H.264/AVC Reference Software Encoder: img_dist

00001 
00002 /*!
00003  *************************************************************************************
00004  * \file img_dist_snr.c
00005  *
00006  * \brief
00007  *    Compute signal to noise ratio (SNR) between the encoded image and the reference image
00008  *
00009  * \author
00010  *    Main contributors (see contributors.h for copyright, address and affiliation details)
00011  *     - Woo-Shik Kim                    <wooshik.kim@usc.edu>
00012  *     - Alexis Michael Tourapis         <alexismt@ieee.org>
00013  *************************************************************************************
00014  */
00015 #include "contributors.h"
00016 
00017 #include <math.h>
00018 
00019 #include "enc_statistics.h"
00020 #include "global.h"
00021 #include "img_distortion.h"
00022 #include "md_distortion.h"
00023 
00024 /*!
00025  ************************************************************************
00026  * \brief
00027  *    Find SNR for all three components
00028  ************************************************************************
00029  */
00030 void find_snr(ImageParameters *p_Img, InputParameters *p_Inp, ImageStructure *imgREF, ImageStructure *imgSRC, DistMetric *metricSSE, DistMetric *metricPSNR)
00031 {
00032   DistortionParams *p_Dist = p_Img->p_Dist;
00033   FrameFormat *format = &imgREF->format;
00034   // Luma.
00035   metricSSE ->value[0] = (float) compute_SSE(imgREF->data[0], imgSRC->data[0], 0, 0, format->height, format->width);
00036   metricPSNR->value[0] = psnr(format->max_value_sq[0], format->size_cmp[0], metricSSE->value[0]);
00037 
00038   // Chroma.
00039   if (format->yuv_format != YUV400)
00040   {   
00041     metricSSE ->value[1] = (float) compute_SSE(imgREF->data[1], imgSRC->data[1], 0, 0, format->height_cr, format->width_cr);
00042     metricPSNR->value[1] = psnr(format->max_value_sq[1], format->size_cmp[1], metricSSE->value[1]);
00043     metricSSE ->value[2] = (float) compute_SSE(imgREF->data[2], imgSRC->data[2], 0, 0, format->height_cr, format->width_cr);
00044     metricPSNR->value[2] = psnr(format->max_value_sq[2], format->size_cmp[2], metricSSE->value[2]);
00045   }
00046    
00047   {
00048     accumulate_average(metricSSE,  p_Dist->frame_ctr);
00049     accumulate_average(metricPSNR, p_Dist->frame_ctr);
00050 
00051     accumulate_avslice(metricSSE,  p_Img->type, p_Img->p_Stats->frame_ctr[p_Img->type]);
00052     accumulate_avslice(metricPSNR, p_Img->type, p_Img->p_Stats->frame_ctr[p_Img->type]);
00053   }
00054 }