[mythtv-users] Shield TV OpenSLES vs. AudioTrack?

[Jim Abernathy]

On 12/20/19 9:41 AM, Yeechang Lee wrote:
> Jim Abernathy says:
>> On the Android Mythtv wiki it suggests for the Shield TV that you should
>> use AudioTrack in the audio options instead of OpenSLES.
>>
>> However, when I switch from OpenSLES to AudioTrack I get audio that
>> breaks up and goes mute. OpenSLES seems to work fine.  I'm on
>> mythtv-frontend for android v31-pre 539 with a backend that is V30.
> Also on 539 on Shield, with a 29 backend.
>
> It's the video decoder, not audio per se, that's the problem. I also
> followed the Wiki Shield settings, and found that AudioTrack audio
> didn't work when using timestretch with h.264 (such as what Comcast
> uses on some channels). In other words, what MediaCodec handles based
> on the Wiki settings; Standard decoder did not have this
> problem. MediaCodec also does not handle captions in h.264.1
>
> I use the following entries in the "Shield" playback profile:
>
> * First: Width Range >1920, Video Formats blank, Decoder Android
>    MediaCodec decoder, Max CPUs 4, Video renderer opengl, Primary
>    deinterlacer Linear blend (2x, HW-GL), Fallback deinterlacer Linear
>    blend (HW-GL)
>
> * Second: Video Formats hevc, Decoder Android MediaCodec decoder, Max
>    CPUs 4, Video renderer opengl, Primary deinterlacer Linear blend
>    (2x, HW-GL), Fallback deinterlacer Linear blend (HW-GL)
>
> * Third: Decoder Standard, Max CPUs 4, Video renderer opengl, Primary
>    deinterlacer Linear blend (2x, HW-GL), Fallback deinterlacer Linear
>    blend (HW-GL)
>
> The idea is to have MediaCodec (Which I presume is Android's
> equivalent to VDPAU/VAAPI/VDA[1]?) handle HEVC format and any format
> above 1920 pixels in width, and have Standard decoder handle
> everything else even if h.264/MPEG4. I got the idea from my Mac;
> MythFrontend on a unibody 2012 Macbook Pro can play a 720p h.264 file
> with the Standard decoder with just one CPU. VDA decoder is not
> necessary and, as of 29, still has some bugs that Standard doesn't.
>
>> My Shield TV is connected to my Samsung UHD 4K via HDMI and the TV
>> sends the audio via optical cable to my AV Receiver. It's a 5.1
>> speaker system and Samsung says they send out the audio from TV to AV
>> Receiver in DTS format.
> My receiver is not connected at the moment, so I'm using my TV's
> speakers with Shield. The TV is supposed to decode DTS, but I have two
> test clips that would not play their DTS tracks—complete with a
> MythFrontend notification stating that audio is diabled— until I
> disabled DTS from Audio | Digital Audio Capabilities. (They're HEVC,
> but I don't think that has anything to do with the audio issue; the
> same thing happens whether I use Standard or MediaCodec decoder.)
>
> [1] Or XVideo for the real old-timers
>
My signal is OTA Mpeg2 so these settings didn't work for me. The audio 
broke up more and lipsync was a big issue and the video was more messed up.

Looks like I'm on OpenSLES for a while, which is not all bad.