gtfcalc.c

来自「适合KS8695X」· C语言 代码 · 共 437 行 · 第 1/2 页

	rightMarginPixels = round(hPixels * c.margin) / (100 * c.cellGran);
	}
    else {
	leftMarginPixels = 0;
	rightMarginPixels = 0;
	}

    /* Find the total number of active pixels in image + margins */
    hTotalActivePixels = hPixels + leftMarginPixels + rightMarginPixels;

    if (type == GTF_lockVF) {
	/* Find the ideal blanking duty cycle */
	idealDutyCycle = c.c - ((c.m * hPeriod) / 1000);
	}
    else if (type == GTF_lockHF) {
	/* Find the ideal blanking duty cycle */
	idealDutyCycle = c.c - (c.m / hFreq);
	}
    else if (type == GTF_lockPF) {
	/* Find ideal horizontal period from blanking duty cycle formula */
	idealHPeriod = (((c.c - 100) + (sqrt((pow(100-c.c,2)) +
	    (0.4 * c.m * (hTotalActivePixels + rightMarginPixels +
	    leftMarginPixels) / dotClock)))) / (2 * c.m)) * 1000;

	/* Find the ideal blanking duty cycle */
	idealDutyCycle = c.c - ((c.m * idealHPeriod) / 1000);
	}

    /* Find the number of pixels in blanking time */
    hBlankPixels = round((hTotalActivePixels * idealDutyCycle) /
	((100 - idealDutyCycle) * c.cellGran)) * c.cellGran;

    /* Find the total number of pixels */
    hTotalPixels = hTotalActivePixels + hBlankPixels;

    /* Find the horizontal back porch */
    hBackPorch = round((hBlankPixels / 2) / c.cellGran) * c.cellGran;

    /* Find the horizontal sync width */
    hSyncWidth = round(((c.hSync/100) * hTotalPixels) / c.cellGran) * c.cellGran;

    /* Find the horizontal sync + back porch */
    hSyncBP = hBackPorch + hSyncWidth;

    if (type == GTF_lockPF) {
	/* Find the horizontal frequency */
	hFreq = (dotClock / hTotalPixels) * 1000;

	/* Find the number of lines in vSync + back porch */
	vSyncBP = round((c.minVSyncBP * hFreq) / 1000);

	/* Find the number of lines in the V back porch alone */
	vBackPorch = vSyncBP - c.vSyncRqd;

	/* Find the total number of lines in the vertical period */
	vTotalLines = vLines + topMarginLines + botMarginLines + vSyncBP
	    + interlace + c.minPorch;

	/* Find the actual vertical field frequency */
	vFieldRate = (hFreq / vTotalLines) * 1000;
	}
    else {
	if (type == GTF_lockVF) {
	    /* Find the horizontal frequency */
	    hFreq = 1000 / hPeriod;
	    }
	else if (type == GTF_lockHF) {
	    /* Find the horizontal frequency */
	    hPeriod = 1000 / hFreq;
	    }

	/* Find the pixel clock frequency */
	dotClock = hTotalPixels / hPeriod;
	}

    /* Return the computed frequencies */
    t->vFreq = vFieldRate;
    t->hFreq = hFreq;
    t->dotClock = dotClock;

    /* Determine the vertical timing parameters */
    t->h.hTotal = (int)hTotalPixels;
    t->h.hDisp = (int)hTotalActivePixels;
    t->h.hSyncStart = t->h.hTotal - (int)hSyncBP;
    t->h.hSyncEnd = t->h.hTotal - (int)hBackPorch;
    t->h.hFrontPorch = t->h.hSyncStart - t->h.hDisp;
    t->h.hSyncWidth = (int)hSyncWidth;
    t->h.hBackPorch = (int)hBackPorch;

    /* Determine the vertical timing parameters */
    t->v.vTotal = (int)vTotalLines;
    t->v.vDisp = (int)vLines;
    t->v.vSyncStart = t->v.vTotal - (int)vSyncBP;
    t->v.vSyncEnd = t->v.vTotal - (int)vBackPorch;
    t->v.vFrontPorch = t->v.vSyncStart - t->v.vDisp;
    t->v.vSyncWidth = (int)c.vSyncRqd;
    t->v.vBackPorch = (int)vBackPorch;
    if (wantInterlace) {
	/* Halve the timings for interlaced modes */
	t->v.vTotal /= 2;
	t->v.vDisp /= 2;
	t->v.vSyncStart /= 2;
	t->v.vSyncEnd /= 2;
	t->v.vFrontPorch /= 2;
	t->v.vSyncWidth /= 2;
	t->v.vBackPorch /= 2;
	t->dotClock /= 2;
	}

