From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 79223] New: extra vsync when reading back pixels in xbmc Date: Sun, 25 May 2014 19:10:07 +0000 Message-ID: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0188318348==" Return-path: Received: from culpepper.freedesktop.org (unknown [131.252.210.165]) by gabe.freedesktop.org (Postfix) with ESMTP id 4605A6E1A6 for ; Sun, 25 May 2014 12:10:07 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org --===============0188318348== Content-Type: multipart/alternative; boundary="1401045007.22Ff0.15546"; charset="us-ascii" --1401045007.22Ff0.15546 Date: Sun, 25 May 2014 19:10:07 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" https://bugs.freedesktop.org/show_bug.cgi?id=79223 Priority: medium Bug ID: 79223 Assignee: dri-devel@lists.freedesktop.org Summary: extra vsync when reading back pixels in xbmc Severity: normal Classification: Unclassified OS: All Reporter: pierre-bugzilla@ossman.eu Hardware: Other Status: NEW Version: unspecified Component: DRM/Radeon Product: DRI Something is causing an extra wait for vsync in xbmc when it needs to read back pixels. This seems to be specific to the radeon driver as I'm not seeing it with nouveau. Test scenario: - Configure xbmc to wait for vsync - Install something that activates xbmc's capture code (e.g. xbmc's boblight plugin) - Play a video whose framerate > screen refresh / 2 You'll see the frame rate reliably locked to screen refresh / 2 under these circumstances. A major problem as you generally want to run with a 24 Hz refresh rate for 24 Hz films. I'm unable to pinpoint exactly the offending GL command as xbmc's rendering is quite complex. I hope you're more experienced in finding these things. :) The rough sequence of events is: 1. xbmc renders the scene 2. Wait for vsync 3. Map PBO and memcpy data. (from previous frame) 4. Render small version of scene 5. glReadPixels into PBO -- You are receiving this mail because: You are the assignee for the bug. --1401045007.22Ff0.15546 Date: Sun, 25 May 2014 19:10:07 +0000 MIME-Version: 1.0 Content-Type: text/html; charset="UTF-8"
Priority medium
Bug ID 79223
Assignee dri-devel@lists.freedesktop.org
Summary extra vsync when reading back pixels in xbmc
Severity normal
Classification Unclassified
OS All
Reporter pierre-bugzilla@ossman.eu
Hardware Other
Status NEW
Version unspecified
Component DRM/Radeon
Product DRI 

Something is causing an extra wait for vsync in xbmc when it needs to read back
pixels. This seems to be specific to the radeon driver as I'm not seeing it
with nouveau.

Test scenario:

 - Configure xbmc to wait for vsync

 - Install something that activates xbmc's capture code (e.g. xbmc's boblight
plugin)

 - Play a video whose framerate > screen refresh / 2

You'll see the frame rate reliably locked to screen refresh / 2 under these
circumstances. A major problem as you generally want to run with a 24 Hz
refresh rate for 24 Hz films.


I'm unable to pinpoint exactly the offending GL command as xbmc's rendering is
quite complex. I hope you're more experienced in finding these things. :)

The rough sequence of events is:

1. xbmc renders the scene
2. Wait for vsync
3. Map PBO and memcpy data. (from previous frame)
4. Render small version of scene
5. glReadPixels into PBO

You are receiving this mail because:
  • You are the assignee for the bug.
--1401045007.22Ff0.15546-- --===============0188318348== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel --===============0188318348==--