C# - Parsing ffmpeg standard output when extracting images

Question

I am extracting single Video frames by starting a ffmpeg process from my c# code. The default behaviour is to write these images to disk. However to speed up processing I want to redirect the ffmpeg standard output to receive the stream and process it further in my program.

I am using arguments similar to this:

-i \"" + Filename + "\" -vf \"scale=640:-1\" -an -vframes 100 -r 1 -f image2 -

This redirects the byte stream to standard output which I can redirect to my program using process.StartInfo.RedirectStandardOutput = true.

This may work fine for movie streams as I only have a singe output, but the call above would produce 10 single images (when writing to hard disk), how can I parse the byte stream from standard output and split it into single files?

Answer 1

I have found a solution which seems to work but strangly enough is not mentioned in the ffmpeg documentation: Use image2pipe as output format.

So for the example above it would be:

-i \"" + Filename + "\" -vf \"scale=640:-1\" -an -vframes 100 -r 1 -f image2pipe -

This redirects the byte stream to stdout and allows to capture and parse the images