[FFmpeg-user] bwdif filter question

[Carl Eugen Hoyos]

> Am 16.09.2020 um 15:58 schrieb Mark Himsley <mark.himsley at gmail.com>:
> 
>> On Mon, 14 Sep 2020 at 15:42, Mark Filipak (ffmpeg) <markfilipak at bog.us> wrote:
>> 
>> Is the input to the bwdif filter fields or frames?
> 
> The input to every filter in a filter chain is a raster of pixels.
> That raster may contain one frame or two fields.

That may not be wrong (apart from Paul’s comment) but I wonder how useful it is:
No matter if the raster contains one field, two interlaced fields or a progressive frame, the filter will always see an input frame.
The fact that there is metadata that may signal the content is also not necessarily helpful as this metadata is typically wrong (often signalling fields when a frame is provided). That’s why the filter ignores the information by default.

(If you provide only one field, no FFmpeg deinterlacer will produce useful output.)

> The bwdif filter will interpret a single raster and is designed to
> output two rasters, each containing one or the other of the fields
> that were contained in the input raster.

You can request that the filter outputs one instead of two rasters for one input raster.

Carl Eugen