[FFmpeg-user] Use processed filename as draw text after tmix, in one pass?

[Steven Kan]

> On Apr 25, 2024, at 1:33 PM, Steven Kan <steven at kan.org> wrote:
> 
>>> Hmmm.
>>> 
>>> This:
>>> 
>>> https://youtu.be/-NB1JzR5aCQ
>>> 
>>> is the result of:
>>> 
>>> ffmpeg -pattern_type glob -i '*.jpg' -vf "split [tmp][main]; [tmp]
>>> crop=iw:ih*0.05:0:ih*0.95, drawtext=text='%{metadata\\:DateTimeOriginal}':
>>> fontfile=/System/Library/Fonts/Helvetica.ttc:fontcolor=white: fontsize=72:
>>> x=(w-text_w)*0.01: y=(h-text_h)*0.01 [text]; [main]
>>> tmix=frames=10:weights='1' [blend]; [blend][text] overlay=0:H*0.95" -y
>>> CombLapseWithTimeStampAndTmixSplit.mp4
>>> 
>>> which approximates the result I'm trying to achieve, but it's cheating,
>>> because it's making a separate stream of the bottom 5% of the video with
>>> the drawtext overlay, and then overlaying that on top of the blended
>>> frames. It appears to work only because there's nothing much happening in
>>> the bottom half of the frames.  If there were any significant bee activity
>>> in the bottom 5% it would be apparent that that section is not getting
>>> tmixed.

Here’s the latest result from the above technique, with the timestamp overlay now limited to just the area that will contain the text:

ffmpeg -thread_queue_size 4096 -pattern_type glob -i '*.jpg' -vf "split [tmp][main]; [tmp] crop=iw*.25:ih*0.05:0:ih*0.95, drawtext=text='%{metadata\\:DateTimeOriginal}': fontfile=/System/Library/Fonts/Helvetica.ttc:fontcolor=white: fontsize=72: x=(w-text_w)*0.01: y=(h-text_h)*0.01 [text]; [main] tmix=frames=50:weights='1' [blend]; [blend][text] overlay=0:H*0.95" -y CombLapseWithTimeStampAndTmixSplit.mp4

which produces:

 https://www.youtube.com/watch?v=N031e2g551A

It will be more interesting as the bees complete more comb, which gives the bees more space to work, which will reveal more comb.

You can see the background flickering behind the timestamp, due to some weird exposure variances that I’ll attempt to address in another thread.