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• Optimizing x264 based remote desktop by dirty regions

  17 novembre 2016, par useprxf

  I was using x264 to achieve remote desktop, but had some problems on handling P_SKIP detection.

  Dirty regions indicate changed areas. For those 16x16 macroblocks which don’t intersect any dirty region, I would like to encode them as P_SKIP macroblocks.

  I tried to add the following code into x264_macroblock_prob_skip_internal function :

  if (! h->isdirty[h->mb.i_mb_x][h->mb.i_mb_y])       // isdirty is a 2-dim array indicating dirty macroblocks
  
      return 1;

  but there is almost no speed-up. I think it may be the information preparation for the macroblock analysis that take influence.

  How to speed up x264 by considering dirty regions ?

• Is there any open source solution to display a remote stream inside a Hololens2 UWP Vuforia application ?

  19 avril 2023, par T777

  What do we need ?

  


  We are trying to develop an application for quality management in which we show an hologram on a metal part as an assitance marking. (using Hololen2 + Vuforia + ModleTargets) The employee uses an sensor to follow this assitance marking and the data will be analyzed live by a test device. The results are outputed on a screen / are visible at an closed source application of the manufacturer of the test device.

  


  Capturing of the video output :
The current plan is to capture the video stream of the test device via capture card. Add a via mrtk2 videopanel inside the vuforia app and stream the captured video to the Hololens2 using obs or an OpenCV python script for screen recording.

  


  What we have tried so far

  


  1) Sending Raw udp stream
via RMTP and decoding + converting with gstreamer server and writing an own library in Unity for Receiving
Result : Temporary stopped, because receiving the udp streams needs connection/ session management (signalling) frame syncing and agreement on video size, color format, frame rate etc.. and we have no solution.
An own implementation of any of this would have high complexity is consuming a lot of time.

  


  2) Using available protocols that i can find on the web
Actually there are some protocols already developed for session creation and streaming :

  


  

  • HTTP streaming (HLS) (Transport + Session)

  


  • RTMP (Transport + Session),

  


  • RTP (Transport) + RTPS (Session),

  


  • WebRTC : Is possible with different protocol stacks
RTMP/TCP/UDP (Transport) + SDP (standardized format for video paramaters) + ICE (p2p)/ WHIP (http, client-server) / Websocket(client-server) (signaling protocols) that can be used and some good open source streaming servers (gstreamer, mediamtx and srs)

  


  


  When using these the video will be encoded typcially with xh264 and need to be decoded on the HoloLens 2. There are APIs to C/C++ native (hardware) decoding libraries like unity-vlc and ffmpeg.NET that needing media library ffmpeg. I could figure out (not tested) that there is an hardware h264 decoder on the HoloLens2 but I have no clue how to access it. Since there I couldnt disvocer any information about HoloLens2 media libraries.

  


  3) Using Unity packages

  


  


  • Unit package WebRTC (https://docs.unity3d.com/Packages/com.unity.webrtc@2.4/manual/index.html) supports multiple transport protocols seem to have no signaling mechanism and

    


  


  • Unity package Render streaming (https://docs.unity3d.com/Packages/com.unity.renderstreaming@3.1/manual/index.html) is a fully integrated unity to unity and unit to browser streaming package with integrated stream Server with web GUI. It offers various streaming protocols (TCP, UDP,rmtp) and signaling mechanism over websocket, http (seems custom and not whip) or Furiouus.
BUT it doesnt support UWP as noted into the documentation. Implementing an example application we could demonstrate an working example with Vuforia, but it fails on build with target UWP on missing libraries.
Similar to : https://www.youtube.com/watch?v=nHRC0uGBnn8

    


  


  


  Will be testing other compile options tomorrow..

  


  

  • Mixed Reality WebRTC (https://github.com/microsoft/MixedReality-WebRTC) :
Various protocol support, Microsoft brought Webrtc specifically to HoloLens.
Deprecated, as fas as I can see just support for Hololens1 and ARM32. So i can not evaluate if trying it with this is worth it.

  


  


  What are the next options ?

  


  

  • Developing a raw udp streaming library with untiy directly.

  


  • Rebuilding the application with visionlib (ARM32) compatible and MixedRealityWebRTC (ARM32)

  


  • Porting ffmpeg + API to UWP ?

  


  • Also there seem some affords to make WebRTC in general available to UWP platforms : https://github.com/microsoft/winrtc

  


  


  The questions

  


  

  • Does Vuforia support ARM32 ?

  


  • How to access hardware decoder of Hololens2 via Unity Code ?

  


  


• fate : Add a target for listing failed tests

  7 novembre 2024, par Martin Storsjö

  fate : Add a target for listing failed tests
  If running tests with "make -j<N> fate", the execution will stop
  
  after the first failing test. To get an overview of the whole
  
  test suite, one rather would run "make -k -j<N> fate", which then
  
  again buries the results about what tests actually failed further
  
  up in the console log.
  Add a target so one can run "make fate-list-failing", to see a list
  
  of all tests that failed the last time they were executed.
  Also add a companion target "fate-clear-reports" which removes all
  
  the old test reports. (When executing a subset of tests, the report
  
  files of all tests that aren't executed stay untouched. This also
  
  allows getting rid of reports for tests that no longer are present
  
  in the testsuite.)
  Co-authored-by : Alexander Strasser <eclipse7@gmx.net>
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] doc/build_system.txt
  • [DH] doc/fate.texi
  • [DH] tests/Makefile