On 26-04-2020 10:51 am, John Hawkinson wrote:
I wanted to execute zoom-and-pan out over a few seconds by parametrizing the 
width and height of the crop filter via sendcmd (the result of which would then 
be handed to a scale filter), and when I try to do this, I get errors that I 
don't understand.

When I use:

   sendcmd=c='0-1 crop w 1146+t*(1920-1146), crop h 1080'

I get:

   Error when evaluating the expression '1146+t*(1920-1146)'

When I use

   sendcmd=c='0-1 crop w 1146+T*(1920-1146), crop h 1080'

I get:

   Unknown function in 'T*(1920-1146)'
   Error when evaluating the expression '1146+T*(1920-1146)'

Neither of these seem to make sense to me. The crop filter docs indicate it 
takes the parameter 't', and the general eval api docs refer to 'T'. I'm not 
sure which (or both?) applies, but both fail in odd ways.

Same problem with a simpler exmpression like '1146+T'.

What am I doing wrong? Console output below.

The temporal parameters t, n and pos are only applicable for x and y expressions. At present, the only way to vary w and h over time is by sending commands with varying constants for w/h. Not very convenient, I know. Open a ticket if you want an enhancement for the crop filter.

Gyan
_______________________________________________
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Reply via email to