Android: Axmol is failing to play wav and mp3 audio file format

[asnagni]

Hello,
On Android platform when we try to preload .wav or .mp3 audio files, the operation will fail. These formats are supposed to be supported by Axmol as far as I understand it. Maybe we need to setup a flag in the project CMake file? We are not sure at this point.

When the app is running, the files are located in a folder named "voiceMesages" in the app writable path.
When we try to preload the files the App will crash.

• axmol version: development branch
• devices test on: Redmi Note 8 & 9, Google Pixel 8, Samsung Galaxy S24, Samsung Galaxy A73 (Android 11, 13 and 14)
• developing environments
  • NDK version: 22.1.7171670
  • Xcode version: N/A
  • Visual Studio: N/A
    • VS version: N/A
    • MSVC version: N/A
    • Windows SDK version: N/A
  • cmake version: 3.29.0
    Steps to Reproduce:

1. Create a simple Axmole project
2. Add the files somewhere in your writable path
3. preload the files
4. Play the sound

audioFiles.zip

Thank you for your help,
Stay safe

[rh101]

Please show the exact code used to preload the audio files

[asnagni]

Hi rh101,
Sure, not a problem. The exact layout is that you have a tableview with a number of cells. When you click on a given table cell, the sound associated to that cell will play the audio file. To help, I would like to point out that it is working without any issue on iOS (iPhone & iPad). Please see the code below and let me know if there is something wrong with the way the API is used :

    bool CChatDialogLayer::playSound(ssize_t idx)
    {
        if (idx < 0 || idx >= m_messages.size()) return false;

        CConnexionMessage::MessageType msgType = m_messages[idx].getType();
        bool playSoundMsg = (msgType == CConnexionMessage::MessageTypeSound);
        if (!playSoundMsg) return false;

        std::string strMsg = m_messages[idx].getText();

        // Check if we have a direct access to the audio file.
        // If not, we need to download it and play it
        std::string file = m_messages[idx].getExistingFilePath();

        if (!file.empty())
        {
            playSoundMsg = true;
        }
        else
        {
            m_savedAudioFileName = strMsg;
            m_audioIdx = idx;

            requestFirebaseDownload((int)CConnexionMessage::MessageTypeSound,strMsg);
            playSoundMsg = false;
        }


        if (playSoundMsg)
        {
#if AX_TARGET_PLATFORM == AX_PLATFORM_IOS
            IOSManager::ConfigureAVAudioSession();
#endif
            AudioEngine::preload(file, [&, file](bool success) {
                if(success)
                {
                    int aid = AudioEngine::play2d(file, false, 1.0f, nullptr);
                    if (aid == AudioEngine::INVALID_AUDIO_ID) return false;

                    m_audioID = aid;
                    m_audioIdx = idx;
                    m_audioFile = file;

                    if(aid != AudioEngine::INVALID_AUDIO_ID)
                    {
                        AudioEngine::setFinishCallback(m_audioID, [&] (int audioID, std::string_view file) {
                            if (audioID == m_audioID)
                            {
                                ssize_t save_idx = m_audioIdx;
                                stopSound(false);
                                m_pTableView->updateCellAtIndex(save_idx);
                            }
                        });
                    }
                }
            });
        }

        return playSoundMsg;
    }

Thank you,
Stay safe

[rh101]

@asnagni The MP3 file is not using the MP3 codec, but rather the MP4A codec, as you can see here:

The file extension is not entirely relevant, so when encoding to MP3, ensure that you're using an MP3 codec, such as this:

This is not a bug with Axmol. The reason the "Test.mp3" file is working on iOS is because the MP4A format is supported on iOS.

[rh101]

The WAV file is in the following format:

I'm not sure if the SAMR format is supported, and it does not seem to be a valid format for WAV files. The correct extension for a file encoded in that format should be .amr or .3ga. Once again, the file extension is not important, but the internal encoding is, so it is not playing the file because it is not actually in a supported WAV format. The "test2.wav" file doesn't play on Windows builds either.

WAV data formats that are supported can be seen here in the cpp-tests project:

For example, PCM, u-Law etc.

In AudioCache.cpp, you can see the supported formats:

[asnagni]

Hi rh101,
Sorry for the delay in my responce. Thank you very much for all the details that you provided. I spent lot of time trying the sounds located test area and they are working. Axmol is working fine without any issue per the document (supported format). Unfortunately for our use case the supported format are a bit limited. I spent some time testing Axmol to see if I could find a solution but finaly a will be using ExoPlayer2 (it supports much more format than MediaPlayer and it is very easy to implement).
That way we will not run the risk of having some crashes due to unsorted format.

 Thank you very much rh101 for your support 👍, I do appreciate.
 Stay safe