stride3d/stride · error · AssetException

Failed to compile a video asset. ffmpeg failed to convert

Error message

Failed to compile a video asset. ffmpeg failed to convert {assetSource}.

What it means

ffmpeg located and invoked for the video asset returned a nonzero exit code or logged errors during conversion/re-encoding (including the stereoscopic sidedata strip on Windows). The compiler aborts with this AssetException naming the source file.

Solutions

1. Run the exact failing ffmpeg command manually to read the real error output
2. Re-encode the source to a common format (mp4/h264) and re-import the asset
3. Check the build log above the exception for ffmpeg's stderr
4. Update ffmpeg to a recent build if option flags are rejected

// pre-check the source decodes cleanly
var probe = ShellHelper.RunProcessAndGetOutputAsync("ffprobe", $"-v error \"{assetSource}\"", logger);
if (probe.Result != 0) logger.Error($"ffmpeg cannot read '{assetSource}'; re-encode before import.");

try
{
    await CompileVideoAsync(asset);
}
catch (AssetException ex) when (ex.Message.Contains("failed to convert"))
{
    logger.Error($"Re-encode '{assetSource}' to mp4/h264 manually and re-import. Details: {ex.Message}");
}

When it happens

Trigger: ShellHelper.RunProcessAndGetOutputAsync(ffmpeg, commandLine, ...) returns ret != 0 or commandContext.Logger.HasErrors after building the conversion command (including sidedataStripCommand on Windows stereoscopic videos).

Common situations: Unsupported source codec/container or DRM-protected video, invalid ffmpeg arguments composed for the platform, corrupt input, stream parameters ffmpeg refuses (e.g. odd dimensions with some pixel formats), ffmpeg version differences rejecting options like -apply_trc or sidedata strip flags.

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 video asset, ffmpeg was not found.
• Failed to compile a sound asset, ffmpeg was not found.
• Failed to compile a sound asset, ffmpeg failed to convert
• No video track found in
• Failed to get HW surface format.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/242b878a4d497e91. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Assets/Media/VideoAssetCompiler.cs:208

                            var trimmingOptions = videoDuration.Enabled ?
                                    $" -ss {startTime.Hours:D2}:{startTime.Minutes:D2}:{startTime.Seconds:D2}.{startTime.Milliseconds:D3}" +
                                    $" -t {duration.Hours:D2}:{duration.Minutes:D2}:{duration.Seconds:D2}.{duration.Milliseconds:D3}": 
                                    "";

                            var commandLine = "  -hide_banner -loglevel error" + // hide most log output
                                              "  -nostdin" + // no interaction (background process)
                                              $" -i \"{assetSource.ToOSPath()}\"" + // input file
                                              $"{trimmingOptions}" + 
                                              "  -f mp4 -vcodec " + targetCodecFormat + // codec
                                              channelFlag + // audio channels
                                              $"  -vf scale={targetSize.Width}:{targetSize.Height} " + // adjust the resolution
                                              sidedataStripCommand +   // strip of stereoscopic sidedata tag
                                              //" -an" + // no audio
                                              //" -pix_fmt yuv422p" + // pixel format (planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples))
                                              $" -y \"{tempFile}\""; // output file (always overwrite)
                            var ret = await ShellHelper.RunProcessAndGetOutputAsync(ffmpeg, commandLine, commandContext.Logger);
                            if (ret != 0 || commandContext.Logger.HasErrors)
                                throw new AssetException($"Failed to compile a video asset. ffmpeg failed to convert {assetSource}.");
                        }
                        else
                        {
                            commandContext.Logger.Info(string.Format("Video Asset Compiler: \"{0}\". No Re-encoding necessary",
                                videoAsset.Source.GetFileName()));

                            // Use temporary file
                            tempFile = assetSource.ToOSPath();
                        }

                        var dataUrl = Url + "_Data";
                        var video = new Video.Video
                        {
                            CompressedDataUrl = dataUrl,
                        };

                        // Make sure we don't compress h264 data
                        commandContext.AddTag(new ObjectUrl(UrlType.Content, dataUrl), Builder.DoNotCompressTag);

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