Unable to convert mp3 into PCM using AudioConverterFillComplexBuffer in AudioFileStreamOpen's AudioFileStream_PacketsProc callback

Question

I have a AudioFileStream_PacketsProc callback set during an AudioFileStreamOpen which handles converting audio packets into PCM using AudioConverterFillComplexBuffer. The issue that I am having is that I am getting a -50 OSStatus (paramErr) after AudioConverterFillComplexBuffer is called. Below is a snippet of what parameters were used in AudioConverterFillComplexBuffer and how they were made:

        audioConverterRef = AudioConverterRef()

        // AudioConvertInfo is a struct that contains information
        // for the converter regarding the number of packets and 
        // which audiobuffer is being allocated
        convertInfo? = AudioConvertInfo(done: false, numberOfPackets: numberPackets, audioBuffer: buffer,
            packetDescriptions: packetDescriptions) 

        var framesToDecode: UInt32 = pcmBufferTotalFrameCount! - end

        var localPcmAudioBuffer = AudioBuffer()
        localPcmAudioBuffer.mData = pcmAudioBuffer!.mData.advancedBy(Int(end * pcmBufferFrameSizeInBytes!))

        var localPcmBufferList = AudioBufferList(mNumberBuffers: 1, mBuffers: AudioBuffer(mNumberChannels: 0, mDataByteSize: 0, mData: nil))
        localPcmAudioBuffer = localPcmBufferList.mBuffers
        localPcmAudioBuffer.mData = pcmAudioBuffer!.mData.advancedBy(Int(end * pcmBufferFrameSizeInBytes!))
        localPcmAudioBuffer.mDataByteSize = framesToDecode * pcmBufferFrameSizeInBytes!;
        localPcmAudioBuffer.mNumberChannels = pcmAudioBuffer!.mNumberChannels

        var localPcmBufferList = AudioBufferList(mNumberBuffers: 1, mBuffers: AudioBuffer(mNumberChannels: 0, mDataByteSize: 0, mData: nil))
        localPcmAudioBuffer = localPcmBufferList.mBuffers

        AudioConverterFillComplexBuffer(audioConverterRef, AudioConverter_Callback, &convertInfo, &framesToDecode, &localPcmBufferList, nil)

Does what could possibly be causing the param error?

Here is the full method for the callback if needed:

func handleAudioPackets(inputData: UnsafePointer<Void>, numberBytes: UInt32, numberPackets: UInt32, packetDescriptions: UnsafeMutablePointer<AudioStreamPacketDescription>) {
        if currentlyReadingEntry == nil {
            print("currentlyReadingEntry = nil")
            return
        }
        if currentlyReadingEntry.parsedHeader == false {
            print("currentlyReadingEntry.parsedHeader == false")
            return
        }

        if disposedWasRequested == true {
            print("disposedWasRequested == true")
            return
        }

        guard let audioConverterRef = audioConverterRef else {
            return
        }

        if seekToTimeWasRequested == true && currentlyReadingEntry.calculatedBitRate() > 0.0 {
            wakeupPlaybackThread()
            print("seekToTimeWasRequested == true && currentlyReadingEntry.calculatedBitRate() > 0.0")
            return
        }

        discontinuous = false

        var buffer = AudioBuffer()
        buffer.mNumberChannels = audioConverterAudioStreamBasicDescription.mChannelsPerFrame
        buffer.mDataByteSize = numberBytes
        buffer.mData = UnsafeMutablePointer<Void>(inputData)


        convertInfo? = AudioConvertInfo(done: false, numberOfPackets: numberPackets, audioBuffer: buffer,
            packetDescriptions: packetDescriptions)


        if packetDescriptions != nil && currentlyReadingEntry.processedPacketsCount < maxCompressedBacketsForBitrateCalculation {
            let count: Int = min(Int(numberPackets), Int(maxCompressedBacketsForBitrateCalculation - currentlyReadingEntry.processedPacketsCount!))
            for var i = 0;i < count;++i{
                let packetSize: Int32 = Int32(packetDescriptions[i].mDataByteSize)
                OSAtomicAdd32(packetSize, &currentlyReadingEntry.processedPacketsSizeTotal!)
                OSAtomicIncrement32(&currentlyReadingEntry.processedPacketsCount!)
            }
        }
        while true {
            OSSpinLockLock(&pcmBufferSpinLock)
            var used: UInt32 = pcmBufferUsedFrameCount!
            var start: UInt32 = pcmBufferFrameStartIndex!
            var end = (pcmBufferFrameStartIndex! + pcmBufferUsedFrameCount!) % pcmBufferTotalFrameCount!
            var framesLeftInsideBuffer = pcmBufferTotalFrameCount! - used
            OSSpinLockUnlock(&pcmBufferSpinLock)

