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在ldecod.c文件的main中调用了init_conf函数，这个函数实际上就实现了程序从配置文件读数据的过程. 之前说过，在JM8.6编码端，Configure函数起着做配置文件encoder_baseline.cfg数据的作用，现在来看看解码端的init_conf函数.
main中是这样调用的：
init_conf(input, argv[1]);其中input是一个结构体指针，字符串指针argv[1]实际上就指向了字符串"decoder.cfg", 进入init_conf函数看看：
void init_conf(struct inp_par *inp, char *config_filename){ FILE *fd; int NAL_mode; // read the decoder configuration file if((fd=fopen(config_filename,"r")) == NULL) { snprintf(errortext, ET_SIZE, "Error: Control file %s not found\n",config_filename); error(errortext, 300); } fscanf(fd,"%s",inp->infile); // H.264 compressed input bitsream // 过滤配置文件中的“注释” fscanf(fd,"%*[^\n]"); fscanf(fd,"%s",inp->outfile); // YUV 4:2:2 input format fscanf(fd,"%*[^\n]"); fscanf(fd,"%s",inp->reffile); // reference file fscanf(fd,"%*[^\n]"); // Frame buffer size fscanf(fd,"%d,",&inp->dpb_size); // may be overwritten in case of RTP NAL fscanf(fd,"%*[^\n]"); if (inp->dpb_size < 1) { snprintf(errortext, ET_SIZE, "Decoded Picture Buffer Size is %d. It has to be at least 1",inp->dpb_size); error(errortext,1); } fscanf(fd,"%d",&(NAL_mode)); // NAL mode fscanf(fd,"%*[^\n]"); switch(NAL_mode) { case 0: inp->FileFormat = PAR_OF_ANNEXB; break; case 1: inp->FileFormat = PAR_OF_RTP; break; default: snprintf(errortext, ET_SIZE, "NAL mode %i is not supported", NAL_mode); error(errortext,400); } fscanf(fd,"%d,",&inp->ref_offset); // offset used for SNR computation fscanf(fd,"%*[^\n]"); fscanf(fd,"%d,",&inp->poc_scale); // offset used for SNR computation fscanf(fd,"%*[^\n]"); if (inp->poc_scale < 1 || inp->poc_scale > 2) { snprintf(errortext, ET_SIZE, "Poc Scale is %d. It has to be 1 or 2",inp->poc_scale); error(errortext,1); }#ifdef _LEAKYBUCKET_ fscanf(fd,"%ld,",&inp->R_decoder); // Decoder rate fscanf(fd, "%*[^\n]"); fscanf(fd,"%ld,",&inp->B_decoder); // Decoder buffer size fscanf(fd, "%*[^\n]"); fscanf(fd,"%ld,",&inp->F_decoder); // Decoder initial delay fscanf(fd, "%*[^\n]"); fscanf(fd,"%s",inp->LeakyBucketParamFile); // file where Leaky Bucket params (computed by encoder) are stored fscanf(fd,"%*[^\n]");#endif fclose (fd);#if TRACE if ((p_trace=fopen(TRACEFILE,"w"))==0) // append new statistic at the end { snprintf(errortext, ET_SIZE, "Error open file %s!",TRACEFILE); error(errortext,500); }#endif if ((p_out=fopen(inp->outfile,"wb"))==0) { snprintf(errortext, ET_SIZE, "Error open file %s ",inp->outfile); error(errortext,500); }/* if ((p_out2=fopen("out.yuv","wb"))==0) { snprintf(errortext, ET_SIZE, "Error open file %s ",inp->outfile); error(errortext,500); }*/ fprintf(stdout,"--------------------------------------------------------------------------\n"); fprintf(stdout," Decoder config file : %s \n",config_filename); fprintf(stdout,"--------------------------------------------------------------------------\n"); fprintf(stdout," Input H.264 bitstream : %s \n",inp->infile); fprintf(stdout," Output decoded YUV 4:2:0 : %s \n",inp->outfile); fprintf(stdout," Output status file : %s \n",LOGFILE); if ((p_ref=fopen(inp->reffile,"rb"))==0) { fprintf(stdout," Input reference file : %s does not exist \n",inp->reffile); fprintf(stdout," SNR values are not available\n"); } else fprintf(stdout," Input reference file : %s \n",inp->reffile); fprintf(stdout,"--------------------------------------------------------------------------\n");#ifdef _LEAKYBUCKET_ fprintf(stdout," Rate_decoder : %8ld \n",inp->R_decoder); fprintf(stdout," B_decoder : %8ld \n",inp->B_decoder); fprintf(stdout," F_decoder : %8ld \n",inp->F_decoder); fprintf(stdout," LeakyBucketParamFile: %s \n",inp->LeakyBucketParamFile); // Leaky Bucket Param file calc_buffer(inp); fprintf(stdout,"--------------------------------------------------------------------------\n");#endif fprintf(stdout,"POC must = frame# or field# for SNRs to be correct\n"); fprintf(stdout,"Frame POC QP SnrY SnrU SnrV Time(ms)\n");} 可见，通过调用init_conf函数，实际上就是把argv[1]对应的配置文件的数据往input对应的结构体中倾倒，像倒茶一般， 这样，程序中的全局的指针变量对应的结构体就获得了配置文件encoder.cfg中的数据.
最后，附带给出配置文件decoder.cfg中的内容:
test.264 ........H.264 coded bitstream
test_dec.yuv ........Output file, YUV 4:2:0 format test_rec.yuv ........Ref sequence (for SNR) 10 ........Decoded Picture Buffer size 0 ........NAL mode (0=Annex B, 1: RTP packets) 0 ........SNR computation offset 1 ........Poc Scale (1 or 2) 500000 ........Rate_Decoder 104000 ........B_decoder 73000 ........F_decoder leakybucketparam.cfg ........LeakyBucket ParamsThis is a file containing input parameters to the JVT H.264/AVC decoder.
The text line following each parameter is discarded by the decoder.
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