On Friday, November 21, 2003, at 02:32 PM, Greg Chapman wrote:
Beware. QTPlayer doesn't know who encoded it. He only knows what the
format is ('mp4v'), and he opens that codec and asks for a
user-readable name.
Right, which is by design in Quicktime... there can only be one decoder
for each media type, right?
If you have 3ivX installed, _all_ your movies with MPEG4 video will be
reported as 3ivX, whether or not 3ivX actually did the work.
Given that 3ivx is a more advanced MPEG-4 decoder, this at least seems
reasonable, since there's no other way to distinguish one MPEG-4 from
another (would it have been possible for 3ivx to only takeover playback
of MPEG-4 ASP content?).
I agree, this is dangerous, as it complicates troubleshooting of MPEG-4
playback, but given Apple hasn't shipped an Advanced Simple Profile
decoder what else could we do? Wouldn't this be the case with any other
Quicktime-based ASP decoder, or would there be a way to avoid taking
over Simple Profile decoding and only handle ASP?
They _are_ doing some real hijacking (3ivX completely disables and
replaces Apple's MPEG4 Video codec), but here they are also hijacking
the right to name MPEG4 Video in general.
This isn't entirely true. It takes over MPEG-4 decoding, but Apple's
MPEG-4 is still an option for decoding.
It seems to me this isn't nefarious (using terms like hijacking seems
to imply that it is), but rather the only option for writing an ASP
decoder. I'm encoding using Apple's MPEG-4 codec right now, even though
I have 3ivx installed.
The only "hijacking" that occurs is at playback, and it seems it's
because it wouldn't be possible to write an alternative MPEG-4 decoder
that DIDN'T do this, would it? So 3ivx can either:
1) Cease to exist; not my preference, it seems like an excellent
encoder;
2) Only handle encoding; not my preference, as then we'd be able to
encode ASP content that we can't playback with the stock decoder.
3) Continue as is...
What other options are there until Apple has shipped a competitive ASP
product?
Also, isn't this the POINT of open standards media? To allow consumer
choice iin encoding and decoding, not vendor lock-in? I'm confused as
to what you consider hijacking... pretty strong words. I admit there is
a risk of troubleshooting complications when having multiple codecs all
registered for the same media type, but isn't this a Quicktime problem
not specific to anything done by 3ivx?
I guess it all comes down to what Apple's plans are for extending
support of MPEG-4 to include more advanced capabilities, at least in
decoding. I'm sure you can't comment on that, but I know we're all
interested.
Thanks for any clarification you can offer,
roger howard
senior digital media specialist
the j. paul getty museum
PS, I'm not a 3ivx apologist, but I am newly re-interested in their
codec, though I have already given my opinion why I can't use it
publicly until Apple has a compatible decoder (I'd love to use 3ivx for
encoding in place of Apple's codec, but would need Apple's support in
decoding... I can do this now for SP content, but not ASP, which is
where the real performance is).
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