I have obtained a copy of Tiger (10.4) from WWDC. The version of QuickTime that comes with this is 6.6 and has a LOT of new AAC encoding options, including what looks like a VBR mode. I don't know how well this is implemented, but if anyone wants screenshots, or wants to host FLAC files of things I can encode for you to test, let me know, I'd be glad to oblige. JUST TO RECAP, THIS IS PRERELEASE SOFTWARE. I don't know what results to expect as I've been too busy testing MPEG-4 AVC all day (which is VERY impressive, btw)

That's very interesting!

If you want, you can play around with the samples I used in my listening tests.

They are all available here:
http://www.rjamorim.com/test/samples/

I think the infamous Waiting would be a good choice.

My god it's buggy! Whenever I try to encode ANYTHING the source ends up at 32khz, even if I explicitly choose 44.1khz. Anyway, I encoded waiting using itunes and quicktime 6.6 at 128kbps, 44khz which worked. At the very least you might be able to use this to test if the ringing issues have stopped. I also took some interesting screenshots.

waiting.m4a

http://www.purrrr.net/temp/tiger/pic1.png
http://www.purrrr.net/temp/tiger/pic2.png
http://www.purrrr.net/temp/tiger/pic4.png

huge images changed to links - moderation

huh is there also already a avc codec included in quicktime 6.6?
if yes, can you maybe upload a small sample of it somewhere (if possible in the .mp4 container)?
also some screenshots from the avc options would be nice

also as there is "stereo l r" listed, does it also support multichannel?

There was only L R in the options dialog when I tested it, but the source I was encoding was only stereo anyway. There are no options at all for AVC except a text field for bit rate. I'm encoding a 1 minute 512x384, 25fps scene from a sitcom I watch at 512kbps as we speak to see how it looks. It looked quite impressive at 256kbps so I'm seeing what this will look like in comparison. I'll post screenshots shortly. Can someone post an HE-AAC mp4 file so I can see if QuickTime 6.6 decodes it yet?

Thanks.

interesting!
would be great if you could upload the sample avc file somewhere, so i can analyse it more deeply

Haha I will, the 512kbps looked so good I'm going to try a 384 one. I'll upload that, and some comparison screenshots comparing the uncompressed version, an Apple MPEG-4 version at the same datarate, and a 3ivx version. (and associated datarates)

where could I download quicktime 6.6

It's not available for download; it is pre release software.

It is a pre-release software and it isn't available for download (yet).

Thank you!
And I want to know when it will be released??

Some time in 2005 or Quicktime alone might be available sooner (at the end of the year).

While I can't comment on the ringing problem from a hearing standpoint, as I could never hear it in the first place with 6.5.1 (my HF hearing isn't so great anymore), I was able to load the decoded file into a spectrum analyzer. The famous HF "notch" seen in the 16-17.5Khz region in 6.5.1 encodings seems to have been corrected; HF content is pretty flat, rolling off around 18Khz. Again, I can't hear much up in that region, so it would be nice if somebody could verify these findings by actually listening to the file.

Here's waiting at 96 (44.1khz) and 64 (32khz) if anybody wants them.

waiting96.mp4
waiting64.mp4

I don't know if it has HE-AAC playback support yet. Can somebody post some content so I can test it?

also, here's a link to some AVC content I encoded, I think bond wanted it. It's 384kbps AVC video with 48kbps AAC audio in a .mov container. Also some screenshots. The datarate is 48.4KB/sec with the audio track removed.

avc384.mov
pic5.png
pic6.png
pic7.png
pic8.png

These pics looks a little oversaturated and yellow to me compared with the original for some reason, might be a bug with the screencapture in 10.4, or it could just be my screen is calibrated differently...anyway it looks close enough.

OMG! A flood of good news regarding QuickTime. Thanks a lot, loophole.

Great thing Apple is supporting AVC. Let's hope they do to it the same they did to AAC and popularize it.



