Will H.264 run smoothly on G4

[atomiton]

My predicament: I need to webcam to a friend in Japan from Canada... I will also be going to Japan in the spring... so I prefer a laptop.

I know about H.264 in tiger. H.264 is not a light codec. It takes a bit o' processing power and I'm concerned about getting the best quality.

I'd like to know if there have been any testing with the H.264 codec on a G4.

That way I can perhaps get a powerbook G4 when they go down in price pending the jan 14 announcements... or would an ibook suffice?

I don't expect you to be experts, and I know proper v-conf hardware has dedicated processing of the H.264 codec and so runs perfectly (incidentally, tandberg and sony both use AAC for audio) but in a home system, i wonder if anyone has seen a real-life (not a controlled test by sj) example of how this could work on a standard laptop over standard DSL?

[maya]

I see no reason why it should not run great on a G3 for that matter. It should even run good if you don't have a xMb broadband connection.

[atomiton]

i am skeptical.

h.264 requires a lot of processing power.

I doubt you could run a full res. video chat on a G3.

I'm not saying it's impossible... but does anyone here use iChat AV and what results (real-life) have you got?

[maya]

Originally Posted by atomiton

i am skeptical.

h.264 requires a lot of processing power.

I doubt you could run a full res. video chat on a G3.

I'm not saying it's impossible... but does anyone here use iChat AV and what results (real-life) have you got?

h.264 content can be viewed on a mobile phone, if you are telling me that a mobile has more power than a G4 and G3 then we are all in trouble.

h.264 is going to be used to encode HDTV for streaming to mobile phone via QT.

Does that answer your question?

[live4ever]

This will depend a lot on the speed of the dsl connection.

h.264 can be very processor intensive at high resolutions and bitrates (ie. HD-DVD), but it's a very scalable codec.

Hopefully Apple will utilize Core Video to off-load most of the processing onto the gfx card.

[crazzyeddie]

Neither of you are really answering his question... But considering that the current iChat AV requires a 1.5ghz G4 or higher and 500kbps line to run 352x288 video chat, I would assume that H.264 would require just about the same, if maybe not more CPU for the added compression.

[atomiton]

thank you crazyeddie...

yes, I know that it's "scalable" to work on 3G cellphones... but there is far less information on a 160x160 cell screen to interpret and scale... so it would require far less processing power.

One question though... i was under the impression that the specs quoted for full video was for the H.264 codec. I was wondering if anyone can give me an idea of the quality of iChat AV to AOL H.263 video on current equipment... let's say a 1.2GHz ibook with maxed out ram. Basically, I just want to know that I'll get fluid v-conf with an ibook (ie. something portable that I can take to japan)...

as for a 500kbps line... h.264 will take care of that, I'm pretty sure. at the same resolution, you will require less power.

I guess I'm coming at this as having seen video conferencing actually WORK on dedicated v-conf hardware of which most uses h.264 (and a variant of AAC-LD [30ms latency]) and as little as 256k... on tandberg hardware (5 figure cost) but I have yet to see a fully functioning ichat yet... perhaps I will have to just go and test it for myself!

Neither of you are really answering his question... But considering that the current iChat AV requires a 1.5ghz G4 or higher and 500kbps line to run 352x288 video chat, I would assume that H.264 would require just about the same, if maybe not more CPU for the added compression.

[crazzyeddie]

If there is an Apple Store close to you, they have iChat AV setup with cameras on (at least) two machines so you can test the video conferencing. I find the quality acceptable using my 1ghz TiBook and 1GB of RAM with 384kbps upload.

[jhar257]

I use iChat AV to have video chats with family in europe regularly and it is great. iChat to AIM video chat was not too successful at first but AOL have finally sorted their software out but it still loses audio regularly making video chats frustrating. iChat to iChat works perfectly every time (rarely loses audio). As for video quality, it is very good even on 100KB/s connections. Anything over 200KB/s is very good. I am eagerly awaiting h.264 for the improved quality.

A tip for the video chat is to make sure you have adiquate lighting as that seems to really makes a difference to the video quality. Maybe the iSight can't cope in low lighting.

[Sir_Giggles]

H.264 is a asymetrically codec meaning alot of horsepower is required to encode the video, while decoding can be done on slower processors. The reason there is a minimum configuration for iChat AV is because the computer has to encode the video before sending it across the net.

G4's can handle mpeg1 and mpeg2 video extremely well because of the velocity engine. So I assume even on a 400mhz G4, H.264 video will play smoothly or at least with help from a Quartz-enabled video card.

G3? You may be outta luck.

