When I render out my blender animation project into a video file, it blurs, pixelates, and glitches in some spots. Why is this happening? Is it because I'm using Ogg Theora with Vorbis as the format?



Blend file

Output video

The input is 1080p video composited with an animation. Don't know why it's pixelating so much. Is it compression?

  • 2
    $\begingroup$ It looks to me like compression artifacts. To test this, try rendering a single frame (F12) and comparing it to the video. $\endgroup$
    – gandalf3
    Commented Mar 31, 2014 at 6:06

1 Answer 1


Your video output looks so bad because of the low quality setting specified in the render output.

First Things first:

You should never render out your 3d renders as movie files, NEVER! The reasons for this are:

  • If you mess up the quality settings you will have to re-render from the beginning

  • If you computer crashes halfway through the rendering all render will be lost and you will have to start over

The only time when you would want to render out a movie in blender is when you have an ready rendered animation as an image sequence and you want to convert it to a single movie.

The proper way:

  1. Render out your animation as an image sequence. The output files should be a very high quality image which is why I would use either: png, tga, exr or whatever will yield a good looking image

  2. In the blender Video Editor load the image sequence as an image sequence.

  3. Now render out as a movie

Back to the actual question. You need to increase your render settings. Here are the important parameters you need to consider increasing:

  • Format

    • Bitrate: The target amount of data per second in your video file

    • GOP: The number of key frames for the color palette. A value of 10 means that during those 10 frames all are drawing frames based on the same 256 colors. If your scene is changing color during this time the quality will suffer.

  • Rate

    • Minimum: The lowest the Bitrate can be per second

    • Maximum: The highest the Bitrate can be per second

I think in your case the following settings would yield satisfactory results

enter image description here

  • $\begingroup$ If I were to render as a sequence of pngs, I could possibly ditch the compositor, render them with an alpha background, and then put them in the video sequencer with alpha over right? $\endgroup$
    – PitaJ
    Commented Mar 31, 2014 at 15:07
  • $\begingroup$ I assume I might also want to drop the GOP down to 2 because there's a lot of flashing and color change in the original video. I'll try this out when I get home. $\endgroup$
    – PitaJ
    Commented Mar 31, 2014 at 15:12
  • $\begingroup$ @Vader: the explanation of GOP. Where did you get the information on the use of palettes for keyframing and a 256 colour limit? Especially in regard to the theora codec. Thanks in advance. $\endgroup$
    – user2859
    Commented Mar 31, 2014 at 16:07
  • $\begingroup$ well it's 8 bit, so that means 256 color per channel. I am not sure about the ogg format. I am just taking a swing. $\endgroup$
    – Vader
    Commented Mar 31, 2014 at 16:09
  • $\begingroup$ I see. So it´s just an arbitrary example. Was just rereading the spec and scratching my head :-). $\endgroup$
    – user2859
    Commented Mar 31, 2014 at 16:17

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