iOS caf转mp3

导入lame库

#include "lame.h"

NSURL *mp3FilePath = [NSURL URLWithString:[self getFullFilePathInDocuments:@"record" fileName:@"mySelfRecord.mp3"]];
    
//sourceUrl是caf的路径
NSURL *recordUrl = [NSURL URLWithString:sourceUrl];
    
@try {
    int read, write;
        
    FILE *pcm = fopen([[recordUrl absoluteString] cStringUsingEncoding:1], "rb"); //source 被转换的音频文件位置
    fseek(pcm, 4*1024, SEEK_CUR); //skip file header
    FILE *mp3 = fopen([[mp3FilePath absoluteString] cStringUsingEncoding:1], "wb"); //output 输出生成的Mp3文件位置
        
    NSLog(@"sour-- %@   last-- %@",sourceUrl,mp3FilePath);
        
    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, 11025.0);
    lame_set_VBR(lame, vbr_default);
    lame_init_params(lame);
        
    do {
        read = fread(pcm_buffer, 2*sizeof(short int), PCM_SIZE, pcm);
        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);
            
        fwrite(mp3_buffer, write, 1, mp3);
            
    } while (read != 0);
        
    lame_close(lame);
    fclose(mp3);
    fclose(pcm);
}
@catch (NSException *exception) {
    NSLog(@"%@",[exception description]);
}
@finally {
    if (mp3FilePath) {
            
    }
}