Re: VP8/VP9 suggested encoder settings for reatime video chat app

[James Zern]

On Tue, May 28, 2013 at 4:46 PM, pps <pavlov...@gmail.com> wrote:
> There is a slide presentation by WebM Project engineer Paul Wilkins (It has
> no mention on the date of the document) regarding realtime capabilities of
> VP8.
> I'm targeting video chat-like usage, we've been using h264 for many years
> and I would like to evaluate capabilities of vp8/libvpx.
>
> At this point all I need want to know: 1) what options to use for configure,
> 2) what settings to use for encoding.
>
> 1) these options that I'm not sure about:
> --enable-postproc
> --disable-spatial-resampling
> --enable-realtime-only
> --enable-onthefly-bitpacking
> --enable-error-concealment
> --enable-multi-res-encoding
> --disable-temporal-denoising
>
> Some of them are total nonsense to me (like --disable-spatial-resampling or
> --enable-onthefly-bitpackin), others seems to be simply confusing:
> --enable-realtime-only. What do these mean, which ones do I need to have on
> or off? I'm mostly targeting current mobile devices (ARM with NEON) and it's
> a video call (QCIF/CIF resolution), e.g. there has to be zero delay.
> It looks like enable-realtime-only does something very different from what
> it sounds: I thought that it will do realtime video call (no delay or
> buffering etc), but it looks like it's actually made to tune itself at
> realtime to take as much as possible CPU as long as it can be done at
> realtime.
>
>
> any advise is appreciated. Thanks
>
For a working example webrtc [1][2] might be a good place to look.
There's really only minimal realtime related information here [3].

[1] http://www.webrtc.org
[2] https://code.google.com/p/webrtc/source/browse/trunk/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
[3] http://www.webmproject.org/docs/encoder-parameters/

[Johann Koenig]

On Tue, May 28, 2013 at 4:46 PM, pps <pavlov...@gmail.com> wrote:
> 1) these options that I'm not sure about:
> --enable-postproc

Disable postproc. It's a decoding option which is not optimized for ARM.

> --disable-spatial-resampling
> --enable-realtime-only

This is a build option which removes code which is not related to
realtime encoding to give you a smaller binary.

> --enable-onthefly-bitpacking
> --enable-error-concealment
> --enable-multi-res-encoding
> --disable-temporal-denoising

I second Jame's suggestion to look at WebRTC.