kopia lustrzana https://github.com/xdsopl/robot36
484 wiersze
13 KiB
C
484 wiersze
13 KiB
C
/*
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robot36 - encode and decode images using SSTV in Robot 36 mode
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Written in 2011 by <Ahmet Inan> <xdsopl@googlemail.com>
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To the extent possible under law, the author(s) have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide. This software is distributed without any warranty.
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You should have received a copy of the CC0 Public Domain Dedication along with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <math.h>
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#include <complex.h>
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#include <time.h>
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#include "pcm.h"
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#include "ddc.h"
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#include "buffer.h"
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#include "yuv.h"
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#include "utils.h"
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#include "img.h"
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void process_line(uint8_t *pixel, uint8_t *y_pixel, uint8_t *uv_pixel, int y_width, int uv_width, int width, int height, int n)
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{
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// we only process after 2 full lines: on odd lines
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if (n % 2)
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for (int y = n-1, l = 0; l < 2 && y < height; l++, y++) {
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for (int x = 0; x < width; x++) {
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#if DN && UP
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uint8_t Y = y_pixel[x + l*y_width];
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uint8_t U = uv_pixel[x/2 + uv_width];
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uint8_t V = uv_pixel[x/2];
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#else
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float y_xf = (float)x * (float)y_width / (float)width;
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float uv_xf = (float)x * (float)uv_width / (float)width;
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int y_x0 = y_xf;
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int uv_x0 = uv_xf;
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int y_x1 = fclampf(0, y_width, y_xf + 1);
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int uv_x1 = fclampf(0, uv_width, uv_xf + 1);
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uint8_t Y = srgb(flerpf(linear(y_pixel[y_x0 + l*y_width]), linear(y_pixel[y_x1 + l*y_width]), y_xf - (float)y_x0));
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uint8_t U = flerpf(uv_pixel[uv_x0 + uv_width], uv_pixel[uv_x1 + uv_width], uv_xf - (float)uv_x0);
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uint8_t V = flerpf(uv_pixel[uv_x0], uv_pixel[uv_x1], uv_xf - (float)uv_x0);
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#endif
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uint8_t *p = pixel + 3 * width * y + 3 * x;
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p[0] = R_YUV(Y, U, V);
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p[1] = G_YUV(Y, U, V);
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p[2] = B_YUV(Y, U, V);
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}
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}
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}
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int vis_code(int *reset, int *code, float cnt_freq, float drate)
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{
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const float tolerance = 0.9;
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const float length = 0.03;
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static int ss_ticks = 0;
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static int lo_ticks = 0;
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static int hi_ticks = 0;
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ss_ticks = fabsf(cnt_freq - 1200.0) < 50.0 ? ss_ticks + 1 : 0;
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lo_ticks = fabsf(cnt_freq - 1300.0) < 50.0 ? lo_ticks + 1 : 0;
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hi_ticks = fabsf(cnt_freq - 1100.0) < 50.0 ? hi_ticks + 1 : 0;
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int sig_ss = ss_ticks >= (int)(drate * tolerance * length) ? 1 : 0;
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int sig_lo = lo_ticks >= (int)(drate * tolerance * length) ? 1 : 0;
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int sig_hi = hi_ticks >= (int)(drate * tolerance * length) ? 1 : 0;
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// we only want a pulse for the bits
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ss_ticks = sig_ss ? 0 : ss_ticks;
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lo_ticks = sig_lo ? 0 : lo_ticks;
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hi_ticks = sig_hi ? 0 : hi_ticks;
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static int ticks = -1;
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ticks++;
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static int bit = -1;
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static int byte = 0;
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if (*reset) {
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bit = -1;
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*reset = 0;
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}
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if (bit < 0) {
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if (sig_ss) {
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ticks = 0;
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byte = 0;
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bit = 0;
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}
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return 0;
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}
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if (ticks <= (int)(drate * 10.0 * length * (2.0 - tolerance))) {
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if (sig_ss) {
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bit = -1;
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*code = byte;
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return 1;
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}
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if (bit < 8) {
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if (sig_lo) bit++;
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if (sig_hi) byte |= 1 << bit++;
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}
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return 0;
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}
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// stop bit is missing.
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if (bit >= 8) {
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bit = -1;
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*code = byte;
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return 1;
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}
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// something went wrong and we shouldnt be here. return what we got anyway.
