What Analysis Happens

I have a common file. structure between JRiver and Roon and actively use both products.

I had a requirement to make some file changes for a view in JRiver which involved Composition, Movement, Work & Part tags . These were changed by SongKong and auto written to the files.

Once this had happened obviously the files were “Changed”.

My understanding is that Roon analyses the files for volume leveling data , in this case this data would not have changed with the other tag changes I had made but Roon set off to re-analyse 20000 or so files (yes it was a big change !!)

If the volume leveling data is already present why does Roon have to re-analyse, what else is it doing . By comparison once the Volume Leveling analysis has happened in JRiver that analysis is not repeated. JRiver made its changes in a matter of minutes , Roon has already taken 2hrs and is still going

Just curious. Roon is chuntering merrily away !!


I asked @brian a couple of days ago something similar. He mentioned that he would remember analysis won’t take place upon metadata-modification but I also encounter this issue.

roon does re-analyse while the audio-part of a file remained completely untouched.
I’m not yet clear when exactly it happened but I could name 3 scenarios which all won’t require a re-anaysis.

  1. if metadata was shortened (since good taggers won’t rewrite the file but overwrite existing bytes within the metadata as required. audio remains untouched.

  2. if metadata was extended, also no re-analysis since the file is a container with 2 things in it, the metadata block and the audio block and since the audio block remains untouched …

  3. a rename / move of the file (physical differnt location). As long as it was known to roon (analysed) there must/should be a CRC across the audio part in the db and prior to an analysis a simple CRC calc could happen and in case it’s a known on, the analysisdata could be straight copied/moved.

All 3 might surely not work if one cleaned the database, since then I do hope that not only the mentioned removed files are cleared but also their audio-analysis data.

Not a big problem, nothing gets destroyed, but it’s a waste of time and effort to re-analyse things without a benefit at all. One might not bother if we talk about 10000 or 50000 tracks but beyond that it requires days until roon is done.

I have the same experience when changing genres. I was tidying things up where I had not been consistent with genre delimiters and also mapping my genres to roon genres. I was surprised to see that trigger audio analysis. So I am curious as well.

All ---- Thank you for the posts and sharing your feedback with us. The insight is very appreciated!

Moving forward, I brought this thread to the attention of members of our tech and DEV team this afternoon to discuss the behavior being reported here. As per the conversation the teams has noted that this is going to get fixed in the future when we start managing audio analysis results globally for the whole user base based on hashes of audio content.


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