Sound Tweak Rpi4

[Tim Curtis]

Are you sure it's caching NAS files? The TODO comment in the code and this issue suggest that only local files (USB, SDCard) are handled. https://github.com/MusicPlayerDaemon/MPD/issues/597

Here's some other items relating to input cache.
https://github.com/MusicPlayerDaemon/MPD/issues/603
https://github.com/MusicPlayerDaemon/MPD/pull/696

[TheOldPresbyope]

All my testing was with a NAS library. Perhaps that explains some of my observations.

New or old, this input_cache feature isn't interesting enough to me to get into another kerfuffle with MaxK over it.

[Tim Curtis]

In any case it sounds like he's leaning toward having it be #songs to pre-fetch rather than amount of RAM for pre-fetching so the feature its prolly going change quite a bit b4 0.22 ships.

[kit1cat]

How do I get back to a working default MPD? Selected Default in Audio config and pressed set, but when I press library button I get the following error. lib-config: Connection to MPD failed?

Sorted : Updating to moOde 6.7.1 seems to have solved the problem.

[the_bertrum]

I'll have a play with some local files later, just for interest. In reality my system is idling along even when I'm listening to large files with SOX resampling, a couple of ssh sessions showing moodeutl -m and moodeutl -t and a library update running at the same time. The benefit conferred by having no network activity at song changeover would be negligible.

[swizzle]

All my testing was with a NAS library. Perhaps that explains some of my observations.

New or old, this input_cache feature isn't interesting enough to me to get into another kerfuffle with MaxK over it.

Features tend to lurk around until they’re finished, since it’s not in the current stable build it’d be new for .22 when it’s released.

As-is I agree it’s not all that interesting though playing the entire song from memory is something audio nerds want as it idles another thread (the goal being to have as little additional work being done as possible while playback is happening, whether or not it actually results in a measurable difference, well...). In that capacity 128-256MB is probably fine.

Loading the entire track before playback would prob hurt responsiveness too much unless you had fast locally attached storage and even then very large files would probably feel gross.

The error kitcat saw was likely due to modifying playerlib.php to include the input_cache directive and switching back to the regular mpd which doesn’t support it.

[DRONE7]

Are you sure it's caching NAS files? The TODO comment in the code and this issue suggest that only local files (USB, SDCard) are handled. https://github.com/MusicPlayerDaemon/MPD/issues/597

Here's some other items relating to input cache.
https://github.com/MusicPlayerDaemon/MPD/issues/603
https://github.com/MusicPlayerDaemon/MPD/pull/696

All I have connected is a NAS and yes it is caching from there..

I have a couple of cd rips from cd reissues of original LP's. These are each 2 tracks in length corresponding to Side A and SideB.
I see the memory usage jump accordingly as each of these is cached prior to mpd playing them.

Caching seems to be on a track by track basis so one of the interesting observations with these large tracks is that after they are loaded  the NAS hard drive spins down. (after it's selected park time set in OMV) whereas ordinary tracks are cached and short enough that the NAS drive continues to spin.

I am using Philrandal's suggestion of 1024 MB and having hit that the cache has now been managed down. Top and System info report total memory usage so depending on what MoOde processes are happening the cache/memory use can appear to grow beyond 1GB before management kicks in. Mine hit 1.12GB before it dropped back.

[kit1cat]

I thought I would run a little experiment, pi 3B+ 512 MB cache with pi4 OMV5 NAS.

Base memory usage 20%
add 1st track 23%
start playing 1st track 27%
add 2nd track 27% no change
start playing 2nd track 32%
add 3rd track 32% no change
start playing 3rd track 46%
Stopped playing 46%

I don't see any change in memory usage until the tracks start playing? The tracks do seem to load into the cache quite quickly once the track starts playing.

[DRONE7]

Cache vs buffers ?
Turn cache off and restart then monitor memory use...does it increase by the audio buffer size as a track begins to play ? (I'm guessing as I've not tried this and I am away from the Pi)
My tests have been with a playlist of 70+ tracks. Cache grows slowly until track 63 where the large tracks (mentioned in my last post) load and then jumps accordingly.

I'm not sure that entering tracks to the playlist one by one is a valid test ? In your example no change after adding the second track seems correct as there was only one existing track so nothing to cache once the first lone track started playing.

bob

[kit1cat]

How do I turn the cache off?