VOC(Creative Labs) conversion error

[pzs-scnu]

I've used SFBAudioEngine to convert mp3 to voc(creative labs audio), my code:

do{
    let decoder = try AudioDecoder(url: url)
    let encoder = try AudioEncoder(url: outputURL, encoderName: .libsndfile)
    encoder.settings =
        [
            .libsndfileMajorFormat: LibsndfileMajorFormat.VOC,
            .libsndfileSubtype: LibsndfileSubtype.PCM_16,
//                .libsndfileFileEndian: LibsndfileFileEndian.big

        ]

    let converter = try AudioConverter(decoder: decoder, encoder: encoder)
    try converter.convert()
    print("convert success")
}
catch{
    print("error \(error.localizedDescription)")
}

when running, error:
error The output format is not supported by Libsndfile.
What kinds of format does the libsndfile lib support? I found some other formats have this error too, although .libsndfileMajorFormat have defined these key/values(LibsndfileMajorFormat.VOC, LibsndfileMajorFormat.MAT4, etc.)

[sbooth]

Yes, there is a chart at https://libsndfile.github.io/libsndfile/formats.html with the supported formats.

I'm not sure what the problem is with this specific format. Did you try stepping through the code to see where the problem occurs or the error is thrown?

[pzs-scnu]

error occurs at:
let converter = try AudioConverter(decoder: decoder, encoder: encoder)
If changed to:
let converter = try AudioConverter(decoder: decoder, encoder: encoder) { _ in
return AVAudioFormat(commonFormat: .pcmFormatInt16, sampleRate: 44100, channels: 2, interleaved: false)!
}
the conversion success, the output file can be created and can also be played by VLC player, But strangelyI found that the generated output voc file always has playing time around 1 minutes length(but the file size 600-700MB) although the source audio has playing time around 50 minutes. other input audio files also have this issue, maybe some more attributes should be set in AudioConverter construction method?

[sbooth]

This was an error in the sndfile encoder- please try #590 and see if it fixes the problem for you.

[pzs-scnu]

SFBLibsndfileEncoder.m updated to #590, my code:

do{
    let decoder = try AudioDecoder(url: url)
    let encoder = try AudioEncoder(url: outputURL, encoderName: .libsndfile)
    encoder.settings =
        [
            .libsndfileMajorFormat: LibsndfileMajorFormat.VOC,
            .libsndfileSubtype: LibsndfileSubtype.PCM_16,
            .libsndfileFileEndian: LibsndfileFileEndian.little    // error The output format is not supported by Libsndfile when using big endian.
                
        ]
    let converter = try AudioConverter(decoder: decoder, encoder: encoder)
    try converter.convert()
    print("convert success")
}
catch{
    print("error \(error.localizedDescription)")
}

the conversion success, but the total paying time is still about 1-2 minutes(the source flac's playing time is 55 minutes), VLC is used for testing.

[sbooth]

Could you share a file that isn't working? I haven't been able to duplicate that behavior so far.

[sbooth]

For some reason I'm unable to download those files. I will keep investigating.

[sbooth]

I deleted the links to prevent spam to your account. I'm still unable to download the files- I get the message 暂时无法提取您需要的文件。

Could you email the links directly to me?

[pzs-scnu]

I’ve sent the audio files as email attachment to you, don’t you receive the email yet?

…

--------------原始邮件-------------- 发件人："Stephen Booth ***@***.***>; 发送时间：2025年8月20日(星期三) 晚上8:11 收件人："sbooth/SFBAudioEngine" ***@***.***>; 抄送："pzs-scnu ***@***.***>;"Author ***@***.***>; 主题：Re: [sbooth/SFBAudioEngine] VOC(Creative Labs) conversion error (Discussion #589) ----------------------------------- I deleted the links to prevent spam to your account. I'm still unable to download the files- I get the message 暂时无法提取您需要的文件。 Could you email the links directly to me? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: ***@***.***>

[sbooth]

It turns out the & in the URLs was converted at some point to & which broke them. I manually edited the URLs and was able to download the files. Thanks.

[sbooth]

I was able to convert the FLAC to VOC using SimplePlayer on macOS and play the VOC back also using SimplePlayer.

The source file has the following FLAC__StreamMetadata_StreamInfo:

(FLAC__StreamMetadata_StreamInfo) {
  min_blocksize = 4096
  max_blocksize = 4096
  min_framesize = 15
  max_framesize = 14362
  sample_rate = 44100
  channels = 2
  bits_per_sample = 16
  total_samples = 147185808
  md5sum = "\xaa\xbah?Dg\U00000001T\x81\U00000018=\xcb(\xe8ES"
}

The output file has the following SF_INFO:

(SF_INFO)  (frames = 147185808, samplerate = 44100, channels = 2, format = 524290, sections = 1, seekable = 1)

I then converted the generated VOC back to FLAC and the MD5 sums matched so I assume the conversion was lossless.

[pzs-scnu]

Yes, the converted VOC audio can be correctly played by SimplePlayer app, but strangely the VLC and OmniPlayer stop at 1 or 2 minutes when playing the VOC audio(although OmniPlayer shows the total time is about 54 minutes. )
Thanks for your answer!