%load_ext yuuno

This command enables Yuuno. When you correctly install yuuno, the variables vs and core will be added to your local environment.

Magics for clip introspection

%diff <clipA>, <clipB> deprecated

This commands allows to compare two clips. Clip-B is shown when you put your mouse over the image.

This functionality will be merged into %preview starting with Yuuno 1.2.

%preview <clip>

This commands shows a preview of the clip.

%encode and %%encode

%encode <clip> [--y4m] [--multi] <COMMAND> ...
%%encode [--y4m] [--multi] <COMMAND> ...

The line-magic (%encode) will take the given expression and tries to encode the clip.
The cell-magic (%%encode) will take the contents of the cell and will encode the last expression that the cell returns.

The --y4m-flag tells Yuuno to output Y4M into the processes' stdin. By default it will just return raw frames.

By default, you can only have one encode running at a time. Use --multi to disable it.

See %reattach for viewing a list of current encodes.

%reattach [<id>] 1.1+

This command allows you to reattach to running encodes. If you have only one encode running, it will directly attach to to the encode.

Otherwise it will show you a list of id and some information about the encode. Use the ID given by its output to attach to a specific encode.

Configuring Yuuno

Jupyter provides a %config magic which you can use to configure Jupyter. Yuuno hooks into it so you can configure Yuuno using the same command.

%config will show you a list of config-sections.
%config <SECTION> shows you a list of configuration options for that section.
%config <SECTION>.<CONFIG> shows you the current value.
%config <SECTION>.<CONFIG>=<VALUE> allows you to change the value.

Here is a small list of potentially useful configuration values.


This section allows you to configure how VapourSynth and Yuuno work with each other.

  • core_accept_lowercase (Default: False) VapourSynth <= R44
    All plugin names are case-insensitive.
    This option is ignored on VapourSynth R45 and onwards.

  • core_add_cache (Default: True)
    Add a cache to all new VapourSynth-clips. It is never a good idea to set this to False

  • core_max_cache_size (Default: None)
    Configures how large the inline caches should be.

  • core_num_threads (Default: num_processors)
    Configures how many worker-threads VapourSynth will use.

  • merge_bands (Default: None) Debug
    Configures how the RGB-planes are extracted by Yuuno.

  • resizer (Default: 'resize.Spline36') Configures which resizer is to be used for converting from the frame-colorspace to RGB24

  • post_processor (Default: None)
    Set this to a function that takes an RGB24-clip and returns an RGB24-clip. This will be the last function called when converting your clip from your color-space to RGB.

  • prefer_props (Default: True)
    When set to true, Yuuno will try to determine the correct YUV-Matrix by using the frame-props of the frame to display.

  • yuv_matrix (Default: '709')
    If Yuuno couldn't determine the correct YUV-Matrix from the frame-props, this value will be used as fallback.


  • icc_profile (Default: 'sRGB') When outputting .png, Yuuno will insert a color-profile to ensure all browsers display the image the same way.

    If it is set to sRGB it will use sRGB. Otherwise specifiy the path to an ICC Color-Profile.

  • zlib_compression (Default: 6)
    Defines how good the .png-file will be compressed. 0 means no compression, 1 is the fastest expression and 9 the slowest.