MediaCodec seems better to use for webrtc.
API and internal implementation is asynchronous.
Down side of MediaCodec is that the class is present only from JellyBeans.
Internally used actual codec class "ACodec" presents since ICS.

OMXCodec is present since stagefright is added to android(foryo).
Almost classes present since beginning of stagefright have one common problem.
APIs of reading data is synchronous.
OMXCodec's api is also synchronous.
Data read by OMXCodec is synchronous.
Reading decoded frame by OMXCodec's client is also synchronous.
Therefore if data do not arrived to OMXCodec,
almost all tasks in OMXCodec freezes and finally emit timeout error.

In B2G, OMXCodec is used for video playback, it was only actual choice at that 
time.
But OMXCode provide the above problem during http video streaming.
For b2g, I am thinking to change the codec for playback from OMXCodec to 
MediaCodec or ACodec(Bug 904177).


sotaro

----- Original Message -----
From: "Eric Rescorla" <[email protected]>
To: "CJ Ku" <[email protected]>
Cc: [email protected]
Sent: Friday, August 30, 2013 9:25:23 AM
Subject: Re: about omxcodec for webrtc

Just to clarify this a bit:

We're currently attempting to get a handle on the potential performance
of HW video codecs in WebRTC via OMX. Since the current phones we
have are H.264, that means prototyping H.264 via OMX but we expect
the results to be fairly extensible to any HW codec, including VP8, VP9,
etc.

-Ekr




On Fri, Aug 30, 2013 at 12:24 AM, <[email protected]> wrote:

> Hi Tony,
> To switch from VP8 to H.264, we need to change not only coding module but
> also some other components in webrtc, such as RTP component.
>
> We need to have a H.264 codec support on B2G to compare the power
> consumption and rendering performance difference between SW codec and HW
> codec.
>
> Currently, we still have some fatal bug need to fix before a workable
> version given.
>
> I create a bug for this task. I think you may follow up this bug
> Bug 911046 - WebRTC OmxCodec coding path support
> _______________________________________________
> dev-media mailing list
> [email protected]
> https://lists.mozilla.org/listinfo/dev-media
>
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