            if framesLeftInsideBuffer == 0 {
                pthread_mutex_lock(&playerMutex)
                while true {
                    OSSpinLockLock(&pcmBufferSpinLock)
                    used = pcmBufferUsedFrameCount!
                    start = pcmBufferFrameStartIndex!
                    end = (pcmBufferFrameStartIndex! + pcmBufferUsedFrameCount!) % pcmBufferTotalFrameCount!
                    framesLeftInsideBuffer = pcmBufferTotalFrameCount! - used
                    OSSpinLockUnlock(&pcmBufferSpinLock)

                    if framesLeftInsideBuffer > 0 {
                        break
                    }

                    if (disposedWasRequested == true
                        || internalState == SSPlayerInternalState.Disposed) {
                        pthread_mutex_unlock(&playerMutex)
                        return
                    }

                    if (seekToTimeWasRequested == true && currentlyPlayingEntry.calculatedBitRate() > 0.0)
                    {
                        pthread_mutex_unlock(&playerMutex)
                        wakeupPlaybackThread()
                        return;
                    }

                    waiting = true
                    pthread_cond_wait(&playerThreadReadyCondition, &playerMutex)
                    waiting = false
                }
                pthread_mutex_unlock(&playerMutex)
            }
            var localPcmAudioBuffer = AudioBuffer()
            var localPcmBufferList = AudioBufferList(mNumberBuffers: 1, mBuffers: AudioBuffer(mNumberChannels: 0, mDataByteSize: 0, mData: nil))
            localPcmAudioBuffer = localPcmBufferList.mBuffers

            if end >= start {
                var framesAdded: UInt32 = 0
                var framesToDecode: UInt32 = pcmBufferTotalFrameCount! - end
                localPcmAudioBuffer.mData = pcmAudioBuffer!.mData.advancedBy(Int(end * pcmBufferFrameSizeInBytes!))
                localPcmAudioBuffer.mDataByteSize = framesToDecode * pcmBufferFrameSizeInBytes!;
                localPcmAudioBuffer.mNumberChannels = pcmAudioBuffer!.mNumberChannels

                AudioConverterFillComplexBuffer(audioConverterRef, AudioConverter_Callback, &convertInfo, &framesToDecode, &localPcmBufferList, nil)

                framesAdded = framesToDecode

                if status == 100 {
                    OSSpinLockLock(&pcmBufferSpinLock)
                    let newCount = pcmBufferUsedFrameCount! + framesAdded
                    pcmBufferUsedFrameCount = newCount
                    OSSpinLockUnlock(&pcmBufferSpinLock);

                    OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                    let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                    currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                    OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                    return
                } else if status != 0 {
                    print("error")
                    return
                }
                framesToDecode = start

                if framesToDecode == 0 {

                    OSSpinLockLock(&pcmBufferSpinLock)
                    let newCount = pcmBufferUsedFrameCount! + framesAdded
                    pcmBufferUsedFrameCount = newCount
                    OSSpinLockUnlock(&pcmBufferSpinLock);

                    OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                    let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                    currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                    OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                    continue
                }

                localPcmAudioBuffer.mData = pcmAudioBuffer!.mData
                localPcmAudioBuffer.mDataByteSize = framesToDecode * pcmBufferFrameSizeInBytes!
                localPcmAudioBuffer.mNumberChannels = pcmAudioBuffer!.mNumberChannels

                AudioConverterFillComplexBuffer(audioConverterRef, AudioConverter_Callback, &convertInfo, &framesToDecode, &localPcmBufferList, nil)
                let decodedFramesAdded = framesAdded + framesToDecode
                framesAdded = decodedFramesAdded

                if status == 100 {
                    OSSpinLockLock(&pcmBufferSpinLock)
                    let newCount = pcmBufferUsedFrameCount! + framesAdded
                    pcmBufferUsedFrameCount = newCount
                    OSSpinLockUnlock(&pcmBufferSpinLock);

                    OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                    let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                    currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                    OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                    return
                } else if status == 0 {
                    OSSpinLockLock(&pcmBufferSpinLock)
                    let newCount = pcmBufferUsedFrameCount! + framesAdded
                    pcmBufferUsedFrameCount = newCount
                    OSSpinLockUnlock(&pcmBufferSpinLock);

