xQx
Posts: 5
Joined: Mon Aug 20, 2012 6:13 am

DTS 5.1 on XBMC

Mon Aug 20, 2012 6:26 am

Has anybody got XBMC working for decoding a 5.1ch DTS track?

I've tried raspbmc, Xbianand OpenELEC - all have the same problem. When I play 720p or 1080p content with a 5.1 channel DTS track, it freezes every 5 - 10 seconds while it catches up.

It doesn't matter if I set xbmc to 5.1 channel or 2 channel speaker setup, it seems it can't keep up with the decode.

I can play Dolby Digital 5.1 no problems, and can play DTS 2 channel fine also.

Can anyone with a HDMI DTS decoder confirm if DTS passthrough works? I've only got a Samsung TV, which supports DD passthrough, but not DTS.

true_devil
Posts: 2
Joined: Wed Aug 22, 2012 2:17 pm

Re: DTS 5.1 on XBMC

Wed Aug 22, 2012 2:29 pm

hi, ive got a z5500 systems which supports DTS and i played a 1080p and 720p file with DTS fine...

Didn't really have to do anything. I have an issue with low sound volume but that PI issue as i dont have an USB sound card with Optical

modenet
Posts: 9
Joined: Mon Aug 20, 2012 10:47 am

Re: DTS 5.1 on XBMC

Wed Aug 22, 2012 5:59 pm

MKV or ISO?

Mister Fab
Posts: 17
Joined: Mon Aug 06, 2012 7:20 am
Location: France - Toulouse

Re: DTS 5.1 on XBMC

Tue Aug 28, 2012 4:25 pm

I had the same problem. Today I installed Xbian 0.6.3 and it seems to be solved now!! :D

aTTila
Posts: 7
Joined: Wed Jul 11, 2012 5:07 am

Re: DTS 5.1 on XBMC

Wed Aug 29, 2012 4:21 am

xQx wrote:Has anybody got XBMC working for decoding a 5.1ch DTS track?

I've tried raspbmc, Xbianand OpenELEC - all have the same problem. When I play 720p or 1080p content with a 5.1 channel DTS track, it freezes every 5 - 10 seconds while it catches up.

It doesn't matter if I set xbmc to 5.1 channel or 2 channel speaker setup, it seems it can't keep up with the decode.

I can play Dolby Digital 5.1 no problems, and can play DTS 2 channel fine also.

Can anyone with a HDMI DTS decoder confirm if DTS passthrough works? I've only got a Samsung TV, which supports DD passthrough, but not DTS.
DTS passthrough should work fine as the stream is passed as is to an av receiver to decode. Skipping videos with DTS 5.1 decoded to stereo is a widely reported issue. Currently DTS decoding is not hardware accelerated which will require a license (same as MPEG2 decoding).

User avatar
Evilbadger
Posts: 29
Joined: Mon Jun 25, 2012 7:12 am
Location: No longer Coventry

Re: DTS 5.1 on XBMC

Wed Aug 29, 2012 9:12 am

Change the System->Video->Playback->A/V sync method to be Audio Clock. This should reduce the frequency of the stutters, if not get rid of them altogether.

If you're still experiencing stuttering playback after that, then the only other option I can suggest is to overclock your RPi. I run my RPi at arm_freq=900 with no discernible issues, but overclocking is not without risks.

Lastb0isct
Posts: 23
Joined: Thu Dec 29, 2011 9:42 pm

Re: DTS 5.1 on XBMC

Wed Aug 29, 2012 11:11 pm

I'm actually playing back DTS tracks on stereo just fine with the audio clock & video clock setup in XBian...

Tompen
Posts: 20
Joined: Tue Aug 14, 2012 4:11 pm

Re: DTS 5.1 on XBMC

Sat Sep 08, 2012 10:52 pm

I do not have a DTS capable receiver. But with the following changes I can now play DTS videos OK.

XBIAN 0.6.3 and then update to 0.7b1

in config.txt, force 25fps (this is to reduce cpu usage when playing movies)
hdmi_group=1
hdmi_mode=33

I increased performance by overclocking:
NOTE: This will VOID warranty. I did some heavy overclocking, including over voltage.

over_voltage=4
arm_freq=1050
core_freq=525
sdram_freq=600

The above settings caused overtemp resets, but other than that it was stable. When using fan it was stable. To solve overheat issue without adding heatsink or fan, I underclocked the parts of GPU that does not need max performance.

h264_freq=210
isp_freq=210
v3d_freq=210

This lowered the temp, I do not need fan anymore. Now it is running hot but stable and no issues. It does not overheat and reset anymore. All my DTS tracks works ok, including 1080p.

I also made sure the XBMC common plugin cache was not installed, because that xbmc addon use some cpu cycles that I rather use to ensure smooth DTS playback.

My pi have SAMSUNG memory, I have heared that other memory in the Pi might not overclock as good. I use a cheap 700mA mobile phone charger to power the pi. I have of course added mpeg2 and vc-1 license.

Disclaimer: This works for me, but there is no guarantee whatsoever that it will work for you. Maybe your Raspberry pi will overheat, burn, break, cause a fire, melt or malfunction. I take no responsibility whatsoever. I am just sharing my experience.

Tompen
Posts: 20
Joined: Tue Aug 14, 2012 4:11 pm

Re: DTS 5.1 on XBMC

Sun Sep 09, 2012 5:13 pm

Oops, typo in the post above, cut and paste error. The stable overclocking scenario that I experiene overheat problems with, was with the following settings in config.txt. In the post above I forgot h264_freq=350 isp_freq=350 v3d_freq=350

over_voltage=4
arm_freq=1050
core_freq=525
sdram_freq=600
h264_freq=350
isp_freq=350
v3d_freq=350

Note: I do not recommend these settings because they cause too high temperature and overheating. I am only mentioning it here to correct the post I made above.

Disclaimer: This works for me, but there is no guarantee whatsoever that it will work for you. Maybe your Raspberry pi will overheat, burn, break, cause a fire, melt or malfunction. I take no responsibility whatsoever. I am just sharing my experience.

thegr8brian
Posts: 11
Joined: Mon Sep 10, 2012 5:42 pm

Re: DTS 5.1 on XBMC

Mon Sep 10, 2012 5:44 pm

Tompen, how are you able to determine failures related to heat? Does something get logged on failure?

Tompen
Posts: 20
Joined: Tue Aug 14, 2012 4:11 pm

Re: DTS 5.1 on XBMC

Tue Sep 11, 2012 8:07 pm

Well. It turns out I was wrong plain and simple. Devs just implemented a check temperature command.
To use it one needs to upgrade firmware. The command to upgrade to latest firmware is:

wget http://goo.gl/1BOfJ -O /usr/bin/rpi-update
chmod -x rpi-update
rpi-update 128

Then to check temperature, the following command:
/opt/vc/bin/vcgencmd measure_temp

I was only around 70 C. 85 C is considered bad.

So after some more digging I noticed a post from dom.
The resets was caused by a safety mechanism in the Broadcom chip due to overcurrent.
Disabled that in config.txt and no more resets :)

This is my (hope to be) final config.txt

hdmi_group=1
hdmi_mode=33
force_turbo=1
current_limit_override=0x5A000020
over_voltage=4
arm_freq=1026
core_freq=513
h264_freq=342
isp_freq=342
v3d_freq=342
sdram_freq=600
decode_MPG2=......
decode_WVC1=......

Return to “Media centres”