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/*
* Microsoft YUV Codec -yuv411 -> rgb conversion functions * * Copyright (c) Microsoft Corporation 1993 * All Rights Reserved * */
#include <windows.h>
#include <windowsx.h>
#include <mmsystem.h>
#include <compddk.h>
#include "msyuv.h"
/*
* This module provides translation from YUV into RGB. It translates * from 8-bit YUV 4:2:2 (as provided by the Spigot video capture driver) * or 7-bit YUV 4:1:1 (as provided by the Bravado driver) into 16-bit RGB555 * or RGB565. All versions use a look-up table built using YUVToRGB555 * or YUVToRGB565 */
#define RANGE(x, lo, hi) max(lo, min(hi, x))
/*
* Convert a YUV colour into a 15-bit RGB colour. * * The input Y is in the range 16..235; the input U and V components * are in the range -128..+127. The conversion equations for this are * (according to CCIR 601): * * R = Y + 1.371 V * G = Y - 0.698 V - 0.336 U * B = Y + 1.732 U * * To avoid floating point, we scale all values by 1024. * * The resulting RGB values are in the range 16..235: we truncate these to * 5 bits each. and return a WORD containing 5-bits each for R, G and B * with bit 15 set to 0. */WORDYUVToRGB555(int y, int u, int v){ int ScaledY = RANGE(y, 16, 235) * 1024; int red, green, blue;
red = RANGE((ScaledY + (1404 * v)) / 1024, 0, 255); green = RANGE( (ScaledY - (715 * v) - (344 * u)) / 1024, 0, 255); blue = RANGE( (ScaledY + (1774 * u)) / 1024, 0, 255);
return (WORD) (((red & 0xf8) << 7) | ((green & 0xf8) << 2) | ((blue & 0xf8) >>3) );}
// same as above but converts to RGB565 instead
WORDYUVToRGB565(int y, int u, int v){ int ScaledY = RANGE(y, 16, 235) * 1024; int red, green, blue;
red = RANGE((ScaledY + (1404 * v)) / 1024, 0, 255); green = RANGE( (ScaledY - (715 * v) - (344 * u)) / 1024, 0, 255); blue = RANGE( (ScaledY + (1774 * u)) / 1024, 0, 255);
return (WORD) (((red & 0xf8) << 8) | ((green & 0xfc) << 3) | ((blue & 0xf8) >>3) );}
/* --- YUV 4:1:1 support ------------------------------------------ */
/*
* the input data is in YUV411 format. There is one 7 bit Luma sample * per pixel, and 1 each 7-bit U and V sample averaged over 4 pixels, * in the following layout: * * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 * Word 0 u6 u5 v6 v5 y6 y5 y4 y3 y2 y1 y0 * * Word 1 u4 u3 v4 v3 y6 y5 y4 y3 y2 y1 y0 * * Word 2 u2 u1 v2 v1 y6 y5 y4 y3 y2 y1 y0 * * Word 3 u0 v0 y6 y5 y4 y3 y2 y1 y0 * * The 7-bit y values are unsigned (0..127), whereas the 7-bit * u and V values are signed (-64..+63). * * * For RGB: we truncate the YUV into a 15-bit format and use a prepared * lookup table to convert the 15-bit YUV into a 15- or 16-bit RGB value. * * The (64 kbyte) rgb555 lookup table is built by BuildYUVToRGB555. * */
/*
* the YUV xlate tables use 5-bits per component with y in the ms bits, and * v in the ls bits. To convert from the above layout, look up the nibbles * containing the chroma bits in these tables and or together the result to * get a word with a 5-bit V component in bits 0..4, and a 5-bit * U component in bits 5..9. Note you only need three lookups since * we discard chroma bits 0 and 1. */WORD ChromaBits65[] = { 0x000, 0x008, 0x010, 0x018, 0x100, 0x108, 0x110, 0x118, 0x200, 0x208, 0x210, 0x218, 0x300, 0x308, 0x310, 0x318};
WORD ChromaBits43[] = { 0x000, 0x002, 0x004, 0x006, 0x040, 0x042, 0x044, 0x046, 0x080, 0x082, 0x084, 0x086, 0x0c0, 0x0c2, 0x0c4, 0x0c6};
WORD ChromaBits2[] = { 0x000, 0x000, 0x001, 0x001, 0x000, 0x000, 0x001, 0x001, 0x020, 0x020, 0x021, 0x021, 0x020, 0x020, 0x021, 0x021};
/*
* build yuv411->RGB555 xlate table */LPVOID BuildYUVToRGB555(PINSTINFO pinst){ LPVOID pXlate; LPWORD pRGB555; WORD w;
