SIRDUKE: pioneering and innovative project to digitise lacquer disks

27 Oct 2021

Audiovisual archives deemed old-fashioned? The SIRDUKE digitisation project proves otherwise. On 27 October, the UNESCO World Day for Audiovisual Heritage, we’ll be presenting this landmark digitisation project to the outside world. We’ve joined forces with VRT and our French colleagues at INA and Gecko to save the audio from some irreparably damaged lacquer disks.

In recent years, we’ve digitally safeguarded over 47,000 shellac and lacquer disks from the VRT archive. But several dozens of these records still remained undigitised because a flaking layer of lacquer had thrown a spanner in the works, and digitising them using the conventional method – with a needle – would only worsen the damage.

Is this unique heritage at risk of being lost forever? Not if the SIRDUKE project has anything to do with it. We’ve joined forces with VRT (link in Dutch), INA and Gecko to give these valuable audio recordings a second life. Together, we’ve trialled some innovative technology using an optical method to reconstruct the audio signal from the records: macro photography.

Just because a record has a groove don't make it in the groove - Stevie Wonder in Sir Duke

SIRDUKE stands for Saphir Innovatively Rescues VRT Disks Using Knowledge and Equipment, with a nod to Stevie Wonder’s famous song, Sir Duke. This American legend in turn took his inspiration for the song from jazz king, Duke Wellington. So we’re in pretty good company.

From photograph to digital soundwave

It’s not the needle but the groove on the record that’s central to this technique. INA (the French National Audiovisual Institute) developed Saphir, a machine that photographs the groove in extremely fine detail. Once these macro photos have been meticulously stitched together, specially developed software closely examines the depth and shape of the groove. This information is then converted into a soundwave that can be played back on a computer – all without a needle in sight.

We are pleased to have provided the tools to help Gecko and meemoo to rescue those important VRT recordings. Thanks to Gecko, meemoo, and VRT for trusting in us and in our Saphir process. - Jean-Hugues Chenot, INA

© Gecko

© Gecko

© Gecko

© Gecko

© Gecko

© Gecko

Results to write home about

All the records have now been successfully digitised and the results are extremely impressive, to say the least. Just like digitisation using the needle method, some background noise is inevitable. But fortunately this is not disturbing in the vast majority of cases. According to Jean-Baptiste Meunier, CEO at Gecko, these results are mainly due to Saphir, a development that Gecko has followed closely from the start. He describes the machine as the missing link in their production chain as specialists in stylus lacquer disc digitization.

We would like to thank meemoo, VRT and INA for making this project possible, and in particular Jean-Hugues Chenot from INA for his invaluable help.

So we can finally enjoy these gems from the history of radio again. The restored recordings date from during and after the Second World War and include reports on cities and international conferences, string quartets and various radio announcements, among other things.

Thanks to this project, we have already been able to save most of our long-lost productions in the lacquer collection. We can now add these audio files to our collection and restore them digitally. Another piece of heritage saved! - Klaas Janssens, sound engineer VRT Archive

Want to find out about the Belgian Committee Against Alcoholism’s fiery appeal to warn about the dangers of alcohol abuse? Listen to it here:

Groundbreaking collaboration

The SIRDUKE project is the result of a fruitful collaboration across national borders. The records that play the leading role in this project originate from the VRT archives, and this Flemish national public-service broadcaster also selected and supplied the damaged records. INA was responsible for providing the technology, and the actual digitisation itself was done by French digitisation company, Gecko. Meemoo had the role of initiator and coordinator on the Belgian side in this project.

With the SIRDUKE project, we’re reviving audio recordings that everyone thought were lost beyond repair. Following on from previous experiments in the US, France and Switzerland, we’re delighted that we’ve been able to help validate the workability of this technique - Brecht Declercq, Manager of Digitisation and Acquisition at meemoo.