    /* Mark as GTF timing using the sync polarities */
    t->interlace = (wantInterlace) ? 'I' : 'N';
    t->hSyncPol = '-';
    t->vSyncPol = '+';
}

void GTF_getConstants(GTF_constants *constants)
{ *constants = GC; }

void GTF_setConstants(GTF_constants *constants)
{ GC = *constants; }

#ifdef  TESTING_GTF

void main(int argc,char *argv[])
{
    FILE        *f;
    double      xPixels,yPixels,freq;
    ibool       interlace;
    GTF_timings t;

    if (argc != 5 && argc != 6) {
	printf("Usage: GTFCALC <xPixels> <yPixels> <freq> [[Hz] [KHz] [MHz]] [I]\n");
	printf("\n");
	printf("where <xPixels> is the horizontal resolution of the mode, <yPixels> is the\n");
	printf("vertical resolution of the mode. The <freq> value will be the frequency to\n");
	printf("drive the calculations, and will be either the vertical frequency (in Hz)\n");
	printf("the horizontal frequency (in KHz) or the dot clock (in MHz). To generate\n");
	printf("timings for an interlaced mode, add 'I' to the end of the command line.\n");
	printf("\n");
	printf("For example to generate timings for 640x480 at 60Hz vertical:\n");
	printf("\n");
	printf("    GTFCALC 640 480 60 Hz\n");
	printf("\n");
	printf("For example to generate timings for 640x480 at 31.5KHz horizontal:\n");
	printf("\n");
	printf("    GTFCALC 640 480 31.5 KHz\n");
	printf("\n");
	printf("For example to generate timings for 640x480 with a 25.175Mhz dot clock:\n");
	printf("\n");
	printf("    GTFCALC 640 480 25.175 MHz\n");
	printf("\n");
	printf("GTFCALC will print a summary of the results found, and dump the CRTC\n");
	printf("values to the UVCONFIG.CRT file in the format used by SciTech Display Doctor.\n");
	exit(1);
	}

    /* Get values from command line */
    xPixels = atof(argv[1]);
    yPixels = atof(argv[2]);
    freq = atof(argv[3]);
    interlace = ((argc == 6) && (argv[5][0] == 'I'));

    /* Compute the CRTC timings */
    if (toupper(argv[4][0]) == 'H')
	GTF_calcTimings(xPixels,yPixels,freq,GTF_lockVF,false,interlace,&t);
    else if (toupper(argv[4][0]) == 'K')
	GTF_calcTimings(xPixels,yPixels,freq,GTF_lockHF,false,interlace,&t);
    else if (toupper(argv[4][0]) == 'M')
	GTF_calcTimings(xPixels,yPixels,freq,GTF_lockPF,false,interlace,&t);
    else {
	printf("Unknown command line!\n");
	exit(1);
	}

    /* Dump summary info to standard output */
    printf("CRTC values for %.0fx%.0f @ %.2f %s\n", xPixels, yPixels, freq, argv[4]);
    printf("\n");
    printf("  hTotal      = %-4d    vTotal      = %-4d\n",
	t.h.hTotal, t.v.vTotal);
    printf("  hDisp       = %-4d    vDisp       = %-4d\n",
	t.h.hDisp, t.v.vDisp);
    printf("  hSyncStart  = %-4d    vSyncStart  = %-4d\n",
	t.h.hSyncStart, t.v.vSyncStart);
    printf("  hSyncEnd    = %-4d    vSyncEnd    = %-4d\n",
	t.h.hSyncEnd, t.v.vSyncEnd);
    printf("  hFrontPorch = %-4d    vFrontPorch = %-4d\n",
	t.h.hFrontPorch, t.v.vFrontPorch);
    printf("  hSyncWidth  = %-4d    vSyncWidth  = %-4d\n",
	t.h.hSyncWidth, t.v.vSyncWidth);
    printf("  hBackPorch  = %-4d    vBackPorch  = %-4d\n",
	t.h.hBackPorch, t.v.vBackPorch);
    printf("\n");
    printf("  Interlaced  = %s\n", (t.interlace == 'I') ? "Yes" : "No");
    printf("  H sync pol  = %c\n", t.hSyncPol);
    printf("  V sync pol  = %c\n", t.vSyncPol);
    printf("\n");
    printf("  Vert freq   = %.2f Hz\n", t.vFreq);
    printf("  Horiz freq  = %.2f KHz\n", t.hFreq);
    printf("  Dot Clock   = %.2f Mhz\n",    t.dotClock);

    /* Dump to file in format used by SciTech Display Doctor */
    if ((f = fopen("UVCONFIG.CRT","w")) != NULL) {
	fprintf(f, "[%.0f %.0f]\n", xPixels, yPixels);
	fprintf(f, "%d %d %d %d '%c' %s\n",
	    t.h.hTotal, t.h.hDisp,
	    t.h.hSyncStart, t.h.hSyncEnd,
	    t.hSyncPol, (t.interlace == 'I') ? "I" : "NI");
	fprintf(f, "%d %d %d %d '%c'\n",
	    t.v.vTotal, t.v.vDisp,
	    t.v.vSyncStart, t.v.vSyncEnd,
	    t.vSyncPol);
	fprintf(f, "%.2f\n", t.dotClock);
	fclose(f);
	}
}

#endif  /* TESTING */