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#include <jxl/encode.h>
#include <jxl/thread_parallel_runner.h>
#include <stdio.h>
#include <stdlib.h>
/* Creates an animated JXL with 4 solid-color 8x8 frames at 500ms each.
Usage: make_anim_jxl <num_loops> <output.jxl>
num_loops: 0=infinite, 1=once, 2=twice, etc.
*/
static const uint8_t kColors[4][3] = {
{255, 0, 0}, /* red */
{0, 255, 0}, /* green */
{0, 0, 255}, /* blue */
{255, 255, 0}, /* yellow */
};
int main(int argc, char** argv) {
if (argc != 3) {
fprintf(stderr, "usage: %s <num_loops> <output.jxl>\n", argv[0]);
return 1;
}
uint32_t num_loops = (uint32_t)atoi(argv[1]);
const char* outpath = argv[2];
const size_t W = 8, H = 8;
JxlEncoder* enc = JxlEncoderCreate(NULL);
if (!enc) {
fprintf(stderr, "JxlEncoderCreate failed\n");
return 1;
}
void* runner = JxlThreadParallelRunnerCreate(NULL, 1);
JxlEncoderSetParallelRunner(enc, JxlThreadParallelRunner, runner);
JxlBasicInfo info;
JxlEncoderInitBasicInfo(&info);
info.xsize = W;
info.ysize = H;
info.bits_per_sample = 8;
info.num_color_channels = 3;
info.num_extra_channels = 0;
info.alpha_bits = 0;
info.have_animation = JXL_TRUE;
info.animation.tps_numerator = 2; /* 2 ticks per second */
info.animation.tps_denominator = 1;
info.animation.num_loops = num_loops;
info.animation.have_timecodes = JXL_FALSE;
info.uses_original_profile = JXL_TRUE; /* required for lossless */
if (JxlEncoderSetBasicInfo(enc, &info) != JXL_ENC_SUCCESS) {
fprintf(stderr, "JxlEncoderSetBasicInfo failed\n");
return 1;
}
JxlColorEncoding color;
JxlColorEncodingSetToSRGB(&color, JXL_FALSE);
if (JxlEncoderSetColorEncoding(enc, &color) != JXL_ENC_SUCCESS) {
fprintf(stderr, "JxlEncoderSetColorEncoding failed\n");
return 1;
}
JxlEncoderFrameSettings* settings = JxlEncoderFrameSettingsCreate(enc, NULL);
JxlEncoderSetFrameLossless(settings, JXL_TRUE);
JxlPixelFormat fmt = {3, JXL_TYPE_UINT8, JXL_NATIVE_ENDIAN, 0};
for (int f = 0; f < 4; f++) {
uint8_t pixels[W * H * 3];
for (size_t i = 0; i < W * H; i++) {
pixels[i * 3 + 0] = kColors[f][0];
pixels[i * 3 + 1] = kColors[f][1];
pixels[i * 3 + 2] = kColors[f][2];
}
JxlFrameHeader fh;
JxlEncoderInitFrameHeader(&fh);
fh.duration = 1; /* 1 tick at 2 ticks/sec = 500ms */
if (JxlEncoderSetFrameHeader(settings, &fh) != JXL_ENC_SUCCESS) {
fprintf(stderr, "JxlEncoderSetFrameHeader failed\n");
return 1;
}
if (JxlEncoderAddImageFrame(settings, &fmt, pixels, sizeof(pixels)) !=
JXL_ENC_SUCCESS) {
fprintf(stderr, "JxlEncoderAddImageFrame failed\n");
return 1;
}
}
JxlEncoderCloseInput(enc);
/* Collect output */
size_t buf_size = 4096;
uint8_t* buf = malloc(buf_size);
size_t total = 0;
JxlEncoderStatus st;
do {
uint8_t* p = buf + total;
size_t avail = buf_size - total;
st = JxlEncoderProcessOutput(enc, &p, &avail);
total = buf_size - avail;
if (st == JXL_ENC_NEED_MORE_OUTPUT) {
buf_size *= 2;
buf = realloc(buf, buf_size);
}
} while (st == JXL_ENC_NEED_MORE_OUTPUT);
if (st != JXL_ENC_SUCCESS) {
fprintf(stderr, "JxlEncoderProcessOutput failed\n");
return 1;
}
FILE* fp = fopen(outpath, "wb");
fwrite(buf, 1, total, fp);
fclose(fp);
free(buf);
JxlEncoderDestroy(enc);
JxlThreadParallelRunnerDestroy(runner);
printf("wrote %zu bytes to %s\n", total, outpath);
return 0;
}