veejay/veejay-current/libyuv/yuvconv.c

/* veejay - Linux VeeJay
 * 	     (C) 2002-2004 Niels Elburg <nelburg@looze.net> 
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <config.h>
#include <stdint.h>
#include <libyuv/yuvconv.h>
/* this routine is the same as frame_YUV422_to_YUV420P , unpack
 * libdv's 4:2:2-packed into 4:2:0 planar 
 * See http://mjpeg.sourceforge.net/ (MJPEG Tools) (lav-common.c)
 */
void yuy2toyv12(uint8_t * _y, uint8_t * _u, uint8_t * _v, uint8_t * input,
		int width, int height)
{

    int i, j, w2;
    uint8_t *y, *u, *v;

    w2 = width / 2;

    //I420
    y = _y;
    v = _v;
    u = _u;

    for (i = 0; i < height; i += 4) {
	/* top field scanline */
	for (j = 0; j < w2; j++) {
	    /* packed YUV 422 is: Y[i] U[i] Y[i+1] V[i] */
	    *(y++) = *(input++);
	    *(u++) = *(input++);
	    *(y++) = *(input++);
	    *(v++) = *(input++);
	}
	for (j = 0; j < w2; j++)
	{
	    *(y++) = *(input++);
	    *(u++) = *(input++);
	    *(y++) = *(input++);
	    *(v++) = *(input++);
	
	}

	/* next two scanlines, one frome each field , interleaved */
	for (j = 0; j < w2; j++) {
	    /* skip every second line for U and V */
	    *(y++) = *(input++);
	    input++;
	    *(y++) = *(input++);
	    input++;
	}
	/* bottom field scanline*/
	for (j = 0; j < w2; j++) {
	    /* skip every second line for U and V */
	    *(y++) = *(input++);
	    input++;
	    *(y++) = *(input++);
	    input++;
	}

    }
}

void yuy2toyv16(uint8_t * _y, uint8_t * _u, uint8_t * _v, uint8_t * input,
		int width, int height)
{

    int i, j, w2;
    uint8_t *y, *u, *v;

    w2 = width / 2;

    //YV16
    y = _y;
    v = _v;
    u = _u;

    for (i = 0; i < height; i ++ )
    {
	for (j = 0; j < w2; j++) {
	    /* packed YUV 422 is: Y[i] U[i] Y[i+1] V[i] */
	    *(y++) = *(input++);
	    *(u++) = *(input++);
	    *(y++) = *(input++);
	    *(v++) = *(input++);
	}
    }
}
/* convert 4:2:0 to yuv 4:2:2 packed */
void yuv422p_to_yuv422(uint8_t * yuv420[3], uint8_t * dest, int width,
		       int height)
{
    unsigned int x, y;


    for (y = 0; y < height; ++y) {
	uint8_t *Y = yuv420[0] + y * width;
	uint8_t *Cb = yuv420[1] + (y / 2) * (width);
	uint8_t *Cr = yuv420[2] + (y / 2) * (width);
	for (x = 0; x < width; x +=2) {
	    *(dest + 0) = Y[0];
	    *(dest + 1) = Cb[0];
	    *(dest + 2) = Y[1];
	    *(dest + 3) = Cr[0];
	    dest += 4;
	    Y += 2;
	    ++Cb;
	    ++Cr;
	}
    }
}



/* convert 4:2:0 to yuv 4:2:2 */
void yuv420p_to_yuv422(uint8_t * yuv420[3], uint8_t * dest, int width,
		       int height)
{
    unsigned int x, y;


    for (y = 0; y < height; ++y) {
	uint8_t *Y = yuv420[0] + y * width;
	uint8_t *Cb = yuv420[1] + (y >> 1) * (width >> 1);
	uint8_t *Cr = yuv420[2] + (y >> 1) * (width >> 1);
	for (x = 0; x < width; x += 2) {
	    *(dest + 0) = Y[0];
	    *(dest + 1) = Cb[0];
	    *(dest + 2) = Y[1];
	    *(dest + 3) = Cr[0];
	    dest += 4;
	    Y += 2;
	    ++Cb;
	    ++Cr;
	}
    }
}

/* convert yuv422 planar to YUYV */
void yuv422_to_yuyv(uint8_t *yuv422[3], uint8_t *pixels, int w, int h)
{
    int x,y;
    uint8_t *Y = yuv422[0];
    uint8_t *U = yuv422[1];
    uint8_t *V = yuv422[2]; // U Y V Y
	for(y = 0; y < h; y ++ )
	{
		Y = yuv422[0] + y * w;
		U = yuv422[1] + (y>>1) * w;
		V = yuv422[2] + (y>>1) * w;
	/*	for(x=0; x < w; x+= 2)
		{
			*(pixels + 0) = Y[0];
			*(pixels + 1) = U[0];
			*(pixels + 2) = Y[1];
			*(pixels + 3) = V[0];
			pixels += 4;
			Y+=2;
			++U;
			++V;
		}
	*/
		for( x = 0 ; x < w ; x += 4 )
		{
			*(pixels + 0) = Y[0];
			*(pixels + 1) = U[0];
			*(pixels + 2) = Y[1];
			*(pixels + 3) = V[0];
			*(pixels + 4) = Y[2];
			*(pixels + 5) = U[1];
			*(pixels + 6) = Y[3];
			*(pixels + 7) = V[1];
			pixels += 8;
			Y+=4;
			U+=2;
			V+=2;
		}
    }
}

/* lav_common - some general utility functionality used by multiple
	lavtool utilities. */

/* Copyright (C) 2000, Rainer Johanni, Andrew Stevens */
/* - added scene change detection code 2001, pHilipp Zabel */
/* - broke some code out to lav_common.h and lav_common.c 
 *   July 2001, Shawn Sulma <lavtools@athos.cx>.  In doing this,
 *   I replaced the large number of globals with a handful of structs
 *   that are passed into the appropriate methods.  Check lav_common.h
 *   for the structs.  I'm sure some of what I've done is inefficient,
 *   subtly incorrect or just plain Wrong.  Feedback is welcome.
 */


/***********************
 *
 * Take a random(ish) clipd mean of a frame luma and chroma
 * Its intended as a rough and ready hash of frame content.
 * The idea is that changes above a certain threshold are treated as
 * scene changes.
 *
 **********************/

int luminance_mean(uint8_t * frame[], int w, int h)
{
    uint8_t *p;
    uint8_t *lim;
    int sum = 0;
    int count = 0;
    p = frame[0];
    lim = frame[0] + w * (h - 1);
    while (p < lim) {
	sum += (p[0] + p[1]) + (p[w - 3] + p[w - 2]);
	p += 31;
	count += 4;
    }

    w = w / 2;
    h = h / 2;

    p = frame[1];
    lim = frame[1] + w * (h - 1);
    while (p < lim) {
	sum += (p[0] + p[1]) + (p[w - 3] + p[w - 2]);
	p += 31;
	count += 4;
    }
    p = frame[2];
    lim = frame[2] + w * (h - 1);
    while (p < lim) {
	sum += (p[0] + p[1]) + (p[w - 3] + p[w - 2]);
	p += 31;
	count += 4;
    }
    return sum / count;
}