[Android] [RFC PATCH 0/2] Use HW Decoders before Android 4.3 for a list of known devices

[Thomas Guillem]

On Tue, Oct 7, 2014 at 6:12 PM, Martin Storsjö <martin at martin.st> wrote:
> On Tue, 7 Oct 2014, Thomas Guillem wrote:
>
>> Hi there,
>>
>> I added a utility class that contains a list of devices that are known to
>> work
>> with MediaCodec and/or OMX before android 4.3. The list is not exhaustive,
>> and
>> it would be great if some other developers add some devices on that list.
>>
>> So, when we are in automatic decoder mode (by default), either we use
>> MediaCodec if Android version >= 4.3 or we use HWDecoderUtil to get the
>> best
>> decoder for that device (with HW_ACCELERATION_FULL flag).
>>
>> I also use that table when user force HW Decoder from the menu. So if
>> someone
>> force HW decoder on a device that is blacklisted, it won't try any HW
>> Decoders.
>> And if someone force HW Decoder on a device that is known to work only on
>> OMX,
>> it won't try MediaCodec.
>>
>> My main issue is that iomx will be more used (see the list), and I only
>> tested
>> OMX with direct rendering (I can't test anymore since I don't have these
>> devices anymore). By the way, I think that iomx-dr is more reliable than
>> iomx.
>
>
> Yes, iomx-dr is probably more reliable than normal iomx.
>
> Also, most of your test results was with a different codebase, right? So
> there might still be corner cases where iomx-dr _should_ work but doesn't
> due to some other missing cornercase.

Yes, most of the devices I listed come from an other player. I only
tested maybe 10 devices with VLC iomx-dr...

>
>
> One consequence for developers is that they need to hack this out whenever
> they want to e.g. try fixing issues in the iomx/mediacodec decoders on
> devices where it's disabled in the automatic codepaths (or want to try to
> make mediacodec work on a device that only tries to use iomx). This is not
> an objection but mostly a mental note, because I'm sure I'll forget it at
> some point...

I already had to hack it to test only mediacodec or only iomx (and now
the hack is only in one place).
Maybe I should add a settings in advanced menu to really force OMX or
MediaCodec (and don't check tables or android version).

>
>> So, I'm not sure if we should use these patches for 1.0 (that use vlc 2.2
>> branch without iomx-dr), or if we should push iomx-dr patches into 2.2. I
>> don't
>> know, it's a big change just before a release...
>
>
> Indeed, it's a big change and I haven't followed all the policies about
> cherrypicking into release branches, but without iomx-dr it's not much point
> in autoenabling iomx at all, I'd say.

Yes I agree. If we can't get iomx-dr, I'll comment out the OMX part of
my table...

>
> // Martin
>
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