if (pinst->pXlate != NULL) { return(pinst->pXlate); }
/*
* allocate a table big enough for 32k 2-byte entries */ pXlate = GlobalLock(GlobalAlloc(GPTR, 2 * 32 * 1024));
pRGB555 = (LPWORD)pXlate;
/*
* build a 15-bit yuv lookup table by stepping through each entry, * converting the yuv index to rgb and storing at that index. The index * to this table is a 15-bit value with the y component in bits 14..10, * u in bits 9..5 and v in bits 4..0. Note that the y component is unsigned, * whereas the u and v components are signed. */ for (w = 0; w < 32*1024; w++) {
/*
* the YUVtoRGB55 conversion function takes values 0..255 for y, * and -128..+127 for u and v. Pick out the relevant bits of the * index for this cell, and shift to get values in this range. * Remember the cast to ensure sign-extension of these (8-bit) values - * and don't assume that chars are signed (they're not on MIPS). */ *pRGB555++ = YUVToRGB555( (w & 0x7c00) >> 7, (signed char) ((w & 0x3e0) >> 2), (signed char) ((w & 0x1f) << 3) ); }
return(pXlate);
}
/*
* build yuv411->RGB565 xlate table */LPVOID BuildYUVToRGB565(PINSTINFO pinst){ LPVOID pXlate; LPWORD pRGB; WORD w;
if (pinst->pXlate != NULL) { return(pinst->pXlate); }
/*
* allocate a table big enough for 32k 2-byte entries */ pXlate = GlobalLock(GlobalAlloc(GPTR, 2 * 32 * 1024));
pRGB = (LPWORD)pXlate;
/*
* build a 15-bit yuv lookup table by stepping through each entry, * converting the yuv index to rgb and storing at that index. The index * to this table is a 15-bit value with the y component in bits 14..10, * u in bits 9..5 and v in bits 4..0. Note that the y component is unsigned, * whereas the u and v components are signed. */ for (w = 0; w < 32*1024; w++) {
/*
* the YUVtoRGB conversion function takes values 0..255 for y, * and -128..+127 for u and v. Pick out the relevant bits of the * index for this cell, and shift to get values in this range. * Remember the cast to ensure sign-extension of these (8-bit) values - * and don't assume that chars are signed (they're not on MIPS). */ *pRGB++ = YUVToRGB565( (w & 0x7c00) >> 7, (signed char) ((w & 0x3e0) >> 2), (signed char) ((w & 0x1f) << 3) ); }
return(pXlate);
}
/*
* translate one frame from yuv411 to 15/16 bit rgb. * * The YUV data is spread over 4 16-bit pixels in the format described * above. Pick out 4 pixels at a time, truncate them to 15-bit yuv, * lookup to translate to 15 or 16-bit rgb (depending on the lookup table * and write out. * * Flip vertically into correct dib format during conversion. */VOIDYUV411ToRGB( PINSTINFO pinst, LPBITMAPINFOHEADER lpbiInput, LPVOID lpInput, LPBITMAPINFOHEADER lpbiOutput, LPVOID lpOutput){ int RowInc; int i, j; DWORD Luma01, Luma23; DWORD Chroma; int Height, Width; int WidthBytes; PWORD pXlate; PWORD pDst; PDWORD pSrc;
Height = lpbiInput->biHeight; Width = lpbiInput->biWidth; WidthBytes = Width*2; // size of (input and output) line
pXlate = pinst->pXlate;
/*
* adjust the source to point to the start of the last line, * and work upwards (to flip vertically into DIB format) */ pSrc = (PDWORD) ( (PUCHAR) lpInput + ((Height - 1) * WidthBytes)); pDst = (PWORD) lpOutput;
/*
* calculate the amount to adjust source by at the end of one line * of copying. At this point we are at the end of line N. We need * to move to the start of line N-1. */ RowInc = (WidthBytes * 2) / sizeof(DWORD);
/* loop copying each scanline */ for (i = 0; i < Height; i++) {
/* loop copying four pixels at a time */ for (j = 0; j < Width; j += 4) {
/*
* get four pixels and convert to 15-bpp YUV */
/* get luma for first 2 pixels + higher chroma bits */ Luma01 = *pSrc++;
/* pick out u,v components using lookup table.
