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main.cテンプレート

June 3, 2020

サウンドファイルを読み込み変換してファイルを新たに出力すると言う処理の流れは本質的な部分以外は同じような処理を繰り返すだけなので, main.cというテンプレートが用意されている. 引数を受け取り, それが適切かどうかチェックし, メモリ確保をし, 値を変数へそれぞれ代入し, 出力ファイルを適切に作成する. そして本質的な処理がなされる. 最後はメモリ解放, と言う流れだ.

/* Copyright (c) 2009 Richard Dobson
/* main.c :  generic soundfile processing main function*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <portsf.h>

/* set size of multi-channel frame-buffer */
#define NFRAMES (1024)

/* TODO define program argument list, excluding flags */
enum {ARG_PROGNAME,ARG_INFILE,ARG_OUTFILE,ARG_NARGS};

int main(int argc, char* argv[])
{
/* STAGE 1 */	
	PSF_PROPS inprops,outprops;									
	long framesread;	
	/* init all dynamic resources to default states */
	int infile = -1,outfile = -1;
	int error = 0;
	PSF_CHPEAK* peaks = NULL;	
	psf_format outformat =  PSF_FMT_UNKNOWN;
	unsigned long nframes = NFRAMES;
	float* inframe = NULL;
	float* outframe = NULL;
	/* TODO: define an output frame buffer if channel width different 	*/
	
/* STAGE 2 */	
	printf("MAIN: generic process\n");						

	/* process any optional flags: remove this block if none used! */
	if(argc > 1){
		char flag;
		while(argv[1][0] == '-'){
			flag = argv[1][1];
			switch(flag){
			/*TODO: handle any  flag arguments here */
			case('\0'):
				printf("Error: missing flag name\n");
				return 1;
			default:
				break;
			}
			argc--;
			argv++;
		}
	}

	/* check rest of commandline */
	if(argc < ARG_NARGS){
		printf("insufficient arguments.\n"
			/* TODO: add required usage message */
			"usage: MAIN infile outfile\n"
			);
		return 1;
	}
	/*  always startup portsf */
	if(psf_init()){
		printf("unable to start portsf\n");
		return 1;
	}
/* STAGE 3 */																							
	infile = psf_sndOpen(argv[ARG_INFILE],&inprops,0);															  
	if(infile < 0){
		printf("Error: unable to open infile %s\n",argv[ARG_INFILE]);
		error++;
		goto exit;
	}
	/* TODO: verify infile format for this application */

	/* allocate space for  sample frame buffer ...*/
	inframe = (float*) malloc(nframes * inprops.chans * sizeof(float));
	if(inframe==NULL){
		puts("No memory!\n");
		error++;
		goto exit;
	}
	/* check file extension of outfile name, so we use correct output file format*/
	outformat = psf_getFormatExt(argv[ARG_OUTFILE]);
	if(outformat == PSF_FMT_UNKNOWN){
		printf("outfile name %s has unknown format.\n"
			"Use any of .wav, .aiff, .aif, .afc, .aifc\n",argv[ARG_OUTFILE]);
		error++;
		goto exit;
	}
	inprops.format = outformat;
	outprops = inprops;
/* STAGE 4 */												
	/* TODO: any other argument processing and setup of variables, 		     
	   output buffer, etc., before creating outfile
	*/

	/* handle outfile */
	/* TODO:  make any changes to outprops here  */

	peaks  =  (PSF_CHPEAK*) malloc(outprops.chans * sizeof(PSF_CHPEAK));
	if(peaks == NULL){
		puts("No memory!\n");
		error++;
		goto exit;
	}

	/* TODO: if outchans != inchans, allocate outframe, and modify main loop accordingly */

	outfile = psf_sndCreate(argv[ARG_OUTFILE],&outprops,0,0,PSF_CREATE_RDWR);
	if(outfile < 0){
		printf("Error: unable to create outfile %s\n",argv[ARG_OUTFILE]);
		error++;
		goto exit;
	}
/* STAGE 5 */	
	printf("processing....\n");								
	/* TODO: init any loop-related variables */

	while ((framesread = psf_sndReadFloatFrames(infile,inframe,nframes)) > 0){
	
		/* <--------  add buffer processing here ------>  */

		if(psf_sndWriteFloatFrames(outfile,inframe,framesread) != framesread){
			printf("Error writing to outfile\n");
			error++;
			break;
		}			
	}

	if(framesread < 0)	{
		printf("Error reading infile. Outfile is incomplete.\n");
		error++;
	}
	else
		printf("Done: %d errors\n",error);
/* STAGE 6 */		
	/* report PEAK values to user */							
	if(psf_sndReadPeaks(outfile,peaks,NULL) > 0){
		long i;
		double peaktime;
		printf("PEAK information:\n");	
			for(i=0;i < inprops.chans;i++){
				peaktime = (double) peaks[i].pos / (double) inprops.srate;
				printf("CH %ld:\t%.4f at %.4f secs\n", i+1, peaks[i].val, peaktime);
			}
	}
/* STAGE 7 */	
	/* do all cleanup  */    									
exit:	 	
	if(infile >= 0)
		if(psf_sndClose(infile))
			printf("%s: Warning: error closing infile %s\n",argv[ARG_PROGNAME],argv[ARG_INFILE]);
	if(outfile >= 0)
		if(psf_sndClose(outfile))
			printf("%s: Warning: error closing outfile %s\n",argv[ARG_PROGNAME],argv[ARG_OUTFILE]);
	if(inframe)
		free(inframe);
	if(peaks)
		free(peaks);
	/*TODO: cleanup any other resources */

	psf_finish();
	return error;
}

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