xvid_stat.c

mpeg4代码,比较具体

      
		framepsnr[filenr] = PSNR(XDIM,YDIM*3/2, in_buffer, XDIM, out_buffer, XDIM);
	
		printf("dectime =%6.1f ms PSNR %5.2f\n",dectime, framepsnr[filenr]);

		if (ARG_SAVEDECOUTPUT)
		{
			sprintf(filename, "%sdec%05d.pgm", filepath, filenr);
			write_pgm(filename, out_buffer);
		}

		/* Read the header if it's pgm stream */ 
		if (ARG_INPUTTYPE)
			status = read_pgmheader(in_file);

		filenr++;

	} while ( (!status) && (filenr<ARG_MAXFRAMENR) );

	
      
/*****************************************************************************
 *         Calculate totals and averages for output, print results
 ****************************************************************************/

	totalsize    /= filenr;
	totalenctime /= filenr;
	totaldectime /= filenr;

	for (i=0;i<filenr;i++)
	{
		switch (frame_type[i])
		{
		case 0:
			Pframes++;
			Ppsnr += framepsnr[i];
			break;
		case 1:
			Iframes++;
			Ipsnr += framepsnr[i];
			break;
		default:
			break;
		}
	}
	
	if (Pframes)
		Ppsnr /= Pframes;	
	if (Iframes)
		Ipsnr /= Iframes;	

	/* calculate statistics for every frametype: P,I */
	for (i=0;i<filenr;i++)
	{	
		switch (frame_type[i])
		{
		case 0:
			if (framepsnr[i] > Pmaxpsnr)
				Pmaxpsnr = framepsnr[i];
			if (framepsnr[i] < Pminpsnr)
				Pminpsnr = framepsnr[i];
			Pvarpsnr += (framepsnr[i] - Ppsnr)*(framepsnr[i] - Ppsnr) /Pframes;
			break;
		case 1:
			if (framepsnr[i] > Imaxpsnr)
				Imaxpsnr = framepsnr[i];
			if (framepsnr[i] < Pminpsnr)
				Iminpsnr = framepsnr[i];
			Ivarpsnr += (framepsnr[i] - Ipsnr)*(framepsnr[i] - Ipsnr) /Iframes;
		default:
			break;
		}
	}
	
	/* Print all statistics */
	printf("Avg. Q%1d %2s ",ARG_QUALITY, (ARG_QUANTI ? " q" : "br"));
	printf("%04d ",(ARG_QUANTI)?ARG_QUANTI:ARG_BITRATE);
	printf("( %.2f bpp) ", (double)ARG_BITRATE*1000/XDIM/YDIM/ARG_FRAMERATE);
	printf("size %6d ", (int)totalsize);
	printf("( %4d kbps ",(int)(totalsize*8*ARG_FRAMERATE/1000));
	printf("/ %.2f bpp) ",(double)totalsize*8/XDIM/YDIM);
	printf("enc: %6.1f fps, dec: %6.1f fps \n",1000/totalenctime, 1000/totaldectime);
	printf("PSNR P(%d): %5.2f ( %5.2f , %5.2f ; %5.4f ) ",Pframes,Ppsnr,Pminpsnr,Pmaxpsnr,sqrt(Pvarpsnr/filenr));
	printf("I(%d): %5.2f ( %5.2f , %5.2f ; %5.4f ) ",Iframes,Ipsnr,Iminpsnr,Imaxpsnr,sqrt(Ivarpsnr/filenr));
	printf("\n");

/*****************************************************************************
 *                            XviD PART  Stop
 ****************************************************************************/

 release_all:

	if (enc_handle)
	{	
		status = enc_stop();
		if (status)    
			fprintf(stderr, "Encore RELEASE problem return value %d\n", status);
	}

	if (dec_handle)
	{
		status = dec_stop();
		if (status)    
			fprintf(stderr, "Decore RELEASE problem return value %d\n", status);
	}

	fclose(in_file);

 free_all_memory:
	free(out_buffer);
	free(divx_buffer);
	free(in_buffer);

	return 0;

