[Qemu-devel] Re: [PATCH v2 03/10] vnc: only use a single zlib stream

[Alexander Graf]

Anthony Liguori wrote:
> On 05/18/2010 08:52 AM, Alexander Graf wrote:
>> Anthony Liguori wrote:
>>   
>>> On 05/18/2010 07:51 AM, Alexander Graf wrote:
>>>     
>>>> Corentin Chary wrote:
>>>>
>>>>       
>>>>> According to http://tigervnc.org/cgi-bin/rfbproto#zlib-encoding
>>>>> zlib encoding only uses a single stream. Current implementation
>>>>> defines
>>>>> 4 streams but only uses the first one. Remove them and only use a
>>>>> single
>>>>> stream.
>>>>>
>>>>>
>>>>>          
>>>> How about when we start to implement zrle or zhextile? Wouldn't those
>>>> need different streams?
>>>>
>>>>        
>>> Only tight uses multiple streams.  zrle just uses one.
>>>      
>> Ah, that's why I put it in there back then. I see :).
>>    
>
> Keep in mind, tight's 4 streams are not the same as zrle or zlib's 1
> stream.  A server is free to send both Tight updates and zrle updates
> if the client supports it.  The client is going to expect that zrle is
> a different compression stream than any of the 4 tight streams.
>
> That's why you can't use the Tight compression level selection
> messages to choose the zlib compression level btw.

So patch 4 is invalid?

Alex