Re: [Qemu-devel] [PATCH] vnc: allow fall back to RAW encoding

[Peter Lieven <pl@kamp.de>]

Am 28.08.2015 um 13:56 schrieb Gerd Hoffmann:
> On Do, 2015-08-27 at 14:46 +0200, Peter Lieven wrote:
>> I have observed that depending on the contents and the encoding it happens
>> that sending data as RAW sometimes would take less space than the encoded data.
>> This is especially the case for small updates or areas with high color images.
>> If sending RAW encoded data is beneficial allow a fall back to RAW encoding
>> for the framebuffer update.
> Do you happen to have some stats for this, especially the "small update"
> case?  We might want to go straight to raw (without trying other
> encodings) for small updates, to avoid encoding things twice.

Interesting idea. I think this magic number is different for each encoding though.
I think its possible to calculate it and then know that a update ip to a given
size cannot be smaller than encoded in raw - no matter what contents
are in that update.

Peter