}

/*****************************************************************************
 *                        "statistical" functions
 *
 *  these are not needed for encoding or decoding, but for measuring
 *  time and quality, there in nothing specific to XviD in these
 *
 *****************************************************************************/



/* Return time elapsed time in miliseconds since the program started */
static double msecond()
{	
#ifndef WIN32
	struct timeval  tv;
	gettimeofday(&tv, 0);
	return tv.tv_sec*1.0e3 + tv.tv_usec * 1.0e-3;
#else
	clock_t clk;
	clk = clock();
	return clk * 1000 / CLOCKS_PER_SEC;
#endif
}


/* 
 * Returns the sum of squared distances (SSD) between two images of dimensions
 * x times y
 */
static double absdistq(int x, int y,
					   unsigned char* buf1, int stride1,
					   unsigned char* buf2, int stride2)
{
	double dist=0.;
	int i,j,val;

	for (i=0;i<y;i++)
	{	
		val=0;
		for (j=0;j<x;j++)
			val+= ((int)buf1[j]-(int)buf2[j])*((int)buf1[j]-(int)buf2[j]);
	
		dist += (double)val;
		buf1 += stride1;
		buf2 += stride2;
	}
	return dist/(x*y);
}


/*
 * Returns the PSNR between to images.
 *
 * This is a common logarithmic measure for "quality" from the world of signal
 * processing if you don't know what it is, simply accept that higher values
 * are better.
 *
 * PSNR represents the ratio of useful signal over noise signal. In our case,
 * useful signal is refernce image, noise signal is the difference between
 * reference and decoded frame from encoded bitstream.
 *
 * The problem is this type of value is dependant of image source and so, is
 * not reliable as a common "quality" indicator.
 * So PSNR computes the ratio of maximum/noise. Maximum being set to 2^bpp/channel
 * This way, PSNR is not dependant anymore of image data type.
 *
 */
static double PSNR(int x, int y,
				   unsigned char* buf1, int stride1,
				   unsigned char* buf2, int stride2)
{
	return 10*(log10(255*255)-log10( absdistq(x, y, buf1, stride1, buf2, stride2) ));
}

/*****************************************************************************
 *                             Usage message
 *****************************************************************************/

static void usage()
{

	fprintf(stderr, "Usage : xvid_stat [OPTIONS]\n");
	fprintf(stderr, "Options :\n");
	fprintf(stderr, " -w integer     : frame width ([1.2048])\n");
	fprintf(stderr, " -h integer     : frame height ([1.2048])\n");
	fprintf(stderr, " -b integer     : target bitrate (>0 | default=900kbit)\n");
	fprintf(stderr, " -f float       : target framerate (>0)\n");
	fprintf(stderr, " -i string      : input filename (default=stdin)\n");
	fprintf(stderr, " -t integer     : input data type (yuv=0, pgm=1)\n");
	fprintf(stderr, " -n integer     : number of frames to encode\n");
	fprintf(stderr, " -q integer     : quality ([0..5])\n");
	fprintf(stderr, " -d boolean     : save decoder output (0 False*, !=0 True)\n");
	fprintf(stderr, " -m boolean     : save mpeg4 raw stream (0 False*, !=0 True)\n");
	fprintf(stderr, " -help          : prints this help message\n");
	fprintf(stderr, " -quant integer : fixed quantizer (disables -b setting)\n");
	fprintf(stderr, " (* means default)\n");

