More idle animation

apps/idle2.c

@@ -0,0 +1,78 @@
+#include <stdlib.h>
+#include <stdint.h>
+
+// Here I use a lcg RNG with a specificaly crafted period to enumerate all pixels
+// and color them by cycling a colormap in a randomish order
+// Same approch as in DOOM (1993)
+// see: Knuth - The Art of Computer Programming, Volume 2: Seminumerical Algorithms
+
+uint32_t hash32(uint32_t d) {
+    // DJB Hash
+    uint32_t h = 0x811c9dc5;
+    h = (h * 16777619) ^ ((d >>  0) & 0xff);
+    h = (h * 16777619) ^ ((d >>  8) & 0xff);
+    h = (h * 16777619) ^ ((d >> 16) & 0xff);
+    h = (h * 16777619) ^ ((d >> 24) & 0xff);
+    return h;
+}
+
+// must be the next prime after NUM_TOTAL_LEDS
+#define IDLE_PRIME 967
+// must be a primitive element of the prime residue field |N/IDLE_PRIM
+#define IDLE_PRIM_ELEM 159
+
+int IDLE_rand(int *seed){
+    return *seed = (*seed * IDLE_PRIM_ELEM ) % IDLE_PRIME;
+}
+
+int IDLE_last_pixel   = 34;
+int IDLE_color_offset = 2;
+
+uint32_t IDLE_colors[5] ={
+    0xd31719,
+    0x0f6851,
+    0xd4772e,
+    0xd84b23,
+    0x3d89a7
+};
+
+
+int Nx, Ny;
+uint8_t *buf;
+
+void SetPixel(int x, int y, uint8_t r, uint8_t g, uint8_t b){
+    buf[3*(x+Nx*y)+0] = r;
+    buf[3*(x+Nx*y)+1] = g;
+    buf[3*(x+Nx*y)+2] = b;
+}
+
+void IDLE_set_pixel(){
+    int i = IDLE_rand(&IDLE_last_pixel)-1;
+    int x = i%Nx;
+    int y = i/Nx;
+    if (i == IDLE_color_offset){
+        IDLE_color_offset++;
+        if (IDLE_color_offset > 100)
+            IDLE_color_offset=2;
+    } 
+    if (i >= Nx*Ny) return;
+    int color_count = sizeof(IDLE_colors)/sizeof(IDLE_colors[0]);
+
+    int color = IDLE_colors[hash32(i+IDLE_color_offset)%color_count];
+    SetPixel(x, y, (color>>16)&0xff, (color>>8)&0xff, (color>>0)&0xff);
+}
+
+int main(int argc, char **argv) {
+    Nx = atoi(argv[1]);
+    Ny = atoi(argv[2]);
+    buf = malloc(Nx*Ny*3);
+    int sleepms = atoi(argv[3]);
+    if (sleepms == 0) sleepms = 30;
+
+    while(1) {
+        IDLE_set_pixel();
+        write(1, buf, Nx*Ny*3);
+        usleep(1000*sleepms);
+
+    }
+}

apps/youtubedl.sh

@@ -1,2 +1,2 @@
 #!/bin/sh
-youtube-dl --no-progress --output - ${3} -f best[height=360] | ffmpeg -f alsa default -re -i - -pix_fmt rgb24 -vf "transpose=1,scale=${1}x${2}" -sws_flags bicubic -sws_dither bayer -vcodec rawvideo -f image2pipe -
+youtube-dl --no-progress --output - ${3}  | ffmpeg -f alsa default -re -i - -pix_fmt rgb24 -vf "transpose=1,scale=${1}x${2}" -sws_flags bicubic -sws_dither bayer -vcodec rawvideo -f image2pipe -

config.py

@@ -21,6 +21,7 @@ WebPort = 8000
 # first app is always running in IDLE    
 Apps = [
     {"guiname": "IDLE", "name": "pixelflut", "cmd": "apps/idle.py", "persistent": True},
+    {"guiname": "IDLE2", "name": "idlec", "cmd": "apps/idle2"},
     {"guiname": "YoutubeDL", "name": "youtubedl", "cmd": "apps/youtubedl.sh"},
     {"name": "framebuffer", "cmd": ["apps/fbcp", "/dev/fb0"]},
 ]