[vlc-devel] [PATCH 2/5] mediacodec: add hevc mimetype

Martin Storsjö martin at martin.st
Wed Oct 8 18:49:45 CEST 2014

On Wed, 8 Oct 2014, John Stebbins wrote:

> On 10/08/2014 08:51 AM, Martin Storsjö wrote:
>> On Wed, 8 Oct 2014, Martin Storsjö wrote:
>>> On Mon, 6 Oct 2014, John Stebbins wrote:
>>>> So, it doesn't work on rk3288 out of the box.  And even after some ugly
>>>> hacks, I'm getting video with green lines
>>>> through it and the image repeated 5 times and squished horizontally.  Not
>>>> sure what that's all about.
>>>> Attaching diff to show ugly hacks and logs just in case you have some ideas
>>>> what the distorted video might be.
>>>> To summarize the hacks, I had to remove the USE_IOMX define because my box
>>>> does not have libiomx.so.  Then, my box does have libOMX_Core.so. but all
>>>> the symbols are prefixed with "RK".  So I had to modify the dlsym calls.
>>>> The rest is just debug messages so I can see what's happening.
>>> Wow, did using OMX straight off work on this one? Or are you running VLC as
>>> root? (Normally the OMX driver requires access to /dev entries that only the
>>> mediaserver can access.) Yesterday you said you enabled building libiomx-kk
>>> (which would be the right way to solve this), did it work better or worse
>>> with that compared with using OMX directly?
>> ... and now I realize this mail was a blast from the past, that you
>> actually originally sent on Monday. So nevermind...
> Yeah, I think your questions were answered in subsequent emails.  But if not, I can provide more information. Just ask.
> The summary right now is that none of my experiments have fully succeeded yet to get accelerated playback of hevc with
> vlc on the Measy B4S.  The closest to success was using the system libOMX_Core.so.  It actually did accelerated
> playback,

I would guess it would work the same if you'd do IOMX decoding but don't 
try the direct rendering stuff, which in your case seems to break the 
setup (while it ideally would fallback to non-dr).

> but the image was badly distorted, as if it were getting copied to a 
surface with the wrong horizontal resolution.

Hmm, ok. If the video is a resolution that needs cropping you might try 
adding your decoder's name in IgnoreOmxDecoderPadding in omxil/utils.c. Or 
you can try manually setting the stride to something else (see 
omxil/omxil.c, look for the IgnoreOmxDecoderPadding function call), 
tweaking it until you get something that looks right.

// Martin

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