Video

1.Foreword

    This filter family deals with interlaced video.

2.Interlacing filters

Decomb telecide 

    This is (yet another) port of Donal Graft. Its aim is to remove combing, including inverse telecine. Note that it does not alter framerate, and that you must use also Decomb decimate to do a proper IVTC.

Decomb decimate 

    This is (yet another) port of Donal Graft. It removes frames according to several strategies. The most common usage is with telecide to do inverse telecide.

Pal Smart 

    This filter is a mix between the two above.

    It evals the current image and the Pal-shifted image, then takes the less interlaced one and smart deinterlace it. Since chroma is not taken into account, it can lead to small chroma error.

    It is a bit on the slow side, but very efficient when the video is of the good type.

    It can be used also as a cheap IVTC, as it will reconstruct the progressive frame, but will keep the video at 30 fps and will not discard duplicates to reach 24 fps.

Deinterlace 

    This filter is a port of Donald Graft smart-deinterlace filter to YV12

    It detects if the image is interlaced and blurs the interlaced parts.

    This filter takes two parameters :

    • Motion threshold : The lower this value, the more easily the interlacing will be detected. Too low means a lot of blurring !
    • Blend threshold : When the video has been detected as interlaced, the parts that are under this threshold are blurred. It must be smaller than the previous threshold

Lavcodec PP deinterlacer 

    This filter is a port of lavcodec deinterlacer

    You can select :

    • Libear blend
    • Linear interpolation
    • Cubic interpolation
    • Median interpolation
    • FFmpeg deinterlacer
    The best is to refer to mplayer/ffmpeg documentation for more details.

Pal Shift 

    This filter takes a field from an image and the other field from the next image.

    A lot of movie (and some DVD) are interlaced this way.

    This filter does not do any check, so activate it, preview it, and if you are happy with the result keep it.

Drop 

    This filter has been written by Ron Reithoffer.

    If a field is too different from spatial/temporal neighbours (VHS drop out) it is discarded and replaced by an average value from previous and next frame line.

    According to the author, this must be the first filter in the filter chain, and will not work well with very interlaced image.

Kernel Deint 

    This filter is a port of Donald Graft kernel deint (avisynth), more stuff here.

    It is very efficient.

3.Fields related filters

Swap fields  

    It is very common that capture card/capture software swaps the fields. It will look like a interlacing effect, but on the whole image, not only on moving part

    This filter swaps the fields back. Here is a short example, first the image which has swapped fields :

    And the ouput of the Swap Fields filter :

Smart Swap fields  

    It is also common that the capture card/software swaps fields back and forth several times. This filter tries to detect if the fields are swapped, and if so swaps them back.

    It is usually better to use this one, rather than the SwapFields filter.

Keep even field  

    This filter will keep even field, i.e. even line numbers.

    It will halve the vertical resolution by 2

Keep odd field  

    Same as above for odd field

Separate Fields  

    This filter will split a image in two images, each one receiving one of the field.

    So you will double the framerate, double the number of images, and halves vertical resolution.

Merge Fields  

    Opposite of above filter.

Stack Fields  

    Each field is put on top of one another. Useful to see if some blending occured/if the fields are progressive.

UnStack Fields  

    Opposite of previous filter.