef struct {
int samplerate;
int sync_len; /* length of synch impulse in samples */
int pix_len; /* length of normal pixel in samples */
int x_width;
double phase;
char *infile;
char *outfile;
} SSTV;
void die(char *err);
int read_JPEG_file (char *filename);
int tx_sync(SNDFILE *snd, SSTV *sstv);
int tx_pixel(unsigned char p, SNDFILE *snd, SSTV *sstv, int typ);
int init_sstv(SSTV *sstv);
void help (void);
int main (int argc, char **argv) {
int x,y;
SSTV sstv;
SNDFILE *out;
SF_INFO out_info;
sstv.samplerate = 48000;
sstv.x_width = 320;
sstv.phase = 0;
sstv.outfile = "out.wav";
sstv.infile = "input.jpg";
while ((x = getopt(argc, argv, "s:i:o:x:h")) != -1) {
switch (x) {
case 's':
sstv.samplerate = atoi(optarg);
break;
case 'i':
sstv.infile = optarg;
break;
case 'o':
sstv.outfile = optarg;
break;
case 'h':
help();
break;
case 'x':
sstv.x_width= atoi(optarg);
break;
}
}
out_info.samplerate = sstv.samplerate;
out_info.channels = 1;
out_info.format = SF_FORMAT_WAV|SF_FORMAT_PCM_16;
if ((out = sf_open(sstv.outfile, SFM_WRITE, &out_info)) == NULL) {
die("Opening soundfile failed.");
}
read_JPEG_file(sstv.infile);
init_sstv(&sstv);
for (y=0; y < 3*256; y++) {
for (x = 0; x < sstv.x_width; x++) {
tx_pixel(pic[x][y], out, &sstv, PIXEL);
}
if (!(y % 3)) {
tx_pixel(0, out, &sstv, SYNC);
}
}
sf_close(out);
return 0;
}
void die(char *err) {
fprintf(stderr, "Error: %s\n", err);
exit(EXIT_FAILURE);
}
int read_JPEG_file (char *filename) {
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
FILE *infile;
JSAMPARRAY buffer;
int row_stride;
int i, row=0;
if ((infile = fopen(filename, "rb")) == NULL) {
die("Can't open input file.");
}
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
(void) jpeg_read_header(&cinfo, TRUE);
(void) jpeg_start_decompress(&cinfo);
if (cinfo.output_width != 320 || cinfo.output_height != 256) {
die ("Input file format wrong. Need 320x256.");
}
row_stride = cinfo.output_width * cinfo.output_components;
buffer = (*cinfo.mem->alloc_sarray)
((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
while (cinfo.output_scanline < cinfo.output_height) {
(void) jpeg_read_scanlines(&cinfo, buffer, 1);
/* each line in buffer: R,G,B,R,G,B -> put to array RRR/GGG/BBB */
for (i=0; i < cinfo.output_width; i++) {
pic[i][row] = buffer[0][3*i];
pic[i][row+1] = buffer[0][3*i+1];
pic[i][row+2] = buffer[0][3*i+2];
}
row+=3;
}
(void) jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);
return 0;
}
int init_sstv(SSTV *sstv) {
/* sync len = 5ms */
sstv->sync_len = sstv->samplerate * 0.005;
/* pixel length, in samples, total pixels 245760, 114s - 1.28s sync
* results in 0.45865885 ms / pixel */
sstv->pix_len = (int) sstv->samplerate * 0.00045865885416666666;
return 0;
}
int tx_pixel(unsigned char p, SNDFILE *snd, SSTV *sstv, int typ) {
int freq;
short int buf[500];
int j, len;
float i=0.0;
double phase=0;
/* normalize char to frequency range of 1500-2300Hz */
if (typ == PIXEL) {
freq = (int) 1500 + 800.0*p/255.0;
len = sstv->pix_len;
}
else {
freq = 1200;
len = sstv->sync_len;
}
/* find back to old phase */
/* while (phase < sstv->phase) {
i++;
phase = 2.0*M_PI*freq*i/sstv->samplerate;
}
*/
i = sstv->phase * sstv->samplerate / (2.0*M_PI*freq);
/* make pixel, starting with that phase */
for (j=0; j < len; j++) {
phase = 2.0*M_PI*freq*i/sstv->samplerate;
i++;
buf[j] = (short int) 25000 * sin(phase);
}
if (phase > 2*M_PI) {
phase -= 2*M_PI;
}
sstv->phase = phase;
if ((i = sf_write_short(snd, buf, j)) != j) {
die("Writing Pixel failed.");
}
return 0;
}
void help (void) {
printf("sstvtx - generates a SSTV Martin 1 image\n");
printf("\n");
printf("Usage: sstvtx -i input.jpg -o output.wav -x x_width -s samplerate\n");
printf("\n");
printf("Written by Fabian Kurz, DJ1YFK; http://fkurz.net/ham/stuff.html#sstvtx\n\n");
exit(EXIT_SUCCESS);
}