[korianton]

it depends on how well Apple makes their H.264 codec for QuickTime. For example, using the x264 codec in VideoLan is unplayable on a Pentium 4 laptop (tested on my friends VAIO ) and kind of slow on my TiBook 1GHz. But I'm sure Apple will make a much better optimized codec compared to open-souce solutions.

[Chaszmyr]

Originally Posted by atomiton

I don't expect you to be experts, and I know proper v-conf hardware has dedicated processing of the H.264 codec and so runs perfectly (incidentally, tandberg and sony both use AAC for audio) but in a home system, i wonder if anyone has seen a real-life (not a controlled test by sj) example of how this could work on a standard laptop over standard DSL?

On a 1ghz PowerBook w/ Cable Modem it runs just fine.

Keep in mind, Apple is still selling G4s, and so it is to soon for them to introduce any unavoidable technology (like iChat AV in Tiger would be) that is not G4 compatible. It simply wouldn't be enough gain to justify the sales they would lose.

[Mikekmac]

Originally Posted by crazzyeddie

Neither of you are really answering his question... But considering that the current iChat AV requires a 1.5ghz G4 or higher and 500kbps line to run 352x288 video chat, I would assume that H.264 would require just about the same, if maybe not more CPU for the added compression.

I don't know where you got those specs for iChat AV. I've used a 700 mhz iBook, an 800 mhz iBook, and a Dual 1.8 G5, and they all work great. The original spec was for a 600 mhz G3. The G3 CPU is pegged at 90- 100%, and the G4s stay around 75%. The G5 used hardly 25% CPU.

[Mikekmac]

I just found those specs, sorry.

http://www.apple.com/ichat/

[grabberslasher]

Originally Posted by m a y a

h.264 content can be viewed on a mobile phone, if you are telling me that a mobile has more power than a G4 and G3 then we are all in trouble.

h.264 is going to be used to encode HDTV for streaming to mobile phone via QT.

Does that answer your question?

There's a big difference between encoding and decoding, so you can drop your smug attitude.

H264 works perfectly on a G4, and I've tested 800MHz upwards. A G3 will probably work but I haven't tested it. And H264 encoding in Quicktime is very slow at the minute. It takes a long (LOOOONG) time to encode something in it.

Hopefully that will speed up before RTM though. But you should be able to use h264 easily.

[BornAgainMac]

Originally Posted by live4ever

Hopefully Apple will utilize Core Video to off-load most of the processing onto the gfx card.

I hope so. That will be huge.

[Sir_Giggles]

QT7 probably will bring the ability to edit H.264 GOP streams.

[atomiton]

I've been busy, so I haven't been able to check this forum... but thank you VERY much all of you.

I'm not worried so much about G3 compatibility... as these will definitely be G4 and likely 1Ghz + processor speeds. I was just a little concerned as to the specs on the site.

H264 works perfectly on a G4, and I've tested 800MHz upwards.

Perfect! Thanks!

The G3 CPU is pegged at 90- 100%, and the G4s stay around 75%. The G5 used hardly 25% CPU.

I have a G5 imac 1.8 at work. even so I can't imagine it being over 50%... but for home (where i will do most of the calls, obviously) i will likely be getting a laptop (ibook?). I don't live too near an apple store... but I will check the apple resellers. Is the motion fluid (I assume yes)? Is there audio latency?

it depends on how well Apple makes their H.264 codec for QuickTime.

that's interesting. I hope it's optimized for the G4 processor as well... or they release a G5 laptop.

H.264 is a asymetrically codec meaning alot of horsepower is required to encode the video, while decoding can be done on slower processors. The reason there is a minimum configuration for iChat AV is because the computer has to encode the video before sending it across the net.

G4's can handle mpeg1 and mpeg2 video extremely well because of the velocity engine. So I assume even on a 400mhz G4, H.264 video will play smoothly or at least with help from a Quartz-enabled video card.

Cool. Okay, so playback isn't a problem... does the velocity engine help in encoding as well?

So, out of curiosity, what is an asymetric codec?

I'm very happy to hear all this good news, I'll soon be video-conf between here and Japan... or I'd say in (horrible) romanized Japanese (watashi wa totemo ureshii desu!)

[Mikekmac]

Altivec most definitely helps in video encoding. When I started with iChat 2 years ago, I used an iMac G4 700, and my G3 700 iBook. The iMac used less CPU, and had smoother playback. Altivec is perfect for Video, it is a pity that more software doesn't take advantage of it.

[atomiton]

Thanks Mike.

I will be purchasing after the 14th... and recommending one to my friend in Japan.

[atomiton]

Just wanted to know if anything has improved since this post was made, what with QT7 and Tiger out for a while now...

has anyone done any real world tests? I'd started a new thread for this, so feel free to answer in either thread.