Lame Encoding iOS in queue -

i'm trying convert wav file mp3 file using lame.

i using code. want in background (or in queue). input file large, can take full control till finishing. can me so?

int read, write; file *pcm = fopen([mergefile cstringusingencoding:1], "rb");  //source fseek(pcm, 4*1024, seek_cur);                                   //skip file header file *mp3 = fopen([mp3filepath cstringusingencoding:1], "wb");  //output  const int pcm_size = 8192; const int mp3_size = 8192; short int pcm_buffer[pcm_size*2]; unsigned char mp3_buffer[mp3_size];  lame_t lame = lame_init(); lame_set_in_samplerate(lame, 44100); lame_set_vbr(lame, vbr_default); lame_init_params(lame);  {     read = fread(pcm_buffer, 2*sizeof(short int), pcm_size, pcm);     nslog(@"");     if (read == 0)         write = lame_encode_flush(lame, mp3_buffer, mp3_size);     else         write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, mp3_size);  } while (read != 0);  lame_close(lame); fclose(mp3); fclose(pcm); 

i use serial nsoperationqueue encoding.

nsoperationqueue *queue = [[nsoperationqueue alloc] init]; queue.maxconcurrentoperationcount = 1; #ifdef __iphone_8_0 queue.qualityofservice = /* nsqualityofservice */; #endif 

you can add jobs this:

[queue addoperationwithblock:^{      /* encoding code goes here */      dispatch_async(dispatch_get_main_queue(), ^{          /* report operation status on completion (delegate, notification, etc...)      }];  }];