I wrote in a previous post that
Youtube changed their way of delivering videos, with the use of
Dynamic Adaptive Streaming over HTTP. On top of that, they
started serving both the audio and the video in separate streams, which
meant trouble for downloader tools like
As I mentioned in that previous post:
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.
And latter, I wrote:
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).
Well, now, we don't have this problem anymore:
The new release of
youtube-dl brings us many goodies, including that it is
possible to automatically combine/merge/multiplex audio and video formats
that Youtube now offers separately (See the previous comments about separate
audio and video).
Now, if you want a 480p video in H.264 format, High profile, with 128kbps
AAC audio (this used to be Youtube's format 35), you can specify format
135+140 on the command-line and it will download both the audio, the video
and multiplex it with
avconv, depending on what you have
Besides being convenient, this automatic downloading and merging makes it unnecessary to write scripts to, say, retrieve all the videos in a playlist that contains a lot of lectures (see one example here, taught by Benedict Gross).
Version 2014.02.17 of
youtube-dl will be soon in your favorite mirror of
the Debian archives.