git-annex/doc/tips/downloading_podcasts.mdwn
Joey Hess f2db6da938
default to yt-dlp and fix progress parsing bugs
I noticed git-annex was using a lot of CPU when downloading from youtube,
and was not displaying progress. Turns out that yt-dlp (and I think also
youtube-dl) sometimes only knows an estimated size, not the actual size,
and displays the progress output slightly differently for that. That broke
the parser. And, the parser was feeding chunks that failed to parse back
as a remainder, which caused it to try to re-parse the entire output each
time, so it got slower and slower.

Using --progress-template like this should avoid parsing problems as well
as future proof against output changes. But it will work with only yt-dlp.

So, this seemed like the right time to deprecate youtube-dl, and default
to yt-dlp when available.

git-annex will still use youtube-dl if that's all that's available.
However, since the progress parser for youtube-dl was buggy, and I don't
want to maintain two different progress parsers (especially since
youtube-dl is no longer in debian unstable having been replaced by
yt-dlp), made git-annex no longer try to parse youtube-dl's progress.

Also, updated docs for yt-dlp being default. It did not seem worth
renaming annex.youtube-dl-options and annex.youtube-dl-command.

Note that yt-dlp does not seem to document the fields available in the
progress template. I found them by reading the source and looking at
the templates it uses internally. Also note that the use of "i" (rather
than "s") in progressTemplate makes it display floats rounded to integers;
particularly the estimated total size can be a float. That also does not
seem to be documented but I assume is a python thing?

Sponsored-by: Joshua Antonishen on Patreon
2023-05-27 13:04:53 -04:00

98 lines
3.9 KiB
Markdown

You can use git-annex as a podcatcher, to download podcast contents.
No additional software is required, but your git-annex must be built
with the Feeds feature (run `git annex version` to check).
All you need to do is put something like this in a cron job:
`cd somerepo && git annex importfeed http://url/to/podcast http://other/podcast/url`
This downloads the urls, and parses them as RSS, Atom, or RDF feeds.
All enclosures are downloaded and added to the repository, the same as if you
had manually run `git annex addurl` on each of them.
git-annex will avoid downloading a file from a feed if its url has already
been stored in the repository before. So once a file is downloaded,
you can move it around, delete it, `git annex drop` its content, etc,
and it will not be downloaded again by repeated runs of
`git annex importfeed`. Just how a podcatcher should behave. (git-annex versions
since 2015 also tracks the podcast `guid` values, as metadata, to help avoid
duplication if the media file url changes; use `git annex metadata ...` to inspect.)
## templates
To control the filenames used for items downloaded from a feed,
there's a --template option. The default is
`--template='${feedtitle}/${itemtitle}${extension}'`
Other available template variables:
feedauthor, itemauthor, itemsummary, itemdescription, itemrights, itemid,
itempubdate, author, title.
## catching up
To catch up on a feed without downloading its contents,
use `git annex importfeed --relaxed`, and delete the symlinks it creates.
Next time you run `git annex addurl` it will only fetch any new items.
## fast mode
To add a feed without downloading its contents right now,
use `git annex importfeed --fast`. Then you can use `git annex get` as
usual to download the content of an item.
## storing the podcast list in git
You can check the list of podcast urls into git right next to the
files it downloads. Just make a file named feeds and add one podcast url
per line.
Then you can run git-annex on all the feeds:
`xargs git-annex importfeed < feeds`
## recreating lost episodes
If for some reason git-annex refuses to download files you are certain are in the podcast, it is quite possible it is because they have already been downloaded. In any case, you can use `--force` to redownload them:
`git-annex importfeed --force http://example.com/feed`
## distributed podcatching
A nice benefit of using git-annex as a podcatcher is that you can
run `git annex importfeed` on the same url in different clones
of a repository, and `git annex sync` will sync it all up.
## centralized podcatching
You can also have a designated machine which always fetches all podcstas
to local disk and stores them. That way, you can archive podcasts with
time-delayed deletion of upstream content. You can also work around slow
downloads upstream by podcatching to a server with ample bandwidth or work
around a slow local Internet connection by podcatching to your home server
and transferring to your laptop on demand.
## youtube channels
You can also use `git annex importfeed` on youtube channels.
It will use yt-dlp to automatically
download the videos.
To download a youtube channel, you need to find the feed associated with that
channel, and pass it to `git annex importfeed`. There does not seem to be
an easy link anywhere to get the feed, but you can construct its url
manually. For a channel url like
"https://www.youtube.com/channel/$foo", the
feed is "https://www.youtube.com/feeds/videos.xml?channel_id=$foo"
Use of yt-dlp is disabled by default as it can be a security risk.
See the documentation of annex.security.allowed-ip-addresses
in [[git-annex]] for details.)
## metadata
As well as storing the urls for items imported from a feed, git-annex can
store additional [[metadata]], like the author, and itemdescription.
This can then be looked up later, used in [[metadata_driven_views]], etc.
To make all available metadata from the feed be stored:
`git config annex.genmetadata true`