Using ':' in -o breaks ffmpeg

[paulguy]

I was trying to download a full playlist from youtube, and I wanted the videos numbered so I could watch in order, so I used:
youtube-dl --playlist-reverse -f bestvideo+171/bestvideo+140 -o "%(autonumber)s: %(title)s-%(id)s.%(ext)s" https://www.youtube.com/playlist?list=PL26B36130624FCAF5

The unfortunate side effect is that ffmpeg believes that the filename is specifying a protocol. I could just use a different character, but I was able to fix it by modifying FFmpegPostProcessor.run_ffmpeg_multiple_files and simply prepending 'file:' to each input_path and the out_path.

[yan12125]

input_path can be remote URLs. (for example M3U8 URLs)

[paulguy]

Well, obviously considerations like that are why I didn't make a pull request, but simply said what I did to fix it. I'm just saying, if it's a file, it should be prefixed with file: so ffmpeg knows it's a file, and you don't get weird issues with filenames like that.

[yan12125]

Oh prepending the filename with './' works. For example:

youtube-dl --playlist-reverse -f bestvideo+171/bestvideo+140 -o "./%(autonumber)s: %(title)s-%(id)s.%(ext)s" "https://www.youtube.com/playlist?list=PL26B36130624FCAF5"

[paulguy]

That isn't really obvious when all you get is "Protocol not found" without searching for it, and there's no real indicator that's even coming from ffmpeg. I had to dig around to find out even that much, then find out that it was because of the colon. It'd make more sense if it just worked as expected, and it's not like it's something that can't be done.

[rg3]

I tend to agree with you here. If you create a script that calls "cp" with user or external information you're expected to use "--" to separate the options from the positional parameters. If ffmpeg uses a proto:object syntax in the output file, the program should add "file://" to prevent these problems. My two cents.

[paulguy]

It does have an explicit protocol syntax, which will force the specific protocol.
http://www.ffmpeg.org/ffmpeg-protocols.html

[jaimeMF]

Thanks for the report, it will use the file: protocol in the next version.