Device to connect classic audio systems to the network https://cgit.xengineering.eu/soundbox/atom?h=0.1.0 2024-02-02T20:21:51Z 2024-02-02T20:21:51Z xengineering me@xengineering.eu 2024-02-02T20:21:51Z urn:sha1:65bd53fb8c324c2237ccd9ce06bb9f3d47222f1f Since the name is contained inside the mail address it is not required to add both. Adding the email address is important for all kinds of feedback. This might include general reactions to the project, feature requests, legal questions or patches for improvements. 2024-02-02T20:21:00Z xengineering me@xengineering.eu 2024-02-02T20:21:00Z urn:sha1:94d7ae0f681a2ab325f865d48a3a5131fdec4ebe This is very important information for every reader so it should be part of the first section. 2024-02-02T20:06:23Z xengineering me@xengineering.eu 2024-01-21T08:28:01Z urn:sha1:8a6065d53dcbc1f0cedd6925681b43c9c5e0b890 The text of each used license is added to the documentation PDF since this might be passed to third parties without the source or build tree. Adding the licenses to the PDF makes sure they are always accessible. 2024-02-02T19:57:44Z xengineering me@xengineering.eu 2024-02-02T17:44:46Z urn:sha1:52e93507245fb2c2421f0d324d6af1724ea847a9 The CERN Open Hardware License is not restricted to mechanical or electrical design files but instead has a very wide scope (see section 1.3 of the OHL). Thus it can be applied to all contents of this repository. Having only one license makes the license structure for this project way easier. Since the OHL is written with hardware in mind it likely fits better to this open hardware project. 2024-01-30T20:14:44Z xengineering me@xengineering.eu 2024-01-30T20:14:44Z urn:sha1:9af2e3c3357ff738700e89dd816fd4162fd3bfcf The lldpd homepage [1] mentions Unix operating systems as host systems, not only Linux. Furthermore there is a possibly working homebrew package for MacOS. [1]: https://lldpd.github.io [2]: https://formulae.brew.sh/formula/lldpd#default 2024-01-30T19:55:46Z xengineering me@xengineering.eu 2024-01-30T19:55:46Z urn:sha1:32be56460a716aa0a1e14b9c29b1b98fb8fe4750 2024-01-30T19:42:07Z xengineering me@xengineering.eu 2024-01-30T19:40:35Z urn:sha1:57e12bcf9aafcd6bea41e895e14fdd2e6f6d8479 Since otherwise the Git describe output / version information is only embedded into the file name the risk is given that Git version information is lost by renaming the file. 2024-01-30T19:33:12Z xengineering me@xengineering.eu 2024-01-30T19:33:12Z urn:sha1:a4906e5da055d9f47b98e16a72b804bbfc6eb3e1 The new format is closer to e.g. 'man 1 printf'. 2024-01-30T19:26:00Z xengineering me@xengineering.eu 2024-01-30T19:26:00Z urn:sha1:718422591a603223ff64f7d056d4b2f986109530 This was never part of an installation but instead of a configuration step. 2024-01-30T19:05:07Z xengineering me@xengineering.eu 2024-01-30T19:05:07Z urn:sha1:8c883f04f9c07d1a14a34daaac99250c0ae6b97e This is the central reference what is required to build soundbox devices. 2024-01-30T18:11:53Z xengineering me@xengineering.eu 2024-01-28T13:23:47Z urn:sha1:9faebc1cfb5153e9b1961863d2930958464f4132 The introduction was very limited so far but is important to manage expectations regarding the device. 2024-01-28T12:33:58Z xengineering me@xengineering.eu 2024-01-28T12:33:58Z urn:sha1:996ee12aa51c8279257991d76d11c14e7e0302f6 This new chapter should be the one with the highest level of details. The section about versioning is also moved there with this commit. 2024-01-27T21:25:30Z xengineering me@xengineering.eu 2024-01-27T21:25:30Z urn:sha1:62d68edfef3afaae315c020f20e0cc6ff7ad5719 Using the date of the build makes it not-reproducible. This should be avoided. Furthermore the date on the front page should anyway reflect when the source of the document was created. Not when it was converted into a PDF. 2024-01-27T21:02:27Z xengineering me@xengineering.eu 2024-01-24T19:43:54Z urn:sha1:c79f077db7a79dd953bee68c51b1c4b863051d62 The following changes are included in this commit: - multicast to unicast - UDP to TCP - Matroska to ogg - MP3 to FLAC Switching to these protocols has several advantages. Avoiding multicast makes it unnecessary to care about the available multicast addresses in the local network. Unicast addresses are anyway assigned by DHCP. In a multi-room setup this has of course the disadvantage that the same data might be streamed via separate connections. The bandwidth requirement would be multiplied by the number of soundbox devices. But since a stream takes around 2 Mbit/s and we live in a world where 100 Mbit/s in a local network should not be a problem the inefficiency can be neglected. Switching from UDP to TCP has the advantage that the stream is transmitted reliably. Furthermore it avoids the situation that multiple clients stream to the same soundbox simultaneously since a single-connection TCP server is used. The switch from Matroska to ogg is done because the ogg format is recommended on the FLAC homepage. FLAC is used instead of MP3 because it is a lossless audio compression format. This is obviously superior compared to the lossy MP3 format regarding audio quality. 