Converting Seestar S50 .mp4 video for use in AstroSurface

Today I wanted to use AstroSurface to stack and process the frames from a video I’d previously recorded with my Seestar S50. I needed to convert the .mp4 recording to a .avi file which AstroSurface could load.

I am a big fan of using FFmpeg for video file manipulation.

I decided that the best idea was to use FFmpeg to:

• decode the original h.264 encoded video
• convert the original yuv420 format into 8 bits-per-channel BGR format
• store the resultant uncompressed video into a .avi file

After some research and fiddling I believe that this is a reasonable command for the conversion:

ffmpeg \
 -i 2024-08-16-220407-Lunar.mp4 \
 -filter 'scale=iw:ih:sws_flags=bitexact+full_chroma_int+accurate_rnd+lanczos,format=bgr24' \
 -c:v rawvideo \
 -map 0:v \
 2024-08-16-220407-Lunar.avi

• -i '<FILENAME>' the source recording from the Seestar S50
• -filter '<FILTER>' convert from source format to 8 bits-per-channel BGR
• -c:v rawvideo set the output video codec to rawvideo
• -map 0:v map only the decoded & converted source video stream into the output file
• '<FILENAME>' the output destination file

References

• The English AstroSurface web page
• Zwo Seestar S50