[Buildroot] [PATCH 2/2] libvncserver: add config option for tightpng encoding support
bos at je-eigen-domein.nl
Fri Dec 26 17:37:15 UTC 2014
On 26.12.2014 18:08, Thomas Petazzoni wrote:
> On Fri, 26 Dec 2014 01:46:15 +0100, Floris Bos wrote:
>> +if BR2_PACKAGE_LIBVNCSERVER
>> +config BR2_PACKAGE_LIBVNCSERVER_TIGHTPNG
>> + bool "TightPNG encoding support"
>> + select BR2_PACKAGE_JPEG
>> + select BR2_PACKAGE_LIBPNG
>> + help
>> + TightPNG encoding speeds up HTML5 based VNC clients like noVNC.
>> + http://wiki.qemu.org/VNC_Tight_PNG
> I've tried to read a bit, but I don't really understand whether JPEG is
> absolutely necessary to get TightPNG support. The webpage you mention
> says "If the client indicates JPEG support by sending a JPEG
> quality pseudo-encoding, then the server can send JPEG, because PNG
> will only replace the basic compression type used in normal tight.",
> which seems to indicate that the JPEG support is only optional.
JPEG and PNG are both necesarry.
Libvncserver will only compile tight.c if HAVE_LIBJPEG
And inside tight.c png is optional, jpeg is not.
>> diff --git a/package/libvncserver/libvncserver.mk
>> index b26d5b9..8479a62 100644
>> --- a/package/libvncserver/libvncserver.mk
>> +++ b/package/libvncserver/libvncserver.mk
>> @@ -56,4 +56,10 @@ else
>> LIBVNCSERVER_CONF_OPTS += --without-zlib
>> +ifeq ($(BR2_PACKAGE_LIBVNCSERVER_TIGHTPNG),y)
>> +LIBVNCSERVER_DEPENDENCIES += libpng
> So we don't really need JPEG support after all, since you don't depend
> on it?
JPEG is added by the existing code:
LIBVNCSERVER_DEPENDENCIES += jpeg
LIBVNCSERVER_CONF_OPTS += --without-jpeg
Wasn't sure whether to touch that, was afraid that would change behavior
for existing users.
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