Patents On MP3 Format Due To Expire

May 14, 2017 by Lewin Day 51 Comments

MP3 took off in the late 90s as the digital music format. It then proceeded to slaughter the CD, and launch the file sharing revolution as well. It’s a proud format that has roots stretching all the way back to the early 1980s, when the possibility of sending music over ISDN lines was first considered. Now the patents on it are beginning to expire and its licencing program has been terminated.

The MP3 standard was the property of Fraunhofer IIS, and the original licencing model was intended such that encoders would be expensive, and decoders relatively inexpensive. This would allow people to buy software to listen to MP3s cheaply, but the creation of MP3s would be expensive, and thus handled by studios and music labels. This all changed when a high-quality MP3 encoder was leaked to the public, and suddenly it became possible to readily convert your CDs at home into the MP3 format.

One hangover of this ownership of the MP3 standard was that when you installed certain FOSS software, such as Audacity or a Linux distro, you would find that you had to go and do some legwork to find an MP3 codec. That was because it wasn’t worth the legal trouble for the FOSS authors to arrange a workaround, and trading in proprietary software is the antithesis to everything they stand for.

However, now that more of the relevant patents are expiring, you can now expect MP3 support to be baked into more software. It may be more than a little late, with more advanced audio formats beginning to take over, but it’s great to know that Fedora, for one, is starting to include MP3 support with their releases.

If you’d like to read more about the history of the MP3, check out this great article from NPR. Fraunhofer have their own great history site, too. If all this talk of advanced audio formats has gotten you excited, check out this MP3 decoder written for the ESP8266.

[Thanks to Tim Trzepacz for the tip!]

Scratchy Brings Digital Clarity To The Vinyl World

April 1, 2017 by Jenny List 18 Comments

If you walk the halls of audiophilia, you may be aware that there has been a huge amount of work put in to software designed to clean up older audio recordings without compromising the quality of the recording itself. Sometimes the results can be amazing, such as when a stereo image is created from parallel mono recordings made before stereo was even a glint in the eye of a 1930s EMI engineer.

Bob Widlar on analogue versus digital. Original: EDN — [Bob Widlar] on analogue versus digital. Original: EDN.

But what if you are at home, without the benefit of a state-of-the-art studio or high-end digital signal processing? How can you then have pop and crackle free sound from your hi-fi when you put on a piece of vinyl? [Paul Wallace] may just have the answer, he’s made a smartphone app called Scratchy which listens to the output of a turntable, identifies the track being played, and plays the appropriate MP3 file for a digital experience from vinyl. It uses the algorithm published by Shazam to recognize tunes. The software also has a learn mode during which it can be taught about new records in the collection. The app itself is written using the Xamarin framework and has its source code in his GitHup repository, so it’s possible it could be produced for other platforms as well as Android.

Now vinyl purists will be speechless with horror at this wanton desecration of their format while audiophiles will be fuming at the smeary-in-the-midrange MP3s, but we can see its appeal if your vinyl is on the grubby side. It’s fair to say though that the stereo here won’t be sporting it, you’ll tear our analogue signal path from our cold dead hands. Take a look for yourselves, he’s put up a video showing it in operation.

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Bantam-sized Jukebox Reproduction Tops The Fabrication Charts

February 4, 2017 by Dan Maloney 2 Comments

Restoring a genuine vintage jukebox is a fun project, but finding suitable candidates can be a difficult proposition. Not only can a full-size machine take a huge bite out of your wallet, it can take up a lot of room, too. So a replica miniature jukebox might be just the thing.

We have to admit, at first glance [Allan_D_Murray]’s project seemed like just another juke upgrade. It was only after diving into his very detailed build log that we realized this classic-looking juke is only about 30″ (80 cm) tall. It’s not exactly diminutive, but certainly more compact than the original Wurlitzer 1015 from which it draws its inspiration. But it sure looks like the real thing. Everything is custom made, from the round-top case to the 3D-printed trim pieces, which are painted to look like chrome-plated castings. The guts of the juke are pretty much what you’d expect these days — a PC playing MP3s. But an LCD monitor occupies the place where vinyl records would have lived in the original and displays playlists of the albums available. There’s an original-looking control panel on the front, and there are even bubblers in the lighted pilasters and arches.

Hats off to [Allan] for such a detailed and authentic tribute to a mid-century classic. But if a reproduction just won’t cut it for you, check out this full-size juke with the original electronics.

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Sansa MP3 Player Runs Doom Unplayably

December 30, 2016 by Lewin Day 25 Comments

DOOM, is there anything it won’t run on? Yes. Your front lawn cannot currently play DOOM. Pretty much everything else can though. It’s a testament to the game’s impact on society that it gets ported to virtually every platform with buttons and a graphical screen.

This video shows a Sansa Clip playing DOOM, but it’s only just barely recognizable. The Sansa Clip has a single color screen, with yellow pixels at the top and grey for the rest of the screen. The monochrome display makes things hard to see, so a dithering technique is used to try and make things more visible. Unfortunately it’s not particularly effective, and it’s difficult to make out little more than the gun at the bottom of the screen.

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Code Like An Egyptian

December 3, 2016 by Al Williams 10 Comments

[Marcelo Maximiano’s] son had a school project. He and a team of students built “The Pyramid’s Secret“–an electronic board game using the Arduino Nano. [Marcelo] helped with the electronics, but the result is impressive and a great example of packaging an Arduino project. You can see a video of the game, below.

In addition to the processor, the game uses a WT5001M02 MP3 player (along with an audio amplifier) to produce music and voices. There’s also a rotary encoder, an LCD, a EEPROM (to hold the quiz questions and answers), and an LED driver. There’s also a bunch of LEDs, switches, and a wire maze that requires the player to navigate without bumping into the wire (think 2D Operation).

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Raspberry Pi Plays All That Jazz

September 10, 2016 by Al Williams 14 Comments

[James Bellafaire] wanted a good looking old radio with a modern sound. Granted, you could hollow the case out and replace it with an iPod. Or you could convert the thing to an Internet radio. But where’s the fun in that?

[James] took a different approach. Part woodworking project, part Raspberry Pi project, and part microcontroller project, he wound up with a hard drive-based music player in a 1930’s case with knobs that control the playback.

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Synchronize Data With Audio From A $2 MP3 Player

June 13, 2016 by Jenny List 32 Comments

Many of the hacks featured here are complex feats of ingenuity that you might expect to have emerged from a space-age laboratory rather than a hacker’s bench. Impressive stuff, but on the other side of the coin the essence of a good hack is often just a simple and elegant way of solving a technical problem using clever lateral thinking.

Take this project from [drtune], he needed to synchronize some lighting to an audio stream from an MP3 player and wanted to store his lighting control on the same SD card as his MP3 file. Sadly his serial-controlled MP3 player module would only play audio data from the card and he couldn’t read a data file from it, so there seemed to be no easy way forward.

His solution was simple: realizing that the module has a stereo DAC but a mono amplifier he encoded the data as an audio FSK stream similar to that used by modems back in the day, and applied it to one channel of his stereo MP3 file. He could then play the music from his first channel and digitize the FSK data on the other before applying it to a software modem to retrieve its information.

There was a small snag though, the MP3 player summed both channels before supplying audio to its amplifier. Not a huge problem to overcome, a bit of detective work in the device datasheet allowed him to identify the resistor network doing the mixing and he removed the component for the data channel.

He’s posted full details of the system in the video below the break, complete with waveforms and gratuitous playback of audio FSK data.

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