This post is just a bunch of random notes, but I think that things are going well, this time.


Just started playing with btrfs after converting a 2TB disk with about 1.3TB of data from ext4 to btrfs. This particular filesystem contains my backup data and I hope that btrfs is able to live up to high standards.

I will probably write a detailed review with my impressions, but suffice to say that it is working fine and I hope that I will be happy for a long time to come. My other filesystems, for the moment, will be ext4.

Coursera Downloader

Thanks to John Lehmann's generosity, now coursera-dl has a new home: a github organization of its own!


Some people may have noticed, others may not, but when downloading videos from Youtube, they apparently are getting more aggressive with the use of Dynamic Adaptive Streaming over HTTP (also called DASH) and, as a result, some (perhaps going to be all in the near future?) of the videos may not be available in the resolution/formats that you used to like (like me, with format number 35).

By the way, one thing that is interesting with youtube videos provided via DASH is that they are available in different streams: one for the video and another for the audio.

What does this mean in practical terms for users of youtube-dl? Well, if you wanted to download videos in resolutions like the 480p (format 35) that I mentioned, then you will probably have to change your way of doing things, until a more automated solution is in place.

You will have to download both the audio and the video and, then, "combine" them (that is, multiplex them) to create one "normal" video file with both the audio and the video. I usually do this via:

ffmpeg -i audio.m4a -i video.mp4 -vcodec copy -acodec copy combined.mp4

If you prefer having a Matroska container instead of an mp4 container (which, BTW, results in smaller muxing overhead), then you can use the command line:

mkvmerge -o combined.mkv audio.m4a video.mp4

Oh, those m4a and mp4 extensions are a new addition that I just sent upstream (in the past, both would have been named with an extension of mp4).

As, an aside, I like formats 135 for video and 140 for audio, for the reasons that I mentioned in a comments to issue 1612:

Otherwise, to download 480p videos (which I do for lectures and so on with other projects of mine, like edx-dl) I have to call youtube-dl twice: once for format 135 and another for format 140, since the old (?) format 35 files are much smaller than the lower resolution 360p files (due to the former being encoded in High profile vs. the latter being encoded in Constrained Baseline profile).

While this is unfortunate for some, this is a good thing for others: I once had a blind user of youtube-dl asking me if he could avoid downloading the whole video just to extract the audio, so that he save on bandwidth. Well, now this is possible.

Expect a new version of youtube-dl to be uploaded soon to Debian unstable.


It is so nice to see the music that I like getting better. It was particularly pleasant to see Tarja Turunen being joined on stage by Floor Jansen.

In fact, it is my impression that the once female-fronted bands are getting more and more into collaborations and side-projects and they are, in many ways, getting more refined. Examples of this includes Floor, Tarja, Anneke van Giersbergen, Sharon den Adel, Kari Rueslåtten and many others that I can't remember right now.

Of course, some thanks to people that take the time to film, and upload/share the videos so that other people not at these events can watch them is highly appreciated and they usually are treated as anonymous, but, of course, this should be fixed.

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