2024-01-21T08:19:43Z xengineering me@xengineering.eu 2024-01-21T08:19:43Z urn:sha1:38d6997e5f6bd725b28c8cc6ed28cda670a2e900 The default streaming guide is now far away from the original taken from the FFmpeg streaming guide. Since the command can handle a lot of inputs its also not useful to send sine waves to soundbox devices. 2024-01-20T20:55:22Z xengineering me@xengineering.eu 2024-01-20T20:55:22Z urn:sha1:090e063a539f6ee6e62e65ada619787930c31eac 2024-01-20T20:25:20Z xengineering me@xengineering.eu 2024-01-20T14:20:02Z urn:sha1:ce3aad39474789faa7e3c8fd49a6f401c8fa3c01 This makes sure the audio-receiving software `ffplay` runs all the time. 2024-01-20T14:12:42Z xengineering me@xengineering.eu 2024-01-20T14:12:42Z urn:sha1:e7f055deddf551c32de631c4579c53589ea14948 2024-01-20T11:05:15Z xengineering me@xengineering.eu 2024-01-19T15:33:22Z urn:sha1:75a661f088ff48b87c67af4ed14d8dc162e3bb93 This makes a soundbox device discoverable via the Link Layer Discovery Protocol (LLDP). That way a client application can lookup the available soundbox devices inside the network to display playback options. 2024-01-14T19:50:59Z xengineering me@xengineering.eu 2024-01-14T19:50:59Z urn:sha1:36341f1e9856e17ad00e3741bb5bc1224aadc225 While transcoding to a lossy formate like MP3 is not recommended [1] forquality reasons it has the advantage that alway UPD / Matroska / MP3 is used for soundbox. That way the stream can be stopped and started at any time without re-launching ffplay on the soundbox device. This could make the SSH connection to the soundbox not longer needed. [1]: https://trac.ffmpeg.org/wiki/Encode/HighQualityAudio#WhenshouldItranscodeaudio 2024-01-14T19:48:43Z xengineering me@xengineering.eu 2024-01-14T19:48:43Z urn:sha1:6a05f26e4a7726fa719a55b5918b0262b27c02ba 2024-01-14T19:27:05Z xengineering me@xengineering.eu 2024-01-14T19:27:05Z urn:sha1:8a47aec3581f0272677ffbbbc9d488c50fbd973d The Matroska format has to advantage that a stream can be stopped and the restarted at any time without executing new commands on the soundbox device. Since Matroska and RTP have similar / redundant features [1] the transport protocol is switched to plain UDP. [1]: https://en.wikipedia.org/wiki/Comparison_of_video_container_formats#cite_note-22 2024-01-14T14:46:35Z xengineering me@xengineering.eu 2024-01-14T14:46:35Z urn:sha1:e94b3cc341a4a641ca41cc95f3b8ae907654e34a 2024-01-14T13:14:45Z xengineering me@xengineering.eu 2024-01-14T13:14:45Z urn:sha1:a7dc6b07781cb7901e9bbcffbe0d5ffa1c690c73 This allows to stream to multiple devices at the same time. Nevertheless it still works for a point to point stream. 2024-01-14T13:10:35Z xengineering me@xengineering.eu 2024-01-14T13:10:35Z urn:sha1:afe7b5fb9921dd990719e5823a7fd30553d3ed23 The soundbox software should be portable to other Raspberry Pis without the HiFiBerry DAC too. 2024-01-14T11:22:51Z xengineering me@xengineering.eu 2024-01-14T11:22:51Z urn:sha1:41c73098b35dd820d22b557363fcd1aaed6133ae 2024-01-14T11:04:06Z xengineering me@xengineering.eu 2024-01-14T11:04:06Z urn:sha1:0b0ca08ee8a4954c59ea2421f7e7dfcf1272baff The music streaming documentation used to enforce re-encoding via ffmpeg to save bandwidth. This led to pretty poor audio quality. This is not the purpose of soundbox. It is assumed that the user wants the highest possible audio quality as default. 2024-01-14T10:44:18Z xengineering me@xengineering.eu 2024-01-06T09:50:09Z urn:sha1:27c2557c21cae2af48b9ba298149c6fe9cceb96f Configuring the Alpine Linux operating system correctly for soundbox is not trivial. Since it is very important it has to be documented in detail. 2024-01-14T10:44:12Z xengineering me@xengineering.eu 2024-01-13T16:04:53Z urn:sha1:5f62cff66916db54f3be0c9fbc6198253ef7b6f0 The tar-based installation is more difficult to explain but has the advantage that the partition size is maximized from the beginning. This is way easier than resizing the partition after the installation. 2024-01-12T21:02:02Z xengineering me@xengineering.eu 2024-01-05T21:14:44Z urn:sha1:bfbdcfad3489f943748fa584972d27c9255d365b This is currently the recommended OS installation for soundbox.