Error operating with streams

[ornic]

This code (as far as I understand) should produce two identical outputs, since we analyze the very same file.

UPD: file AFAIK should not produce errors

var analyzerOptions = new FFMpegCore.FFOptions
{
    LogLevel = FFMpegCore.Enums.FFMpegLogLevel.Verbose
};

var jsonSerializationOptions = new JsonSerializerOptions { WriteIndented = true };

using var fileStream = File.OpenRead("BAD.mp4");

var fileAnalysisResult = await FFMpegCore.FFProbe.AnalyseAsync(fileStream, analyzerOptions);
Console.WriteLine($"Analysis STREAM:\n{JsonSerializer.Serialize(fileAnalysisResult, jsonSerializationOptions)}");

fileAnalysisResult = await FFMpegCore.FFProbe.AnalyseAsync("BAD.mp4", analyzerOptions);
Console.WriteLine($"Analysis FILE:\n{JsonSerializer.Serialize(fileAnalysisResult, jsonSerializationOptions)}");

But the first (and only first) result have errors: [mov,mp4,m4a,3gp,3g2,mj2 @ 0x55d9b146d2c0] stream 0, offset 0x81c: partial file

I have an example built using Debian 12, .NET 8, FFMpeg 5.1.6 and FFMpegCore 5.1.0 here: https://github.com/ornic/FFMpegCore-debian-pipe-bug

[tiesont]

Are you expecting errors (assuming as much from the BAD.mp4 filename)?

[ornic]

No, this name is just a result of many hours of testing 😿

Console ffmpeg / ffprobe work well with it. All major versions: 5, 6 and 7. Streams on windows (while debugging in Visual studio) also worked. But in swarm we got errors, so I began to dig.

I also tried Ubuntu instead of Debian, but streams not working there as well with ffmpeg 6.x

[tiesont]

I'm a bit too old school to know for sure what a "swarm" is, but assuming it means there could be multiple processes running the same action, you might be running into the InvalidOperationException generated by the Pre() method here: https://github.com/rosenbjerg/FFMpegCore/blob/main/FFMpegCore/FFMpeg/Arguments/PipeArgument.cs

Basically, the FileStream can't be opened again, since it's already open. Suppose one troubleshooting step would be to copy the stream into a MemoryStream and pass that instead. I know MemoryStream works for me, but I'm also not (yet) dealing with scaling to a server farm / microservices architecture, so...

Pipes are handled differently on Unix-derived OSes: https://github.com/rosenbjerg/FFMpegCore/blob/main/FFMpegCore/FFMpeg/Pipes/PipeHelpers.cs , so that's another possibility - might be helpful to note the version(s) of .NET and/or Mono installed.

(Quick caveat: while the comment headers indicate that I'm a contributor, I've mostly just committed some documentation, so don't take anything I suggest as "this is how FFMpegCore works")

[ornic]

I'm a bit too old school to know for sure what a "swarm" is

It is a cluster of docker containers. Child version of Kubernetes.

but assuming it means there could be multiple processes running the same action, you might be running into

Nope. Unfortunately.

I tried all sorts of tricks with streams, but even "array stream" of MemoryStream produces the same error.

Pipes are handled differently on Unix-derived OSes

I suppose that is the root of the problem here, but I don't have enough time for self-education and digging this root out. :(

Not all files produce the same problem, so, I suppose, there are some "magic byte sequence" that brokes the pipe.

might be helpful to note the version(s) of .NET and/or Mono installed

Thanks, I add that to the original post. In truth, I specifically made an example repo with one-command run and very simple code to minimize the work of someone with enough attitude to weed the problem out.