I need to know if youtube API V3 supports searching inside a specific youtube playlist? And is there any other way to do that?
For doing full-text search in closed captions (CC) in a Youtube channel you may download all the subtitles from the channel and do local text search in it:
$ youtube-dl --write-auto-sub --skip-download "https://www.youtube.com/channel/UC6oh54zIYKyW6hgBiZzLLsA"
that will download about 160 .vtt text files
$ grep -i -C 2 'autumn' *.vtt
Note: Option --write-auto-sub
should be used when author of videos didn't upload text.
Otherwise use --write-sub
.