I have 1300 frames, and I convert them at 21fps. That should be over a minute of footage from my sequence of images, but the lossless command I'm using is producing an 18 second video out of the 1300 frames. Am I doing this wrong?

Command:

ffmpeg -framerate 21 -i Blots_%04d.0001_x2-standard-scale-2_00x.tif -c:v libx264rgb -crf 0 Blots.mp4 

The video in Media Player Classic says it only draws 337 frames at 21fps.

I have 1300 frames, and I convert them at 21fps. That should be over a minute of footage from my sequence of images, but the lossless command I'm using is producing an 18 second video out of the 1300 frames. Am I doing this wrong?

Command:

ffmpeg -framerate 21 -i Blots_%04d.0001_x2-standard-scale-2_00x.tif -c:v libx264rgb -crf 0 Blots.mp4 

The video in Media Player Classic says it only draws 337 frames at 21fps.

I also tried the following which resutls in the same size file and issue:

ffmpeg -r 21 -i Blots_%04d.0001_x2-standard-scale-2_00x.tif -c:v libx264rgb -crf 0 Blots.mp4