[theora] Theora blurriness in Windows players

Torrance torrance123 at gmail.com
Sun Feb 7 12:32:02 PST 2010

I'm surprised Chrome on Windows is fine for you.

I've recently been playing with making a custom video UI. In Chrome on a
Mac, if I enlarge a video to fit the browser window ("pseudo
fullscreen") the block boundaries of the video image are very
distinctive, giving it a highly pixelated feeling. I'm not sure what
both Firefox or Safari (with xiphqt backend) are doing, but they're
softening the block borders significantly, making the image appear of
reasonable quality even at twice its native resolution.


p.s. Does anyone know of a website or mailing list of documenting people
writing custom html5 video interfaces? The mixture of browsers not
following the specs precisely and the difficulty of regularly having to
handle poorly formed video files (including files outputted by
ffmpeg2theora) is making it a rather difficult endeavour.

On 8/02/10 6:43 AM, Dave Johnson wrote:
> It appears that safari has some blurriness too. I encoded high
> qualiety theora video using xiphqt.
> The video is at tsg.davefilms.us <http://tsg.davefilms.us>
> Dave Johnson
> 6195496830
> http://www.davefilms.us
>> On Feb 6, 2010 10:56 PM, "Basil Mohamed Gohar"
>> <abu_hurayrah at hidayahonline.org
>> <mailto:abu_hurayrah at hidayahonline.org>> wrote:
>> I just finished using my mother's PC which is running Windows XP.  I
>> downloaded & installed, or already had installed, the latest versions of
>> VLC Media Player (1.0.5), Media Player Classic - Home Theater (last
>> release was in August 2009), Miro (already installed), Mozilla Firefox
>> (3.6), Google Chrome (latest from website today), Opera (10.50 Alpha,
>> latest build from the website), and SMplayer (the recommended GUI for
>> Mplayer on Windows, apparently, again, latest from website today).
>> ALL of the players, with the exception of Mozilla Firefox (3.6) & Google
>> Chrome displayed significant blurriness.  In fact, the sharpest render
>> came from Mozilla Firefox, something I found quite interesting.  Miro
>> may or may not have had the same issue, but it crashed while playing the
>> file, after first saying it didn't support Ogg Theora files (!), AFTER
>> showing a preview.  It then played it the second time I tried to load
>> it, but then crashed.  I was unable to play a video standalone in Opera
>> - I suppose this is because it supports playing the videos within
>> <video>, but not as a standalone file (i.e., directly from the URL).  I
>> did not take the time yet to prepare a simple page to replicate this
>> test in that manner.
>> The two files I used for testing were the following:
>> http://media.basilgohar.com/preview/theora/balcony-2-vga30p.y4m-q10.ogv
>> http://media.basilgohar.com/preview/theora/balcony-4-vga30p.y4m-q10.ogv
>> What inspired me to make this test is the fact that gmaxwell (I think)
>> in #theora mentioned the problem, and linked to a reddit comment he made
>> in response to someone's criticism of libtheora's quality compared with
>> some H.264 video.  I thought to just test VLC first, but when I noticed
>> it again in SMplayer, I just decided to test all the players that I
>> could find.  After this test, I am much dismayed to find that the vast
>> majority of users will be experiencing subpar Theora performance, as
>> outside of Firefox & Google Chrome, the blurriness appears to be
>> present.  I am fairly sure that all of the above-mentioned media
>> players, aside from Firefox, use some form of libav*.  However, I
>> thought Google Chrome likewise used an ffmpeg-based video library, which
>> I thought was libav*.
>> I believe this to be a significant hindrance to adoption of Theora as
>> video standard, because the latest versions of a wide variety of players
>> all appear to display this bug.
>> Notably absent is any mention of Xiph-based decoders, such as DirectShow
>> filters.  I did not take the same to test those yet, but perhaps I will
>> take some more time and do that on my own PC.
>> --
>>      Basil Mohamed Gohar
>> abu_hurayrah at hidayahonline.org <mailto:abu_hurayrah at hidayahonline.org>
>> http://www.basilgohar.com/blog
>> basilgohar on irc.freenode.net <http://irc.freenode.net>
>> GPG Key Fingerprint:  5AF4B362
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