Reading/playing .wav files

Comments

• abc

  August 2003

  : Hi all,
  : A friend of mine gave me a C program that opens and plays .wav files. It follows:
  :
  : #include
  : #include
  : #include
  : #include
  : #include
  :
  : #define BUFSZ 4096
  :
  : int main(int argc,char *argv[])
  : {
  : int devfd, sampfd;
  : int len,i;
  : char *dev="/dev/dsp";
  : unsigned char sampbuf[BUFSZ];
  : /* Open /dev/dsp/ */
  : if((devfd = open(dev,O_WRONLY)) < 0)
  : {
  : if(errno == EBUSY)
  : fprintf(stderr, "%s in use
  ", dev);
  : fprintf(stderr, "%s: %s
  ",dev,strerror(errno));
  : exit(EXIT_FAILURE);
  : }
  : if(argc==2)
  : {
  : if((sampfd=open(argv[1],O_RDONLY)) < 0)
  : {
  : perror(argv[1]);
  : exit(EXIT_FAILURE);
  : }
  : /* Read a block, write a block */
  : while((len=read(sampfd,sampbuf,BUFSZ)) > 0)
  : write(devfd,sampbuf,len);
  : /* Close the descriptors and get outta here */
  : close(sampfd);
  : }
  : close(devfd);
  : exit(EXIT_SUCCESS);
  : }
  :
  : First off, I'm using Mandrake.
  :
  : If I use the command syntax cc play.c -o play I get an executable file that is able to 'play' standard .wav files, i.e. play mywave.wav.
  : If I use the command syntax cc play.c I get a.out of course, but when I try to execute it as a.out mywave.wav it plays this horrible screaching noise. The original executable file still works but I can't copy it to another filename w/o the same problem happening, i.e. cp play hold, etc. It also does weird stuff like if I move between default consoles and try to play the file by calling the previously executed command by using the 'up' arrow keys it tells me when I hit enter that the /dev/dsp device is busy. Someone told me that he thinks that it has to do w/the argv, argc variables and that the a.out file is attempting to play itself. Any suggestions. Thanks.
  : jbowers9
  :
  
  err ... i really doubt that just dumping the file on dsp will work - you might as well do cat filename>/dev/dsp (the non-playable wav header for starters; then what kind of endianness the file has, etc.)
  
  as for your 2 different results, the screeching is probably the 'correct' program output; on the other hand, if you do just 'play file.wav' you'll get /usr/bin/play (your location may vary) to (correctly) play the file. (if you do have '.' in the path, it's probably at the end, not at the beginning). try './play filename.wav'
  for the screeching effects.
  
• Jeff P.

  August 2003

  : : Hi all,
  : : A friend of mine gave me a C program that opens and plays .wav files. It follows:
  
  : err ... i really doubt that just dumping the file on dsp will work - you might as well do cat filename>/dev/dsp (the non-playable wav header for starters; then what kind of endianness the file has, etc.)
  :
  : as for your 2 different results, the screeching is probably the 'correct' program output; on the other hand, if you do just 'play file.wav' you'll get /usr/bin/play (your location may vary) to (correctly) play the file. (if you do have '.' in the path, it's probably at the end, not at the beginning). try './play filename.wav'
  : for the screeching effects.
  
  
  
  Maybe try this:
  [code]
  #include
  int main(int argc, char **argv){
  esd_play_file("wav", argv[1], 0);
  }
  [/code]
  
  To compile you need something like this:
  [code]
  gcc -L/usr/local/lib -lesd -laudiofile -lm -lasound esdtest.c
  [/code]