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

[Corentin Chary <corentin.chary@gmail.com>]

On Thu, Jul 8, 2010 at 11:48 AM, Daniel P. Berrange <berrange@redhat.com> 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.

We discussed that issue on #qemu-gsoc, and Anthony told me htat:
"if it gets sent with a different encoding, then you don't need
anyone's approval, you just need an encoding number
but if it's a pseudo-encoding that modifies an existing encoding, then
the author of the existing encoding must be on board"

Thanks,
-- 
Corentin Chary
http://xf.iksaif.net