Repository: yt-dlp
Issue: Sponsorblock integration and YouTube via MPV
Labels: enhancement

### Checklist

- [X] I'm asking a question and **not** reporting a bug/feature request
- [X] I've looked through the [README](https://github.com/yt-dlp/yt-dlp#readme)
- [X] I've read the [guidelines for opening an issue](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#opening-an-issue)
- [X] I've searched the [bugtracker](https://github.com/yt-dlp/yt-dlp/issues?q=) for similar questions including closed ones

### Question

Hi, 
I've searched through the readme and did a cursory search through the issues, and I haven't seen anyone ask this question. 

For a while now, yt-dlp works with sponsorblock, and is able to create chapters in the download for the various categories. When I'm using yt-dlp with MPV to play youtube videos via URL, I would like yt-dlp to pass along those chapters to MPV, so that I can easily skip those sections. 

How can I tell yt-dlp to pass along those chapters to MPV while playing the video from URL? I've added the log output of one of those videos that has a lot of sponsorblock categories, unfortunately they don't make it to the MPV player. Only by downloading the full video, then opening it from disk can I access those chapters. Is there a method to pass along those chapter markings to MPV while the video is being played from URL? I know that I can tell MPV to select specific video qualities via the following option in mpv.conf:

`ytdl-format=bestvideo[height<=?1080]+bestaudio/best`

for example, but I haven't had any luck to get the sponsorblock chapters to work. Is there anything I'm missing here, and is what I want to do even possible in the first place?

### Verbose log

```shell
C:\Users\users\Videos>youtube-dl -v -f 299+140 --sponsorblock-mark all https://www.youtube.com/watch?v=at-xZA5U1ps
[debug] Command-line config: ['-v', '-f', '299+140', '--sponsorblock-mark', 'all', 'https://www.youtube.com/watch?v=at-xZA5U1ps']
[debug] Encodings: locale cp1252, fs utf-8, out utf-8, err utf-8, pref cp1252
[debug] yt-dlp version 2022.03.19.025804 [f1ddb8f] (win_exe)
[debug] Python version 3.8.10 (CPython 64bit) - Windows-10-10.0.19044-SP0
[debug] exe versions: ffmpeg 2022-03-07-git-e645a1ddb9-essentials_build-www.gyan.dev (setts), ffprobe 2022-03-07-git-e645a1ddb9-essentials_build-www.gyan.dev
[debug] Optional libraries: brotli, Cryptodome, mutagen, sqlite, websockets
[debug] Proxy map: {}
[debug] [youtube] Extracting URL: https://www.youtube.com/watch?v=at-xZA5U1ps
[youtube] at-xZA5U1ps: Downloading webpage
[youtube] at-xZA5U1ps: Downloading android player API JSON
[debug] Loading youtube-nsig.577098c0 from cache
[debug] [youtube] Decrypted nsig SHZ-fTYqpnWLrPUq => GKnGghRx-0Jkhg
[debug] Sort order given by extractor: quality, res, fps, hdr:12, source, codec:vp9.2, lang, proto
[debug] Formats sorted by: hasvid, ie_pref, quality, res, fps, hdr:12(7), source, vcodec:vp9.2(10), acodec, lang, proto, filesize, fs_approx, tbr, vbr, abr, asr, vext, aext, hasaud, id
[SponsorBlock] Fetching SponsorBlock segments
[debug] SponsorBlock query: https://sponsor.ajay.app/api/skipSegments/39a4?service=YouTube&categories=%5B%22outro%22%2C+%22preview%22%2C+%22music_offtopic%22%2C+%22sponsor%22%2C+%22selfpromo%22%2C+%22interaction%22%2C+%22poi_highlight%22%2C+%22intro%22%2C+%22filler%22%5D&actionTypes=%5B%22skip%22%2C+%22poi%22%5D
[SponsorBlock] Found 12 segments in the SponsorBlock database
[info] at-xZA5U1ps: Downloading 1 format(s): 299+140
[debug] Invoking downloader on "https://rr2---sn-uxa0n-t8gz.googlevideo.com/videoplayback?expire=1647816752&ei=0Fs3YufXCNKtkgal_oywBA&ip=75.157.135.34&id=o-ANksHN1_1dpuf8doJUt_8u1lqKJR9Gf0e5mBsnBCh4kG&itag=299&source=youtube&requiressl=yes&mh=j9&mm=31%2C26&mn=sn-uxa0n-t8gz%2Csn-vgqsrnek&ms=au%2Conr&mv=m&mvi=2&pl=22&initcwndbps=1917500&vprv=1&mime=video%2Fmp4&gir=yes&clen=805188650&dur=1413.295&lmt=1638926785689517&mt=1647794449&fvip=2&keepalive=yes&fexp=24001373%2C24007246&c=ANDROID&txp=5532432&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRgIhAPCJMxOCh5YrC9m8Vc8h_TC3MUff_uen_P7kuFJkQJGTAiEAqVoNhVRgCbmihdAIIbgSvUSdTQEzveYKfvuLemdgfds%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgNF606WR9VvxbV9yKDgQZ_1GornunBYe7Bex95VPDc-wCIQD2UEl9-fNX7M5aoY8-rkUaiutvF8xybOUusa5NvFxJ8w%3D%3D"
[download] Destination: What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f299.mp4
[download] 100% of 767.89MiB in 00:27
[debug] Invoking downloader on "https://rr2---sn-uxa0n-t8gz.googlevideo.com/videoplayback?expire=1647816752&ei=0Fs3YufXCNKtkgal_oywBA&ip=75.157.135.34&id=o-ANksHN1_1dpuf8doJUt_8u1lqKJR9Gf0e5mBsnBCh4kG&itag=140&source=youtube&requiressl=yes&mh=j9&mm=31%2C26&mn=sn-uxa0n-t8gz%2Csn-vgqsrnek&ms=au%2Conr&mv=m&mvi=2&pl=22&initcwndbps=1917500&vprv=1&mime=audio%2Fmp4&gir=yes&clen=22874243&dur=1413.352&lmt=1638926598444503&mt=1647794449&fvip=2&keepalive=yes&fexp=24001373%2C24007246&c=ANDROID&txp=5531432&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=AOq0QJ8wRQIgfHePe3KOh_8P5DQB33-7PxXOgvPY02WdmaFcC2KzpssCIQCHm2ZgnfqhBbUPlIAB14V45KtKXbxxhh-ITGPZSY6Y7w%3D%3D&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AG3C_xAwRQIgNF606WR9VvxbV9yKDgQZ_1GornunBYe7Bex95VPDc-wCIQD2UEl9-fNX7M5aoY8-rkUaiutvF8xybOUusa5NvFxJ8w%3D%3D"
[download] Destination: What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f140.m4a
[download] 100% of 21.81MiB in 00:00
[Merger] Merging formats into "What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].mp4"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f299.mp4" -i "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f140.m4a" -c copy -map "0:v:0" -map "1:a:0" -movflags "+faststart" "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].temp.mp4"
Deleting original file What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f140.m4a (pass -k to keep)
Deleting original file What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].f299.mp4 (pass -k to keep)
[debug] ffprobe command line: ffprobe -hide_banner -show_format -show_streams -print_format json "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].mp4"
[Metadata] Adding metadata to "What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].mp4"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].mp4" -i "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].meta" -map 0 -dn -ignore_unknown -c copy -map_metadata 1 -movflags "+faststart" "file:What does a Gong Sound Like when Hit with a 1189mph Baseball - Smarter Every Day 267 [at-xZA5U1ps].temp.mp4"
```