}

/*****************************************************************************
 *                       Input and output functions
 *
 *      the are small and simple routines to read and write PGM and YUV
 *      image. It's just for convenience, again nothing specific to XviD
 *
 *****************************************************************************/

static int read_pgmheader(FILE* handle)
{	
	int bytes,xsize,ysize,depth;
	char dummy[2];
	
	bytes = fread(dummy,1,2,handle);

	if ( (bytes < 2) || (dummy[0] != 'P') || (dummy[1] != '5' ))
   		return 1;

	fscanf(handle,"%d %d %d",&xsize,&ysize,&depth); 
	if ( (xsize > 1440) || (ysize > 2880 ) || (depth != 255) )
	{
		fprintf(stderr,"%d %d %d\n",xsize,ysize,depth);
	   	return 2;
	}
	if ( (XDIM==0) || (YDIM==0) )
	{
		XDIM=xsize;
		YDIM=ysize*2/3;
	}

	return 0;
}

static int read_pgmdata(FILE* handle, unsigned char *image)
{	
	int i;
	char dummy;
	
	unsigned char *y = image;
	unsigned char *u = image + XDIM*YDIM;
	unsigned char *v = image + XDIM*YDIM + XDIM/2*YDIM/2; 

	/* read Y component of picture */
	fread(y, 1, XDIM*YDIM, handle);
 
	for (i=0;i<YDIM/2;i++)
	{
		/* read U */
		fread(u, 1, XDIM/2, handle);

		/* read V */
		fread(v, 1, XDIM/2, handle);

		/* Update pointers */
		u += XDIM/2;
		v += XDIM/2;
	}

    /*  I don't know why, but this seems needed */
	fread(&dummy, 1, 1, handle);

	return 0;
}

static int read_yuvdata(FILE* handle, unsigned char *image)
{
   
	if (fread(image, 1, IMAGE_SIZE(XDIM, YDIM), handle) != (unsigned int)IMAGE_SIZE(XDIM, YDIM)) 
		return 1;
	else	
		return 0;
}

static int write_pgm(char *filename, unsigned char *image)
{
	int loop;

	unsigned char *y = image;
	unsigned char *u = image + XDIM*YDIM;
	unsigned char *v = image + XDIM*YDIM + XDIM/2*YDIM/2;

	FILE *filehandle;
	filehandle=fopen(filename,"w+b");
	if (filehandle)
	{
		/* Write header */
		fprintf(filehandle,"P5\n\n%d %d 255\n", XDIM,YDIM*3/2);

		/* Write Y data */
		fwrite(y, 1, XDIM*YDIM, filehandle);

		for(loop=0; loop<YDIM/2; loop++)
		{
			/* Write U scanline */
			fwrite(u, 1, XDIM/2, filehandle);

			/* Write V scanline */
			fwrite(v, 1, XDIM/2, filehandle);

			/* Update pointers */
			u += XDIM/2;
			v += XDIM/2;

		}

		/* Close file */
		fclose(filehandle);

		return 0;
	}
	else
		return 1;
}

/*****************************************************************************
 *     Routines for encoding: init encoder, frame step, release encoder
 ****************************************************************************/

#define FRAMERATE_INCR 1001

/* Initialize encoder for first use, pass all needed parameters to the codec */
static int enc_init(int use_assembler)
{
	int xerr;
	
	XVID_INIT_PARAM xinit;
	XVID_ENC_PARAM xparam;

	if(use_assembler) {

#ifdef ARCH_IA64
		xinit.cpu_flags = XVID_CPU_FORCE | XVID_CPU_IA64;
#else
		xinit.cpu_flags = 0;
#endif
	}
	else {
		xinit.cpu_flags = XVID_CPU_FORCE;
	}

	xvid_init(NULL, 0, &xinit, NULL);

	xparam.width = XDIM;
	xparam.height = YDIM;
	if ((ARG_FRAMERATE - (int)ARG_FRAMERATE) < SMALL_EPS)
	{
		xparam.fincr = 1;
		xparam.fbase = (int)ARG_FRAMERATE;
	}
	else
	{
		xparam.fincr = FRAMERATE_INCR;
		xparam.fbase = (int)(FRAMERATE_INCR * ARG_FRAMERATE);
	}
	xparam.rc_reaction_delay_factor = 16;
    xparam.rc_averaging_period = 100;
    xparam.rc_buffer = 10;
	xparam.rc_bitrate = ARG_BITRATE*1000; 
	xparam.min_quantizer = ARG_MINQUANT;
	xparam.max_quantizer = ARG_MAXQUANT;
	xparam.max_key_interval = (int)ARG_FRAMERATE*10;

