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/*
* Copyright (c) 2018 Vasile Vilvoiu (YO7JBP) <vasi.vilvoiu@gmail.com>
*
* libsstv is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See LICENSE for details.
*/
#include "libsstv.h"
#include "sstv.h"
/*
* Colorspace conversion macros
* Kudos to Leszek Szary
* https://stackoverflow.com/questions/1737726/how-to-perform-rgb-yuv-conversion-in-c-c
*/
#define CLIP(X) ( (X) > 255 ? 255 : (X) < 0 ? 0 : X)
#define CRGB2Y(R, G, B) CLIP((19595 * R + 38470 * G + 7471 * B ) >> 16)
#define CRGB2Cb(R, G, B) CLIP((36962 * (B - CLIP((19595 * R + 38470 * G + 7471 * B ) >> 16) ) >> 16) + 128)
#define CRGB2Cr(R, G, B) CLIP((46727 * (R - CLIP((19595 * R + 38470 * G + 7471 * B ) >> 16) ) >> 16) + 128)
#define CYCbCr2R(Y, Cb, Cr) CLIP( Y + ( 91881 * Cr >> 16 ) - 179 )
#define CYCbCr2G(Y, Cb, Cr) CLIP( Y - (( 22544 * Cb + 46793 * Cr ) >> 16) + 135)
#define CYCbCr2B(Y, Cb, Cr) CLIP( Y + (116129 * Cb >> 16 ) - 226 )
/*
* User-defined memory allocation functions
*/
sstv_malloc_t sstv_malloc_user = NULL;
sstv_free_t sstv_free_user = NULL;
sstv_error_t
sstv_init(sstv_malloc_t alloc_func, sstv_free_t dealloc_func)
{
/* Check that either both or none of the functions are provided */
if ((!alloc_func && dealloc_func) || (alloc_func && !dealloc_func)) {
return SSTV_BAD_INITIALIZERS;
}
/* Keep user functions for allocation/deallocation */
sstv_malloc_user = alloc_func;
sstv_free_user = dealloc_func;
return SSTV_OK;
}
sstv_error_t
sstv_convert_image(sstv_image_t *img, sstv_image_format_t format)
{
if (!img) {
return SSTV_BAD_PARAMETER;
}
if (img->format == format) {
/* no conversion necessary */
return SSTV_OK;
}
if (img->format == SSTV_FORMAT_Y) {
/* can't convert from grayscale to anything */
return SSTV_UNSUPPORTED_CONVERSION;
}
/* perform conversion */
uint32_t num_px = img->width * img->height;
uint32_t i;
switch (format) {
case SSTV_FORMAT_Y:
{
switch (img->format) {
case SSTV_FORMAT_Y:
/* identity, do nothing */
break;
case SSTV_FORMAT_YCBCR:
/* condense first channel */
for (i = 0; i < num_px; i ++) {
img->buffer[i] = img->buffer[i * 3];
}
break;
case SSTV_FORMAT_RGB:
/* extract Y from RGB and set as first channel */
for (i = 0; i < num_px; i ++) {
int32_t r = img->buffer[i * 3 + 0];
int32_t g = img->buffer[i * 3 + 1];
int32_t b = img->buffer[i * 3 + 2];
img->buffer[i] = CRGB2Y(r, g, b);
}
break;
default:
return SSTV_UNSUPPORTED_CONVERSION;
}
}
break;
case SSTV_FORMAT_YCBCR:
{
switch (img->format) {
case SSTV_FORMAT_YCBCR:
/* identity, do nothing */
break;
case SSTV_FORMAT_RGB:
for (i = 0; i < num_px; i ++) {
int32_t r = img->buffer[i * 3 + 0];
int32_t g = img->buffer[i * 3 + 1];
int32_t b = img->buffer[i * 3 + 2];
img->buffer[i * 3 + 0] = CRGB2Y(r, g, b);
img->buffer[i * 3 + 1] = CRGB2Cb(r, g, b);
img->buffer[i * 3 + 2] = CRGB2Cr(r, g, b);
}
break;
default:
return SSTV_UNSUPPORTED_CONVERSION;
}
}
break;
case SSTV_FORMAT_RGB:
{
switch (img->format) {
case SSTV_FORMAT_YCBCR:
for (i = 0; i < num_px; i ++) {
int32_t y = img->buffer[i * 3 + 0];
int32_t b = img->buffer[i * 3 + 1];
int32_t r = img->buffer[i * 3 + 2];
img->buffer[i * 3 + 0] = CYCbCr2R(y, b ,r);
img->buffer[i * 3 + 1] = CYCbCr2G(y, b ,r);
img->buffer[i * 3 + 2] = CYCbCr2B(y, b ,r);
}
break;
case SSTV_FORMAT_RGB:
/* identity, do nothing */
break;
default:
return SSTV_UNSUPPORTED_CONVERSION;
