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Turning it up to eleven

In an electronics market in China last month, I found these intriguing items for sale.

Okay, “MP3” I understand. The MPEG-1 standard for digital media storage and transmission contained three audio formats. These were MPEG-1 audio layers 1, 2 and 3. Of these, layer 3 provided the highest audio quality, became the standard for compressed digital audio, and “MPEG-1 layer 3” became abbreviated to “MP3”.

“MP4” is slightly more problematic. The successor standard to MPEG-1 was MPEG-2. MPEG-2 is very important, but mainly because it contains much more advanced video formats than MPEG-1. DVDs and most digital television applications use MPEG-2 video. In terms of audio, MPEG-2 contains the three existing formats from MPEG-1 (including MP3) and a more advanced format called Advanced Audio Coding (AAC). Perhaps confusingly, AAC is very seldom used with MPEG-2 video, which is much more frequently paired with the MPEG-1 audio formats, or with Dolby AC-3 (which is not part of any of the MPEG standards).

However, AAC is also part of the MPEG-4 family of standards. (There is no MPEG-3). Due partly to AAC being the favourite audio standard of Apple, AAC is commonly paired with the video standards of MPEG-4, the two most common of which are the Advanced Simple Profile (MPEG-4 part 2) and the now favoured Advanced Video Coding (MPEG-4 part 10, known also as ITU-T H.264). This partnering between AAC and the MPEG-4 family of standards can mean that AAC audio is sometimes referred to as “MP4 audio”, with “MP4” as an abbreviation of “MPEG-4”, even though AAC as a format technically preceded MPEG-4. In addition, media of this form is often encoded using the MPEG-4 part 14 container format, which usually has the file suffix “.mp4”. Thus it makes a certain amount of sense for an AAC or MPEG-4 capable media player to be referred to as an “MP4 player”. In this case the “4” in MP4 means something different to the “3” in MP3, but there is some logic to it.

As to what an MP5 player might be, that is on a par with the European commission announcing that we must take steps to “put Europe into the lead of the transition to Web 3.0”, I fear. Sadly, I think it is unlikely that they are selling these.

10 comments to Turning it up to eleven

  • Could you specify the “much more advanced video formats” in MPEG-2? My understanding was that the video encoding differences amounted to interlacing support.

  • Bod

    I dunno, Michael. You might have it all wrong and what they mean is one of these …
    cute little things which I think would make a welcome addition to my Xmas stocking if someone would be generous enough to give me one.

  • Bod

    Ugh. Sorry team. Redundant post.

    Mouse-button happy again.

  • Andrew L

    Try translating your entire post into Chinese and then explaining it to a team of marketers. That should give you some idea of how those signs got made.

  • Stuart: The compression system was also refined and improved considerably. Basically MPEG-1 was designed for low resolution VHS quality images (352×240 or 352×288). It does theoretically support much higher resolutions than this, but the required bit-rate increases so rapidly as you increase the resolution that it is not practical for higher resolutions. MPEG-2 scales much better (right up to HDTV resolutions) which is why it became a standard for all kinds of uses, whereas MPEG-1 was only used for a couple of niches (VCDs and early digital satellite TV) that have been largely superceded.

    That said, I take your point. MPEG-2 video isn’t really that more advanced, as it is a very similar codec to MPEG-1 and the transition was much more evolutionary than the later transition to MPEG-4. What I probably should have said is “more useful”. MPEG-1 video had shrtcomings that led it to be rapidly superceded. MPEG-1 audio was good enough for the tasks that most people wanted to use it for, and was therefore not rapidly superceded.

  • Bruce Hoult

    Good clear explanation and should especially be read by those who think MP3 is good and pure and open while AAC is evil and proprietary to Apple.

    In fact the reverse is the case, as you have to pay 2% royalties on music distributed in the form of MP3 while AAC is royalty-free.

    Incidentally, AAC is playable on at least the following:

    Microsoft Zune
    Sandisk Sansa e200R
    Sony PlayStation Portable
    Sony Walkman S-Series players
    Sony Ericsson phones
    Nokia phones
    Palm OS PDAs
    Microsoft Xbox 360
    Sony PlayStation
    Apple iPod/iPhone

  • Alsadius

    I don’t know, a store selling mp3 music, mp4 movies, and mp5 submachine guns would be pretty sweet. I’m not sure whether it’d be better than Alcohol, Tobacco, and Firearms, but it’d be pretty close.

  • Adam Maas

    .mp4 is a common extension for MPEG-4 audio or video files.

  • J.M. Heinrichs

    The mp5 might be a misspelled mb5.

    Cheers

  • Paul Marks

    MP5’s are fine.

    However, my Guatemala loved their H&K – M3s

    The M3 is heavy, they admitted that, tough going to carry on long marches (they did not have many helecopters and had to hunt the cong on foot – which at least meant they kept the ground they took as there was no flying away from it, it was kill or be killed no exit possible).

    However, the M3 (they claimed) was very accurate and reliable – and could kill cong at virtually any range.