animation fails to create a movie with 'ffmpeg_file' backend

[vlsd]

I am having trouble saving my animations using ffmpeg 2.0.1
The temp files get created, but the call to ffmpeg fails with the following error:

Option vframes (set the number of video frames to record) cannot be applied to input file _tmp%07d.png -- you are trying to apply an input option to an output file or vice versa. Move this option before the file it belongs to.
Error parsing options for input file _tmp%07d.png.
Error opening input files: Invalid argument

I am assuming the way in which ffmpeg takes arguments has changed between versions?

[WeatherGod]

I am curious why ffmpeg thought the file name is "_tmp%07d.png". Maybe the movie had zero frames and that string didn't get formatted?

[vlsd]

ffmpeg is not complaining about the file name, it's complaining that I am trying to use an output flag (vframes can only be applied to output files) to an input file. Prior to version 2.0 it did not check if this was the case, or maybe just threw a warning, but now it fails.

[WeatherGod]

I realize that. I am just curious as to how ffmpeg even got a name with a
format specifier in it. This means there is a code path such that the
format string doesn't get formatted. This could point to a slightly
different issue.

[vlsd]

ffmpeg expects the format string in there and does the expansion internally. It's a feature so that when you call it from command line you don't have to build a list of files first.

[WeatherGod]

Ah, ok. That makes sense.

[tacaswell]

This was fixed in #2615