当我绕过speex编码/解码步骤时,原始音频输出是正确的。我想要的是从录音回放中捕获的整个缓冲区被编码,解码并发送回播放循环。在几个项目我不确定的是:Speex编码/解码导致嘶嘶声噪声(Objective-c)
- 什么大小来分配的enc_buffer和dec_buffer
- 在speex_bits_read_from(SpeexBits *位字符*字节,INT LEN)
- 指定什么长什么最大尺寸指定INT speex_bits_write(SpeexBits *位字符*字节,INT MAX_LEN)
这里是我的Speex编解码器的初始化:
#define SAMPLE_RATE 8000
#define MAX_FRAMES 100
#define FRAME_SIZE 160
enc_state = speex_encoder_init(&speex_nb_mode);
dec_state = speex_decoder_init(&speex_nb_mode);
spx_int32_t tmp;
tmp=5;
speex_encoder_ctl(enc_state, SPEEX_SET_QUALITY, &tmp);
tmp=1;
speex_encoder_ctl(enc_state, SPEEX_SET_COMPLEXITY, &tmp);
speex_encoder_ctl(enc_state, SPEEX_GET_FRAME_SIZE, &enc_frame_size);
speex_decoder_ctl(dec_state, SPEEX_GET_FRAME_SIZE, &dec_frame_size);
tmp = SAMPLE_RATE;
speex_encoder_ctl(enc_state, SPEEX_SET_SAMPLING_RATE, &tmp);
speex_decoder_ctl(dec_state, SPEEX_SET_SAMPLING_RATE, &tmp);
speex_bits_init(&enc_bits);
speex_bits_init(&dec_bits);
//Unsure of this allocation size
enc_buffer = (char*)malloc(sizeof(char)*enc_frame_size*MAX_FRAMES);
dec_buffer = (spx_int16_t*)malloc(sizeof(spx_int16_t)*dec_frame_size*MAX_FRAMES);
我的编码/解码方法:
-(char*)encodeAudioBuffer:(spx_int16_t*)audioBuffer withByteSize:(int)numberOfFrames andWriteSizeTo:(int*)inSize{
speex_bits_reset(&enc_bits);
speex_encode_int(enc_state, audioBuffer, &enc_bits);
//Unsure of this third argument. 'numberOfFrames' is the stored number of input frames from my recording callback.
*inSize = speex_bits_write(&enc_bits, enc_buffer, numberOfFrames*enc_frame_size);
return enc_buffer;
}
-(spx_int16_t*)decodeSpeexBits:(char*)encodedAudio withEncodedSize:(int)encodedSize andDecodedSize:(int)decodedSize{
//Unsure of this third argument. 'encodedSize' is the number written to *inSize in the encode method
speex_bits_read_from(&dec_bits, encodedAudio, encodedSize*dec_frame_size);
speex_decode_int(dec_state, &dec_bits, dec_buffer);
return dec_buffer;
}
而且他们被称为是这样的:
- (void)encodeBufferList:(AudioBufferList*)bufferList withNumberOfFrames:(int)numberOfFrames{
AudioBuffer sourceBuffer = bufferList->mBuffers[0];
int speexSize = 0;
char* encodedAudio = [speexCodec encodeAudioBuffer:(spx_int16_t*)sourceBuffer.mData withByteSize:numberOfFrames andWriteSizeTo:&speexSize];
spx_int16_t* decodedAudio = [speexCodec decodeSpeexBits:encodedAudio withEncodedSize:speexSize andDecodedSize:sourceBuffer.mDataByteSize];
memcpy(audioBuffer.mData, sourceBuffer.mData, numberOfFrames * sizeof(SInt32));
}
其中 “bufferList” 是从我录制/播放回调返回。有人可以确认我正在填充缓冲区吗?我看到报道here类似的问题,但不能看到在我的代码我可以做一个错误:
static OSStatus recordingCallback(void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32 inNumberFrames, AudioBufferList *ioData)
{
AudioBuffer buffer;
OSStatus status;
AudioStreamer *input = (__bridge AudioStreamer*) inRefCon;
buffer.mDataByteSize = inNumberFrames * sizeof(SInt16);
buffer.mNumberChannels = 1;
buffer.mData = malloc(inNumberFrames * sizeof(SInt16));
AudioBufferList bufferList;
bufferList.mNumberBuffers = 1;
bufferList.mBuffers[0] = buffer;
status = AudioUnitRender([input rioAUInstance], ioActionFlags, inTimeStamp, inBusNumber, inNumberFrames, &bufferList);
[input encodeBufferList:&bufferList withNumberOfFrames:inNumberFrames];
return noErr;
}
static OSStatus playbackCallback(void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32 inNumberFrames, AudioBufferList *ioData)
{
AudioStreamer* input = (__bridge AudioStreamer*)inRefCon;
UInt32 size = MIN(ioData->mBuffers[0].mDataByteSize, [input audioBuffer].mDataByteSize);
memcpy(ioData->mBuffers[0].mData, input.audioBuffer.mData, size);
return noErr;
}
通过编码/解码,因为它代表产生的噪声是一种颗粒感静态的嘶嘶声,但它不是完全随机的信息 - 当我吹进麦克风时,我可以在噪音背后听到它。
任何帮助把这个问题睡在床上将不胜感激。一旦我把所有东西都整理出来,我很可能最终会写博客,似乎很多人都遇到了设置此编解码器的各种小问题。
现在这个工作吗?我面临同样的问题 – GauravSTomar