FaceTime on the Mac

The FaceTime Beta UI. On the left is the image from your camera and on the right is your addressbook, recent calls, and favorites list.This morning Apple, INC made several announcements, including availability of a beta FaceTime application for OSX 10.6 and later.  As I mentioned, FaceTime is a Snow Leopard only application and requires an account with Apple to use (i'm using my MobileMe account, but I believe any iTunes Store account would work as well).

The experience is pretty good, I was able to quickly do a facetime chat with my brother, both from the desktop and my iPhone4 (he was on the desktop beta for both.  The quality from the phone was much better, but that's because I'm using a 3rd party webcam on my MacPro which is much lower quality than the current line of built-in cameras on the Macbook Pro's, iMacs, and the Monitors.

Like the iPhone4, this is most likely a streaming h.264 video stream, though i'm unsure the specs being used for the encode, i'll root around and see if i can figure that out this week and do an update.

Details on iPhone 4 video

I know, I know, I need to finish posting about the iPad video (i had it half written and it got deleted in a tragic blog accident).  While I pull myself together to rewrite it, I thought I'd post some clips fro the iPhone 4 camera showing what its cameras can do.

 I've published 4 different clips - 2 from the rear camera which records 720p content and two from the front facing camera which does 480p content.  One clip from each is is direct sunlight, while the other is in shade. The details that stand out to me is the 720p camera records at 10.5 Mbps and the 480p records around 3.5 Mbps.  The video codec, of course, is H.264 (Apple's consumer codec of choice). Ironically, Final Cut Pro can not yet edit H.264 content very well, but iMovie for the iPhone has been released for editing short movies right on the phone.

All in all, for a phone video camera, it does a fairly good job, though the colors on the flowers in the sunlight seem a little over saturated (though only on the rear facing HD camera).  People are already taking advantage of that HD camera for more than just home movies - I found this link pointing to a short film shot and edited (in iMovie) on the iPhone 4 by Michael Koerbel.

Want to check the videos out for yourself?  Click here to download all four clips.

Here are the details from the MediaInfo:

Front Facing Camera Report (640x480)

General / Container Stream #1

Total Video Streams for this File.................1

Total Audio Streams for this File.................1

Video Codecs Used.................................AVC

Audio Codecs Used.................................AAC LC-PS

File Format.......................................MPEG-4

Play Time.........................................14s 326ms

Total File Size...................................6.24 MiB

Total Stream BitRate..............................3 656 Kbps

Encoded with......................................4.0

Encoding Library..................................Apple QuickTime

Video Stream #1

Codec (Human Name)................................AVC

Codec (FourCC)....................................avc1

Codec Profile.....................................Baseline@L3.0

Frame Width.......................................640 pixels

Frame Height......................................480 pixels

Frame Rate........................................29.970 fps

Total Frames......................................429

Display Aspect Ratio..............................4:3

Scan Type.........................................Progressive

Color Space.......................................YUV

Codec Settings (Summary)..........................1 Ref Frames

QF (like Gordian Knot)............................0.389

Codec Settings (CABAC)............................No

Codec Settings (Reference Frames).................1

Video Stream Length...............................14s 313ms

Video Stream BitRate..............................3 583 Kbps

Video Stream BitRate Mode.........................VBR

Bit Depth.........................................8 bits

Video Stream Size.................................6.11 MiB (98%)

Video Stream Title................................Core Media Video

Date of Original Encoding.........................UTC 2010-06-29 21:19:12

Color Primaries...................................BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M

Transfer Characteristics..........................BT.709-5, BT.1361

Matrix Coefficients...............................BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M

Audio Stream #1

Codec.............................................AAC

Codec (FourCC)....................................40

Audio Stream Length...............................14s 326ms

Audio Stream BitRate..............................64.0 Kbps

Audio Stream BitRate Mode.........................CBR

Number of Audio Channels..........................2

Audio Channel's Positions.........................Front: L R

Sampling Rate.....................................44.1 KHz

Audio Stream Size.................................112 KiB (2%)

Audio Stream Title................................Core Media Audio

Date of Original Encoding.........................UTC 2010-06-29 21:19:12

Rear Facing Camera Report (1280 x 720)

General / Container Stream #1

Total Video Streams for this File.................1

Total Audio Streams for this File.................1

Video Codecs Used.................................AVC

Audio Codecs Used.................................AAC LC-PS

File Format.......................................MPEG-4

Play Time.........................................17s 461ms

Total File Size...................................21.9 MiB

Total Stream BitRate..............................10.5 Mbps

Encoded with......................................4.0

Encoding Library..................................Apple QuickTime

Video Stream #1

Codec (Human Name)................................AVC

Codec (FourCC)....................................avc1

Codec Profile.....................................Baseline@L3.1

Frame Width.......................................1 280 pixels

Frame Height......................................720 pixels

Frame Rate........................................29.970 fps

Total Frames......................................523

Display Aspect Ratio..............................16:9

Scan Type.........................................Progressive

Color Space.......................................YUV

Codec Settings (Summary)..........................1 Ref Frames

QF (like Gordian Knot)............................0.379

Codec Settings (CABAC)............................No

Codec Settings (Reference Frames).................1

Video Stream Length...............................17s 451ms

Video Stream BitRate..............................10.5 Mbps

Video Stream BitRate Mode.........................VBR

Bit Depth.........................................8 bits

Video Stream Size.................................21.8 MiB (99%)

