Ability to skip defining inputs and do it manually via extra args

[YuriMalinov]

Right now it's required to provide at least one input. I've got situation when:

1. input definition is complex: -f lavfi -i aevalsrc=0
2. it has to be before extra_args because they refer to it (-map, -shortest)

There was no way to do it besides extending FFmpegBuilder and just copying this method commenting out inputs check - and this way it worked well just with all args defined through addExtraArgs.

Maybe I'm missing something in ffmpeg usage - I've tried several args order in command line and it complained about -i going after other args.

[bramp]

Thanks for the report. Would you provide me an example of a full command line, so I can fully understand the issue.

[YuriMalinov]

Thanks for reply.. I should have posted command before.

I'm solving following problem: there are several videos, some with audio, some without and I need to concat them into one larger video.

To do so first I copy videos without sound stream adding to them null audio stream, command looks like this:
ffmpeg.exe -y -v error -f lavfi -i aevalsrc=0 -i 1.mp4 -vcodec copy -acodec aac -map 0:0 -map 1:0 -shortest 1-no-audio.mp4

Some parts are kind of magic for me now, so maybe there are better ways. At least -f lavfi -i aevalsrc=0 is kind of single thing which shouldn't be split into parts. And also -map requires input to be defined before.

Changing order to something like
ffmpeg.exe -y -v error -vcodec copy -acodec aac -map 0:0 -map 1:0 -shortest -f lavfi -i aevalsrc=0 -i 1.mp4 1-no-audio.mp4
or ffmpeg.exe -y -v error -f lavfi -i aevalsrc=0 -vcodec copy -acodec aac -map 0:0 -map 1:0 -shortest -i 1.mp4 1-no-audio.mp4
breaks things with error like "Option map (set input stream mapping) cannot be applied to input file 1.mp4 -- you are trying to apply an input option to an output file or vice versa. Move this option before the file it belongs to".

[igracia]

Perhaps #75 would solve this?

[Euklios]

Closed thanks to #339.
I also just added a test for the command mentioned above