Hi

I have a series of videos of moving particles (multiple particles per frame / 
movie), and would like to add a circle around each particle and add a label. At 
the moment I am using a script in R to plot, for each frame, these circles and 
labels into a png with alpha channel, combine the pngs to a movie, and overlay 
this movie to the original movie (see the thread 'Overlay images to frames in 
video’ for the background).

Now I realised, that the actual plotting of the labels takes up nearly 40% of 
the time of the R script and I would like to make this process faster.

I have found “draw_text” (https://ffmpeg.org/ffmpeg-filters.html#drawtext), but 
I have no idea how I could do this. We can assume that I have a text file with 
the following columns:

FRAME: the frame on which the labels and circle should be plotted
X:     the x-coordinate
Y:     the y=coordinate
LABEL: label for the point

Also possibly important, there are multiple (many) particles for which circles 
and labels need to be plotted on each frame. 

I also found the “sendcmd” 
(https://ffmpeg.org/ffmpeg-filters.html#sendcmd_002c-asendcmd) but I do not get 
my head around how I can combine these two.

Any help appreciated,

Rainer


--
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, 
UCT), Dipl. Phys. (Germany)

Orcid ID: 0000-0002-7490-0066

Department of Evolutionary Biology and Environmental Studies
University of Zürich
Office Y34-J-74
Winterthurerstrasse 190
8075 Zürich
Switzerland

Office: +41 (0)44 635 47 64
Cell:           +41 (0)78 630 66 57
email:      rainer.k...@uzh.ch
                rai...@krugs.de
Skype:     RMkrug

PGP: 0x0F52F982



Attachment: smime.p7s
Description: S/MIME cryptographic signature

_______________________________________________
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