From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from lo.gmane.org ([80.91.229.12]:59543 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752762Ab0BPJvv (ORCPT ); Tue, 16 Feb 2010 04:51:51 -0500 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1NhK5r-0002Wz-5t for linux-media@vger.kernel.org; Tue, 16 Feb 2010 10:51:47 +0100 Received: from 80-218-69-65.dclient.hispeed.ch ([80.218.69.65]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 16 Feb 2010 10:51:47 +0100 Received: from auslands-kv by 80-218-69-65.dclient.hispeed.ch with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 16 Feb 2010 10:51:47 +0100 To: linux-media@vger.kernel.org From: Michael Subject: tw68: Congratulations :-) and possible vsync problem :-( Date: Tue, 16 Feb 2010 10:51:23 +0100 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit Sender: linux-media-owner@vger.kernel.org List-ID: Hello I have tested a TW6805 based mini-pci card with the new tw68-v2 driver from git (22 January 2010). First of all: Congratulations! It is really working great. However, I noticed some frame errors here and then. It is not easy to identify what the reason is. It looks a bit like a buffer problem as it happens more often, if there is some load on the system. Here is a simple way how I can reproduce the frame errors: mplayer -framedrop -fs -vo x11 tv:// -tv device=/dev/video0:width=640:height=480:normid=3 With this command, cpu load goes to 100% on my low powered geode system. The frame errors are very obvious. It looks like a vsync problem as the wrong frames always start somewhere in the middle. There is no horizontal shift visible. Reducing the image size: mplayer -framedrop -fs -vo x11 tv:// -tv device=/dev/video0:width=320:height=240:normid=3 gives a drop in CPU load to 13%. No more frame errors. Also using hardware accelerated video playback (xv) reduces CPU load to some 20% and removes the frame errors: mplayer -framedrop -fs -vo xv tv:// -tv device=/dev/video0:width=640:height=480:normid=3 Still, even here, occasionally there are some frame errors, depending on what happens on the system. These can be induced as follows. Using this program: mkfifo /tmp/mp mplayer -framedrop -fs -vf screenshot -vo xv tv:// -tv device=/dev/video0:normid=3 -slave -input file=/tmp/mp /dev/null When this test prog runs, you can issue commands to mplayer, e.g. echo pause > /tmp/mp This pauses mplayer. A second echo pause > /tmp/mp starts mplayer again. Here the first frame shows the error. The same happens if you issue: echo screenshot 0 > /tmp/mp This captures a screenshot and saves it into the current pwd. Again, when mplayer takes the shot, there comes one error frame (probably also wrong vsync). Btw. using instead a bttv based card all these tests run without frame errors. Does this information help to identify and remove the bug? Best regards Michael