yt-dlp plugin for converting Bilibili danmaku into ASS format. Powered by biliass.

Requires yt-dlp 2023.01.02 or above.

You can install or upgrade this package with pip:

pip install -U yt-dlp-danmaku

yt-dlp --write-subs --use-postprocessor danmaku https://www.bilibili.com/video/BV1Sm4y1N78J

Bilibili videos are originally mp4 format, but this format does not support ASS subtitle. Therefore, you need to use another format that supports it, such as mkv:

yt-dlp --embed-subs --use-postprocessor danmaku --remux-video mkv https://www.bilibili.com/video/BV1Sm4y1N78J

You can then try playing this video with players that support ASS subtitles, such as mpv and VLC.

You need to run FFmpeg yourself to do this. Here is an example how you can do that:

yt-dlp --write-subs --use-postprocessor danmaku --output input https://www.bilibili.com/video/BV1Sm4y1N78J
ffmpeg -i input.mp4 -vf subtitles=input.danmaku.ass output.mp4
rm input.mp4 input.danmaku.ass

yt-dlp --write-subs --use-postprocessor danmaku:when=before_dl --skip-download https://www.bilibili.com/video/BV1Sm4y1N78J

mpv --script-opts=ytdl_hook-ytdl_path=yt-dlp --ytdl-raw-options=use-postprocessor=danmaku:when=before_dl,write-subs=,no-simulate=,skip-download= https://www.bilibili.com/video/BV1Sm4y1N78J

You can turn on and off danmaku by using j (by default). Add --sid=1 to turn on danmaku on start. You can add these options to your mpv config file.

Notice: this will leave an ASS file in the current directory. Delete it afterwards if you do not want it.

You can pass options to this plugin. For example, to set the opacity of danmaku texts to 0.1 and reserve the bottom 150 pixels, use --use-postprocessor danmaku:text_opacity=0.1;reserve_blank=150. All available options:

Run biliass -h for more information about these options.

See the Plugin Development section of the yt-dlp wiki.

MIT.