Re: [Qemu-devel] [PATCH v2 08/18] vnc: tight add PNG encoding

[Daniel P. Berrange]

On Thu, Jul 08, 2010 at 03:10:31PM +0200, Corentin Chary wrote:
> On Thu, Jul 8, 2010 at 11:48 AM, Daniel P. Berrange <address@hidden> wrote:
> > On Wed, Jul 07, 2010 at 08:57:56PM +0200, Corentin Chary wrote:
> >> Introduce a new encoding: VNC_ENCODING_TIGHT_PNG [1] (-269) with a new
> >> tight filter VNC_TIGHT_PNG (0x0A). When the client tells it supports the 
> >> Tight PNG
> >> encoding, the server will use tight, but will always send encoding pixels 
> >> using
> >> PNG instead of zlib. If the client also told it support JPEG, then the 
> >> server can
> >> send JPEG, because PNG will only be used in the cases zlib was used in 
> >> normal tight.
> >
> > I know that VNC_ENCODING_TIGHT_PNG / -260 is already allocated to
> > QEMU in the RFB specification. Who is the authority for allocating
> > tight filter numbers, and have they recorded/approved use of 0x0A
> > for this PNG capability ?
> >
> 
> Tight PNG should considered as a new encoding, not as a tight pseudo encoding.
> When using Tight PNG, the server will send rect updates with -260, not 7.

Why layer this into the rest of the Tight protocol decoding then ? What
benefit does it offer over a more straightforward standalone "PNG" encoding,
that was completely independant of any tight based encoding.

Regards,
Daniel
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