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Search found 3 results on 1 pages for 'extaudiofile'.

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• AudioFileWriteBytes fails with error code -40

  - by alexbw

  I'm trying to write raw audio bytes to a file using AudioFileWriteBytes(). Here's what I'm doing: void writeSingleChannelRingBufferDataToFileAsSInt16(AudioFileID audioFileID, AudioConverterRef audioConverter, ringBuffer *rb, SInt16 *holdingBuffer) { // First, figure out which bits of audio we'll be // writing to file from the ring buffer UInt32 lastFreshSample = rb->lastWrittenIndex; OSStatus status; int numSamplesToWrite; UInt32 numBytesToWrite; if (lastFreshSample < rb->lastReadIndex) { numSamplesToWrite = kNumPointsInWave + lastFreshSample - rb->lastReadIndex - 1; } else { numSamplesToWrite = lastFreshSample - rb->lastReadIndex; } numBytesToWrite = numSamplesToWrite*sizeof(SInt16); Then we copy the audio data (stored as floats) to a holding buffer (SInt16) that will be written directly to the file. The copying looks funky because it's from a ring buffer. UInt32 buffLen = rb->sizeOfBuffer - 1; for (int i=0; i < numSamplesToWrite; ++i) { holdingBuffer[i] = rb->data[(i + rb->lastReadIndex) & buffLen]; } Okay, now we actually try to write the audio from the SInt16 buffer "holdingBuffer" to the audio file. The NSLog will spit out an error -40, but also claims that it's writing bytes. No data is written to file. status = AudioFileWriteBytes(audioFileID, NO, 0, &numBytesToWrite, &holdingBuffer); rb->lastReadIndex = lastFreshSample; NSLog(@"Error = %d, wrote %d bytes", status, numBytesToWrite); return;

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• How to convert m4a file to aac adts file in Xcode?

  - by Bird Hsuie

  I have a mp4 file copied from iPod lib and saved to my Document for my next step, I need it to convert to .mp3 or .aac(ADTS type) I use this code and failed... -(IBAction)compressFile:(id)sender{ NSLog (@"handleConvertToPCMTapped"); // open an ExtAudioFile NSLog (@"opening %@", exportURL); ExtAudioFileRef inputFile; CheckResult (ExtAudioFileOpenURL((__bridge CFURLRef)exportURL, &inputFile), "ExtAudioFileOpenURL failed"); // prepare to convert to a plain ol' PCM format AudioStreamBasicDescription myPCMFormat; myPCMFormat.mSampleRate = 44100; // todo: or use source rate? myPCMFormat.mFormatID = kAudioFormatMPEGLayer3 ; myPCMFormat.mFormatFlags = kAudioFormatFlagsCanonical; myPCMFormat.mChannelsPerFrame = 2; myPCMFormat.mFramesPerPacket = 1; myPCMFormat.mBitsPerChannel = 16; myPCMFormat.mBytesPerPacket = 4; myPCMFormat.mBytesPerFrame = 4; CheckResult (ExtAudioFileSetProperty(inputFile, kExtAudioFileProperty_ClientDataFormat, sizeof (myPCMFormat), &myPCMFormat), "ExtAudioFileSetProperty failed"); // allocate a big buffer. size can be arbitrary for ExtAudioFile. // you have 64 KB to spare, right? UInt32 outputBufferSize = 0x10000; void* ioBuf = malloc (outputBufferSize); UInt32 sizePerPacket = myPCMFormat.mBytesPerPacket; UInt32 packetsPerBuffer = outputBufferSize / sizePerPacket; // set up output file NSString *outputPath = [myDocumentsDirectory() stringByAppendingPathComponent:@"m_export.mp3"]; NSURL *outputURL = [NSURL fileURLWithPath:outputPath]; NSLog (@"creating output file %@", outputURL); AudioFileID outputFile; CheckResult(AudioFileCreateWithURL((__bridge CFURLRef)outputURL, kAudioFileCAFType, &myPCMFormat, kAudioFileFlags_EraseFile, &outputFile), "AudioFileCreateWithURL failed"); // start convertin' UInt32 outputFilePacketPosition = 0; //in bytes while (true) { // wrap the destination buffer in an AudioBufferList AudioBufferList convertedData; convertedData.mNumberBuffers = 1; convertedData.mBuffers[0].mNumberChannels = myPCMFormat.mChannelsPerFrame; convertedData.mBuffers[0].mDataByteSize = outputBufferSize; convertedData.mBuffers[0].mData = ioBuf; UInt32 frameCount = packetsPerBuffer; // read from the extaudiofile CheckResult (ExtAudioFileRead(inputFile, &frameCount, &convertedData), "Couldn't read from input file"); if (frameCount == 0) { printf ("done reading from file"); break; } // write the converted data to the output file CheckResult (AudioFileWritePackets(outputFile, false, frameCount, NULL, outputFilePacketPosition / myPCMFormat.mBytesPerPacket, &frameCount, convertedData.mBuffers[0].mData), "Couldn't write packets to file"); NSLog (@"Converted %ld bytes", outputFilePacketPosition); // advance the output file write location outputFilePacketPosition += (frameCount * myPCMFormat.mBytesPerPacket); } // clean up ExtAudioFileDispose(inputFile); AudioFileClose(outputFile); // show size in label NSLog (@"checking file at %@", outputPath); [self transMitFile:outputPath]; if ([[NSFileManager defaultManager] fileExistsAtPath:outputPath]) { NSError *fileManagerError = nil; unsigned long long fileSize = [[[NSFileManager defaultManager] attributesOfItemAtPath:outputPath error:&fileManagerError] fileSize]; } any suggestion?.......thanks for your great help!

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• Progressive download using Matt Gallagher's audio streamer

  - by Fernando Valente

  I'm a completely n00b when talking about audio. I'm using Matt Gallagher's audio streamer on my radio app. How may I use progressive download? Also, ExtAudioFile is a good idea too :) Edit: Used this: length = CFReadStreamRead(stream, bytes, kAQDefaultBufSize); if(!data) data =[[NSMutableData alloc] initWithLength:0]; [data appendData:[NSData dataWithBytes:bytes length:kAQDefaultBufSize]]; Now I can save the audio data using writeToFile:atomically: NSData method, but the audio won't play. Also, if I try to load it on a AVAudioPlayer, I get an error.

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