TIFB_SET_SCINFO / Screen Transformation: Scaling

Hello,

I tried to scale my application (720x480) on a 720p screen - but get only distorted output.

I tried all the following:

• 720x480 -> 720x480   - shows right content, but no scaling
• 740x500 -> 740x500   - shows right content, but no scaling
• 720x480 -> 1280x720 - distorted (full screen)
• 720x480 -> 1278x718 - distorted (full screen - with 2px border)
• 720x480 -> 1080x720 - distorted (full screen - correct ratio)
• 720x480 -> 1008x672 - distorted (correct ratio with border)

The code looks like this:

    int fd = open( "/dev/fb0", O_SYNC );

    if (fd == -1) {
        perror("failed to open display device\n");
        return -1;
    }

    struct ti81xxfb_scparams        scprms;
    struct ti81xxfb_region_params    regp;

    scprms.inwidth   = SCREEN_WIDTH;        /* 720 */
    scprms.inheight  = SCREEN_HEIGHT;       /* 480 */
    scprms.outwidth  = 1280 - 2;
    scprms.outheight =  720 - 2;
    scprms.coeff     = NULL;

    if (ioctl(fd, TIFB_SET_SCINFO, &scprms) < 0) {
        perror("TIFB_SET_SCINFO.\n");
        close(fd);
        exit(1);
    }

    if (ioctl(fd, TIFB_GET_PARAMS, &regp) < 0) {
        perror("TIFB_GET_PARAMS\n");
        close(fd);
        exit(1);
    }

    regp.scalaren = TI81XXFB_FEATURE_ENABLE;
   
    if (ioctl(fd, TIFB_SET_PARAMS, &regp)< 0) {
        perror("TIFB_SET_PARAMS\n");
        close(fd);
        exit(1);
    }

    close( fd );

Best regards,

Charly