{"record":{"id":"cbc31121fd1086ff","repo":"NickeManarin/ScreenToGif","slug":"error-while-encoding-the-preset-type-with-ffmpeg","errorCode":null,"errorMessage":"Error while encoding the {preset.Type} with FFmpeg.","messagePattern":"Error while encoding the (.+?) with FFmpeg\\.","errorType":"exception","errorClass":"Exception","httpStatus":null,"severity":"error","filePath":"ScreenToGif/Util/EncodingManager.cs","lineNumber":1862,"sourceCode":"        }\n\n        var fileInfo = new FileInfo(preset.FullPath);\n\n        //Execute the second pass, cleaning up the logs.\n        if (!string.IsNullOrWhiteSpace(secondPass))\n        {\n            //I could try using as a single command.\n            //ffmpeg -y -hwaccel auto {I} -c:v h264_nvenc -pix_fmt yuv420p -vf \"scale=trunc(iw/2)*2:trunc(ih/2)*2\" -pass 1 -f avi NUL\n            //&&\n            //ffmpeg -y -hwaccel auto {I} -c:v h264_nvenc -pix_fmt yuv420p -vf \"scale=trunc(iw/2)*2:trunc(ih/2)*2\" -pass 2 -f avi {O}\n\n            log += Environment.NewLine + SecondPassFfmpeg(secondPass, id, tokenSource, LocalizationHelper.Get(\"S.Encoder.Processing.Second\"));\n\n            EraseSecondPassLogs(preset.FullPath);\n        }\n\n        if (!fileInfo.Exists || fileInfo.Length == 0)\n            throw new Exception($\"Error while encoding the {preset.Type} with FFmpeg.\") { HelpLink = $\"Command:\\n\\r{firstPass + Environment.NewLine + secondPass}\\n\\rResult:\\n\\r{log}\" };\n    }\n\n    private static string SecondPassFfmpeg(string command, int id, CancellationTokenSource tokenSource, string processing)\n    {\n        var log = \"\";\n\n        var process = new ProcessStartInfo(UserSettings.All.FfmpegLocation)\n        {\n            Arguments = command,\n            CreateNoWindow = true,\n            ErrorDialog = false,\n            UseShellExecute = false,\n            RedirectStandardError = true\n        };\n\n        using (var pro = Process.Start(process))\n        {\n            var indeterminate = true;","sourceCodeStart":1844,"sourceCodeEnd":1880,"githubUrl":"https://github.com/NickeManarin/ScreenToGif/blob/a4d0a67c2131cd048ceec86cd40afc2f1a06f2fd/ScreenToGif/Util/EncodingManager.cs#L1844-L1880","documentation":"EncodeWithFfmpeg completes the ffmpeg process run (optionally a second pass) and then inspects new FileInfo(preset.FullPath). If the output file does not exist or has Length == 0, it throws Exception with a HelpLink carrying the firstPass+secondPass commands and the captured ffmpeg log. The exception means ffmpeg ran but produced no usable output.","triggerScenarios":"ffmpeg exited but preset.FullPath is missing or zero bytes. Typical causes: ffmpeg returned non-zero (bad codec, missing encoder build, invalid filter), the two-pass first pass failed silently, an invalid scale/pix_fmt argument, frames missing on disk, or the output path was unwritable.","commonSituations":"ffmpeg build without the required encoder (e.g. no libx264 / libvpx / h264_nvenc); older ffmpeg version (HasOlderFfmpegVersion) using deprecated flags; corrupted/empty source frames; AV quarantining output; unsupported hardware acceleration flag on a GPU that lacks it.","solutions":["Read the HelpLink — it contains the exact ffmpeg commands and the full log identifying the failure line.","Update ffmpeg to a recent static build that includes the needed encoders (libx264, libvpx-vp9, etc.).","If using hardware acceleration (nvenc/qsv), verify the GPU supports it or fall back to software encoders.","Verify preset.FullPath's folder is writable and excluded from AV scanning."],"exampleFix":"// before\nif (!fileInfo.Exists || fileInfo.Length == 0)\n    throw new Exception($\"Error while encoding the {preset.Type} with FFmpeg.\") { HelpLink = $\"Command:\\n\\r{firstPass + Environment.NewLine + secondPass}\\n\\rResult:\\n\\r{log}\" };\n\n// after\nif (!fileInfo.Exists || fileInfo.Length == 0)\n    throw new Exception($\"Error while encoding the {preset.Type} with FFmpeg. Output missing or empty. See HelpLink for command and log.\") { HelpLink = $\"Command:\\n\\r{firstPass + Environment.NewLine + secondPass}\\n\\rResult:\\n\\r{log}\" };","handlingStrategy":"try-catch","validationCode":"// Pre-flight: confirm the encoder exists in this ffmpeg build\nvar encoders = await PathHelper.GetFfmpegEncoders(); // -encoders output parsed\nif (!encoders.Contains(requiredEncoder)) /* warn user */","typeGuard":"// n/a","tryCatchPattern":"try { await EncodeWithFfmpeg(...); }\ncatch (Exception ex)\n{\n    var log = ex.HelpLink; // contains command + ffmpeg log\n    LogWriter.Log(ex, $\"ffmpeg encode failed.\\n{log}\");\n    throw;\n}","preventionTips":["Always read the HelpLink — it carries the exact command and ffmpeg's error log.","Keep ffmpeg up to date; older builds lack modern encoders (nvenc, libvpx-vp9, av1).","Validate the output folder is writable and AV-excluded before starting a long encode."],"tags":["ffmpeg","encoding","empty-output","native-dependency"],"backgroundTag":null,"analyzedSha":"a4d0a67c2131cd048ceec86cd40afc2f1a06f2fd","analyzedAt":"2026-08-13T11:12:06.147Z","schemaVersion":2},"datasetVersion":"2026-08-13T14:17:21.547Z"}