android ios语音转码,iOS实现录音转码MP3及转码BASE64上传示例
iOS 录音转码MP3及转码BASE64上传
一，开始录音
NSLog(@"开始录音");
[self startRecord];
- (void)startRecord
{
//删除上次生成的文件，保留最新文件
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([NSTemporaryDirectory() stringByAppendingString:@"myselfRecord.mp3"]) {
[fileManager removeItemAtPath:[NSTemporaryDirectory() stringByAppendingString:@"myselfRecord.mp3"] error:nil];
}
if ([NSTemporaryDirectory() stringByAppendingString:@"selfRecord.wav"]) {
[fileManager removeItemAtPath:[NSTemporaryDirectory() stringByAppendingString:@"selfRecord.wav"] error:nil];
}
//开始录音
//录音设置
NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init];
//设置录音格式 AVFormatIDKey==kAudioFormatLinearPCM
[recordSetting setValue:[NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];
//设置录音采样率(Hz) 如：AVSampleRateKey==8000/44100/96000(影响音频的质量), 采样率必须要设为11025才能使转化成mp3格式后不会失真
[recordSetting setValue:[NSNumber numberWithFloat:11025.0] forKey:AVSampleRateKey];
//录音通道数 1 或 2 ，要转换成mp3格式必须为双通道
[recordSetting setValue:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
//线性采样位数 8、16、24、32
[recordSetting setValue:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
//录音的质量
[recordSetting setValue:[NSNumber numberWithInt:AVAudioQualityHigh] forKey:AVEncoderAudioQualityKey];
//存储录音文件
recordUrl = [NSURL URLWithString:[NSTemporaryDirectory() stringByAppendingString:@"selfRecord.wav"]];
//初始化
audioRecorder = [[AVAudioRecorder alloc] initWithURL:recordUrl settings:recordSetting error:nil];
//开启音量检测
audioRecorder.meteringEnabled = YES;
audioSession = [AVAudioSession sharedInstance];//得到AVAudioSession单例对象
if (![audioRecorder isRecording]) {
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];//设置类别,表示该应用同时支持播放和录音
[audioSession setActive:YES error:nil];//启动音频会话管理,此时会阻断后台音乐的播放.
[audioRecorder prepareToRecord];
[audioRecorder peakPowerForChannel:0.0];
[audioRecorder record];
}
}
二，停止录音
[self endRecord];
- (void)endRecord
{
[audioRecorder stop]; //录音停止
[audioSession setActive:NO error:nil]; //一定要在录音停止以后再关闭音频会话管理(否则会报错)，此时会延续后台音乐播放
}
三，转码成MP3
- (void)transformCAFToMP3 {
mp3FilePath = [NSURL URLWithString:[NSTemporaryDirectory() stringByAppendingString:@"myselfRecord.mp3"]];
@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
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 = (int)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 {
NSLog(@"MP3生成成功");
base64Str = [self mp3ToBASE64];
}
}
四，上传需要转码BASE64
- (NSString *)mp3ToBASE64{
NSData *mp3Data = [NSData dataWithContentsOfFile:[NSTemporaryDirectory() stringByAppendingString:@"myselfRecord.mp3"]];
NSString *_encodedImageStr = [mp3Data base64Encoding];
NSLog(@"===Encoded image:\n%@", _encodedImageStr);
return _encodedImageStr;
}
备注：其中可以直接生成的.caf .wav 有压缩的MP3需要转格式，不能直接录音生成
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。