Mp3HD

Key takeaways

Mp3HD belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Mp3HD to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Mp3HD from memory before moving on to harder problems.

Reference excerpt

MPEG-1 Audio Layer III HD (more commonly known by its abbreviation mp3HD) was an audio compression codec developed by Technicolor, formerly known as Thomson. It featured lossless compression of audio data, and was usually backwards compatible with the MP3 format by storing two data streams in one file.

Development mp3HD was released in March 2009 as a lossless competitor to the already popular FLAC, Apple Lossless, and WavPack. In theory, the format provided a convenient container in the form of a single file, which included the standard lossy stream playable on any mp3-capable device and the lossless data which was stored in the ID3v2 tag. To play the lossless data, the user needed a compatible mp3HD player with decoder. Otherwise, only the lossy data would be played. Files produced by the algorithm were substantially smaller than the uncompressed source files, though they are roughly comparable to other lossless formats. Since 2009, Technicolor updated the format and encoding tools to make it more efficient, while adding a plugin for Winamp (Windows only), a DirectShow filter for Windows Media Player, and an mp3HD converter. As of April 2013, the MP3HD website, specification and encoder software are no longer available, and promotion of the format has been abandoned.

Encoding The only available mp3HD encoder was the Technicolor toolkit which contained a command-line encoder and decoder. This could be used with the Exact Audio Copy to rip CDs into WAVE files and then automatically convert them to mp3HD files. Another method was the mp3HD Converter, which could convert WAVE files to mp3HD and decompress them back to WAVE files. mp3HD supported CD audio (PCM) at 44.1 and 48 kHz sampling rates at 16 bit/sample. Nero Burning ROM also supports converting to mp3HD with Nero Recode.

Audio quality The lossless mp3HD stream allowed for exact replication of CD-quality audio tracks. Average bitrates varied between 500 kbit/s to 900 kbit/s depending on genre, similar to other lossless codecs. The lossy stream used the same bit rates as a normal MP3 file and the lossy portion could use VBR or CBR depending on the user's preference for compression and quality.

Pros and cons Pros

Exact replica of a CD. Lossy/lossless hybrid. Size is about the same compared to other lossless formats. Usually backwards compatible with standard MP3 players. Retains .mp3 file extension. Popularity of the MP3 brand. Cons

Not widespread due to lack of support. The nature of the codec was very Windows-centric, and didn't have much software support there, which may have ultimately helped contribute to its failure. There also simply weren't a lot of programs to work with it on Mac and Linux. Much larger files than standard MP3. Larger files than most pure lossless formats which do have widespread support. No quality boost if player only supports standard mp3. Lossless portion is stored in an ID3v2 tag. The size of ID3v2 tags is limited to 256 MB by specification. The lossless portion cannot be larger than this. Editing the ID3v2 tag can inadvertently result in losing the lossless data, turning the file a standard MP3. Despite being marketed as backwards compatible, some software that wasn't aware of what the lossless data was would read into the tag and incorrectly display the runtime of the song. This is made possible due to the fact that the ID3 tagging format was never part of the MPEG Audio specification, and the use of the tag for arbitrary data instead of metadata is undefined by the ID3 specification, there are no actual guarantees how software that reads an ID3 tag will interpret dozens or hundreds of MB of data in such a tag. The ease of data loss and undefined nature of storing arbitrary data in an ID3 tag makes the concept ill-suited for this purpose, and rather something of a gross hack which only happens to work as intended due to luck (if the backwards compatibility does not fail catastrophically due to undefined behavior) or specialized software that knows exactly what mp3HD is. The mp3HD files were one big file (instead of WavPack's lossy plus correction-file method) whether they play back as mp3HD or not. As of 2023, most platforms play FLAC files, and it is always lossless.

Products that support mp3HD Hardware

Samsung IceTouch (YP-H1), Samsung announced that they will be releasing the first mp3 player capable of playing mp3HD lossless part of the format at CES 2010. They were supposed to be released sometime in 2010, but as of April 8, 2011 nothing has been released. Samsung YP-Z3 is the world first mp3 player released to support mp3HD (released end of August 2011) Samsung YP-R2 (released in November 2011) Software

Winamp w/ plugin (Windows only) Windows Media Player w/ direct show filter mp3/HD/surround/SX player (Windows and Mac)

Alternative technologies Lossless

FLAC WavPack Monkey's Audio ALAC TTA

See also Lossless Compression Lossy Compression Audio Compression

References

External links Technical specification Download

Worked examples

Example 1 — a first encounter with Mp3HD

Start with the simplest possible case. Write down what Mp3HD claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Mp3HD before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Mp3HD ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Mp3HD

In research: Mp3HD appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Mp3HD in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Mp3HD is common in secondary-school and first-year university syllabi. It links to neighbouring topics Audio codecs, Digital audio, Lossless audio codecs, so understanding it makes those chapters shorter.
In everyday life: Look for Mp3HD outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Mp3HD in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mp3HD means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Mp3HD out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mp3HD in simple terms?

MPEG-1 Audio Layer III HD (more commonly known by its abbreviation mp3HD) was an audio compression codec developed by Technicolor, formerly known as Thomson. It featured lossless compression of audio data, and was usually backwards compatible with the MP3 format by storing two data streams in one f…

Why does Mp3HD matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Mp3HD?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Mp3HD.