How to improve Timelapse quality

[dbainbridge]

What configuration do I need to change in order to drastically improve the quality of the mp4 Timelapse nightly video? It currently is too grainy especially when it catches the aurora.

[aaronwmorris]

Remind me what camera and settings you currently use?

[dbainbridge]

ZWO 178MC. The jpeg images look really good but video looks crappy.

[dbainbridge]

I already have the FFMPEG bitrate set to 5000k and see artifacts like this:

[aaronwmorris]

Does it clean up later in the video?

[dbainbridge]

No, because it is mostly Aurora so looks "awful" (at least compared to original images).. https://vimeo.com/811295758. When there isn't aurora it normally looks good and only have that initial blockiness like you are talking about at the beginning and then cleans up later. But with aurora all night it never recovers.

[aaronwmorris]

Yeah, the same thing happens when you have clouds with almost no contrast or details. The FFMPEG settings I have implemented are terrible in that condition. Let me do some investigation.

[dbainbridge]

I'm trying -crf 20 and got rid of the other bitrate specification line and regenerating now.

[dbainbridge]

I changed it to this:
cmd = [ 'ffmpeg', '-y', '-loglevel', 'level+warning', '-f', 'image2', '-r', '{0:d}'.format(self.config['FFMPEG_FRAMERATE']), #'-start_number', '0', #'-pattern_type', 'glob', '-i', '{0:s}/%05d.{1:s}'.format(str(self.seqfolder_p), self.config['IMAGE_FILE_TYPE']), '-vcodec', '{0:s}'.format(self.config['FFMPEG_CODEC']), '-crf', '20', '-pix_fmt', 'yuv420p', '-movflags', '+faststart', ]

But did not notice any difference. Verified the timestamp of the mp4 file was updated. File size is near same.

[dbainbridge]

Can't seem to get ANY improvement.. for some reason with options I've tried.

[dbainbridge]

What do I need to restart when I modify Timelapse.py? Isn't wasn't taking my changes since I needed to restart something. Rebooting does but not sure what minimum I need to do for it to pick up my changes.

[aaronwmorris]

You have to restart the entire indi-allsky service for the new python code to go into effect.

systemctl --user restart indi-allsky

When you are doing testing, its usually easiest to just run the service from the command line.

source virtualenv/indi-allsky/bin/activate

./allsky.py run

[aaronwmorris]

I tried -qscale:v 15 with really good results. 5, 15, 25, 31 all resulted in the same file size. It took 40 minutes to generate and was 10x larger than normal... but it looked good.

I have been reading that the order of the parameters for ffmpeg is important. I will play with it some more.

[aaronwmorris]

Looks like you just have to really bump up the bit rate. 20000k shows a significant improvement similar to the qscale option. I am testing with a 290mm and 385mc, which are only 1k cameras. The files are much bigger, but show almost no noticeable compression artifacts.

In your case with the 178mc, which is basically a 4k camera, you may even consider 40000k (or higher) if you are outputting native resolution.

[aaronwmorris]

I would really like to see that video with the enhanced bitrate.

[aaronwmorris]

Did you ever get a chance to regenerate that timelapse with the increased bitrate?