[mythtv-users] MythTV Raspberry Pi2 frontend testers

[Lawrence Rust]

On Sat, 2016-01-02 at 12:28 +1100, rob e wrote:
> hi Lawrence,
> another round of testing ... with alsa fix in place ie. something to set 
> appropriate flags for ac3 and dts
> 
> I've also supplied some test file grabs, based on the files i am using 
> to test (other than music)
> Note that VLC will play flac etc. on this Pi => the hardware and OS are 
> capable
> 
> The test sequence is intended to be the same in each case
> 
> 1) OpenMax Stereo, no ac3 no dts 
> (mythtv_log_afix_openmax_hdmi_stereo_noac3dts_all_60102.log )
>    mpeg2 stereo - no sound
>    mpeg2 ac3 - no sound
>    mkv dts - no sound
>    music flac - no sound
> 
> 2) OpenMax Stereo, with ac3 with dts 
> (mythtv_log_afix_openmax_hdmi_stereo_withac3dts_all_60102.log )
>    mpeg2 stereo - no sound
>    mpeg2 ac3 - good sound
>    mkv dts - sound works, video stutters badly
>    music flac - no sound
> 
> 3) OpenMax 5.1, no ac3 no dts 
> (mythtv_log_afix_openmax_hdmi_51_noac3dts_all_60102.log )
>    mpeg2 stereo - no sound
>    mpeg2 ac3 - no sound
>    mkv dts - no sound
>    music flac - no sound
> 
> 4) OpenMax 5.1, with ac3 with dts 
> (mythtv_log_afix_openmax_hdmi_51_withac3dts_all_60102.log )
>    mpeg2 stereo - no sound
>    mpeg2 ac3 - good sound
>    mkv dts - sound works, video stutters badly
>    music flac - no sound
> 
> link to test files (roughly 30sec grabs), generated via copy and "truncate"
> https://www.dropbox.com/s/xzejfdsywp91297/vid_test_fils.zip?dl=0
> 
> link to log files
> https://www.dropbox.com/s/nt4ixsmbco6xqki/mythtv_pi_test_redger_160102a.zip?dl=0
> 
> this set includes an alsa fix file (alsa_config_fix.txt) to be installed as
> /usr/share/alsa/cards/bcm2835.conf

Rob,

Many thanks for running these tests and the test clips.  However,
looking at the logs I can't see anything that indicates an OpenMAX
problem or gives any indication why you hear no sound in PCM mode.

I tried playing all 3 clips on my RPi and I hear stereo sound from my
HDMI monitor when I select the OpenMAX:hdmi output and select stereo
speakers.  The sound becomes 'choppy' if I select 5.1 or 7.1 speakers -
that would be expected.

There's nothing but static when I enable AC3 or DTS, but that's expected
as my monitor only accepts PCM and from your report that's when your
receiver plays sound, so digital pass through is working.

I'm at a loss to explain why you can't play PCM sound to your HDMI
connected receiver.  There must be a configuration issue.  Maybe you
have to tell your receiver manually when it's in PCM mode?

Is the problem to do with /boot/config.txt?  I have this:

# 1920x1080 @ 50Hz 16:9, clock:148MHz progressive
disable_overscan=1
hdmi_group=1 # CEA mode
hdmi_mode=31
hdmi_drive=2
gpu_mem=256

Apart from the MPEG license, I have no other settings in config.txt.

Thanks for the ALSA config info.  All I need to do now is convince the
family that I should move the TV sound system into the office so that I
can check digital sound with the RPi !!

-- Lawrence Rust