Re: [Qemu-devel] [PATCH/RFC 0/7] Screendump to UNIX socket & in PNG format

["Daniel P. Berrange" <berrange@redhat.com>]

On Mon, Mar 12, 2012 at 02:11:26PM +0100, Marc-André Lureau wrote:
> Hi,
> 
> The current screendump command can only save to disk very large PPM files.
> 
> The following patches add support for screendump in a UNIX socket,
> following the syntax used for migration URI: "unix:/path/to/socket".

To facilitate interaction with security frameworks like SELinbux and
AppArmour, it is even better for the mgmt app to just be able to pass a
pre-opened FD across the monitor, rather than using UNIX sockets.


> The last 3 patches add support for dumping in PNG format. This can
> reduce the size of the image by a great factor (x10 is not unusual),
> and is also a more convenient format than PPM. Currently, it dumps
> in PNG by checking if the path ends with ".png", we may want to
> have a seperate option for that instead, or use this syntax only
> if the path begins with "unix:" (or any foo:) for example.

We can let it guess format by default, but we should provide a way
to force the format via an optional arg.

> Next, I would like to add support for a scaling factor too (a typical
> use case is to show a small thumbnail of the desktop). Specifying
> only the requested "width" or "height" should be supported. Should
> we rely on pixman to do this work?

My suggestion would be to use Gdk-Pixbuf, since that also gives you support
for saving to arbitrary file formats, as well as scaling, etc.

Daniel
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