For those wondering why the Ext won't merge. It is reported that large-size video is very likely to be interrupted while downloading, which will fail in starting any follow-up process (including merging) even such download can be continued to finish. So it is suggested to have another ffmpge-based media converter Ext and do the merging manually, which maybe the season those function in early version be cancelled.

Succeeds where others fail. Works well except for the highest HD videos. Those are streamed by YT as separate audio/video. This fails to capture and then merge those separate HD streams. However, 720P is good enough for my research purposes. Not looking for a theater experience. Addon may present too many confusing options for noobs, tho.

Since around 1 year, the extension doesn't merge the audio file with the video file anymore : finally, we end up with a video without sound.

the only application that allows me to download private videos from you tube

it works

It is a MUST add-on for FF w/YouTube

It used to work but at this point? Not sure anymore.
Downloads both the audio and video but doesn't compile em. And if it was doing it there is like Zero notification on the progress.

I had used it for so long, did a really great job. Now it stopped working because of "Batch downloading is interrupted", its a pity.

Installed the executable and ffmpeg and included the path. And then NOTHING.No logo below videos. NOTHING.

it's work! Thanks

works fine but the download speed is very slow