From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53792)
	by lists.gnu.org with esmtp (Exim 4.71) (envelope-from <pl@kamp.de>)
	id 1ZVOKh-0007tQ-7y
	for qemu-devel@nongnu.org; Fri, 28 Aug 2015 14:25:00 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pl@kamp.de>) id 1ZVOKc-0000xv-7b
	for qemu-devel@nongnu.org; Fri, 28 Aug 2015 14:24:59 -0400
Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:47106 helo=mx01.kamp.de)
	by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from <pl@kamp.de>)
	id 1ZVOKb-0000xI-SR
	for qemu-devel@nongnu.org; Fri, 28 Aug 2015 14:24:54 -0400
Message-ID: <55E0A770.7020707@kamp.de>
Date: Fri, 28 Aug 2015 20:24:48 +0200
From: Peter Lieven <pl@kamp.de>
MIME-Version: 1.0
References: <1440679585-13984-1-git-send-email-pl@kamp.de>
	<1440762963.20725.3.camel@redhat.com>
In-Reply-To: <1440762963.20725.3.camel@redhat.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] vnc: allow fall back to RAW encoding
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: qemu-devel@nongnu.org

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