What I need is an equivalent of explainshell.com, but for FFMPEG invocations.
(You may ask, "what about explainshell.com"? Well, in the case of FFMPEG, explainshell doesn't explain shit.)
So I'm running:
ffmpeg -i output/test0/%08d.png -pix_fmt yuv420p -vcodec libx264 -strict experimental -r 60 -i 17.mp3 -acodec copy output/test0.mp4
I expect this to mux together a video stream (input is a series of PNGs, output is x264 at 60 fps) and an audio stream (input is mp3, output is unchanged) into an mp4.
This ffmpeg is compiled with --enable-libx264 and has succeeded on similar invocations before.
It fails with: "Unknown decoder 'libx264'"
*Decoder*? Why are you decoding x264?
Answer was simple but oh god I would not have guessed it without help from Mastodon:
https://mastodon.manalejandro.com/@ale/112338345238064172
Here's explainshell's take on my input. It correctly identifies all flags, but not the significance of their order:
Also, @ecn recommends this tool, which looks super useful, but not for this case, as it's for *constructing* ffmpeg arguments not *debugging* ones you already have:
