H.264/AVC Reference Software Encoder: rdpicdecision.c Source File

00001 
00002 /*!
00003 *************************************************************************************
00004 * \file rdpicdecision.c
00005 *
00006 * \brief
00007 *    Perform RD optimal decisions between multiple coded versions of the same picture
00008 *
00009 * \author
00010 *    Main contributors (see contributors.h for copyright, address and affiliation details)
00011 *     - Alexis Michael Tourapis         <alexismt@ieee.org>
00012 *************************************************************************************
00013 */
00014 
00015 #include "global.h"
00016 #include <math.h>
00017 
00018 
00019 /*!
00020  ************************************************************************
00021  * \brief
00022  *    RD decision between possible encoding cases
00023  ************************************************************************
00024  */
00025 int rd_pic_decision(double snrY_version1, double snrY_version2, int bits_version1, int bits_version2, double lambda_picture)
00026 {
00027   double cost_version1, cost_version2;
00028 
00029   cost_version1 = (double) bits_version1 * lambda_picture + snrY_version1;
00030   cost_version2 = (double) bits_version2 * lambda_picture + snrY_version2;
00031   //printf("%d %d %.2f %.2f %.2f %.2f \n",bits_version1,bits_version2,snrY_version1,snrY_version2,cost_version1,cost_version2);
00032   if (cost_version2 > cost_version1 || (cost_version2 == cost_version1 && snrY_version2 >= snrY_version1) )
00033     return (0);
00034   else
00035     return (1);
00036 }
00037 
00038 /*!
00039  ************************************************************************
00040  * \brief
00041  *    Picture Coding Decision
00042  ************************************************************************
00043  */
00044 int picture_coding_decision (Picture *picture1, Picture *picture2, int qp)
00045 {
00046   double lambda_picture;
00047   int spframe = (img->type == SP_SLICE);
00048   int bframe = (img->type == B_SLICE);
00049   double sse_picture1, sse_picture2;
00050 
00051   if (params->NumberBFrames)
00052     lambda_picture = (qp < 20 ? 0.55 : 0.68) * pow (2, (qp - SHIFT_QP) / 3.0) * (bframe || spframe ? 2 : 1);
00053   else
00054     lambda_picture = (qp < 20 ? 0.55 : 0.68) * pow (2, (qp - SHIFT_QP) / 3.0);
00055 
00056   sse_picture1 = picture1->distortion.value[0] + picture1->distortion.value[1] + picture1->distortion.value[2];
00057   sse_picture2 = picture2->distortion.value[0] + picture2->distortion.value[1] + picture2->distortion.value[2];
00058  
00059   return rd_pic_decision(sse_picture1, sse_picture2, picture1->bits_per_picture, picture2->bits_per_picture, lambda_picture);
00060 }
00061