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bit = -1;
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*code = byte;
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return 1;
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}
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int cal_header(float cnt_freq, float dat_freq, float drate)
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{
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const float break_len = 0.01;
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const float leader_len = 0.3;
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const float break_tolerance = 0.7;
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const float leader_tolerance = 0.3;
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static float dat_avg = 1900.0;
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const float dat_a = 1.0 / (drate * 0.00238 + 1.0);
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dat_avg = dat_a * dat_freq + (1.0 - dat_a) * dat_avg;
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static int break_ticks = 0;
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static int leader_ticks = 0;
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break_ticks = fabsf(cnt_freq - 1200.0) < 50.0 ? break_ticks + 1 : 0;
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leader_ticks = fabsf(dat_avg - 1900.0) < 50.0 ? leader_ticks + 1 : 0;
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int sig_break = break_ticks >= (int)(drate * break_tolerance * break_len) ? 1 : 0;
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int sig_leader = leader_ticks >= (int)(drate * leader_tolerance * leader_len) ? 1 : 0;
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static int ticks = -1;
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ticks++;
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static int got_break = 0;
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if (sig_leader && !sig_break && got_break &&
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ticks >= (int)(drate * (leader_len + break_len) * leader_tolerance) &&
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ticks <= (int)(drate * (leader_len + break_len) * (2.0 - leader_tolerance))) {
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got_break = 0;
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return 1;
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}
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if (sig_break && !sig_leader &&
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ticks >= (int)(drate * break_len * break_tolerance) &&
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ticks <= (int)(drate * break_len * (2.0 - break_tolerance)))
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got_break = 1;
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if (sig_leader && !sig_break) {
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ticks = 0;
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got_break = 0;
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}
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return 0;
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}
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int decode(int *reset, struct img **img, char *img_name, float cnt_freq, float dat_freq, float drate)
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{
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const int width = 320;
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const int height = 240;
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const double sync_porch_sec = 0.003l;
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const double porch_sec = 0.0015l;
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const double y_sec = 0.088l;
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const double uv_sec = 0.044l;
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const double hor_sec = 0.15l;
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const double hor_sync_sec = 0.009l;
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const double seperator_sec = 0.0045l;
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const float sync_tolerance = 0.7;
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static int sync_porch_len = 0;
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static int porch_len = 0;
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static int y_len = 0;
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static int uv_len = 0;
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static int hor_len = 0;
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static int hor_sync_len = 0;
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static int seperator_len = 0;
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static int hor_ticks = 0;
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static int latch_sync = 0;
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static int y_width = 0;
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static int uv_width = 0;
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static uint8_t *y_pixel = 0;
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static uint8_t *uv_pixel = 0;
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static int init = 0;
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if (!init) {
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sync_porch_len = sync_porch_sec * drate;
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porch_len = porch_sec * drate;
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y_len = y_sec * drate;
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uv_len = uv_sec * drate;
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hor_len = hor_sec * drate;
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hor_sync_len = hor_sync_sec * drate;
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seperator_len = seperator_sec * drate;
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y_width = y_len;
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uv_width = uv_len;
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y_pixel = malloc(y_width * 2);
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memset(y_pixel, 0, y_width * 2);
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uv_pixel = malloc(uv_width * 2);
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memset(uv_pixel, 0, uv_width * 2);
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init = 1;
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}
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hor_ticks = fabsf(cnt_freq - 1200.0) < 50.0 ? hor_ticks + 1 : 0;
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// we want a pulse at the falling edge
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latch_sync = hor_ticks > (int)(sync_tolerance * hor_sync_len) ? 1 : latch_sync;
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int hor_sync = (cnt_freq > 1299.0) && latch_sync;
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latch_sync = hor_sync ? 0 : latch_sync;
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// we wait until first sync
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if (*reset && !hor_sync)
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return 0;
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static int y = 0;
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static int odd = 0;
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static int y_pixel_x = 0;
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static int uv_pixel_x = 0;
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static int ticks = -1;
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ticks++;
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// data comes after first sync
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if (*reset && hor_sync) {
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*reset = 0;
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ticks = 0;
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y_pixel_x = 0;
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uv_pixel_x = 0;
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y = 0;
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odd = 0;
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if (*img)
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close_img(*img);
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if (img_name) {
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if (!open_img_write(img, img_name, width, height))
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exit(1);
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} else {
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if (!open_img_write(img, string_time("%F_%T.ppm"), width, height))
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exit(1);
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}
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return 0;
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}
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// if horizontal sync is too early, we reset to the beginning instead of ignoring
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if (hor_sync && (ticks < (hor_len - sync_porch_len))) {
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ticks = 0;
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y_pixel_x = 0;
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uv_pixel_x = 0;
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}
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// we always sync if sync pulse is where it should be.
