[Spice-devel] [PATCH v5 00/20] Add GStreamer support for video streams

[Frediano Ziglio]

> 
> On Mon, 31 Aug 2015, Fabio Fantoni wrote:
> [...]
> > Is possible add to optionally enable streaming on client request instead
> > enable/disable on start only spice-server side?
> 
> Spice already supports streaming video using its built-in MJPEG encoder.
> That streaming can be disabled/configured using the server-side
> StreamingVideo setting.
> 
> This patch series simply makes it possible to widden the supported video
> codecs through the use of GStreamer. As such it is completely
> independent from the mechanism used to decide whether to stream video or
> not. Thus any change to the latter policy should be made as a separate
> patch.
> 
> 
> > Also codec selection based on client parameter I think can be good
> > instead  check only if is supported.
> 
> My take on this is that it's the server which will perform the video
> encoding and the codec that's used will have a big impact on server CPU
> and on bandwidth use (maybe to a lesser extent). So the server
> administrator should have the last say on which codec is best suited to
> his server's server CPU/bandwidth capacity.
> 
> That take is probably less relevant outside the context of a virtual
> desktop server but in those cases the user running the client probably
> also controls the machine running the Spice server so he can still pick
> which codec to use.
> 
> 

One thing that scare me with this set of patches are the variability of some
codecs. For current formats there is just a capabilities exchange like "I
support this format", "ok, I'll use it". But what would happen if h264 is
enabled and the server start encoding with parameters which the client
cannot support? Think about a thin client wanting to connect. Thin client
is expecting baseline profiles but then server try to push high profile
streams and the client cannot handle it although can handle h264?

Frediano