关于AAC,Ogg和MP3的更多信息

今早关于音频文件格式的反馈中的一些亮点:

  • We’re probably only at the cusp of widespread support for AAC industry-wideMany of the top-selling non-iPod players listed at Amazon don’t support AACMost Sansa players don’t, and none of Creative’s do.

    It’s not outlandish to predict that within a few years, AAC will be as widely supported as MP3.

  • MP3’s patent situation is somewhat murky, or at the very least, murkier than AAC’sThere are companies other than Thomson claiming patent rights to MP3, includingSisvel公司Audio MPEG

  • With regard to Ogg Vorbis, or the idea of “free” codecs in general, the consensus seems to be that this is an ugly patent lawsuit waiting to happenYes, the creators of Ogg Vorbis have released the format (and source code for encoding and playback) openly, but the holders of the patents behind MP3 (and other patented codecs) very likely consider part of Ogg Vorbis to violate their patentsIf Apple, or any other company with a serious amount of money behind it, were to use Ogg Vorbis in a mainstream widely-used product, it could lead to an expensive lawsuit.

    Do software patents suck? YesIs it possible that Ogg Vorbis does not actually infringe on anyone’s patent, but that some patent holder could sue and win even though they shouldn’t? Yes. The point is, Ogg Vorbis is intended to be free, and it would be great if it were free, but no one with deep pockets has yet tested the water to see whether it really isWorse, there are some experts who do believe that Ogg violates at least one significant patent.

    You can argue about how big a risk it would be for Apple to use a free format like Ogg Vorbis, but you can’t argue that it would be risk-free.

  • 以上所有适用于FLACVSApple无损The most likely explanation for why Apple chose to create their own lossless format rather than use FLAC has nothing to do with technical quality or a lock-in strategy, but rather that they didn’t feel FLAC was defensible patent-wise.

  • A bunch of readers emailed with a suggestion I hadn’t considered before: that the confusion over whether AAC is an “Apple format” is in some measure a byproduct of the format’s acronym, and that many people assume that one of the A’s in “AAC” stands for “Apple”(It stands for “Advanced Audio Coding”.) If it were called, say, “MP4” instead, it might be more clear that it’s the successor to MP3.