No DirectPlay and no DTS - only 12MBit - transcoding

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1

Hy folks,

 

newbie here from Germany, running my first PI with RasPlex.

 

My setup was / is:

  • MacMini I5 8GB RAM with USB3 HDs for content, running OS X 10.9.5 and latest PMS
  • (MacMini Core2Duo 2GHz 2GB RAM with OS X 10.6.8 and latest PHT (32bit))
  • HDMI to LG TV
  • Optical to my YAMAHA AVR, supporting DTS, AC3, etc.

I replaced the C2D MacMini with an PI B+, 512MB, microSD and RasPlex 0.5.1

 

After some issues with an noname IR remote (USB) (solved) I have the following issues while Playback on the PI, connected to LAN:

never tried USB-WLAN

  • source is a Blueray rip mkv file (33GB)
  • 2 Audio tracks DTS, 2 AC3
  • PI is running at 950MHz
  • using a fine 2000mA PSU
  • PI -> TV = HDMI, TV -> AVR = optical

As from my experience with PHT on the MacMini, I chose DirectPLAY for Video, AVR is capable for AC3 and DTS and a buffer of 10%.

 

The result is a stuttering playback with 10s/1s play-pause interval.

 

As read here in the forum I tried without solution so far:

  • tick / untick AC3 and DTS
  • increase / decrease the buffer size
  • Force transcoding instead of DirectPlay

I found one setting running smooth, untick DTS and transcode to 12Mbit but when I ssh into the PI, I saw CPU utilization is 46% (so some headroom available) and, for sure, no DTS audio.

 

Are there any errors in my settings or some suggestions to get the best experience out from the PI with RasPlex in my environment?

 

Thanks a lot in advance.

2

If you don't have content that needs to be transcoded, try switching FFMPEG AVIO on, a high a bitrate file won't work without it.  Having said that, the bitrate might be too high for the Pi to handle, what is the average bitrate reported in the Plex media info?

DTS only works when you tick that passthrough box, otherwise the RPi will decode the audio and try output it via PCM, which is CPU intensive.

3

Before I switched to a Pi2 I was running a Pi B (not a +). I had no problems direct playing 1:1 BluRay Rips! As long as you purchase VC-1 and MPEG2 codecs and overclock (had mine set to 1000/500/500/6). And like KnightOrc mentioned make sure you have FFMPEG AVIO on!

4

Thanks so far.

@KnightOrc:

The rip is:

 

VideoCodec H264
Bitrate 35891 kbps
Sprache English
Bit Depth 8
CABAC 1
Chroma Subsampling 4:2:0
Color Space yuv
Spielzeit 1:40:32
Frame Rate 23.976 fps
Frame Rate Mode cfr
Has Scaling Matrix 0
Height 1080
Level 4.1
Profile high
Ref Frames 2
Scan Type progressive
Width 1920

@digiot:

I read about the codecs, but haven't purchased VC-1 and MPEG2 codecs yet, cause I haven't MPEG2 coded vids (I assumed).

But FFMPEG AVIO I'll give a try tonight.

I will report the results.

5

Your movie might have a too high a bitrate for the RPi1 to handle via its network port, interested to hear if AVIO fixes it.

6

No, not for this file.

But anything <20MBit now is running fine as DirectPlay, e.g.:

&nbsp;

VideoCodec H264
Bitrate 18960 kbps
Bit Depth 8
CABAC 1
Chroma Subsampling 4:2:0
Color Space yuv
Spielzeit 1:34:41
Frame Rate 23.976 fps
Frame Rate Mode cfr
Has Scaling Matrix 0
Height 1080
Level 5.1
Profile high
Ref Frames 2
Scan Type progressive
Width 1920

Even with DTS @ 1536kbps.

Thank you for the tip with AVIO.

7

No, not for this file.
 
But anything <20MBit now is running fine as DirectPlay, e.g.:

 

VideoCodec H264
Bitrate 18960 kbps
Bit Depth 8
CABAC 1
Chroma Subsampling 4:2:0
Color Space yuv
Spielzeit 1:34:41
Frame Rate 23.976 fps
Frame Rate Mode cfr
Has Scaling Matrix 0
Height 1080
Level 5.1
Profile high
Ref Frames 2
Scan Type progressive
Width 1920
Even with DTS @ 1536kbps.
 
Thank you for the tip with AVIO.

Yes, 20Mbit is the upper threshold set in Rasplex. Anything above that will automatically be transcoded, see the sticky on RPi https://forums.plex.tv/topic/100345-rpi-transcoding/?p=589864Transcoding