Reducing the size of video files using ffmpeg

[Erick José Ramo Da Silva]

Dear colleagues,

Erick Silva from São Paulo State University (Brazil) here.
A while ago, someone posted a way to reduce the *.avi file size using ffmpeg while keeping compatibility with OpenCASA.
I managed to reduce the file size to about 2/3 (~58 MB to 38 MB) using:

ffmpeg -i input.avi -vcodec rawvideo -pix_fmt gray output.avi

However, I have old files here that are only 2 MB. I am afraid I cannot find the command line to do that.
Does anyone have it?

Thanks a lot!
Kind regards,
Erick

Erick J. R. Silva, Ph.D.

Assistant Professor

Department of Biophysics and Pharmacology

Institute of Biosciences of Botucatu

Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP)

Rua Prof. Dr. Antonio Celso W. Zanin, S/N

Botucatu-SP, Brasil, 18618-689 

Phone: +55 14 3880-0223
E-mail: ejr.s...@unesp.br // ersi...@gmail.com

Researcher ID: D-2976-2009

Scopus ID: 36176142500

ORCID: https://orcid.org/0000-0002-9330-8658

CV Lattes: http://lattes.cnpq.br/4726447529800886

[Felipe Martínez-Pastor]

Hi Erick,

I understand that you had color videos and you could make them smaller by removing the color information. Maybe you can make them smaller by using png compression or MJPEG compression (e.g., (e.g.  ffmpeg -i input.avi -codec: mjpeg output.avi; careful, it is lossy and I don't recommend it if you need to replicate your analyses in the future).

Could you develop your question about the 2 MB videos? Maybe they are already in greyscale. Unfortunately, the AVI reader for ImageJ only reads uncompressed video or MJPEG compressed. Fiji has an FFMPEG extension (add the ffmpeg source in the Update section), enabling to manage more formats, but it is not integrated in OpenCASA.

I take the opportunity to remind that OpenCASA is FOSS and anyone can contribute!

Regards,

Felipe