Plexamp: bandwidth usage


#1

Hi,

I was trying out plexamp remotely (playing some flac files), and I've found that it seems to continually pull data from the server while playing, and is even stuttering during play back.

If I compare it to the web player (in Chrome) the chome player seems to pull for a short period (15-20s at 3-4Mbps) for an initial buffer, and then pulls more data when the buffer remaining is small.

Plexamp seems to pull at 5-6 Mbps constantly, and unless I pause play back for a few seconds it stutters and stalls. Actually it seems that by stopping playback (with stop in the menu) it still pulls down a steady 5-6Mbps, checking disk activity in resource monitor shows it's not obviously writing to disk.

The PMS server shows that both chrome and plexamp are using direct play, the server is a synology 1511+, with version 1.10.0.4523. I do have a bandwidth cap on uploads set to 6 Mbps (just to avoid saturating my uplink)

Is this a known issue, or outside of the expected usage of plexamp at the moment? Checking the Plexamp appdata folder doesn't show any log files to look at.

Playing back an mp3 seems to work without stuttering, but it's still pulling 5-6Mbps.

Thanks,
Chris


#2

Hi, exactly the same here, i got the same problem when i play my flac files remotely. Is it possible to

  • cache the music
  • enable transcoding

Thanks !


#3

What is the bitrate of your file? If you have a 6 Mbps limit and your file is larger than that, well that will be a problem.


#4

Hmm, we try to cache ahead (up to 18 megabytes, IIRC). So it should read this amount ahead as fast as it can.

It’s possible the web app is transcoding. We don’t support that yet inside Plexamp.


#5

PMS said direct play for both chrome and plexamp.

File is 32MB in size, and 4m36s long. dbpoweramp says that it’s bit rate is 1,411 kbps, so under the 6Mbps.

Thought I’d try at home (so local to the NAS) and it doesn’t even play anything. Very strange.


#6

I’m experiencing the same issue when I try to play my flac music (nothing crazy, just standard 16/44). I started up an album and got massive stuttering, so I paused for a minute to let it catch up. It then played fine for about 20 seconds, then the stuttering began again. PlexAmp was downloading heavily all the while.

The file I was trying to play is about 43MB in size, but my network monitor shows almost 500MB downloaded from my home IP via PlexAmp across the whole ordeal. Downloading continued for some time after stopping playback.

My server’s just a Macbook Pro, no upload limit set. Playback is fine via the web player (with the obvious caveat of no gapless).

edit: mp3 albums appear to play flawlessly. The song is cached and plays without stuttering. When I skip to near the end of a track, I see just enough network activity to precache the next track, which then plays smoothly.


#7

I think I am experiencing the same issue, but I have noticed a few more things as well.

Stuttering takes place on any songs/albums upon start-up only. After waiting for a few minutes post-start-up, these issues stop (even on albums that would not have been cached by waiting).

If anyone else can confirm what I am experiencing, that would be helpful, as I don’t want to scream about something that is just a coincidence (although reliably repeated).


#8

Update: today, flac playback seems to be be going smoothly. It appears that playback suffered while PlexAmp was downloading its 520MB(!) of whatever after initial setup. Any hint as to what that might have been?


#9

I’ve been streaming 24/192 flac files without issue today, from my humble Synology DS116. One major difference tho: I have a 750/750 no-caps fiber at home where my DS116 sits and I was streaming to my laptop at work. I work for a hosting provider so we have several 10gbps links sharing the load.

Sounds to me like Plexamp might be a little bandwidth hungry?


#10

Yeah, we’re tracking an issue around FLAC bandwidth needs. Maybe Plexamp is just downloading the file 5-10 times to ENSURE there are no flipped bits. I kid, I kid.


#11

Glad I’m not going nuts. Nothing wrong with checking that the lossless format hasn’t lost any bits :slight_smile:


#12

+1 I experience the same problem with plenty of bandwidth available.


#13

Looks like v1.0.1 has fixed this problem, as the start of playback there’s ~20s period of traffic then it settles down. There are then the odd spike at 10s or intervals.

Then ~20-30s before the end of track it does another pull (presumably the next track)

So looks like it’s fixed. (or definitely improved)


#14

I’ve noticed the stuttering problem, but only SINCE installing v1.0.1. :frowning:


#15

Just to see if it makes a difference, find the mpd.conf file and try editing these two lines and see if it helps :slight_smile:

audio_buffer_size       "16384"
buffer_before_play      "5%"

#16

@elan said:
Just to see if it makes a difference, find the mpd.conf file and try editing these two lines and see if it helps :slight_smile:

I will give that a try, thanks!

For osx users this is the location of the mpd.conf file:
/Applications/Plexamp.app/Contents/Resources/helpers/mpd.conf


#17

I tried to tweak those mpd audio_buffer_size & buffer_before_play settings but i was unable to fully resolve the stuttering problem.

In the mpd.log i get a lot of replay_gain messages when the stuttering starts:

Jan 18 11:31:54: replay_gain: scale=0.379752
Jan 18 11:31:54: replay_gain: scale=0.379752
Jan 18 11:31:55: replay_gain: scale=0.379752

#18

@alexandergeeraerts said:
I tried to tweak those mpd audio_buffer_size & buffer_before_play settings but i was unable to fully resolve the stuttering problem.

In the mpd.log i get a lot of replay_gain messages when the stuttering starts:

Jan 18 11:31:54: replay_gain: scale=0.379752
Jan 18 11:31:54: replay_gain: scale=0.379752
Jan 18 11:31:55: replay_gain: scale=0.379752

I’m seeing exactly the same thing. And at first I thought it was only on FLAC files, but I’m seeing it on MP3s (~200 kbps) as well.

I am happy to upload any relevant logs. I love this product and want to see it succeed!


#19

Can you guys explain what you changed? (And I assume you restarted the app between tests?)

e.g. did you try something like

audio_buffer_size       "16384"
buffer_before_play      "50%"

And are you playing remote/local?


#20

I tried al sort of settings and combinations, both lower and higher than the default values.

This happens when playing remote, using the web version works perfectly on the same server. (direct play flac)
Anything else I should give a try?