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title: Vaporwave in Pocket C.H.I.P. Framebuffer
tags: chip hack 100daystooffload
date: 2021-03-19
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Intro
In the ever expanding ways to hack my Pocket C.H.I.P., and my recent
discovery of Vaporwave, I couldn’t help but combine the two and have a
looping music video device on my desktop. Note this is not running in
X, but in the console framebuffer, which gives it more
ＡＥＳＴＨＥＴＩＣＳ.
[my Pocket C.H.I.P.]: https://www.ecliptik.com/Pocket-CHIP/
[Vaporwave]: https://en.wikipedia.org/wiki/Vaporwave
[Vaporwave in Pocket C.H.I.P]
[Vaporwave in Pocket C.H.I.P]: /assets/images/posts/chip_vaporwave/chip-vaporwave.png
NEON PALM MALL in C.H.I.P. Framebuffer
Required Software
The C.H.I.P. is fully upgraded to Debian Buster, and there were some
oddities with getting dpkg sorted out, so the package installs may not
work exactly as defined here but are a general guide. It’s also
booting into the console framebuffer and not X, so there’s no desktop
environment or window manager running.
[booting into the console framebuffer]: http://www.chip-community.org/index.php/Setting_up_text_mode_on_PocketCHIP_4.3
The following tools are used,
- mplayer, for playback with framebuffer and armhf support
- alsa-utils, specifically alsamixer to control volume from console
- youtube-dl, download video+audio from youtube
- ffmpeg, combine video+audio from youtube-dl
[mplayer]: https://mplayerhq.hu/design7/news.html
[alsa-utils]: https://github.com/alsa-project/alsa-utils
[youtube-dl]: https://youtube-dl.org/
[ffmpeg]: https://ffmpeg.org/
Install packages,
$ sudo apt-get update
$ sudo apt-get install -y ffmpeg mplayer alsa-utils
Install youtube-dl,
$ sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
$ sudo chmod a+rx /usr/local/bin/youtube-dl
Downloading Videos
Using youtube-dl, download a Vaporwave video. The Pocket C.H.I.P. is
very particular about the screen resolution and codec of the video.
Anything larger than the C.H.I.P. screen (480×272) will give an error,
and some codecs won’t play. I found the following format combination
works best for video playback.
- resolution: 320x240@240p
- container: mp4
- codec: avc1
For this example we’ll save NEON PALM MALL (Vaporwave Mix + Video).
[NEON PALM MALL (Vaporwave Mix + Video)]: https://www.youtube.com/watch?v=FZUfiW3W1KY
First, use the -F argument to display the list of available formats
and choose the one that best matches,
$ youtube-dl -F https://www.youtube.com/watch?v=FZUfiW3W1KY
[youtube] FZUfiW3W1KY: Downloading webpage
[info] Available formats for FZUfiW3W1KY:
format code extension resolution note
249 webm audio only tiny 48k , webm_dash container, opus @ 48k (48000Hz), 18.74MiB
250 webm audio only tiny 64k , webm_dash container, opus @ 64k (48000Hz), 24.76MiB
251 webm audio only tiny 127k , webm_dash container, opus @127k (48000Hz), 48.90MiB
140 m4a audio only tiny 129k , m4a_dash container, mp4a.40.2@129k (44100Hz), 49.55MiB
394 mp4 192x144 144p 51k , mp4_dash container, av01.0.00M.08@ 51k, 25fps, video only, 19.82MiB
160 mp4 192x144 144p 53k , mp4_dash container, avc1.4d400b@ 53k, 25fps, video only, 20.33MiB
278 webm 192x144 144p 67k , webm_dash container, vp9@ 67k, 25fps, video only, 25.81MiB
133 mp4 320x240 240p 93k , mp4_dash container, avc1.4d400d@ 93k, 25fps, video only, 35.73MiB
395 mp4 320x240 240p 106k , mp4_dash container, av01.0.00M.08@ 106k, 25fps, video only, 40.57MiB
242 webm 320x240 240p 126k , webm_dash container, vp9@ 126k, 25fps, video only, 48.47MiB
396 mp4 480x360 360p 188k , mp4_dash container, av01.0.01M.08@ 188k, 25fps, video only, 72.01MiB
134 mp4 480x360 360p 221k , mp4_dash container, avc1.4d4015@ 221k, 25fps, video only, 84.73MiB
243 webm 480x360 360p 229k , webm_dash container, vp9@ 229k, 25fps, video only, 87.72MiB
397 mp4 640x480 480p 334k , mp4_dash container, av01.0.04M.08@ 334k, 25fps, video only, 127.98MiB
244 webm 640x480 480p 396k , webm_dash container, vp9@ 396k, 25fps, video only, 151.83MiB
135 mp4 640x480 480p 430k , mp4_dash container, avc1.4d401e@ 430k, 25fps, video only, 164.88MiB
18 mp4 480x360 360p 435k , avc1.42001E, 25fps, mp4a.40.2 (44100Hz), 166.58MiB (best)
Find the best format to fit the requirements above, in this example
format code 133 will work best for video.
Download the video and audio (use bestaudio to automatically choose)
and merge into an mp4 container,
$ youtube-dl -f 133+bestaudio --merge-output-format mp4 https://www.youtube.com/watch?v=FZUfiW3W1KY
[youtube] FZUfiW3W1KY: Downloading webpage
[download] NEON PALM MALL (Vaporwave Mix + Video)-FZUfiW3W1KY.f133.mp4 has already been downloaded
[download] 100% of 35.73MiB
[download] Destination: NEON PALM MALL (Vaporwave Mix + Video)-FZUfiW3W1KY.f140.m4a
[download] 100% of 49.55MiB in 00:19
[ffmpeg] Merging formats into "NEON PALM MALL (Vaporwave Mix + Video)-FZUfiW3W1KY.mp4"
Deleting original file NEON PALM MALL (Vaporwave Mix + Video)-FZUfiW3W1KY.f133.mp4 (pass -k to keep)
Deleting original file NEON PALM MALL (Vaporwave Mix + Video)-FZUfiW3W1KY.f140.m4a (pass -k to keep)
Playback
By default the console will blank after a period of time, turn that
off so the screen is always on,
$ setterm -blank 0
Use mplayer to playback the video, the fbdev2 device must be used,
trying directfb for fbdev will result in an mplayer playback error.
$ mplayer -vo fbdev2 -fs -zoom NEON\ PALM\ MALL\ \(Vaporwave\ Mix\ +\ Video\)-FZUfiW3W1KY.mp4
If sound is too loud or quiet, ssh into the C.H.I.P. and use alsamixer
to adjust the volume.
Keyboard controls for mplayer will work on the C.H.I.P. keyboard, with
q to quit and arrow keys to browse the video.
Notes
Overall resource usage isn’t bad, about 25% CPU when playing the video
back with just a slight audio glitch now and then. If CPU gets
stressed, audio and playback will glitch even more. There are ways to
tune mplayer to perform better on lower end systems like the C.H.I.P.,
but I won’t go into detail here as there are many guides out there.
Depending on the video, the mp4 output format may not work and give a
ERROR: Stream #1:0 -> #0:1 (copy) when trying to merge video+audio,
using mkv for the output format is a workaround.