                    OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                    let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                    currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                    OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                    continue
                } else if status != 0 {
                    print("error")
                    return
                } else {
                    var framesAdded: UInt32 = 0
                    var framesToDecode: UInt32 = start - end
                    localPcmAudioBuffer.mData = pcmAudioBuffer!.mData.advancedBy(Int(end * pcmBufferFrameSizeInBytes!))
                    localPcmAudioBuffer.mDataByteSize = framesToDecode * pcmBufferFrameSizeInBytes!;
                    localPcmAudioBuffer.mNumberChannels = pcmAudioBuffer!.mNumberChannels

                    var  convertInfoo: UnsafePointer<Void> = unsafeBitCast(convertInfo, UnsafePointer<Void>.self)

                    status = AudioConverterFillComplexBuffer(audioConverterRef, AudioConverter_Callback, &convertInfoo, &framesToDecode, &localPcmBufferList, nil)

                    framesAdded = framesToDecode

                    if status == 100 {
                        OSSpinLockLock(&pcmBufferSpinLock)
                        let newCount = pcmBufferUsedFrameCount! + framesAdded
                        pcmBufferUsedFrameCount = newCount
                        OSSpinLockUnlock(&pcmBufferSpinLock);

                        OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                        let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                        currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                        OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                        return
                    } else if status == 0 {
                        OSSpinLockLock(&pcmBufferSpinLock)
                        let newCount = pcmBufferUsedFrameCount! + framesAdded
                        pcmBufferUsedFrameCount = newCount
                        OSSpinLockUnlock(&pcmBufferSpinLock);

                        OSSpinLockLock(&currentlyReadingEntry!.spinLock!)
                        let newFramesAddedCount = currentlyReadingEntry.framesQueued! + Int64(framesAdded)
                        currentlyReadingEntry!.framesQueued! = newFramesAddedCount
                        OSSpinLockUnlock(&currentlyReadingEntry!.spinLock!)
                        continue
                    } else if status != 0 {
                        print("error")
                        return
                    }

                }
            }
        }
    }

Do you have a link to a runnable project, say in github? – Rhythmic Fistman Jul 27 '15 at 01:41 — Rhythmic Fistman, Jul 27 '15 at 01:41

score 5 · Accepted Answer · edited May 23 '17 at 10:26

5

Hej @3254523, I have some answers with possible solutions for you. I hope to guide you in the right way in spite of I am not expert in this major. So, the problem is for sure the configuration of:

AudioBufferList

Here the links that probes the hints of this -50 OSStatus related to the AudioBufferList: http://lists.apple.com/archives/coreaudio-api/2012/Apr/msg00041.html https://forums.developer.apple.com/thread/6313

Now, we have to focus in a solutions. Looking through your AudioBufferList, you have no assigned any value but mNumberBuffers which is 1. Try to change the values in the following way(as it shown in the second link):

var localPcmBufferList = AudioBufferList(mNumberBuffers: 2, mBuffers: AudioBuffer(mNumberChannels: 2, mDataByteSize: UInt32(buffer.count), mData: &buffer))

If still is not working, we have to focus to correct it properly, hence here you can find the solution to the -50 OSStatus in AudioConverterFillComplexBuffer although not in swift:

AudioConverterFillComplexBuffer return -50 (paramErr)

iPhone: AudioBufferList init and release

edited May 23 '17 at 10:26

Community

1
1

answered Jul 24 '15 at 22:13

juanmajmjr

1,055
7
11

still trying it out @juanmajmjr – 3254523 Jul 27 '15 at 19:22
i'm getting a 1768846202 (input error) now that i put the mNumberBuffers as `1`. what could that be? – 3254523 Jul 27 '15 at 21:50
Hej @3254523 , this is another kind of error. Try to change that number and see the behavior. Also you can find more information in the following link, although the issue was not totally solved: http://stackoverflow.com/questions/1374674/audio-unit-and-writing-to-file – juanmajmjr Jul 28 '15 at 09:05
do you have skype/gchat @juanmajmjr? – 3254523 Jul 28 '15 at 15:38
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/84486/discussion-between-juanmajmjr-and-3254523). – juanmajmjr Jul 28 '15 at 15:56

score 0 · Answer 2 · answered May 28 '20 at 07:24

a nice example taken from AudioKit

Audio File Services ( to read the MP3 format and write AIFF or WAV )
Audio File Conversion Services ( to convert the MP3 data to PCM, or to encode from PCM to some other codec if you were to write a file )

A given converter can't convert between two encoded formats.

you can do MP3-to-PCM or PCM-to-AAC

While to do MP3-to-AAC, needs two converters

score 0 · Answer 3 · answered May 29 '20 at 06:59

Easy to do with tanersener/mobile-ffmpeg

      let command = "-i input.mp3 -f s16le -acodec pcm_s16le -ac 1 -ar 44100  output.raw"
      let result = MobileFFmpeg.execute(command)
           switch result {
           case RETURN_CODE_SUCCESS:
               print("command exe completed successfully.\n")
           case RETURN_CODE_CANCEL:
               print("command exe cancelled by user.\n")
           default:
               print("command exe failed with rc=\(result) and output=\(String(describing: MobileFFmpegConfig.getLastCommandOutput())).\n")
          }

Unable to convert mp3 into PCM using AudioConverterFillComplexBuffer in AudioFileStreamOpen's AudioFileStream_PacketsProc callback

3 Answers3

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