如何将WAV / CAF文件的样本数据转换为字节数组？

我需要能够以编程方式读取WAV（或CAF）文件，并将样本（音频）数据作为字节数组提取。 什么是最简单/最快捷的方式？

Answer 1

假设您使用的是iOS或OS X，您需要AudioToolbox框架，特别是AudioFile.h的API（如果需要在读取时将音频数据转换为其他格式，则需要ExtAudioFile.h ）。

例如，

 #include  ... AudioFileID audioFile; OSStatus err = AudioFileOpenURL(fileURL, kAudioFileReadPermission, 0, &audioFile); // get the number of audio data bytes UInt64 numBytes = 0; UInt32 dataSize = sizeof(numBytes); err = AudioFileGetProperty(audioFile, kAudioFilePropertyAudioDataByteCount, &dataSize, &numBytes); unsigned char *audioBuffer = (unsigned char *)malloc(numBytes); UInt32 toRead = numBytes; UInt64 offset = 0; unsigned char *pBuffer = audioBuffer; while(true) { err = AudioFileReadBytes(audioFile, true, offset, &toRead, &pBuffer); if (kAudioFileEndOfFileError == err) { // cool, we're at the end of the file break; } else if (noErr != err) { // uh-oh, some error other than eof break; } // advance the next read offset offset += toRead; // advance the read buffer's pointer pBuffer += toRead; toRead = numBytes - offset; if (0 == toRead) { // got to the end of file but no eof err break; } } // Process audioBuffer ... free(audioBuffer); 

Answer 2

这是我从iPhone中获取NSData的音乐文件并为ARC更新的内容

 - (NSData *)readSoundFileSamples:(NSString *)filePath { // Get raw PCM data from the track NSURL *assetURL = [NSURL fileURLWithPath:filePath]; NSMutableData *data = [[NSMutableData alloc] init]; const uint32_t sampleRate = 16000; // 16k sample/sec const uint16_t bitDepth = 16; // 16 bit/sample/channel const uint16_t channels = 2; // 2 channel/sample (stereo) NSDictionary *opts = [NSDictionary dictionary]; AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:assetURL options:opts]; AVAssetReader *reader = [[AVAssetReader alloc] initWithAsset:asset error:NULL]; NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey, [NSNumber numberWithFloat:(float)sampleRate], AVSampleRateKey, [NSNumber numberWithInt:bitDepth], AVLinearPCMBitDepthKey, [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved, [NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey, [NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey, nil]; AVAssetReaderTrackOutput *output = [[AVAssetReaderTrackOutput alloc] initWithTrack:[[asset tracks] objectAtIndex:0] outputSettings:settings]; [reader addOutput:output]; [reader startReading]; // read the samples from the asset and append them subsequently while ([reader status] != AVAssetReaderStatusCompleted) { CMSampleBufferRef buffer = [output copyNextSampleBuffer]; if (buffer == NULL) continue; CMBlockBufferRef blockBuffer = CMSampleBufferGetDataBuffer(buffer); size_t size = CMBlockBufferGetDataLength(blockBuffer); uint8_t *outBytes = malloc(size); CMBlockBufferCopyDataBytes(blockBuffer, 0, size, outBytes); CMSampleBufferInvalidate(buffer); CFRelease(buffer); [data appendBytes:outBytes length:size]; free(outBytes); } return data; }