ubuntu-phone team mailing list archive

[Simon Fels <simon.fels@xxxxxxxxxxxxx>]

On 12.04.2016 14:31, Marco Graziotti wrote:
> So, you think it's possible to developing the Miracast support for Meizu MX4?

It is possible for sure. The actual part we're talking about here is the
hardware encoding we're reusing from Android. Android 5.x introduced a
small layer around the actual hardware encoder we're using for a small
and simple implementation. Backporting those bits to Android 4.x is
possible but requires some work.

The most important thing about this is that the Android side source code
for the MX4 is private and not available to the public. So if someone
from the community wants to start helping out here we need to do this on
one of the devices supported by the phablet Android source tree (see [1]).

The actual bits we need is the MediaCodecSource class (see [2]). We're
using this one through libhybris and then in aethercast to encode frames
we're receiving from mir. This class is not available in Android 4.x
(yet). There are other options to work around this or work more closely
with the MediaCodec class (which we're already using for video encoding
through libhybris). But none of those was investigated yet.

If someone wants to help us, backporting the MediaCodecSource to an
Android 4.x tree is the first step. This can be done without targetting
the MX4 as we can port things easily across different Android 4.x trees
once we have a working version. You can have a look at [3] to see how
you can build the Android 4.x tree for the Nexus 4.

regards,
Simon

[1]: https://code-review.phablet.ubuntu.com/#/admin/projects/
[2]:
http://androidxref.com/5.1.1_r6/xref/frameworks/av/media/libstagefright/MediaCodecSource.cpp
[3]:
https://developer.ubuntu.com/en/start/ubuntu-for-devices/porting-new-device/