Here are some samples from former listening tests I conduced:
http://www.rarewares.org/rja/41_30sec.mp4
http://www.rarewares.org/rja/Bachpsichord.mp4

Hmm, they're just reported and play back as 22khz stereo files. Oh well at least it doesn't hang like last time...maybe in QT 7 when it's released...

Thanks for the info, loophole! I'll be able to test this later tonight, as well.

How did the H.264 vs. 3ivx comparison go? Hopefully Apple's H.264 codec isn't as bad as their MPEG-4 SP codec.

fantastic!

is it possible to output avc streams inside the .mp4 container and not inside .mov? would be great if you could upload a avc-in-mp4 file, cause currently i am not able to play avc-in-mov, but players for avc-in-mp4 exist already (for example videolan and enviviotv)

thanks a lot!

Nope, there's no option to use the mp4 container. The codec itself seems really preliminary. Encoding a 5 minute clip took over an hour. And the only option for the encoder is bitrate.

so the codec is not listed under "export -> movie to mpeg-4"?

does it work to open an encoded avc-in-mov in qt and than passtrough the video to .mp4 under "movie to mpeg-4" without reencoding?

Hehe, from the direction the discussion is taking, this should probably belong to the A/V forum instead of the AAC one.

It should be pretty trivial to remux video data from mov to mp4 if one has the fileformat specs and some coding skills.

IIRC the 3ivX splitter also supports mov so it should be possible to do this in graphedit.

the question is not related to placing avc in mp4 "somehow", but following iso 14996-15 and till now the 3ivx muxer/splitter (nor any other of the popular mp4 muxers around) will definitely not be able to handle avc in mp4 or mov correctly!
avc is stored in a specific way in .mp4 which makes it possible to exploit all the possibilities the codec offers, therefore a mp4 muxer/player not knowing it will most likely not handle it

therefore it would be also interesting to have some really spec compliant avc-in-mp4 files for testing interoperability aso, i hoped that quicktime could already produce such files...

on the other hand placing avc in mov is nowhere defined till now afaik, not to speak of that its nowhere supported, so it isnt really usable for testing

You can't use graphedit et al for any of this, because the only available implemention of Apple's AVC is on Mac OS X 10.4 Developer Preview, in QuickTime 6.6 and from what I know GraphEdit is not available on OS X. I just doing a movie to MPEG-4 export but yes, the passthrough option is unavailable. The QuickTime file format is completely documented, can't you extract what information you need from the provided file? FWIW I tried playing this back with VLC and nothing...meanwhile 320x240 30fps video at 128kbps looks damn good. There are still some glitches with it (weird flashes or something, I can't explain it, every second or every few seconds...might be when there's a keyframe. It has a lot of work to go but looks VERY promising. KILLS 3ivx at the same bit rate. And I encoded the 3ivx using constant quality too, so it should have the upper hand, vs being constrained to a certain bit rate like the apple codec)

mov is documented, ok, but i doubt any (publically available) docs about placing avc in mov exist already.

Keyframe overcompression is one of the noticable flaws in Apple's SP codec, so the AVC codec might have the same problem.

As for 3ivx, constant quality doesn't stick to a bitrate at all, so that part makes no sense. Try Average Bitrate (maybe even two-pass). And then compare the file sizes to make sure they're close.

Anyone else listened to the sample by QT 6.6 or done more extensive testing? If there is no ringing (or other regressions) I'm tempted to leave the 6.5.1 encoder..

AVC in mov is propably very close to AVC in mpeg-4 because mpeg-4 is based on mov and it would be logical to mux it same way without inventing the wheel again..

Screenshot of Audio Export.

The VBR option is greyed out for me. The only Audio option I can use is the one selected.




Bryan

hm it would be logical but i am not so sure about it, as there are indeed differences between .mov and .mp4, making the two relatively more different than for example .mp4 and .3gp

the first (small) thing i saw apple doesnt do like the mpeg-4 standard is for example how they label the stream:
mpeg-4: avc1
apple: jvt2

http://www.purrrr.net/temp/tiger/avc384.mov - i can´t download from here.