[mythtv-users] HDMI audio issues on Intel NUC

[Stuart Auchterlonie]

On 08/07/15 08:24, Matt W wrote:
> Hi -- I'm running a frontend on an Intel NUC D34010WYK. The backend is
> another box, running the same version of Debian and MythTV, connected
> over gigabit wired network.  I am using the current release version:
> 
> mythtv at myth-nuc:~/frontend.logs$ mythfrontend --version
> 
> Please attach all output as a file in bug reports.
> MythTV Version : e4f65c8
> MythTV Branch : tag: v0.27.4
> Network Protocol : 77
> Library API : 0.27.20140719-1
> QT Version : 4.8.6
> 
> Options compiled in:
>  linux profile use_hidesyms using_alsa using_oss using_backend
> using_bindings_php using_dvb using_frontend using_hdhomerun
> using_ceton using_hdpvr using_ivtv using_joystick_menu using_libxml2
> using_lirc using_mheg using_opengl using_opengl_video using_qtwebkit
> using_qtscript using_qtdbus using_taglib using_v4l2 using_x11
> using_xrandr using_profiletype using_mythlogserver using_bindings_php
> using_mythtranscode using_opengl using_vaapi using_ffmpeg_threads
> using_mheg using_libxml2
> 
> OS is Debian Jessie/8:  3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1
> 
> using the VAAPI normal profile (needed SNA acceleration set), the
> video looks good and does 1080 content well.
> 
> Audio is another matter. It will work for some content but gets
> intermittent on LiveTV playback and some recorded shows. I get "ALSA:
> WriteAudio: buffer underrun" and plenty of "ALSA: Try to manually
> increase audio buffer with: echo 576 | sudo tee
> /proc/asound/card0/pcm3p/sub0/prealloc" (no matter what number I push
> into the prealloc).
> 
> Upmixing is turned off, but sometimes it seems to help in playback
> when changed manually in the playback 'auto detect' button.  But then
> not long after, the audio will go out and the log will show buffer
> underruns.
> 
> Can someone recommend some troubleshooting methods here?  My usual net
> search skills have yielded nothing concrete. Any help is appreciated!
> thanks
> -Matt

Is it all your recordings or only specific content types?

If a specific content type what is the output from

$ mythffprobe <recording_file>

substitute <recording_file> with a filename of a recording


Regards
Stuart