Connecting to linux RDP - Client does not support H.264 in YUV420 mode
Connecting to linux RDP - Client does not support H.264 in YUV420 mode
I have KDE (6.3.4) remote desktop set up. I can connect to the Linux machine using RDP if I use the official Microsoft remote desktop client.
If I try to connect using RDM (2025.1.13.3), I see these errors on the host. below. I tried changing a bunch of options for experience and display and stuff in advanced like codec level and rendering engine. It seems like none of the options make any difference because the log output is always the same. Am I missing anything? I'll also attach the RDM log.
Apr 17 10:19:53 datacenter-xps xdg-desktop-portal-kde[2304]: xdp-kde-remotedesktop: MegaAuth: Failed to lookup permissions: "No entry for remote-desktop"
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:951] [2397:6318] [WARN][com.winpr.negotiate] - AcceptSecurityContext status SEC_I_CONTINUE_NEEDED [0x00090312]
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:952] [2397:6318] [WARN][com.winpr.negotiate] - AcceptSecurityContext status SEC_I_COMPLETE_NEEDED [0x00090313]
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: org.kde.krdp: New client connected: Unspecified platform Unspecified version
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: org.kde.krdp: Client does not support H.264 in YUV420 mode!
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:992] [2397:6330] [ERROR][com.freerdp.core] - rdp_set_error_info:freerdp_set_last_error_ex ERRINFO_GRAPHICS_SUBSYSTEM_FAILED [0x0001112F]
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:993] [2397:6330] [ERROR][com.freerdp.channels.rdpgfx.server] - context->CapsAdvertise failed with error 20
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:993] [2397:6330] [ERROR][com.freerdp.channels.rdpgfx.server] - rdpgfx_recv_caps_advertise_pdu failed with error 20!
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:993] [2397:6330] [ERROR][com.freerdp.channels.rdpgfx.server] - Error while parsing GFX cmdId: RDPGFX_CMDID_CAPSADVERTISE (0x0012)
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:993] [2397:6330] [ERROR][com.freerdp.channels.rdpgfx.server] - rdpgfx_server_receive_pdu failed with error 20!
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:993] [2397:6330] [ERROR][com.freerdp.channels.rdpgfx.server] - rdpgfx_server_handle_messages failed with error 20
Apr 17 10:19:53 datacenter-xps krdpserver[2397]: [10:19:53:994] [2397:6318] [ERROR][com.freerdp.core.transport] - BIO_read returned a system error 0: Success
All Comments (25)
Hello
I'm not sure that we build FreeRDP with H264 support on macOS, I'd need to look into that.
Can you try changing the codec level to "7" in the "Advanced" tab of the RDP session in RDM? Let me know if it helps. If it doesn't help, try "6" as well.
Thanks and kind regards,
Richard Markievicz
I tried all the codec levels, none of them made a difference.
Hello
You might try setting a lower colour depth, but having looked at the readme for krdpserver it looks like it only works with clients that are H264 capable.
I'll open a ticket to add that on our side; I'm not sure how tricky it is but I'll post back with an update once I've some more information.
Sorry for the inconvenience.
Kind regards,
Richard Markievicz
Unfortunately, the color settings didn't matter either. If you can add this option to the program that would be awesome. In the mean time I can use the Microsoft client.
Hello
Thanks for the follow up.
I've done some local testing here and with H264 support, the performance improvement in our RDP client is quite pronounced. As you note, enabling that feature should also allow you to connect to krdp servers where that isn't currently possible.
I've got a ticket open to properly integrate this and I'll come back to this thread when there's some progress. From my initial tests it doe not seem that difficult.
Thanks for your patience
Kind regards,
Richard Markievicz
Hello
I wanted to update you that I didn't forget about this issue. We have made some progress. Our FreeRDP builds now support H264, which I've tested and it works well, but there is integration work to be done.
We'll depend on OpenH264 for this; and Cisco has stringent license requirements that must be met on our side to meeting the licensing obligation with MPEG-LA. I've opened a ticket with the RDM Mac team specifying exactly what needs to be done to integrate this cleanly. I can't provide a timeline for that but the changes are relatively easy so I hope it can be done soon.
In the meantime, thanks for your patience and please don't hesitate with further questions or comments
Kind regards,
Richard Markievicz
No problem, I have a workaround for now. Thanks for keeping at it.
Hello,
The latest version of RDM Mac (2025.2.11.0) should now support H264.
If you need anything else, don't hesitate to communicate with us.
Best regards,
Michel Lambert