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if (hor_sync && (ticks >= (hor_len - sync_porch_len)) &&
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(ticks < (hor_len + sync_porch_len))) {
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process_line((*img)->pixel, y_pixel, uv_pixel, y_width, uv_width, width, height, y++);
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if (y == height) {
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close_img(*img);
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*img = 0;
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return 1;
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}
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odd ^= 1;
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ticks = 0;
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y_pixel_x = 0;
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uv_pixel_x = 0;
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}
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// if horizontal sync is missing, we extrapolate from last sync
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if (ticks >= (hor_len + sync_porch_len)) {
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process_line((*img)->pixel, y_pixel, uv_pixel, y_width, uv_width, width, height, y++);
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if (y == height) {
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close_img(*img);
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*img = 0;
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return 1;
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}
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odd ^= 1;
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ticks -= hor_len;
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// we are not at the pixels yet, so no correction here
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y_pixel_x = 0;
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uv_pixel_x = 0;
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}
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static int sep_count = 0;
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if ((ticks > (sync_porch_len + y_len)) &&
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(ticks < (sync_porch_len + y_len + seperator_len)))
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sep_count += dat_freq < 1900.0 ? 1 : -1;
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// we try to correct from odd / even seperator
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if (sep_count && (ticks > (sync_porch_len + y_len + seperator_len))) {
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odd = sep_count < 0;
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sep_count = 0;
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}
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if ((y_pixel_x < y_width) && (ticks >= sync_porch_len))
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y_pixel[y_pixel_x++ + (y % 2) * y_width] = fclampf(255.0 * (dat_freq - 1500.0) / 800.0, 0.0, 255.0);
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if ((uv_pixel_x < uv_width) && (ticks >= (sync_porch_len + y_len + seperator_len + porch_len)))
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uv_pixel[uv_pixel_x++ + odd * uv_width] = fclampf(255.0 * (dat_freq - 1500.0) / 800.0, 0.0, 255.0);
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return 0;
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}
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int demodulate(struct pcm *pcm, float *cnt_freq, float *dat_freq, float *drate)
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{
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static float rate;
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static int channels;
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static int64_t factor_L;
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static int64_t factor_M;
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static int out;
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static float dstep;
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static float complex cnt_last = -I;
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static float complex dat_last = -I;
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static float complex *cnt_q;
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static float complex *dat_q;
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static struct ddc *cnt_ddc;
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static struct ddc *dat_ddc;
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static struct buffer *buffer;
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static int cnt_delay;
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static int dat_delay;
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static short *pcm_buff;
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static int init = 0;
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if (!init) {
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init = 1;
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rate = rate_pcm(pcm);
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channels = channels_pcm(pcm);
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#if DN && UP
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// 320 / 0.088 = 160 / 0.044 = 40000 / 11 = 3636.(36)~ pixels per second for Y, U and V
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factor_L = 40000;
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factor_M = 11 * rate;
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int64_t factor_D = gcd(factor_L, factor_M);
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factor_L /= factor_D;
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factor_M /= factor_D;
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#endif
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#if DN && !UP
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factor_L = 1;
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// factor_M * step should be smaller than pixel length
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factor_M = rate * 0.088 / 320.0 / 2;
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#endif
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#if !DN
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factor_L = 1;
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factor_M = 1;
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#endif
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// we want odd number of taps, 4 and 2 ms window length gives best results
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int cnt_taps = 1 | (int)(rate * factor_L * 0.004);
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int dat_taps = 1 | (int)(rate * factor_L * 0.002);
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fprintf(stderr, "using %d and %d tap filter\n", cnt_taps, dat_taps);
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*drate = rate * (float)factor_L / (float)factor_M;
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dstep = 1.0 / *drate;
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fprintf(stderr, "using factor of %ld/%ld, working at %.2fhz\n", factor_L, factor_M, *drate);
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cnt_q = malloc(sizeof(float complex) * factor_L);
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dat_q = malloc(sizeof(float complex) * factor_L);
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// same factor to keep life simple and have accurate horizontal sync
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cnt_ddc = alloc_ddc(factor_L, factor_M, 1200.0, 200.0, rate, cnt_taps, kaiser, 2.0);
