Feature request: ability to specify fallback formats via -f

[betathetatau]

Please follow the guide below

• You will be asked some questions and requested to provide some information, please read them carefully and answer honestly
• Put an x into all the boxes [ ] relevant to your issue (like that [x])
• Use Preview tab to see how your issue will actually look like

---

Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2016.11.08.1. If it's not read this FAQ entry and update. Issues with outdated version will be rejected.

• I've verified and I assure that I'm running youtube-dl 2016.11.08.1

Before submitting an issue make sure you have:

• At least skimmed through README and most notably FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones

What is the purpose of your issue?

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

---

The following sections concretize particular purposed issues, you can erase any section (the contents between triple ---) not applicable to your issue

---

Description of your issue, suggested solution and other information

Feature request: the ability to specify one or more format code fallbacks with the -f parameter, separated by semicolon delimiters (;). Should work with any site. Two examples:

youtube-dl -f http-720p;http-360p https://vimeo.com/44583147
-- would download http-720p if available;
ELSE, would download http-360p if available;
ELSE, returns standard "ERROR: requested format not available" message and stops.

youtube-dl -f 22;135+140;135,171;18 https://www.youtube.com/watch?v=zDZFcDGpL4U
-- would download 22 if available;
ELSE, would download 135 and 140 (and merge them) if both 135 and 140 are available;
ELSE, would download 135 and 171 (and NOT merge them) if both 135 and 171 are available;
ELSE, would download 18 if available;
ELSE, returns standard "ERROR: requested format not available" message and stops.

Basically, this feature simply implies placing the portion of youtube-dl's code which tests the validity of the -f specification into a while() loop that repeats the test for each substring between semicolons. The while loop ends only upon finding the first match, or upon running out of possibilities.

The reason I need this feature (and believe others would benefit from it too) is that it would make batch downloading easier for those who would normally just do "-f best", but who have slow broadband and/or storage space limitations and/or preferences for certain container formats and/or preferences for specific download protocols (i.e. http vs. hls). My feature request is therefore just a way of restricting the action of "-f best" so that it operates within a user-specified list of qualities/formats/protocols -- and according to the user's own personal definition of best;to;worst.

[dstftw]

Did you even read FAQ? It's already supported with /.