debcrafters-packages team mailing list archive

[Antoine Lassagne <2127792@xxxxxxxxxxxxxxxxxx>]

** Description changed:

  There is image distorsion in gnome-remote-desktop when a Blackwell GPU
  is in use and NVENC is responsible for the video streaming.
  
- A fix was just released by nvidia upstream:
+ Upstream issue: https://gitlab.gnome.org/GNOME/gnome-remote-
+ desktop/-/issues/263
+ 
+ A fix was just released by nvidia upstream, and also backported to GNOME 48: https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/344
  https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/346
+ 
+ ---------------------------
+ SRU Justification:
+ 
+ [ Impact ]
+ 
+  * This is a hardware enablement SRU.
+ 
+  * gnome-remote-desktop, when used alongside NVENC for video streaming,
+ simply does not work, because the image is broken.
+ 
+  * With the above, the streaming is fixed.
+ 
+ [ Fix ]
+ 
+  * Nvidia devices never supported `NV_ENC_PARAMS_FRAME_FIELD_MODE_MBAFF`.
+ Though the code worked for past, it causes interlaced line artifacts on
+ Blackwell GPUs.
+ 
+ * Using `NV_ENC_PARAMS_FRAME_FIELD_MODE_FRAME` and changing
+ `grd-cuda-avc-utils` to produce progressive frames works on
+ Blackwell and on older GPU generations.
+ 
+ [ Test Plan ]
+ 
+  * Test gnome-remote-desktop with and without the fix. Make sure which
+ backend is in use. This can be checked by running `nvidia-smi dmon` and
+ observing an encoder activity >0%. The repro only occurs when the NVENC
+ path is used. CPU encoding path or non-H264 streaming is unaffected
+ 
+ * Run the same test on an older GPU generation (Maxwell, ideally)
+ 
+ 
+ [ Where problems could occur ]
+ 
+  * Given the nature of the fix, it should not impact non-nvidia machines.
+  * Also, the  fix comes from nvidia themsleves, and it's in GNOME 48 and 49 already, so it's pretty safe.

-- 
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https://bugs.launchpad.net/bugs/2127792

Title:
  Images are corrupted on blackwell GPUs

Status in gnome-remote-desktop package in Ubuntu:
  New
Status in gnome-remote-desktop source package in Noble:
  New
Status in gnome-remote-desktop source package in Questing:
  New
Status in gnome-remote-desktop source package in Resolute:
  New

Bug description:
  There is image distorsion in gnome-remote-desktop when a Blackwell GPU
  is in use and NVENC is responsible for the video streaming.

  Upstream issue: https://gitlab.gnome.org/GNOME/gnome-remote-
  desktop/-/issues/263

  A fix was just released by nvidia upstream, and also backported to GNOME 48: https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/344
  https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/346

  ---------------------------
  SRU Justification:

  [ Impact ]

   * This is a hardware enablement SRU.

   * gnome-remote-desktop, when used alongside NVENC for video
  streaming, simply does not work, because the image is broken.

   * With the above, the streaming is fixed.

  [ Fix ]

   * Nvidia devices never supported `NV_ENC_PARAMS_FRAME_FIELD_MODE_MBAFF`.
  Though the code worked for past, it causes interlaced line artifacts on
  Blackwell GPUs.

  * Using `NV_ENC_PARAMS_FRAME_FIELD_MODE_FRAME` and changing
  `grd-cuda-avc-utils` to produce progressive frames works on
  Blackwell and on older GPU generations.

  [ Test Plan ]

   * Test gnome-remote-desktop with and without the fix. Make sure which
  backend is in use. This can be checked by running `nvidia-smi dmon`
  and observing an encoder activity >0%. The repro only occurs when the
  NVENC path is used. CPU encoding path or non-H264 streaming is
  unaffected

  * Run the same test on an older GPU generation (Maxwell, ideally)

  
  [ Where problems could occur ]

   * Given the nature of the fix, it should not impact non-nvidia machines.
   * Also, the  fix comes from nvidia themsleves, and it's in GNOME 48 and 49 already, so it's pretty safe.

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