stride3d/stride · error · AssetException

Failed to compile a sound asset, ffmpeg failed to convert

Error message

Failed to compile a sound asset, ffmpeg failed to convert {assetSource}

What it means

ffmpeg was found and launched, but the conversion of the sound source to raw PCM (f32le) exited nonzero or logged errors. The compiler treats this as a failed conversion and throws an AssetException naming the source file.

Solutions

1. Run the same ffmpeg command manually on the source file to see the real codec/error output
2. Verify the asset's stream Index, SampleRate, and channel settings match the source media
3. Re-encode or re-export the source audio to a standard format (e.g. wav) and re-import
4. Check the build log above the exception for ffmpeg's stderr messages

// pre-flight the conversion with ffprobe/ffmpeg exit code
var probe = ShellHelper.RunProcessAndGetOutputAsync("ffprobe", $"-v error \"{assetSource}\"", logger);
if (probe.Result != 0) logger.Error($"Source media unreadable by ffmpeg: {assetSource}");

try
{
    await CompileSoundAsync(asset);
}
catch (AssetException ex) when (ex.Message.Contains("failed to convert"))
{
    logger.Error($"Re-encode '{assetSource}' to wav with ffmpeg manually; check stream index/sample rate settings. Details: {ex.Message}");
}

When it happens

Trigger: ShellHelper.RunProcessAndGetOutputAsync returns a nonzero exit code, or commandContext.Logger.HasErrors is true after running ffmpeg with the pcm_f32le conversion command line.

Common situations: Unsupported/corrupt audio file format or codec, wrong stream Index parameter pointing at a nonexistent stream, SampleRate/channels values ffmpeg cannot produce from the source, file path with characters that break the command line quoting.

Understand the failure class

Background: "API error: {status}" and "HTTP 401/403/404/429/5xx" errors: non-2xx HTTP responses explained — this error's family across 27 libraries.

Related errors

• Failed to compile a sound asset, ffmpeg was not found.
• Failed to compile a video asset, ffmpeg was not found.
• Failed to compile a video asset. ffmpeg failed to convert
• Failed to get Vertex BufferData for entity
• Failed to get Indices BufferData for entity

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/1eebd2badb33efe0. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Assets/Media/SoundAssetCompiler.cs:63

                // Get absolute path of asset source on disk
                var assetDirectory = Parameters.Source.GetParent();
                var assetSource = UPath.Combine(assetDirectory, Parameters.Source);

                // Execute ffmpeg to convert source to PCM and then encode with Celt
                var tempFile = Path.GetTempFileName();
                try
                {
                    var channels = Parameters.Spatialized ? 1 : 2;
                    var commandLine = "  -hide_banner -loglevel error" + // hide most log output
                                      $" -i \"{assetSource.ToOSPath()}\"" + // input file
                                      $" -f f32le -acodec pcm_f32le -ac {channels} -ar {Parameters.SampleRate}" + // codec
                                      $" -map 0:{Parameters.Index}" + // stream index
                                      $" -y \"{tempFile}\""; // output file (always overwrite)
                    var ret = await ShellHelper.RunProcessAndGetOutputAsync(ffmpeg, commandLine, commandContext.Logger);
                    if (ret != 0 || commandContext.Logger.HasErrors)
                    {
                        throw new AssetException($"Failed to compile a sound asset, ffmpeg failed to convert {assetSource}");
                    }

                    var encoder = new Celt(Parameters.SampleRate, CompressedSoundSource.SamplesPerFrame, channels, false);

                    var uncompressed = CompressedSoundSource.SamplesPerFrame * channels * sizeof(short); //compare with int16 for CD quality comparison.. but remember we are dealing with 32 bit floats for encoding!!
                    var target = (int)Math.Floor(uncompressed / (float)Parameters.CompressionRatio);

                    var dataUrl = Url + "_Data";
                    var newSound = new Sound
                    {
                        CompressedDataUrl = dataUrl,
                        Channels = channels,
                        SampleRate = Parameters.SampleRate,
                        StreamFromDisk = Parameters.StreamFromDisk,
                        Spatialized = Parameters.Spatialized,
                    };

                    //make sure we don't compress celt data

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