Nero Digital is a brand name applied to a suite ofMPEG-4-compatible video and audio compressioncodecs developed byNero AG ofGermany andAteme ofFrance. The audio codecs are integrated into theNero Digital Audio+ audio encoding tool forMicrosoft Windows, and the audio & video codecs are integrated into Nero'sRecodeDVD ripping software.

Nero certifies certain DVD player/recorder devices as Nero Digital compatible,^[1] and licenses the codec technology tointegrated circuit manufacturers.^[2]

The video codecs were developed byAteme,^[3] and according to an interview with Nero AG developer Ivan Dimkovic, the audio codecs are improved versions of Dimkovic's olderPsyTEL AAC Encoder.^[4] The audio codec is now available as a free stand-alone package calledNero AAC Codec.

Nero Digital can generate streams in the3GP/MPEG-4 Part 14 (".mp4") container format and includes two video and two audio codecs:

• ASP (one of about 20 profiles defined in MPEG-4 Part 2)
• AVC (also known as MPEG-4 Part 10 or H.264)
• AAC-LC (the most widely usedAAC profile defined inMPEG-4 Part 3)
• HE-AAC (defined in MPEG-4 Part 3, sometimes referenced as "aacPlus" or other, similar trademarks)

The codecs are compliant with theISO/IEC standard, with the exception of subtitles and chapter information. The video streams generated by Nero Digital can be played back on some stand-alone hardware players and softwaremedia players such as the company's ownNero Showtime.

Recode cannot rip encrypted DVD movie discs, but is able to importdecrypted DVD images for encoding. Nero Digital also does not ship its codecs as stand-aloneDirectShow orVfW modules, preventing them from being used for general-purpose video editing. The product is not bundled with a video editor.

The Nero Digital video codecs have been featured in video compression comparisons:

• In the2003 Doom9 codec comparison, the ASP codec was the fastest of all the codecs, but fared relatively poorly in quality.
• The Nero Digital AVC codec was pronounced the winner of the2004 Doom9 codec comparison. ND ASP did not compete.
• In the2005 Doom9 codec comparison, the ASP codec was still the fastest and fared better than previously in quality, but not well enough to make it to the finals. The AVC codec came in second overall.
• In May 2005, it won theC't magazine video codec quality comparison, competing against other AVC codecs such asx264, VideoSoft's codec, theMainConcept codec and theSorenson codec.
• Nero Digital AVC also won an informal 2005 'Movie Metric Benchmark challenge,' with up to a 1dB quality gain overDivX at the same bitrate.

• List of multimedia codecs

• Nero AAC Codec
• Nero AAC Information at Hydrogenaudio Knowledgebase

• Video codecs
• Audio codecs