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Hi everyone!I'm developing an application that ingest raw AAC data directly from a socket. So I have "packets" in ADTS format extracted from a socket. I have been trying to convert this compressed audio packets to PCM so I can enqueue and play them. I have developed the PCM player but I have been unable to convert to PCM. I have been trying different ways but I cannot accomplish this. I'm using AudioConverterFillComplexBufferbut I'm always receiving some kind of error which I cannot solve. So far, I'm in a situation where the logs shows something like:2018-07-08 21:27:51.359716+0200 streaming-test-v3[43319:14013195] AACDecoder.cpp:189:Deserialize: Too few bits left in input buffer 2018-07-08 21:27:51.360047+0200 streaming-test-v3[43319:14013195] AACDecoder.cpp:220:DecodeFrame: Error deserializing packet 2018-07-08 21:27:51.360393+0200 streaming-test-v3[43319:14013195] [ac] ACMP4AACBaseDecoder.cpp:1337:ProduceOutputBufferList: (0x7ff4f705b240) Error decoding packet 54: err = -1, packet length: 1 2018-07-08 21:27:51.360691+0200 streaming-test-v3[43319:14013195] [ac] ACMP4AACBaseDecoder.cpp:1346:ProduceOutputBufferList: 'A0' AudioConverterFillComplexBuffer error: 1852797029I have a lot of doubts regarding this methods:Should I skip the ADTS header? (7-9 bytes)What should be the outputBuffer length and allocation capacity? How can I set it? I don't know which size the decoded frames gonna haveWhy is it saying too few bits left in input buffer?I'm streaming a single channel stream, but I had way some problems with this streaming a raw PCM and playing it.I'm posting my code in case someone can help me.Setup the audio converter func setupAudioConverter() { var outputFormat = AudioStreamBasicDescription.init( mSampleRate: 44100, mFormatID: kAudioFormatLinearPCM, mFormatFlags: kLinearPCMFormatFlagIsSignedInteger, mBytesPerPacket: 2, mFramesPerPacket: 1, mBytesPerFrame: 2, mChannelsPerFrame: 1, mBitsPerChannel: 16, mReserved: 0) // let outputFormat = AVAudioFormat(commonFormat: AVAudioCommonFormat, sampleRate: 44100.0, channels: 1, interleaved: false) var inputFormat = AudioStreamBasicDescription.init( mSampleRate: 44100, mFormatID: kAudioFormatMPEG4AAC, mFormatFlags: UInt32(MPEG4ObjectID.AAC_LC.rawValue), mBytesPerPacket: 0, mFramesPerPacket: 0, mBytesPerFrame: 0, mChannelsPerFrame: 1, mBitsPerChannel: 0, mReserved: 0) // let inputFormat = AVAudioFormat(streamDescription: &inputDesc) let status: OSStatus = AudioConverterNew(&inputFormat, &outputFormat, &audioConverter) if (status != 0) { print("setup converter error, status: \(status)") } print("audioConverter: \(audioConverter)") } 2. This is the input callback for FillComplexBuffervar inputDataVar: AudioConverterComplexInputDataProc = {( aAudioConverter: AudioConverterRef, aNumDataPackets: UnsafeMutablePointer<UInt32>, aData: UnsafeMutablePointer<AudioBufferList>, aPacketDesc: UnsafeMutablePointer<UnsafeMutablePointer<AudioStreamPacketDescription>?>?, aUserData: UnsafeMutableRawPointer?) -> OSStatus in var userData = UnsafeMutablePointer<PassthroughUserData>(OpaquePointer(aUserData)!).pointee if userData.mDataSize == 0 { aNumDataPackets.pointee = 0 return -9078 } print("aUserData: \(aUserData)") print("UserData: \(userData)") if aPacketDesc != nil { userData.mPacket.mStartOffset = 0 userData.mPacket.mVariableFramesInPacket = 0 userData.mPacket.mDataByteSize = userData.mDataSize aPacketDesc?.pointee = UnsafeMutablePointer<AudioStreamPacketDescription>(&userData.mPacket) } UnsafeMutablePointer<AudioBufferList>(OpaquePointer(aData)!).pointee.mBuffers.mNumberChannels = userData.mChannels UnsafeMutablePointer<AudioBufferList>(OpaquePointer(aData)!).pointee.mBuffers.mDataByteSize = userData.mDataSize UnsafeMutablePointer<AudioBufferList>(OpaquePointer(aData)!).pointee.mBuffers.mData = userData.mData userData.mDataSize = 0 return noErr } 3. And the decode frame function func decodeAudioFrame(frame: Data) { var frameCopy = frame if audioConverter == nil { self.setupAudioConverter() } var ***1: UInt32 = UInt32(frame.count) var ***2 = 0 var prop = AudioConverterGetProperty(audioConverter!, kAudioConverterPropertyMaximumOutputPacketSize, &***1, &***2) let packetDescription: AudioStreamPacketDescription = AudioStreamPacketDescription.init(mStartOffset: 0, mVariableFramesInPacket: 0, mDataByteSize: UInt32(frameCopy.count)) var userData: PassthroughUserData = PassthroughUserData(mChannels: 1, mDataSize: UInt32(frame.count), mData: &frameCopy, mPacket: packetDescription) let buffer = UnsafeMutablePointer<Int16>.allocate(capacity: frameCopy.count) let audioBuffer: AudioBuffer = AudioBuffer.init(mNumberChannels: 1, mDataByteSize: UInt32(MemoryLayout.size(ofValue: buffer)), mData: buffer) var decBuffer: AudioBufferList = AudioBufferList.init(mNumberBuffers: 1, mBuffers: audioBuffer) var outPacketDescription: AudioStreamPacketDescription? = AudioStreamPacketDescription.init() memset(&outPacketDescription, 0, MemoryLayout.size(ofValue: outPacketDescription)) var numFrames: UInt32 = 1 let status = AudioConverterFillComplexBuffer( audioConverter!, inputDataVar, &userData, &numFrames, &decBuffer, &outPacketDescription!) if status != 0 { print("AudioConverterFillComplexBuffer error: \(status)") } print("numFrames: \(numFrames)") }Thank you everyone. In fact, I hope @theAnalogKid can give some light in my path, because this is getting hard.