[FFmpeg-devel] [WIP][PATCH] avfilter: add video oscilloscope filter

[Dave Rice]

> On Apr 26, 2017, at 2:37 AM, Paul B Mahol <onemda at gmail.com> wrote:
> 
> On 4/26/17, Dave Rice <dave at dericed.com> wrote:
>> 
>> 
>> I'm curious why floats are used for x,y coordinates within a frame rather
>> than integers.
> 
> So it the position be set relatively. And for similar results for
> different resolutions.

Having been used to other filters with integers as x,y, this seems a bit unintuitive to me. In other filters relative positions are set by variables, such as ih/2 as opposed to 0.5. If staying with floats, I'd suggest that the documentation include examples for the use of calling specific lines by integer by including math in the options. Perhaps the statistical area could also state the x,y coords of the two ends of the scope as ints so that a viewer of the image would be clear to what line(s) are included in the analysis.

>> It appears that the plotted scope is padded to 300, though the trace usually
>> is 256 (2^8) lines tall. Are the other 44 lines intended to store something?
>> 
> 
> Yes, some statistics numbers.
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