ffmpeg output file does not contain any stream

[SVMartin]

Hi,

I am new to UMS, but it looks like a proper piece of software! Nevertheless I ran into the following issue.

I have UMS running on a VM that has a fresh install of Ubuntu 20.04 LTS server. The client is a Yamaha AV receiver for which I'm creating a new renderer file. The receiver cannot handle ogg vorbis files so they need to be transcoded.

I also have mp3 files, which play perfectly, but the folders that have the ogg vorbis files show up empty on the client.

I have hidden the transcoding directory in my UMS configuration: I just want the client to show the files and UMS transcode if necessary. I don't want to bother the user (me) with separate directories.

First check: is that how it should work, or do I have wrong expectations?

Second, the problem might be in ffmpeg transcoding. In the last line (see attachment) it says that the output file does not contain any stream.

Edit: i checked these files, they can be played perfectly with any random music player like VLC or rhythmbox.

Any help is greatly appreciated!

[SVMartin]

Ok, some additional research.

The -an argument disables audio. That is weird when transcoding an audio-only track.

The -f image2 argument is related to formats (https://ffmpeg.org/ffmpeg-formats.html#image2-1), while there is no image in the audio stream. Weird again.

dn, sn and vf arguments are also related to video only.

Is UMS trying to transcode the ogg vorbis audio file as was it a video file?

[Nadahar]

It's not unthinkable, considering that OGG is a container aka "video" format. I would of course be a bug, but it's still not that unlikely.

[SVMartin]

Ah, never investigated some time to look into what ogg and vorbis actually are. Just read the wikipedia pages, that helps!

You might be right; I hope it can be solved by some configuration change, or can somebody tell me if/where I should report the bug?

I created these files about 15 years ago. I converted my CD collection and wanted good quality. At that time ogg vorbis had higher quality and resulted in smaller files than mp3 (and it is royalty free). I could convert the files to high quality mp3's, but I prefer not to.

BTW, why is UMS doing all this work at startup? Shouldn't it make sense to analyze the format of files when they are requested by a client and then take appropriate action (which depends on the possibilities of the client)?

[Nadahar]

The log you have attached is useless, don't expect any replies to that. It needs to be the full log and in TRACE mode. The output from FFmpeg ifself isn't very helpful unless you know what UMS is trying to do at the time. It looks to me like the little excerpt might be an attempt to create a thumbnail for the file, which has nothing to do with actual playback. That would explain "-an" etc. But, without the log, there's no telling what's happening.

I don't quite understand the paranoia about the log files many have these days. If you're worried about sharing the names of your media files, create a folder somewhere used for testing, put one or a few files in there which is suitable for "disclosure", configure UMS to only share this folder and then start the TRACE session. It will only log the files that are "shared".

[Nadahar]

Crosspost - to answer your last comment: It's way too soon to conclude that there's a bug, without the logs all we can do is guess. If there's a bug, Github would probably be the best place to report it.

There should be no reason to convert the files manually, UMS should be perfectly capable of doing that. The reason it's not, might be because of a bug or might be because of the renderer configuration.

The behavior you describe is the way UMS worked prior to version 7.x. But, some people then complain that browsing is too slow (because parsing happens as you browse for the first time). In addition, it kind of breaks the "media library", where media files are categorized and listed based on database information, not filesystem information. Any files that haven't yet been "browsed" will be unknown to the database, and thus people will complain that things are "missing" from the media library.

There should be an option to turn off startup scan somewhere if you still think the previous behavior is preferable.

[SVMartin]

Thanks for sharing your thoughts and knowledge!

Now I understand why it can be beneficial to do the scanning up front; likely that holds for my system as well, as it is running on my FreeNAS box powered by a slow atom Your explanation also helps me to better understand that configuration item.

I'll start a trace run, brb!

[SVMartin]

Here is the full trace log!

[Nadahar]

I can't see any attempts to play in that log file. All I see is file scanning and (failed) thumbnail creation. Did you try to play one of the files while creating this log?

[SVMartin]

Oops! Expected the issue already to have occured..

When browsing the contents of the folder the Yamaha receiver says no content found.

Attached is a zip file containing the trace log, but also my ums.conf and renderer config (the only one I'm using).