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-rw-r--r--src/encoder.c186
1 files changed, 141 insertions, 45 deletions
diff --git a/src/encoder.c b/src/encoder.c
index 65edc18..7d5655a 100644
--- a/src/encoder.c
+++ b/src/encoder.c
@@ -10,11 +10,42 @@
#include "luts.h"
/*
+ * Frequencies (all expressed in Hz)
+ */
+#define LEADER_FREQ 1900
+#define BREAK_FREQ 1200
+
+#define VIS_START_STOP_FREQ 1200
+#define VIS_LOW_FREQ 1300
+#define VIS_HIGH_FREQ 1100
+
+#define SYNC_FREQ 1200
+#define PORCH_FREQ 1500
+
+#define DATA_BASE_FREQ 1500
+#define DATA_BANDWIDTH 800
+
+/*
+ * Durations (useconds)
+ */
+#define LEADER_TONE_USEC 300000
+#define BREAK_USEC 10000
+#define VIS_BIT_USEC 30000
+
+/*
* Computation helpers
*/
-#define MILLISAMPLES_FROM_MICROSECONDS(time_us, sample_rate) ((uint64_t)(time_us) * (uint64_t)(sample_rate) / 1000)
+#define MICROSAMPLES_FROM_MICROSECONDS(time_us, sample_rate) ((uint64_t)(time_us) * (uint64_t)(sample_rate))
#define DPHASE_FROM_FREQ(freq, sample_rate) ((((uint64_t)(freq)) << 32) / (uint64_t)(sample_rate))
+#define BYTE_TO_FREQ(b) (DATA_BASE_FREQ + (b) * DATA_BANDWIDTH / 255)
+
+#define FSK(ctx, usamples, freq) \
+ { \
+ (ctx)->fsk.phase_delta = DPHASE_FROM_FREQ((freq), context->sample_rate); \
+ (ctx)->fsk.remaining_usamp += usamples; \
+ }
+
/*
* Encoder state
*/
@@ -56,7 +87,7 @@ typedef struct {
/* output configuration */
sstv_mode_t mode;
- size_t sample_rate;
+ uint32_t sample_rate;
/* current state */
sstv_encoder_state_t state;
@@ -65,9 +96,16 @@ typedef struct {
struct {
uint32_t phase;
uint32_t phase_delta;
- size_t remaining_samples;
+ uint64_t remaining_usamp;
} fsk;
+ /* mode timings */
+ struct {
+ uint32_t sync_usamp;
+ uint32_t porch_usamp;
+ uint32_t pixel_usamp;
+ } timings;
+
/* state extra info */
union {
struct {
@@ -76,8 +114,8 @@ typedef struct {
} vis;
struct {
- size_t curr_line;
- size_t curr_col;
+ uint32_t curr_line;
+ uint32_t curr_col;
} scan;
} extra;
} sstv_encoder_context_t;
@@ -90,7 +128,7 @@ static uint64_t default_encoder_context_usage = 0x0;
sstv_error_t
-sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, size_t sample_rate)
+sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, uint32_t sample_rate)
{
sstv_encoder_context_t *ctx = NULL;
@@ -101,7 +139,7 @@ sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, size_t
/* check image properties */
{
- size_t w, h;
+ uint32_t w, h;
sstv_image_format_t fmt;
sstv_error_t rc;
@@ -125,7 +163,7 @@ sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, size_t
return SSTV_ALLOC_FAIL;
}
} else {
- size_t i;
+ uint32_t i;
/* use default contexts */
for (i = 0; i < SSTV_DEFAULT_ENCODER_CONTEXT_COUNT; i++) {
if ((default_encoder_context_usage & (0x1 << i)) == 0) {
@@ -145,7 +183,64 @@ sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, size_t
ctx->sample_rate = sample_rate;
ctx->state = SSTV_ENCODER_STATE_START;
ctx->fsk.phase = 0; /* start nicely from zero */
- ctx->fsk.remaining_samples = 0; /* so we get initial state change */
+ ctx->fsk.remaining_usamp = 0; /* so we get initial state change */
+
+ /* initialize mode timings */
+ switch (mode) {
+ /*
+ * PD modes
+ */
+ case SSTV_MODE_PD50:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(286, sample_rate);
+ break;
+
+ case SSTV_MODE_PD90:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(532, sample_rate);
+ break;
+
+ case SSTV_MODE_PD120:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(190, sample_rate);
+ break;
+
+ case SSTV_MODE_PD160:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(382, sample_rate);
+ break;
+
+ case SSTV_MODE_PD180:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(286, sample_rate);
+ break;
+
+ case SSTV_MODE_PD240:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(382, sample_rate);
+ break;
+
+ case SSTV_MODE_PD290:
+ ctx->timings.sync_usamp = MICROSAMPLES_FROM_MICROSECONDS(20000, sample_rate);
+ ctx->timings.porch_usamp = MICROSAMPLES_FROM_MICROSECONDS(2080, sample_rate);
+ ctx->timings.pixel_usamp = MICROSAMPLES_FROM_MICROSECONDS(286, sample_rate);
+ break;
+
+ /*
+ * Invalid mode
+ */
+ default:
+ if (sstv_free_user) {
