How to get AC3 passthrough on Freescale IMX6 Yocto image ?

[Arun Raghavan]

On 17 November 2014 13:39, Subodh Chiwate <subodh.chiwate at ufomoviez.com> wrote:
> Hi,
> I am using a SABRE-SD IMX6 Quad board.
> I have built the image using instructions from freescale git for
> 3.10.31+. (Not using X11, instead trying with directfb ).
>
> I have working gstreamer 0.10 and 1.0 on board and can decode audio and
> playback on HDMI
> using the following settings for ALSA.
> https://community.freescale.com/docs/DOC-93745

That seems to be a dmix-based setup, so will probably be broken (or at
least suboptimal) if you try to run PulseAudio with that config.

> But I need to pass the audio directly to HDMI for decoding.
> Is pulseaudio a must for getting passthrough to work ?
>
> Please let me know in case more information from my setup is needed.

You should be able to play out to the device if it is properly
encapsulated in IEC61937 frames (which it will be if you try to play
AC3/DTS/... through alsasink). Some ALSA devices need to be opened
with appropriate parameters to ensure bistreaming works, so you'll
need to see if that's needed on yours (on PCs, this is something like
the last section of
http://www.mythtv.org/wiki/Configuring_Digital_Sound).

-- Arun