Bad quality in FLV playback

[Eduard Christian Dumitrescu]

While watching the exact same FLV (FLash Video) file on Ubuntu Linux 7.10 (with all updates) and on Microsoft Windows 2000, I realized that, unfortunately, the playback quality was far lower in Ubuntu ("pixelization" effect), and playback was jaggy (lots of short and frequent lags).
The video player I used on Windows was Microsoft Windows Media Player, and on Ubuntu I tried both gxine and totem (gstreamer), but the effect remained the same.
The computer has an ATI Radeon graphics card, with Xv enabled on Linux, and a 2GHz processor. I easily reproduced the problem with other files, on other computers.

I think it's important that Ubuntu the highest-quality playback possible for all supported video formats.

If you have any ideas whatsoever, please ask. I will try to do my best to answer in the next ~12h after your reply.

Thank you for being there!

[Sebastien Bacher (seb128)]

Do you have the issue on other vdeo formats too? What videodriver do you use?

[Eduard Christian Dumitrescu (inventatoru)]

No, just FLV (even though I also get very bad quality with RealVideo files -- I should probably file another bug for this one), I tested with MPEG-2 and DivX. I had no problem watching MPEG-2 and DivX at maximum quality. The trouble is with the codec, I think.

[Stefan Nuxoll (snuxoll)]

FLV is naturally low quality, especially depending on where you get it, I'm not sure if this is a bug myself.

[Eduard Christian Dumitrescu (inventatoru)]

@Stefan: if you (re-?)read the bug description, you will find out Windows Media Player manages to get high quality out of the FLV files, while totem, gxine and mplayer on ubuntu linux play FLV files with bad quality.

[Kurt von Finck (mneptok)]

Eduard,

FLV and Flash are proprietary codecs, formats, and tools. The fact you see different quality in Windows vs. Linux is probably due more to the deltas in the Windows and Linux Flash codebase at Adobe than it is to any inherent Ubuntu media handling.

If that's the case, we can do nothing about this bug. Only Adobe has access to the Flash codebase, and only Adobe can fix issues with Flash quality diversion across platforms.

I'm not saying your bug report is without merit. Instead, I'm making you aware that Adobe may well be the better recipient.

La revedere si multumesc.

[Eduard Christian Dumitrescu (inventatoru)]

Apparently, ffmpeg does the job of decoding FLVs. ffmpeg is open-source so problems can be fixed. I will reassign this bug to ffmpeg now.

[John Dong (jdong)]

Are you sure this only happens with FLV files? This sounds like the classic
fglrx Xv bug where textures are not smoothly scaled to fullscreen size but
rather are crudely blown up all pixelated. This is a bug in AMD's proprietary
video drives beyond any of our control. I'm not going to take any Launchpad time
to get on my soapbox about this (as an owner of an ATI X1400 I've suffered
greatly over the past few years)... but it's clear that we are all at the mercy
of ATI for fixing this.

[John Dong (jdong)]

I should add, FLV decoding and upscaling on my ATI running fglrx 8.40.4 + xgl works fine (earlier and later versions are both crap with xvideo, as is running 8.40.4 without Xgl)

It also looks flawless on my Intel.

ffmpeg does the job of decoding the FLVs, but it is your graphics card driver's xvideo capabilities that ultimately determine the quality of output.

With mplayer and some other players, it is possible to work around this with high-quality software scaling but that is CPU intensive and not the topic of this bug report.

[Eduard Christian Dumitrescu (inventatoru)]

I got the same problem even when I tested without Xv; I tried both GL and X-shm/XImage output. By the way, the driver I am using is not 'fglrx', but 'ati'.

[Reinhard Tartler (siretart)]

Thanks for taking your time to report this bug. You have reported a bug in the ffmpeg library. In order to be able to actually fix this bug, we must be able to

  * reproduce it
  * check if it happens with the latest version

You can help with the first point by attaching an example file to this bug report. Please note that a proper attachment is preferred over a link to some remote site. Remote side that are password protected or otherwise restriced (like services like rapidshare.com and similar) are absolutely not acceptable.

For the 2nd point, the MOTUMedia team provide updated packages for xine-lib and ffmpeg in their PPA for past ubuntu releases. See http://launchpad.net/~motumedia/+archive for instructions how to enable that archive. Please add this repository to your /etc/apt/sources.list, update your system and make sure, that you have the package 'ffmpeg-dbg' installed (use 'sudo apt-get dist-upgrade && sudo apt-get install ffmpeg-dbg'). Please make sure that you always report the exact version of the package that you are testing. This information can be obtained using the command 'dpkg -l ffmpeg-dbg'.

Thank you for your cooperation.

[Jonathan Thomas (echidnaman)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!

[Ante (anton-ragnarsson+launchpad)]

I have also noticed the playback quality difference between ffmpeg and e.g. adobe's flash player for flv videos.
My comparisons are done on Mac OS X, but the issue is clearly in video decompression, so platform shouldn't matter.

To reproduce:
- go to a site with flv media, like http://svtplay.se/
- select a show, play it in the embedded flash player and notice the quality.
- download the same program (using rtmpdump) and watch it in mplayer.

Example:
- flash: http://svtplay.se/t/103535/uppdrag_granskning
- external: rtmp://fl11.c90901.cdn.qbrick.com/90901/_definst_/kluster/20090408/UG_090408

At first I thought it might have to do with differences in how the flash player and rtmpdump fetches the rtmp stream, like the official player getting better quality. But playing the downloaded file in the Adobe flash tools (creating a swf file to play the flv file) got me the same quality seen in the online player.

I have tried different versions of mplayer, but the result is the same. (for example: mplayer dev-SVN-r27545-4.0.1)
VLC shows the same blocky artifacts as mplayer.

[Ante (anton-ragnarsson+launchpad)]

The bug isn't invalid. Added repro steps.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ffmpeg - 4:0.6~svn20100505-1ubuntu1

---------------
ffmpeg (4:0.6~svn20100505-1ubuntu1) maverick; urgency=low

  * merge from debian/experimental. remaining changes:
    - don't disable encoders
    - don't build against libfaad, libdirac and libopenjpeg (all in universe)

ffmpeg (4:0.6~svn20100505-1) experimental; urgency=low

  * update to new upstream. Closes: #569727
    - fixes various segfaults and other minor feature improvements
      Closes: #374931, #522449, #501891, #559712, #420231, #369127, #538082,
              #298095, #294422, #561553, #525385, #495274, #420230
      LP: #305286, #457106, #529200, #301723, #305315, #336479, #420230,
          #412063, #428912, #432181, #440591, #453732, #453732, #453732,
      #514259, #515243, #521472, #530186, #530186, #197842, #483317,
     #483317, #539407, #280098, #331255, #566107, #569823, #570305,
     #573190
  * Fixup lintian overrides for new upstream snapshot
  * Bump Standards-Version to 3.8.4
  * Many upstream changes, see upstream Changelog for details
 -- Reinhard Tartler <email address hidden> Wed, 26 May 2010 00:01:17 +0200