	/* I use a small value here, since will not encode whole movies, but short clips */

	xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xparam, NULL);
	enc_handle=xparam.handle;

	return xerr;
}

static int enc_stop()
{
	int xerr;

	xerr = xvid_encore(enc_handle, XVID_ENC_DESTROY, NULL, NULL);
	return xerr;

}

static int enc_main(unsigned char* image, unsigned char* bitstream,
					unsigned char* hints_buffer,
					long *streamlength, long* frametype, long* hints_size)
{
	int xerr;

	XVID_ENC_FRAME xframe;
	XVID_ENC_STATS xstats;

	xframe.bitstream = bitstream;
	xframe.length = -1; 	/* this is written by the routine */

	xframe.image = image;
	xframe.colorspace = XVID_CSP_YV12;	/* defined in <xvid.h> */

	xframe.intra = -1; /* let the codec decide between I-frame (1) and P-frame (0) */

	xframe.quant = ARG_QUANTI;	/* is quant != 0, use a fixed quant (and ignore bitrate) */

	xframe.motion = motion_presets[ARG_QUALITY];
	xframe.general = general_presets[ARG_QUALITY];
	xframe.quant_intra_matrix = xframe.quant_inter_matrix = NULL;

	xframe.hint.hintstream = hints_buffer;

	if(ARG_HINTMODE == HINT_MODE_SET) {
		xframe.hint.hintlength = *hints_size;
		xframe.hint.rawhints = 0;
		xframe.general |= XVID_HINTEDME_SET;
	}

	if(ARG_HINTMODE == HINT_MODE_GET) {
		xframe.hint.rawhints = 0;
		xframe.general |= XVID_HINTEDME_GET;
	}

	xerr = xvid_encore(enc_handle, XVID_ENC_ENCODE, &xframe, &xstats);

	if(ARG_HINTMODE == HINT_MODE_GET)
		*hints_size = xframe.hint.hintlength;

	/*
	 * This is statictical data, e.g. for 2-pass. If you are not
	 * interested in any of this, you can use NULL instead of &xstats
	 */
	*frametype = xframe.intra;
	*streamlength = xframe.length;

	return xerr;
}

/*****************************************************************************
 * Routines for decoding: init encoder, frame step, release encoder
 ****************************************************************************/

/* init decoder before first run */
static int dec_init(int use_assembler)
{
	int xerr;

	XVID_INIT_PARAM xinit;
	XVID_DEC_PARAM xparam;

	if(use_assembler)

#ifdef ARCH_IA64
		xinit.cpu_flags = XVID_CPU_FORCE | XVID_CPU_IA64;
#else
	xinit.cpu_flags = 0;
#endif

	else
		xinit.cpu_flags = XVID_CPU_FORCE;

	xvid_init(NULL, 0, &xinit, NULL);
	xparam.width = XDIM;
	xparam.height = YDIM;

	xerr = xvid_decore(NULL, XVID_DEC_CREATE, &xparam, NULL);
	dec_handle = xparam.handle;

	return xerr;
}

/* decode one frame  */
static int dec_main(unsigned char *m4v_buffer, unsigned char *out_buffer,
					int m4v_size)
{
	int xerr;
	XVID_DEC_FRAME xframe;

	xframe.bitstream = m4v_buffer;
	xframe.length = m4v_size;
	xframe.image = out_buffer;
	xframe.stride = XDIM;
	xframe.colorspace = XVID_CSP_YV12;             /* XVID_CSP_USER is fastest (no memcopy involved) */

	xerr = xvid_decore(dec_handle, XVID_DEC_DECODE, &xframe, NULL);

	return xerr;
}

/* close decoder to release resources */
static int dec_stop()
{
	int xerr;
	xerr = xvid_decore(dec_handle, XVID_DEC_DESTROY, NULL, NULL);

	return xerr;
}

/* EOF */