Buffer next videos in the playlist

[sebast889]

I would like to load a Youtube playlist and buffer them before they start playing. For example if I load a playlist with 5 videos and I'm still on the first video which has fully buffered I would then like it for mpv to start buffering video 2 then video 3 etc. so I don't have to wait for it to download only once start to play video 2. Is it currently possible to do this? If not, is it possible to add a way to do this?

[haasn]

It's almost possible, but needs a bit of massaging. mpv can already pre-buffer videos from a playlist, even ones from a remote source, since e277fad.

The problem is that youtube videos are not real URLs until they're processed by the ytdl_hook.lua, which runs only once the URL is actually being played back.

With a bit of refactoring, this could be made to where ytdl_hook.lua is instead called (at arbitrary times, not necessarily just when attempting playback) by mpv to resolve youtube URLs. Then --prefetch-playlist could be made to work with them.

[sebast889]

Oh, nice. It would be great if it could be made to work with youtube/ytdl URLs!

[bitingsock]

I have a working prototype if anyone would like to try: https://gist.github.com/bitingsock/f9a87ea158035d4a36899b559d611228
It only gets the url and title for now. On line 6 ("< 10") you can set how much time ytdl gets called before the demuxer reaches the end of the cache. By default, it will call at 10 seconds from the end of the cache. You still need --prefetch-playlist for it to start buffering, assuming it actually is working. It does not support DASH playback as it just uses the "-f best" format.

[bitingsock]

So it looks like when the demuxer reaches eof it checks for prefetch and the url has to be resolved at that time. Can the prefetch code be recalled after this point to try again?

[sebast889]

@bitingsock I've tried to get it to work by fiddling with line 6 value but can't get it doesn't buffer before the next video. Don't know if I'm doing anything wrong. Maybe I will try on another machine (though the script seems to be windows only..can it be made to work on nix?)

[bitingsock]

I think if you remove ".exe" from line 2 it should work on *nix. Keep in mind, the active cache shown in mpv does not include the the prefetch buffer. I had to monitor network traffic in order to verify.

[bitingsock]

I've discovered that a lot of usefulness of my script doesn't actually work :(
It appears --prefetch-playlist doesn't actually fill the cache with subsequent data and merely opens the url and keeps it active, downloading what appears to be header and metadata and mpv just waits for that file to actually be playing before downloading any more.

[ge9]

At least for youtube, we can get internal audio urls by -O url option of youtube-dl (yt-dlp) and pass them to mpv for gapless playback. if we use -O title together and translate the input to .m3u format, we can display its title. Note that this does not support video data (because internal urls are audio- or video-only), and urls will expire in 6 hours (according to the expire= parameter in urls).

[ge9]

This is my yt-mpv.sh (works as yt-mpv.sh [youtube URL with playlist id] [number of musics to play] [other mpv options])

#!/bin/sh
cd /path/to/mpv_dir
ARR=(`echo $1 | sed -r "s/^.*(www|music)\.youtube\.com\/watch\?v=[^&]+&list=([^&]+)&index=([^&]+)$/\1 \2 \3/"`)
if [ ${ARR[0]} = "www" ]; then
  NA_OPTION="--compat-options no-youtube-unavailable-videos"
fi
INDEX=${ARR[2]}
if [ "$2" != "0" ]; then
  END_INDEX=`expr $INDEX + $2 - 1`
fi
shift 2
yt-dlp $NA_OPTION -f 251 --extractor-args "youtube:lang=ja" -O title -O url -I $INDEX:$END_INDEX ${ARR[1]} | sed '1~2 s/^/#EXTINF:-1,/' | sed '1i#EXTM3U' | ./mpv.exe --player-operation-mode=pseudo-gui --prefetch-playlist=yes --playlist=- $@

[bukowa]

Hey it's been a while, did anything change?

[gabreek]

I think I solved the problem. First, I modified an existing mpv-handler to handle adding videos to
the queue via the mpv socket. Then, I implemented prefetch compatibility by using yt-dlp to extract
the direct video URLs before adding them to the queue. Now, I've finished implementing full playlist
handling.

To enable this, you need to configure mpv to use a socket and then use my custom protocol handler,
which manages the queue externally.

Here's a breakdown of how the solution works:

• External Protocol Handler: I've built a handler (mpv-handler) that intercepts mpv:// URLs. This
  handler contains all the logic, so no changes to mpv's core are needed.

• Playlist Detection & Prefetching: When a URL is passed, the handler uses yt-dlp to check if it's a
  playlist. If it is, it fetches the direct, playable URLs for the videos. This is the crucial
  pre-fetching step that avoids buffering, as mpv receives a direct link to the media, not just a
  webpage URL.

• Queueing via IPC Socket: The handler then sends these direct URLs to the running mpv instance via
  its IPC socket, using the loadfile append command to build the queue seamlessly in the
  background.

• Interactive Control: To make it user-friendly, if a playlist is detected, the handler shows a zenity
  dialog asking the user how many videos to queue (with '0' for all). It has a 10-second timeout that
  defaults to queueing the entire playlist. The user can also choose to play only the first video,
  ignoring the rest of the playlist.

How to use it:

1. Configure your mpv.conf
   Create or edit your ~/.config/mpv/mpv.conf with these recommended settings for the best experience.
   The handler is designed to work with these options.

 # --- IPC and Handler Configuration ---
# Enables the socket for the handler to communicate with mpv (required).
input-ipc-server=/tmp/mpvsocket

# --- YouTube/Streaming Quality ---
 # The handler will read this format to pre-fetch the correct quality.
ytdl-format=bestvideo[height<=?1920][fps<=?30][vcodec^=avc]+bestaudio/best

# Ensures mpv's internal hook uses the correct yt-dlp binary
script-opts=ytdl_hook-ytdl_path=/usr/local/bin/yt-dlp

# --- Caching and Prefetching ---
# These options ensure smooth playback and minimize buffering for streamed content.
prefetch-playlist=yes
cache=yes
demuxer-readahead-secs=300
demuxer-max-bytes=500M

2. Use the Custom Handler
   You need to compile and install my mpv-handler and associate it with the mpv:// protocol on your
   system (e.g., using a .desktop file on Linux).

3. (Optional) Install zenity
   For the interactive playlist dialog, you need to have zenity installed. If it's not found, the dialog
   is skipped, and the handler will default to loading the entire playlist.

This approach effectively solves the pre-loading issue by preparing a queue of direct media links for
mpv to consume, all managed by the external handler. You can find the code for the handler here: https://github.com/gabreek/mpv-handler-queue

browser script: https://greasyfork.org/en/scripts/542145-play-with-mpv-enhanced

enqueue mode need to be activated in the script configuration, available via settings pannel:

• Access: On any of the supported sites (YouTube, Twitch, etc.), hover your mouse over the bottom-left corner of the screen. A settings gear icon will appear. Click it.

I don't have a windows machine atm so unfortunatelly code is written for linux you'll need to write some code to get it working on windows