Xpra: Ticket #1713: black and white mode
We already have "png/L" support, but we could add a global black-and-white mode to try to save bandwidth:
- jpeg supports
TJPF_GRAY
- all the video encoders would need a csc step
- webp would need csc too
I'm not sure this will save enough bandwidth: the self-tuning video encode heuristics normally switch to YUV420P for video, and that already reduces the space taken by the colours to 33% or less of the bitstream.
For non-video, it may allow us to use a lossless encoding more often than we would otherwise.
Wed, 27 Dec 2017 19:26:55 GMT - Antoine Martin: milestone changed
- milestone
changed from 2.3 to future
I don't see the point:
- many things don't degrade well
- none of the video encoders take grayscale as input
- the cost of chroma is a small overhead (just a 33% with YUV420P - worst case scenario - often less if the video encoder interpolates chroma and luma)
- the cost of a single lossless refresh dwarfs any savings we might have made at that point - best to make efficient use of the encodings we have than to invent new ones
Sun, 23 Sep 2018 06:50:34 GMT - Antoine Martin: status, milestone changed
- status
changed from new to assigned
- milestone
changed from future to 2.5
Let's give it a go: libyuv does have a ARGBGrayTo
function we can use for video and webp codecs.
Thu, 22 Nov 2018 08:55:16 GMT - Antoine Martin: milestone changed
- milestone
changed from 2.5 to 3.1
All the encoding related tickets are scheduled for 3.1
Wed, 20 Mar 2019 05:06:15 GMT - Antoine Martin: milestone changed
- milestone
changed from 3.1 to 4.0
Milestone renamed
Sat, 21 Sep 2019 12:28:45 GMT - Antoine Martin: milestone changed
- milestone
changed from 4.0 to 4.1
Thu, 11 Jun 2020 15:37:26 GMT - Antoine Martin: status changed; resolution set
- status
changed from assigned to closed
- resolution
set to fixed
Updates:
(also works from the tray menu)
- r26699 supports grayscale mode for 'jpeg' and 'webp' via pillow
- r26700 supports grayscale with video modes (via
ARGBGrayTo
)
Fri, 14 Aug 2020 10:18:39 GMT - Antoine Martin:
Fixups in r27138.
Sat, 23 Jan 2021 05:31:47 GMT - migration script:
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1713