mirror of https://github.com/mpv-player/mpv
100 lines
2.3 KiB
C
100 lines
2.3 KiB
C
// This small util discovers your audio driver's behaviour
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//#define OUTBURST 512
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//#define OUTBURST 4096
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#define MAX_OUTBURST 32768
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <sys/soundcard.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <unistd.h>
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// Returns current time in microseconds
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unsigned int GetTimer(){
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struct timeval tv;
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struct timezone tz;
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// float s;
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gettimeofday(&tv,&tz);
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// s=tv.tv_usec;s*=0.000001;s+=tv.tv_sec;
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return (tv.tv_sec*1000000+tv.tv_usec);
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}
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static unsigned char a_buffer[MAX_OUTBURST];
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void inline print_info(int audio_fd){
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#if 1
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audio_buf_info zz;
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ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &zz);
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printf("Status: %3d/%d (%d byte/frag) free: %6d\n",
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zz.fragments, zz.fragstotal, zz.fragsize, zz.bytes);
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#endif
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}
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int main(){
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int audio_buffer_size=0;
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int r;
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int xxx=1024*2;
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int audio_fd;
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char *dsp="/dev/dsp";
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unsigned int t0,t1,t2;
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int outburst;
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audio_fd=open(dsp, O_WRONLY);
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if(audio_fd<0){
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printf("Can't open audio device %s\n",dsp);
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return 1;
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}
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// ioctl(audio_fd, SNDCTL_DSP_RESET, NULL);
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// ioctl(audio_fd, SNDCTL_DSP_RESET, NULL);
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r=AFMT_S16_LE;ioctl (audio_fd, SNDCTL_DSP_SETFMT, &r);
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r=1; ioctl (audio_fd, SNDCTL_DSP_STEREO, &r);
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r=44100; if(ioctl (audio_fd, SNDCTL_DSP_SPEED, &r)==-1)
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printf("audio_setup: your card doesn't support %d Hz samplerate\n",r);
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r=0; ioctl (audio_fd, SNDCTL_DSP_GETBLKSIZE, &r);
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printf("fragment size = %d\n",r);
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outburst=r; if(outburst>4096) outburst=4096;
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print_info(audio_fd);
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t0=t1=GetTimer();
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while(xxx-->0){
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char c='B';
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fd_set rfds;
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struct timeval tv;
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FD_ZERO(&rfds); FD_SET(audio_fd,&rfds);
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tv.tv_sec=0; tv.tv_usec = 0;
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// if(select(audio_fd+1, NULL, &rfds, NULL, &tv)) c=' ';
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print_info(audio_fd);
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r=0; ioctl (audio_fd, SNDCTL_DSP_GETODELAY, &r); printf("delay = %d\n",r);
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r=write(audio_fd,a_buffer,outburst);
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t2=GetTimer();
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if(r<0) printf("Error writting to device\n"); else
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if(r==0) printf("EOF writting to device???\n"); else {
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printf("%c %6.3f %6.3f [%6d] writting %3d of %3d bytes in %7d us\n",c,
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(float)audio_buffer_size/(44100.0f*4.0f),(float)(t1-t0)*0.000001f,
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audio_buffer_size,r,outburst,t2-t1);
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audio_buffer_size+=r;
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}
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t1=t2;
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}
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close(audio_fd);
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return 0;
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}
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