#39 Ogg Vorbis Support Broken in Tiger

open
nobody
5
2005-02-19
2005-02-19
ylon
No

As probably was expected, support is broken in Tiger so far.

Discussion

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    Here's some info from Apple's QuickTime engineering group, from internal bug
    ID 4049440:

    "QuickTime's sound playback in QT7 is now based on CoreAudio instead of
    on Sound Manager. Therefore the Ogg Vorbis decoder ('sdec' component) is
    now being invoked from a CoreAudio AudioConverter via
    SoundConverterFillBuffer instead of by means of the chain of Sound
    Manager components used for playback in QuickTime 6. This is a different
    code path into the decoder that all other sdecs we know of support.
    "Vorbis is unusual because it makes use of audio blocks that overlap in
    time via low-level multiplexing. There is no direct support for this in QuickTime
    sound media. To force a fit, the movie importer that's part of Ogg Vorbis for
    QuickTime creates sound media that's carefully laid out to ensure that blocks
    are delivered to the sdec in the appropriate fashion via the old
    implementation of Sound Media. It's quite possible that the expectations of
    the sdec are violated when the audio data is delivered to it via a CoreAudio
    AudioConverter. But we just don't know enough about how the Ogg Vorbis
    components work to be able to say. [...] I believe that the developers will
    need to be involved for us to make progress on this issue."

    From CoreAudio engineering:
    "I'd strongly recommend that these developers write an Audio Codec and not
    a Sound Mgr codec. Given that this is beta software, I'd recommend that the
    developers work with QT dev relations to resolve this issue."

    --Jens Alfke (jens at apple dot com)