[geekmaster]

And here is the relevant code that takes the pre-dithered content piped in from raw2gmv or from a pre-dithered video (gmv) file, and converts it to whatever the framebuffer requirements dictate for the kindle models and boot modes supported (all of them, as of the PW).

PHP Code:

//----- gmlib global vars ----- 
enum GMLIB_op {GMLIB_INIT,GMLIB_CLOSE,GMLIB_UPDATE,GMLIB_VSYNC}; 
u8 *fb0=NULL;     // framebuffer pointer 
int fdFB=0;      // fb0 file descriptor 
int teu=0;      // eink update time 
u32 fs=0;      // fb0 stride 
u32 MX=0;     // xres (visible) 
u32 MY=0;    // yres (visible) 
u32 VY=0;   // (VY>MY): mxcfb driver 
u8 ppb=0;  // pixels per byte 
u32 fc=0; // frame counter 
#define FBSIZE (600/8*800) 
//================================== 
// gmplay4 - play video on 4-bit fb0 
//---------------------------------- 
void gmplay4(void) { 
    u32 i,x,y,b,p,off=(MY/2-400)*fs+MX/4-150,fbsize=FBSIZE; u8 fbt[FBSIZE]; 
    while (fread(fbt,fbsize,1,stdin)) { teu+=130; // teu: next update time 
        if (getmsec()>teu+1000) continue; // drop frame if > 1 sec behind 
        gmlib(GMLIB_VSYNC); // wait for fb0 ready 
        for (y=0;y<800;y++) for (x=0;x<600;x+=8) { 
            b=fbt[600/8*y+x/8]; i=y*fs+x/2+off; 
            p=(b&1)*240; b>>=1; fb0[i]=p|(b&1)*15; b>>=1; 
            p=(b&1)*240; b>>=1; fb0[i+1]=p|(b&1)*15; b>>=1; 
            p=(b&1)*240; b>>=1; fb0[i+2]=p|(b&1)*15; b>>=1; 
            p=(b&1)*240; b>>=1; fb0[i+3]=p|(b&1)*15; 
        } fc++; gmlib(GMLIB_UPDATE); 
    } 
} 
//================================== 
// gmplay8 - play video on 8-bit fb0 
//---------------------------------- 
void gmplay8(void) { 
    u32 i,x,y,b,fbsize=FBSIZE; u8 fbt[FBSIZE]; 
    while (fread(fbt,fbsize,1,stdin)) { teu+=130; // teu: next update time 
        if (getmsec()>teu+1000) continue; // drop frame if > 1 sec behind 
        gmlib(GMLIB_VSYNC); // wait for fb0 ready 
        for (y=0;y<800;y++) for (x=0;x<600;x+=8) { 
            b=fbt[600/8*y+x/8]; i=y*fs+x; 
            fb0[i]=(b&1)*255; b>>=1; fb0[i+1]=(b&1)*255; b>>=1; 
            fb0[i+2]=(b&1)*255; b>>=1; fb0[i+3]=(b&1)*255; b>>=1; 
            fb0[i+4]=(b&1)*255; b>>=1; fb0[i+5]=(b&1)*255; b>>=1; 
            fb0[i+6]=(b&1)*255; b>>=1; fb0[i+7]=(b&1)*255; 
        } fc++; gmlib(GMLIB_UPDATE); 
    } 
} 


I will add more details about how it works here, but again, there are already some details in the relevant posts:
https://www.mobileread.com/forums/sho...d.php?t=177455