Video Stream Title................................Core Media Video

Date of Original Encoding.........................UTC 2010-06-29 21:18:46

Color Primaries...................................BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M

Transfer Characteristics..........................BT.709-5, BT.1361

Matrix Coefficients...............................BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M

Audio Stream #1

Codec.............................................AAC

Codec (FourCC)....................................40

Audio Stream Length...............................17s 461ms

Audio Stream BitRate..............................64.0 Kbps

Audio Stream BitRate Mode.........................CBR

Number of Audio Channels..........................2

Audio Channel's Positions.........................Front: L R

Sampling Rate.....................................44.1 KHz

Audio Stream Size.................................136 KiB (1%)

Audio Stream Title................................Core Media Audio

Date of Original Encoding.........................UTC 2010-06-29 21:18:46





What Video Codec does iPhone's FaceTime use?

When Apple announced the new iPhone 4 this week, one of the coller features announced was the front facing camera and the new FaceTime feature.  Of course, its early days for thinking about video chat on the go, but as someone who travels quite a bit for work, I really like the idea of having access to a quick video conferencing type option on the go.

Of course, the video geek in me immediately wondered about the video specs behind this.  Steve announced it shared H.264 with iChat, amonst other things, but i wondered what else was invovled.  I found this list over at Apple Insider:

• H.264 and AAC, its ISO/MPEG video and audio codecs (just like iChat).
• SIP (Session Initiation Protocol), the open IETF signaling protocol for VoIP used by iChat AV.
• STUN (Session Traversal Utilities for NAT), an IETF standard for dealing with lots of different kinds of NAT. 
• TURN (Traversal Using Relay NAT), an IETF standard for allowing a client behind NAT to receive incoming requests like a server.
• ICE (Interactive Connectivity Establishment) an IETF standard which helps set up connections through NAT firewalls. 
• RTP (Real-time Transport Protocol), an iETF standard for delivering media streams in VoIP.
• SRTP (Secure RTP) an IETF standard designed to provide encryption, message authentication and integrity for the data streams.
• H.264 and AAC, its ISO/MPEG video and audio codecs (just like iChat).SIP (Session Initiation Protocol), the open IETF signaling protocol for VoIP used by iChat AV.STUN (Session Traversal Utilities for NAT), an IETF standard for dealing with lots of different kinds of NAT. TURN (Traversal Using Relay NAT), an IETF standard for allowing a client behind NAT to receive incoming requests like a server.ICE (Interactive Connectivity Establishment) an IETF standard which helps set up connections through NAT firewalls. RTP (Real-time Transport Protocol), an iETF standard for delivering media streams in VoIP.SRTP (Secure RTP) an IETF standard designed to provide encryption, message authentication and integrity for the data streams.

These specs would lead me to believe this is can be adopted into a wide range of products, which is good.  the usefulness of this product goes down dramatically if i can only do video calls to other iphone 4's on wifi (which was what was suggested in the keynote).  Skype is nervously eyeing this and I for one hope they adopt it, as this is what i've used for most of my video calls to date.

Image Comparisons of x264 to H.264

In my previous post about x264 I'd promised some side by side comparisons and hadn't delivered as yet (sorry, I've been busy).  Well, while i'm here at BAVC, encoded some content for one of the groups (Power Poetry) of their trailer.  We compared that to the H.264 version they had just done and the results were quite different.  The basic video settings were the same in each (data rate and key frames were set to automatic) but in the x264 side, I used the same advanced settings from the previous post.

click the image for full size

click image for full size

click image for full size

When I get some free time, i'll post a few more tests and some actual movies, but I thought i'd share these to show there is definitely some benefit to testing out the x264 plugin.

Using x264 Plugin in Compressor

I'll admit it, I've had a love hate relationship with Compressor pretty much since Day One. I love the convenience of having an app tied directly to the timeline for encoding, but have always felt a little disappointed by the options and quality of what was offered for encoding that it offered. Still, I've stuck with it for certain encoding events (such as for dvd content, rough cuts, and archives at high bit rates). It's not that I believe its a bad application, just one that has languished in the shadow of many other priorities. With some much going on in the broad range of tools Final Cut Studio that offers, its bound to happen that some applications don't get the priority we wish they did.

Click to read more ...