Editing RFB (protocol) (section)

== Encoding types ==

Multiple encodings are part of the negotiation. Some of the encodings are pseudo-encodings used to advertise the ability to handle a certain extension.{{cn|date=September 2024}} Encodings include:<ref name="rfbproto">{{cite web |title=The RFB Protocol, Community Edition |url=https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst |website=GitHub |date=12 May 2025 |language=en}}</ref>

* Raw
* Zlib
* Tight
* XZ
* [[H.264]]
* Tight PNG

Of the publicly-defined picture-based encodings, the most efficient ones are the Tight encoding types. Two types of encodings are defined by TightVNC: Tight Encoding (a mixture of rectangle, palette and gradient filling with zlib and JPEG, plus a Zlib-plus-filter "basic compression")<ref>{{cite web |title=VNC Tight Encoder - Comparison Results |url=https://www.tightvnc.com/archive/compare.html |website=www.tightvnc.com}}</ref> and Tight PNG Encoding (Tight encoding with basic compression replaced with [[Portable Network Graphics|PNG]] data).

[[H.264]] has been researched for encoding RFB data, but the preliminary results (using Open H.264 format) were described as lackluster by a [[TurboVNC]] developer. It does become more efficient with fewer I-frames (keyframes), but CPU utilization remains a problem.<ref>{{cite web |last1=Commander |first1=DR |title=A Study on the Usefulness of H.264 Encoding in a VNC Environment |url=https://turbovnc.org/About/H264 |website=turbovnc.org}}</ref>