Skip to content

Latest commit

 

History

History
80 lines (46 loc) · 5.17 KB

README.md

File metadata and controls

80 lines (46 loc) · 5.17 KB
Raw

moOde CD play

This repo contains code to add a CD playback function to the Raspberry Pi-based moOde audio player (http://moodeaudio.org).

The code assumes that a CD drive suitable for audio playback is already connected to the Raspberry Pi hosting the moOde player and is recognized by Raspbian as device /dev/cdrom.

Status

On May the 14th, I restarted to develop that small project that was sleeping since a year.

History

This work began as a contribution to the moOde project from Ashley Cox (https://ashleycox.co.uk/), communicated in email correspondence in the summer of 2019 with Tim Curtis (moOde maintainer) and Kent Reed (TheOldPresbyope). That contribution subsequently has been modified and extended by Kent Reed. In his emails, Cox granted the moOde project full permission to use his contribution. An MIT license is used in this repo to grant explicitly this permission by both authors to all users. It is believed to be compatible with the GPL license used in the moOde codebase.

Similar work is described in https://github.com/TongboZhang/Moode_Extension. See additional links there.

On May 14, 2021, I forked the moOdeCDPlayer project maintained by [TheOldPresbyope] (https://github.com/TheOldPresbyope) and started redeveloping the code of the two main scripts and adding a few other pieces of code. During the following long weekend I completely rewrote the main scripts and replaced them with a python application moodecdplayer. Due to the very low similarity of the new code to Kent's original (TheOldPresbyope), and to remove any confusion between the two now separate projects, I renamed the moOdeCDPlay repository to moOdeCDPlayer.

Design Intent

We intend the moOde CD playback function to mimic the behavior of a standalone CD player.

When an audio CD is inserted into the player, the new CD is inspected and the MPD queue is filled with its tracks.

When the CD is ejected, using the player's manual eject button, the items corresponding to the CD are removed from the MPD queue. If any of the tracks on the CD were playing, the playback will stop.

After the CD is ejected, moOde only keeps the metadata of the CD tracks and the album art in a cache. This is done to speed up the next play of the same CD. The music on the CD is not stored on the raspberry. So saving a track as a favorite or setting it on the clock radio will result in an error later when moOde tries to play it.

Responsiveness

This responsiveness was estimated by previous developpers. I never timed them again. But that information can be useful for people not used to listen this old fashionned music devices.

An optical CD drive is very slow compared to other storage devices. Then, too, the nature of the CDDA (compact disk digital audio) encoding complicates retrieving audio tracks from the CD. In addition, there is internal buffering involved.

Some sample timings (expect variations with different hardware):

  • Load a CD and display the track list: 12s
  • Select track 1 and begin playing: 14s
  • Change from track to track: 3s
  • Return to track 1 from track 7: 10s

Moving backwards and forwards within a track also takes time.

The moOde time dial reading is suspect while these actions are occurring.

Once extracted, on the other hand, an audio CD track is played back at 44.1KHz/16bit just as if it were decoded from, say, a FLAC-encoded file.

Planned Evolution of Releases

  • In Version 0 (the orginal release by TheOldPresbyope), the CD track list consists of primitive "cdda:///1", cdda:///2", etc., entries. The default moOde logo is displayed for all tracks, and, for each track played, the information displayed below the logo is an ugly "File does not exist" and "Unknown artist - Unknown album"

  • Version EC1 is able to extract the track metadata from the CD text or MusicBrainz. But the information displayed below the logo is still ugly.

  • Version EC1.1 displays correctly information displayed below the logo. The cover of the disk, when available on MisicBrainz is installed but a refresh of th UI is need to show it up on the screen.

Installation

The Version 0 code is contained in two simple scripts, two corresponding systemd service files, and a udev ruleset.

The simplest method of installation is to click the green github "Clone or download" button and then click the "Download ZIP" button which appears. The zip file moOdeCDPlay-master.zip will be offered for download to your local host.

  1. Download and transfer this file to the /home/pi directory in the target moOde player

  2. On the target moOde player, go to the /home/pi directory and unzip the file

  3. Change to the /home/pi/moOdeCDPlayer-master directory which has been created

  4. Execute the command . install.sh.

  5. Once the script finishes successfully, you should reboot. At this point the moOde CD playback function should be working and you can delete both moOdeCDPlay-master.zip and the moOdeCDPlay-master directory.

Good listening!

Odds and Ends

Hardware

This code was developed on the following system

  • moOde 7.2.1
  • RPi3B
  • DVD player : HL-DT-ST DVDRAM GT30N [purchased new on-line for less than 20€]. It is a bit too noisy