exemple record in raylib

.gitignore

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+a.out
+output.mp4
+preuve-a-conviction

Makefile

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+all:
+	gcc main.c -lraylib
+
+run: all
+	./a.out
+	mpv ./output.mp4
+
+clean:
+	rm -f ./a.out output.mp4

main.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#include "raylib.h"
+#include "rlgl.h"
+
+void draw_frame(int frame)
+{
+    BeginDrawing();
+    {
+        ClearBackground(BEIGE);
+        DrawText(TextFormat("frame: %d", frame), 0, 0, 50, RED);
+        DrawRectangle(frame*3, frame*2, 50, 50, BLUE);
+    }
+    EndDrawing();
+}
+
+int main()
+{
+    int pipefd[2];
+    pid_t pid;
+
+    if (pipe(pipefd) == -1) {
+        printf("ERR: pipe\n");
+        return -1;
+    }
+
+    pid = fork();
+    if (pid == -1) {
+        printf("ERR: fork\n");
+        return -1;
+    }
+
+    if (pid == 0) {
+        close(pipefd[1]);
+
+        dup2(pipefd[0], STDIN_FILENO);
+        close(pipefd[0]);
+
+        execlp("ffmpeg", "ffmpeg",
+               "-y",
+               "-f", "rawvideo",
+               "-pix_fmt", "rgba",
+               "-s", "900x600",
+               "-r", "60",
+               "-i", "-",
+               "output.mp4",
+               NULL);
+
+        // unreachable if ffmpeg launch
+        printf("ERR: execlp");
+        return -1;
+    } else {
+        close(pipefd[0]);
+
+        InitWindow(900, 600, "screen record test");
+        // NOTE: lower FPS if frame bug
+        SetTargetFPS(60);
+        Vector2 scale = GetWindowScaleDPI();
+        int width = GetScreenWidth();
+        int height = GetScreenHeight();
+
+        int frame;
+        for (frame = 0; frame < 300; frame++) {
+            draw_frame(frame);
+
+            int w = width*scale.x;
+            int h = height*scale.y;
+
+            unsigned char *screen_data = rlReadScreenPixels(w, h);
+            write(pipefd[1], screen_data, w*h*4*sizeof(*screen_data));
+
+            RL_FREE(screen_data);
+        }
+
+        close(pipefd[1]);
+        wait(NULL);
+
+        printf("%d frame in %.02fs\n", frame, GetTime());
+    }
+}