VirtualDub MSU Smart Deblocking Filter

MSU Graphics & Media Lab (Video Group)

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Algorithm: Dr. Dmitriy Vatolin,
Anton Obuhov, Sergey Grishin
Implementation: Anton Obuhov


Filter is intended for recovering quality of video ripped from DVD (for example, when it contains 4 hours of video data), VideoCD, shot on cameraphone or after decompressing by DivX, XviD, H.26x (H.261, H.263, H.264). It performs the accurate blockiness artifact removal, which appears as the grid of squares laid over the video.

Filter automatically determines the blockiness' strength on the frame and in the concrete part of it, the processed video contains maximum details from the original video. The blockiness criterions guarantee the accurate work of every filter component in both hard and soft blockiness cases. Thus, filter will process marginally when on scenes with slow motion, while it will smooth very hard in the case of fast motion in the same film.

The main advantages of the filter are:

  • The processing raises the PSNR quality metric of processed video in comparison with the original video
  • Real-time processing on 2*CIF video
  • Improved hard blockiness processing (video shot by cameraphones or web cameras)
  • The unaligned blockiness processing option
  • Simple and convenient user interface with the on-the-fly filter processing results in the Preview window
The full change list can be found in the "Change log" section.


Filter's interface

Filter's interface allows to adjust the main parameters of processing.
Tip: The "Preview" button allows to instantly observe the results of filter settings modification.
Tip: You can speed up the processing by unchecking some options.

Use block preprocessor
Enables block preprocessing. You can see the example of degraded movie with a lot of blockiness, deblocked with preprocessing and without it:

Decompressed frame

Without block preprocessing

With block preprocessing

Preprocess unaligned
In case of slow motion unaligned blockiness may appear. Such blockiness is the problem for the most of deblocking techniques. If the option "Preprocess unaligned" is checked, the filter searches areas with unaligned blockiness and processes them. There are some examples below:

Decompressed frame

Without unaligned
blockiness processing

With unaligned
blockiness processing

Preprocess chroma
Enables preprocessing of color planes.

Decompressed frame

Without chroma preprocessing

With chroma preprocessing

Process chroma
Enables processing of color planes.

Decompressed frame

Without chroma processing

With chroma processing

Using AviSynth

Filter supports Job Control, and it can be used from AviSynth. Example:

LoadVirtualDubPlugin("...\MSU_Smart_Deblocking.vdf","MSU_Smart_Deblocking", 0)
clip=AVISource("source.avi", false, "RGB24") 
clip.ConvertToRGB32.MSU_Smart_Deblocking(1, 1, 1, 1)

The values passed to the filter in line 3:
1) Enable block preprocessor (0,1)
2) Preprocess unaligned (0,1)
3) Preprocess chroma (0,1)
4) Process chroma (0,1)


Let's take a look on how filter processes the test sequence "Battle" (XviD, 1-pass, CBR, 100kbs):

Decompressed frame

MSU Deblocking

MSU Smart Deblocking

The next sample is an example of processing the sequence "flower" (XviD, 1-pass, CBR, 100kbs):

Decompressed frame

MSU Deblocking

MSU Smart Deblocking


Change log

MSU Smart Deblocking 0.8:
Improved block preprocessing algorithm
Improved main deblocking algorithm
The processing improves the PSNR quality metric of uncompressed and the processed videos
Speed and memory optimization, in comparison with the version 0.5:
        • without preprocessing - up to 2.7 times
        • with preprocessing - up to 2.4 times
Real-time processing of 2*CIF video
Simple user interface
Removed the "directional filtration" option
Fixed problem with yellow hue of the processed video

MSU Smart Deblocking 0.5:
Improved main deblocking algorithm
Improved color processing algorithm
Improved blockiness preprocessor
Improved unaligned blockiness preprocessor
Added directional filtering control (on/off)
Added save/load directional filtering parameters in job control
Added Edge Sensitivity control
Fixed blockiness creation bug in flat background areas
Minimal speed optimization

MSU Smart Deblocking 0.1:
First public release

See also

For common questions about filter's work please contact us
For commercial license of this filter (commercial usage is not free) please contact us сontact email

Another resources

Video resources:

Last updated: 12-May-2022

Server size: 8069 files, 1215Mb (Server statistics)

Project updated by
Server Team and MSU Video Group

Project sponsored by YUVsoft Corp.

Project supported by MSU Graphics & Media Lab