* u and v will be the bottom 10 bits of each pixel, so * convert to this layout */ Chroma = ChromaBits65[(Luma01 >> 12) & 0xf] | ChromaBits43[ (Luma01 >> 28) & 0xf ];
/* next two pixels + lower chroma bits */ Luma23 = *pSrc++;
/* pickup u and v bits 2 - ignore bits 1, 0 since
* we only use 5-bits per component for conversion */ Chroma |= ChromaBits2[ ( Luma23 >> 12) & 0xf];
/*
* combine luma for pix 0 with common chroma bits to * get 15-bit yuv, then lookup to convert to * rgb and store. */ *pDst++ = pXlate[ ((Luma01 & 0xf8) << 7) | Chroma]; *pDst++ = pXlate[ ((Luma01 & 0xf80000) >> 9) | Chroma]; *pDst++ = pXlate[ ((Luma23 & 0xf8) << 7) | Chroma]; *pDst++ = pXlate[ ((Luma23 & 0xf80000) >> 9) | Chroma];
} // loop per 4 pixels
/* move source pointer back to next line */ pSrc -= RowInc; } // loop per row
}
/* YUV 4:2:2 support ------------------------------------------ */
/*
* The captured data is in YUV 4:2:2, 8-bits per sample. * The data is laid out in alternating Y-U-Y-V-Y-U-Y-V format. Thus * every DWORD contains two complete pixels, in the * form (msb..lsb) V..Y1..U..Y0 * All 3 components (y, u and v) are all unsigned 8-bit values in the range * 16..235. * * We have to double scan lines for >= 480 line formats since * the hardware only captured one field maximum. * */
/*
* build a translation table to translate between YUV and RGB555. * * This builds a lookup table with 32k 1-word entries: truncate the YUV * to 15bits (5-5-5) and look-up in this xlate table to produce the * 15-bit rgb value. */LPVOID BuildYUV422ToRGB555(PINSTINFO pinst){ LPVOID pXlate; LPWORD pRGB555; WORD w;
if (pinst->pXlate != NULL) { return(pinst->pXlate); }
/*
* allocate a table big enough for 32k 2-byte entries */ pXlate = GlobalLock(GlobalAlloc(GPTR, 2 * 32 * 1024));
pRGB555 = (LPWORD)pXlate;
/*
* build a 15-bit yuv lookup table by stepping through each entry, * converting the yuv index to rgb and storing at that index. The index * to this table is a 15-bit value with the y component in bits 14..10, * u in bits 9..5 and v in bits 4..0. Note that the y component is unsigned, * whereas the u and v components are signed. */ for (w = 0; w < 32*1024; w++) {
/*
* the YUVtoRGB55 conversion function takes values 0..255 for y, * and -128..+127 for u and v. Pick out the relevant bits of the * index for this cell, and shift to get values in this range. * Subtract 128 from u and v to shift from 0..255 to -128..+127 */ *pRGB555++ = YUVToRGB555( (w & 0x7c00) >> 7, ((w & 0x3e0) >> 2) - 128, ((w & 0x1f) << 3) - 128 ); }
return(pXlate);
}
/*
* build a translation table to translate between YUV and RGB 5-6-5 * * This builds a lookup table with 32k 1-word entries: truncate the YUV * to 15bits (5-5-5) and look-up in this xlate table to produce the * 16-bit rgb value. */LPVOID BuildYUV422ToRGB565(PINSTINFO pinst){ LPVOID pXlate; LPWORD pRGB; WORD w;
if (pinst->pXlate != NULL) { return(pinst->pXlate); }
/*
* allocate a table big enough for 32k 2-byte entries */ pXlate = GlobalLock(GlobalAlloc(GPTR, 2 * 32 * 1024));
pRGB = (LPWORD)pXlate;
/*
* build a 15-bit yuv lookup table by stepping through each entry, * converting the yuv index to rgb and storing at that index. The index * to this table is a 15-bit value with the y component in bits 14..10, * u in bits 9..5 and v in bits 4..0. Note that the y component is unsigned, * whereas the u and v components are signed. */ for (w = 0; w < 32*1024; w++) {