+ sstv_free_user(ctx);
+ }
+ return SSTV_BAD_MODE;
+ }
/* set output */
*out_ctx = ctx;
@@ -157,7 +252,7 @@ sstv_create_encoder(void **out_ctx, sstv_image_t image, sstv_mode_t mode, size_t
sstv_error_t
sstv_delete_encoder(void *ctx)
{
- size_t i;
+ uint32_t i;
if (!ctx) {
return SSTV_BAD_PARAMETER;
@@ -190,9 +285,8 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
/* start communication */
if (context->state == SSTV_ENCODER_STATE_VIS_STOP_BIT) {
context->state = SSTV_ENCODER_STATE_SYNC;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1200, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(20000, context->sample_rate);
context->extra.scan.curr_line = 0;
+ FSK(context, context->timings.sync_usamp, SYNC_FREQ);
return SSTV_OK;
}
@@ -202,17 +296,15 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
&& (context->extra.scan.curr_line < context->image.height-1))
{
context->state = SSTV_ENCODER_STATE_SYNC;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1200, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(20000, context->sample_rate);
context->extra.scan.curr_line += 2;
+ FSK(context, context->timings.sync_usamp, SYNC_FREQ);
return SSTV_OK;
}
/* sync->porch */
if (context->state == SSTV_ENCODER_STATE_SYNC) {
context->state = SSTV_ENCODER_STATE_PORCH;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1500, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(2080, context->sample_rate);
+ FSK(context, context->timings.porch_usamp, PORCH_FREQ);
return SSTV_OK;
}
@@ -227,10 +319,9 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
context->state = SSTV_ENCODER_STATE_Y_EVEN_SCAN;
- size_t pix_offset = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
+ uint32_t pix_offset = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
uint8_t y = context->image.buffer[pix_offset * 3];
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1500 + y * 800 / 255, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(190, context->sample_rate);
+ FSK(context, context->timings.pixel_usamp, BYTE_TO_FREQ(y));
context->extra.scan.curr_col ++;
return SSTV_OK;
@@ -247,13 +338,12 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
context->state = SSTV_ENCODER_STATE_RY_SCAN;
- size_t pix_offset_l0 = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
- size_t pix_offset_l1 = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
+ uint32_t pix_offset_l0 = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
+ uint32_t pix_offset_l1 = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
uint8_t r1 = context->image.buffer[pix_offset_l0 * 3 + 2];
uint8_t r2 = context->image.buffer[pix_offset_l1 * 3 + 2];
uint8_t r = (r1 + r2) / 2;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1500 + r * 800 / 255, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(190, context->sample_rate);
+ FSK(context, context->timings.pixel_usamp, BYTE_TO_FREQ(r));
context->extra.scan.curr_col ++;
return SSTV_OK;
@@ -270,13 +360,12 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
context->state = SSTV_ENCODER_STATE_BY_SCAN;
- size_t pix_offset_l0 = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
- size_t pix_offset_l1 = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
+ uint32_t pix_offset_l0 = context->image.width * context->extra.scan.curr_line + context->extra.scan.curr_col;
+ uint32_t pix_offset_l1 = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
uint8_t b1 = context->image.buffer[pix_offset_l0 * 3 + 1];
uint8_t b2 = context->image.buffer[pix_offset_l1 * 3 + 1];
uint8_t b = (b1 + b2) / 2;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1500 + b * 800 / 255, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(190, context->sample_rate);
+ FSK(context, context->timings.pixel_usamp, BYTE_TO_FREQ(b));
context->extra.scan.curr_col ++;
return SSTV_OK;
@@ -293,10 +382,9 @@ sstv_encode_pd_state_change(sstv_encoder_context_t *context)
context->state = SSTV_ENCODER_STATE_Y_ODD_SCAN;
- size_t pix_offset = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
+ uint32_t pix_offset = context->image.width * (context->extra.scan.curr_line + 1) + context->extra.scan.curr_col;