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dat_ddc = alloc_ddc(factor_L, factor_M, 1900.0, 800.0, rate, dat_taps, kaiser, 2.0);
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// delay input by phase shift of other filter to synchronize outputs
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cnt_delay = (dat_taps - 1) / (2 * factor_L);
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dat_delay = (cnt_taps - 1) / (2 * factor_L);
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// minimize delay
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if (cnt_delay > dat_delay) {
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cnt_delay -= dat_delay;
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dat_delay = 0;
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} else {
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dat_delay -= cnt_delay;
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cnt_delay = 0;
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}
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pcm_buff = (short *)malloc(sizeof(short) * channels * factor_M);
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// 0.1 second history + enough room for delay and taps
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int buff_len = 0.1 * rate + factor_M
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+ fmaxf(cnt_delay, dat_delay)
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+ fmaxf(cnt_taps, dat_taps) / factor_L;
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buffer = alloc_buffer(buff_len);
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// start immediately below
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out = factor_L;
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}
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if (out >= factor_L) {
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out = 0;
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if (!read_pcm(pcm, pcm_buff, factor_M)) {
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init = 0;
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free(pcm_buff);
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free_ddc(cnt_ddc);
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free_ddc(dat_ddc);
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free_buffer(buffer);
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return 0;
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}
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float *buff = 0;
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for (int j = 0; j < factor_M; j++)
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buff = do_buffer(buffer, (float)pcm_buff[j * channels] / 32767.0);
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do_ddc(cnt_ddc, buff + cnt_delay, cnt_q);
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do_ddc(dat_ddc, buff + dat_delay, dat_q);
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}
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*cnt_freq = fclampf(1200.0 + cargf(cnt_q[out] * conjf(cnt_last)) / (2.0 * M_PI * dstep), 1100.0, 1300.0);
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*dat_freq = fclampf(1900.0 + cargf(dat_q[out] * conjf(dat_last)) / (2.0 * M_PI * dstep), 1500.0, 2300.0);
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if (cabsf(cnt_q[out]) > cabsf(dat_q[out]))
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*dat_freq = 1500.0;
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else
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*cnt_freq = 1300.0;
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cnt_last = cnt_q[out];
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dat_last = dat_q[out];
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out++;
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return 1;
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}
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int main(int argc, char **argv)
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{
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struct pcm *pcm;
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char *pcm_name = "default";
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char *img_name = 0;
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if (argc != 1)
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pcm_name = argv[1];
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if (argc == 3)
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img_name = argv[2];
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if (!open_pcm_read(&pcm, pcm_name))
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return 1;
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info_pcm(pcm);
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float rate = rate_pcm(pcm);
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if (rate * 0.088 < 320.0) {
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fprintf(stderr, "%.0fhz samplerate too low\n", rate);
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return 1;
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}
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int channels = channels_pcm(pcm);
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if (channels > 1)
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fprintf(stderr, "using first of %d channels\n", channels);
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int vis_mode = 0;
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int dat_mode = 0;
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int vis_reset = 0;
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int dat_reset = 0;
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struct img *img = 0;
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float cnt_freq = 0.0;
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float dat_freq = 0.0;
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float drate = 0.0;
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while (demodulate(pcm, &cnt_freq, &dat_freq, &drate)) {
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if (cal_header(cnt_freq, dat_freq, drate)) {
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vis_mode = 1;
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vis_reset = 1;
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dat_mode = 0;
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dat_reset = 1;
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fprintf(stderr, "%s got calibration header\n", string_time("%F %T"));
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}
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if (vis_mode) {
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int code = 0;
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if (!vis_code(&vis_reset, &code, cnt_freq, drate))
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continue;
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if (0x88 != code) {
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fprintf(stderr, "%s got unsupported VIS 0x%x, ignoring\n", string_time("%F %T"), code);
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vis_mode = 0;
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continue;
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}
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fprintf(stderr, "%s got VIS = 0x%x\n", string_time("%F %T"), code);
|
|
dat_mode = 1;
|
|
dat_reset = 1;
|
|
vis_mode = 0;
|
|
}
|
|
|
|
if (dat_mode) {
|
|
if (decode(&dat_reset, &img, img_name, cnt_freq, dat_freq, drate))
|
|
dat_mode = 0;
|
|
}
|
|
}
|
|
|
|
if (img)
|
|
close_img(img);
|
|
|
|
close_pcm(pcm);
|
|
|
|
return 0;
|
|
}
|
|
|