}
}
break;
default:
return SSTV_BAD_FORMAT;
}
/* all ok */
img->format = format;
return SSTV_OK;
}
sstv_error_t
sstv_get_mode_image_props(sstv_mode_t mode, size_t *width, size_t *height, sstv_image_format_t *format)
{
switch (mode) {
/* PD modes */
case SSTV_MODE_PD90:
if (width) *width = 320;
if (height) *height = 256;
if (format) *format = SSTV_FORMAT_YCBCR;
break;
case SSTV_MODE_PD120:
if (width) *width = 640;
if (height) *height = 496;
if (format) *format = SSTV_FORMAT_YCBCR;
break;
case SSTV_MODE_PD160:
if (width) *width = 512;
if (height) *height = 400;
if (format) *format = SSTV_FORMAT_YCBCR;
break;
case SSTV_MODE_PD180:
if (width) *width = 640;
if (height) *height = 496;
if (format) *format = SSTV_FORMAT_YCBCR;
break;
case SSTV_MODE_PD240:
if (width) *width = 640;
if (height) *height = 496;
if (format) *format = SSTV_FORMAT_YCBCR;
break;
default:
return SSTV_BAD_MODE;
}
return SSTV_OK;
}
sstv_error_t
sstv_create_image_from_mode(sstv_image_t *out_img, sstv_mode_t mode)
{
size_t w, h;
sstv_image_format_t fmt;
sstv_error_t rc;
rc = sstv_get_mode_image_props(mode, &w, &h, &fmt);
if (rc != SSTV_OK) {
return rc;
}
return sstv_create_image_from_props(out_img, w, h, fmt);
}
sstv_error_t
sstv_create_image_from_props(sstv_image_t *out_img, size_t w, size_t h, sstv_image_format_t format)
{
size_t bsize;
if (!out_img) {
return SSTV_BAD_PARAMETER;
}
/* function needs memory allocator */
if (!sstv_malloc_user) {
return SSTV_BAD_USER_ALLOC;
}
/* element size */
switch (format) {
case SSTV_FORMAT_Y:
bsize = 1;
break;
case SSTV_FORMAT_YCBCR:
case SSTV_FORMAT_RGB:
bsize = 3;
break;
default:
return SSTV_BAD_FORMAT;
}
/* compute total size */
bsize *= w * h;
/* allocate buffer */
out_img->buffer = (uint8_t *)sstv_malloc_user(bsize);
if (!out_img->buffer) {
return SSTV_ALLOC_FAIL;
}
/* keep image specs */
out_img->width = w;
out_img->height = h;
out_img->format = format;
/* done */
return SSTV_OK;
}
sstv_error_t
sstv_pack_image(sstv_image_t *out_img, size_t width, size_t height, sstv_image_format_t format, uint8_t *buffer)
{
if (!out_img || !buffer) {
return SSTV_BAD_PARAMETER;
}
/* package image */
out_img->width = width;
out_img->height = height;
out_img->format = format;
out_img->buffer = buffer;
/* done */
return SSTV_OK;
}
sstv_error_t
sstv_delete_image(sstv_image_t *img)
{
if (!img) {
return SSTV_BAD_PARAMETER;
}
/* free buffer if allocated */
if (!sstv_free_user) {
return SSTV_BAD_USER_DEALLOC;
}
sstv_free_user(img->buffer);
/* reset fields */
img->width = 0;
img->height = 0;
img->buffer = NULL;
/* done */
return SSTV_OK;
}
sstv_error_t
sstv_pack_signal(sstv_signal_t *sig, sstv_sample_type_t type, size_t capacity, void *buffer)
{
if (!sig) {
return SSTV_BAD_PARAMETER;
}
switch(type) {
case SSTV_SAMPLE_INT8:
case SSTV_SAMPLE_UINT8:
sig->size = capacity;
break;
case SSTV_SAMPLE_INT16:
sig->size = 2 * capacity;
break;
default:
return SSTV_BAD_SAMPLE_TYPE;
}
sig->buffer = buffer;
sig->type = type;
sig->capacity = capacity;
sig->count = 0;
/* done */
return SSTV_OK;
}
uint8_t
sstv_get_visp_code(sstv_mode_t mode)
{
switch (mode) {
case SSTV_MODE_PD90:
return 99;
case SSTV_MODE_PD120:
return 95;
case SSTV_MODE_PD160:
return 226;
case SSTV_MODE_PD180:
return 96;
case SSTV_MODE_PD240:
return 225;
default:
return 0;
}
}
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