uint8_t y = context->image.buffer[pix_offset * 3];
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1500 + y * 800 / 255, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(190, context->sample_rate);
+ FSK(context, context->timings.pixel_usamp, BYTE_TO_FREQ(y));
context->extra.scan.curr_col ++;
return SSTV_OK;
@@ -313,32 +401,36 @@ sstv_encode_state_change(sstv_encoder_context_t *context)
/* leader tone #1 */
if (context->state == SSTV_ENCODER_STATE_START) {
context->state = SSTV_ENCODER_STATE_LEADER_TONE_1;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1900, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(300000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(LEADER_TONE_USEC, context->sample_rate),
+ LEADER_FREQ);
return SSTV_OK;
}
/* break */
if (context->state == SSTV_ENCODER_STATE_LEADER_TONE_1) {
context->state = SSTV_ENCODER_STATE_BREAK;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1200, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(10000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(BREAK_USEC, context->sample_rate),
+ BREAK_FREQ);
return SSTV_OK;
}
/* leader tone #2 */
if (context->state == SSTV_ENCODER_STATE_BREAK) {
context->state = SSTV_ENCODER_STATE_LEADER_TONE_2;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1900, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(300000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(LEADER_TONE_USEC, context->sample_rate),
+ LEADER_FREQ);
return SSTV_OK;
}
/* VIS start bit */
if (context->state == SSTV_ENCODER_STATE_LEADER_TONE_2) {
context->state = SSTV_ENCODER_STATE_VIS_START_BIT;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1200, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(30000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(VIS_BIT_USEC, context->sample_rate),
+ VIS_START_STOP_FREQ);
context->extra.vis.visp = sstv_get_visp_code(context->mode);
context->extra.vis.curr_bit = 0;
return SSTV_OK;
@@ -351,27 +443,31 @@ sstv_encode_state_change(sstv_encoder_context_t *context)
uint8_t bit = (context->extra.vis.visp >> context->extra.vis.curr_bit) & 0x1;
context->state = SSTV_ENCODER_STATE_VIS_BIT;
context->extra.vis.curr_bit ++;
- context->fsk.phase_delta = DPHASE_FROM_FREQ((bit ? 1100 : 1300), context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(30000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(VIS_BIT_USEC, context->sample_rate),
+ (bit ? VIS_HIGH_FREQ : VIS_LOW_FREQ));
return SSTV_OK;
}
/* VIS stop bit */
if (context->state == SSTV_ENCODER_STATE_VIS_BIT) {
context->state = SSTV_ENCODER_STATE_VIS_STOP_BIT;
- context->fsk.phase_delta = DPHASE_FROM_FREQ(1200, context->sample_rate);
- context->fsk.remaining_samples += MILLISAMPLES_FROM_MICROSECONDS(30000, context->sample_rate);
+ FSK(context,
+ MICROSAMPLES_FROM_MICROSECONDS(VIS_BIT_USEC, context->sample_rate),
+ VIS_START_STOP_FREQ);
return SSTV_OK;
}
/* call state change routine for specific mode */
switch (context->mode) {
/* PD modes */
+ case SSTV_MODE_PD50:
case SSTV_MODE_PD90:
case SSTV_MODE_PD120:
case SSTV_MODE_PD160:
case SSTV_MODE_PD180:
case SSTV_MODE_PD240:
+ case SSTV_MODE_PD290:
return sstv_encode_pd_state_change(context);
default:
@@ -395,7 +491,7 @@ sstv_encode(void *ctx, sstv_signal_t *signal)
/* main encoding loop */
while (1) {
/* state change? */
- if (context->fsk.remaining_samples < 1000) {
+ if (context->fsk.remaining_usamp < 1000000) {
rc = sstv_encode_state_change(context);
if (rc != SSTV_OK) {
return rc;
@@ -407,7 +503,7 @@ sstv_encode(void *ctx, sstv_signal_t *signal)
}
/* make sure we don't skip a state */
- if (context->fsk.remaining_samples < 1000) {
+ if (context->fsk.remaining_usamp < 1000000) {
/* this should not happen for a proper sample rate */
return SSTV_INTERNAL_ERROR;
}
@@ -421,7 +517,7 @@ sstv_encode(void *ctx, sstv_signal_t *signal)
}
/* encode sample and continue */
- context->fsk.remaining_samples -= 1000;
+ context->fsk.remaining_usamp -= 1000000;
context->fsk.phase += context->fsk.phase_delta;
switch(signal->type) {
case SSTV_SAMPLE_INT8:
generated by cgit v1.2.3 (git 2.39.1) at 2025-11-23 02:34:00 +0000