/*
* the YUVtoRGB conversion function takes values 0..255 for y, * and -128..+127 for u and v. Pick out the relevant bits of the * index for this cell, and shift to get values in this range. * Subtract 128 from u and v to shift from 0..255 to -128..+127 */ *pRGB++ = YUVToRGB565( (w & 0x7c00) >> 7, ((w & 0x3e0) >> 2) - 128, ((w & 0x1f) << 3) - 128 ); }
return(pXlate);
}
/*
* translate YUV 4:2:2 into 16-bit RGB using a lookup table. Flip vertically * into DIB format during processing. Double scanlines for formats of * 480 lines or greater. Produces 565 or 555 format RGB depending on the * xlate table. */VOIDYUV422ToRGB( PINSTINFO pinst, LPBITMAPINFOHEADER lpbiInput, LPVOID lpInput, LPBITMAPINFOHEADER lpbiOutput, LPVOID lpOutput){ int RowInc; int i, j; DWORD uv55, dwPixel; int WidthBytes; // width of one line in BYTES
BOOL bDuplicate = FALSE; PDWORD pSrc, pDst; int Height, Width; PWORD pXlate; int InputHeight;
Height = lpbiInput->biHeight; InputHeight = Height; Width = lpbiInput->biWidth; WidthBytes = Width*2; // size of (input and output) line
pXlate = pinst->pXlate;
/*
* adjust the destination to point to the start of the last line, * and work upwards (to flip vertically into DIB format) */ pDst = (PDWORD) ( (LPBYTE)lpOutput + (Height - 1) * WidthBytes ); pSrc = (PDWORD) lpInput;
/*
* do we need to duplicate scans to fill the destination ? */ if (Height >= 480) { bDuplicate = TRUE;
/*
* we need to skip one line each time we copy a line */ RowInc = WidthBytes * 2 + (Width * 2);
InputHeight = Height/2;
} else {
/*
* calculate the amount to adjust pDst by at the end of one line * of copying. At this point we are at the end of line N. We need * to move to the start of line N-1. */ RowInc = WidthBytes + (Width * 2);
}
/* remember we are adding to a DWORD pointer */ RowInc /= sizeof(DWORD);
/* loop copying each scanline */ for (i = InputHeight; i > 0; i--) {
/* loop copying two pixels at a time */ for (j = Width ; j > 0; j -= 2) {
/*
* get two pixels and convert to 15-bpp YUV */
dwPixel = *pSrc++;
/*
* dwPixel now has two pixels, in this layout (MSB..LSB): * * V Y1 U Y0 * * convert to 2 yuv555 words and lookup in xlate table */
/* get common u and v components to lower 10 bits */ uv55 = ((dwPixel & 0xf8000000) >> 27) | ((dwPixel & 0x0000f800) >> 6);
/* build each yuv-655 value by truncating
* y to 5 bits and adding the common u and v bits, * look up to convert to rgb, and combine two pixels * into one dword */ dwPixel = pXlate[ ((dwPixel & 0xf8) << 7) | uv55 ] | (pXlate[((dwPixel & 0xf80000) >> 9) | uv55 ] << 16);
/* write two pixels to destination */ *pDst++ = dwPixel;
} // loop per 2 pixels
/* move dest pointer back to next line */ pDst -= RowInc;
} // loop per row
if (bDuplicate) {
PBYTE pbDst;
/*
* Note that since we started at the last line, and didn't duplicate, * we placed data in lines 1, 3, 5 etc that needs to be copied * to lines 0, 2, 4 etc. */ for (i = 0, pbDst = lpOutput; i < (int) Height; i+= 2) {
/*
* duplicate the scan line. We point at the first of the * two lines - the data is in the second of the * two lines. */ RtlCopyMemory(pbDst, pbDst + WidthBytes, WidthBytes);
/* skip this pair to get to the next line to be converted */ pbDst += WidthBytes * 2; } }}
VOID FreeXlate(PINSTINFO pinst){
GlobalFree(GlobalHandle(pinst->pXlate));
pinst->pXlate = NULL;}
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