** Bug watch added: freedesktop.org Bugzilla #21522 https://bugs.freedesktop.org/show_bug.cgi?id=21522
** Also affects: xserver-xorg-video-intel via https://bugs.freedesktop.org/show_bug.cgi?id=21522 Importance: Unknown Status: Unknown ** Description changed: I'm using Ubuntu 9.04 64bits with xserver-xorg-video-intel 2.7.0 from this ppa: https://launchpad.net/~ubuntu-x-swat/+archive/x-updates/ [ lspci -nn | grep VGA ]: 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) Description of the problem: Whenever I view videos (with totem-gstreamer or mplayer), I can see red pixelation in reds. Here you can see what it looks like (taken from a thread on Doom9's forum discussing this problem on Windows : http://forum.doom9.org/showthread.php?t=141066 ) http://pwp.netcabo.pt/kado/off.png I've attached another screenshot that I made myself below. After some research, I found out this problem may be due to bad chroma upsampling. Below is an explanation I read on the Doom9's forum: "Well, since our eyes are less sensitive to chroma than to luma (i.e. we notice changes in brightness more than changes in color) video is usually compressed with the chroma (i.e. the color information) at half the resolution of the luma (brightness information) - that's part of what makes YV12 what it is. For conversion back to RGB (which is what displays, well, display) you of course need to scale the chroma data so it's the same size as the luma data, and if you get blocks it has been done by point resizing (i.e. by making every "chroma pixel" twice as big), whereas my shader turns the point resizing into bilinear resizing (i.e. I interpolate between the existing values to make the chroma smoother)." This problem occurs with SD (DVD) and HD (Bluray) progressive content. I've already filed a bug on buzilla freedesktop: http://bugs.freedesktop.org/show_bug.cgi?id=21522 + + [lspci] + + 00:00.0 Host bridge [0600]: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub [8086:2a40] (rev 07) + Subsystem: Lenovo Device [17aa:20e0] + 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) + Subsystem: Lenovo Device [17aa:2114] ** Tags added: gm45 intel jaunty videoplayback xorg -- [GM45] Bad chroma upsampling on videos https://bugs.launchpad.net/bugs/371605 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
