Thursday, September 14, 2006

iPod H.264 video quality test

QuickTime 7.1.3 brings us new 640x480 H.264 video files that are compatible with the latest iPods (and the last generation iPods after the 1.2 software update).

However, as suspected, the 1.5 Mbps video bitrate limitation (along with the encoder settings) can be problematic with some content.

To illustrate this, I have taken this Cornell Laboratory of Ornithology HD video and re-encoded it to 320x180 (0.8 Mbps, 11.5 MB) using QuickTime 7.1.2 and 640x360 (1.6 Mbps, 23.1 MB) using QuickTime 7.1.3, with their respective default "Export Movie to iPod" settings.

Although the re-encoded 640x360 video looks fairly good in most areas, unfortunately in some spots the results are not pretty.

Here is a screengrab of the original high definition video, scaled down to 640x360 in QuickTime Player:

Here is the HD video re-encoded to 640x360 using QuickTime 7.1.3's "Export Movie to iPod" function:

Here is the HD video re-encoded to 320x180 using QuickTime 7.1.2's "Export Movie to iPod" function, and scaled up to 640x360 in QuickTime Player:

While there is (not surprisingly) a noticeable improvement going from 320x180 to 640x360 when viewing video at larger screen sizes, a higher bitrate (or different settings) for the latter would have been preferred. Unfortunately, it's likely that hardware limitations of the iPod prevent use of higher bitrate H.264, since it may be too difficult for the iPod's CPU to decode cleanly. (This is in contrast to last year's 320x240 H.264 limitation, which seems now to have been an intentional software limitation.) Overall though, the video looks pretty reasonable, and will satisfy most users, even with TV playback from the iPod.

[Update 2006-09-14]

It appears that several third party video encoders do not support the Baseline Low Complexity Profile required by the iPod for 640x480 H.264 video. For example, video encoded at that resolution directly from DVD using the popular Handbrake application does not work on the iPod. MPEG4 video continues to work fine, however.

Tuesday, September 12, 2006

iTunes 7 and new iPods released. And iTV!

As predicted, Apple released new iPods and iTunes 7. Of particular interest is the fact that the iPod can now display 640x480 H.264 at 1.5 Mbps. It's not quite the 720x480 at 2.0 Mbps I had hoped, but it is still a major step forward and sufficient for years to come. Close enough. However, I would consider avoiding installing iTunes 7 for now, since many people are reporting that it has serious memory leak issues, with iTunes sometimes eating up as much as half a GB of memory. On the other hand, the new CoverFlow feature (programmed by none other than Catfish at Ars) is very nice, as are other features such as the ability to classify media by type. The new GUI may be an acquired taste, but we'd better get used to it, since we'll probably be seeing much more of it in OS X 10.5 Leopard.

The new iPod shuffle has undergone quite the form factor change. It's sooo tiny, despite having a 1 GB capacity. The iPod nanos got a memory capacity upgrade, as well as colours similar to the previous iPod mini, although it's rather odd though that the 8 GB version only comes in black. In addition, both the shuffle and nano are now made of metal.

The predictions of a new set top media box also proved accurate. Apple previewed a device codenamed iTV for our living rooms. This device comes with HDMI and component outputs, and can play back video from the internet or a computer with iTunes over a wired or wireless network. It will not be released until 2007 however.

Now all we need is that iPod phone...

It's Showtime

If you open up iTunes and try to enter the Music Store, you are now greeted with the above screen in anticipation of Apple's media related event today titled "It's Showtime".

It's telling that the screen says the "iTunes Store" is being updated, not the "iTunes Music Store". This lends support to the widely held belief that the event is about movie downloads. Along with this is likely the release of a new version of iTunes, as well as possibly a new series of iPods. Some have also speculated about other new hardware, such as an Airport Express with video support, or a set top box for the living room.

The event is scheduled to take place at 10 am PST, so we will know all the details in just a few more hours.

Monday, September 11, 2006

Apple Taiwan selling Intel "iMac G5"


Apple back in the SPEC game

In recent times, Apple had not submitted CPU performance results to the Standard Performance Evaluation Corporation, presumably because the G4 processors used in Macs lagged so far behind competing x86 processors. Apple pushed SPEC benchmarks when it started using the G5, but never formally submitted those benchmark results. Similarly, they have used SPEC to promote its new Intel Macs in marketing materials, but Apple has also recently started submitting SPEC benchmark results officially.

For marketing purposes, Apple uses the SPEC2000 benchmarks probably because that's what most of the world uses. However, Apple has only officially submitted results for the brand new SPEC CPU2006 series of benchmarks. Currently the only results available are for the previous iMac Core Duo 2.0 model, with SPECint_base200 = 10.1, and SPECfp_base2006 = 8.88. At least for integer performance, that puts the Intel Core Duo 2.0 in the ballpark of the 2.6 GHz AMD Athlon 64 FX-60, despite being a low power laptop oriented chip. (These Core Duo benchmarks are performed under Mac OS X, and use the latest Intel compilers. It should be noted however, that these Linux Athlon benchmarks are performed with gcc, which may be slower.)

It will be interesting to see how a 2.33 GHz Core 2 Duo Merom fares in these tests. My guess is that it should be close to 50% faster than Core Duo 2.0. That's what Apple claims for SPEC CPU2000 at least: