Posted Fri Mar 26, 2010 at 11:25 AM PDT by Joshua Zyber
Editor's Note: Each Friday, High-Def Digest's own HD Advisor will answer a new round of questions from our readers. If you have home theater questions you need answered, send an email to [email protected]
Answers by Joshua Zyber
120 Hz without Frame Interpolation
Q: I just read your HD Advisor 50 and have a question about your suggestion that frame interpolation can be turned off. If you turn it off, do you lose the advantage (e.g. reduced motion blur) of the faster refresh rate that 120 Hz TVs have? Is there then any need to buy a 120 Hz TV if you don't like that "camcorder" look? Or can you still have the increased refresh rate without frame interpolation? I have a 60 Hz 1080p TV, and I'm wondering if going to 120Hz has any advantage to me if I'm one of those people that hates that artificial video look.
A: Yes, when you turn off the frame interpolation feature on a 120 Hz HDTV, you will still benefit from the fast refresh rate. A 120 Hz TV always runs at 120 Hz, and will automatically convert any input signal to that frame rate. It will not slow down its refresh rate to 60 Hz just because you've turned off frame interpolation.
120 Hz was chosen for these displays because it's an even multiple of 60 Hz (the common frame rate of NTSC and broadcast HD sources) and 24 Hz (the frame rate of 1080p content on Blu-ray). When frame interpolation is turned off, the TV will apply 2:2 Pulldown to all 60 Hz input signals. This means that each frame in the source is doubled and refreshed twice as fast, without any interpolation. The TV will also apply 5:5 Pulldown to 24 Hz sources, which duplicates each frame 5 times. A simple multiplication of the original frames will look seamless to your eye, but will reduce the motion blur inherent to LCD displays.
When frame interpolation is applied, that does more than just multiply the original frames in the content. The TV uses pieces of the original frames to create brand new "in-between" frames. Those artificial frames are what makes the picture smeary and causes movies to look like they were shot on camcorder.
3-D Shutter Glasses
Q: I have a shutter glasses that I purchased with my Samsung DLP 3-D ready TV. I was wondering if they will work with the new Samsung 3-D TVs that are coming out?
A: As far as I'm aware, those shutter glasses will only work with the TVs they were made for. The type of 3-D that Samsung and Mitsubishi built into their previous "3-D ready" DLP TVs was an older format that only provided approximately 540p resolution to each eye. The new 3-D standard being released this year has been completely overhauled, and will now provide full 1080p resolution to each eye. Also, the old shutter glasses were designed to work at a standard 60 Hz refresh rate, while the new 3-D format requires a 120 Hz rate. That alone should prevent the old glasses from syncing with the new hardware.
And, let's face it, even if the old glasses could be made to sync with the new TVs, the manufacturers want you to buy new glasses for your new TV anyway. I'm sure they'd change all the emitter frequencies just to prevent you from using the old glasses.
Blu-ray Player with 2 HDMI Outputs
Q: I am in the market to purchase a new Blu-ray player a little better than my PS3. One thing that I'm looking for is a player that actually bitstreams Dolby TrueHD and DTS-HD Master Audio instead of decoding internally. Another thing I'm looking for if possible is a player that has two HDMI ports (1 for video and 1 for audio) so I can be sure that I don't get any interference between the two signals passing through the same HDMI. The reason that I'm even looking for this is because I have noticed that certain movies that have gotten really good audio ratings in reviews I've felt were very underwhelming on my Onkyo system. So I'm questioning if I'm getting some interference on some discs. I had heard that they were coming out with players that have 2 ports. Is there such a player that has 2 HDMI ports. If so, are they worth it?
A: Blu-ray players with separate HDMI outputs for video and audio do exist. These are generally high-end models targeted to the audiophile crowd, such as the Denon DVD-A1UDCI (MSRP $4,500).
It so happens that Panasonic will be releasing a new 3-D Blu-ray player with two HDMI outputs, model DMP-BDT350, later this year. Because 3-D video requires an HDMI 1.4 connection, it may not be able to pass through existing A/V receivers that only have HDMI 1.3. A Blu-ray player with two HDMI outputs will allow users to route the video directly from player to TV by HDMI 1.4, while routing the audio to an HDMI 1.3 receiver separately.
The more pertinent question here is whether you need to go to this effort in your specific circumstance. In my opinion, no. HDMI has more than enough bandwidth to accommodate carrying video and audio on the same cable. You will not get any interference between the two. These are digital data streams. The cable cannot "color" the end results of a digital transmission, as might happen with analog signals.
If you've been disappointed by the sound quality of highly-reviewed Blu-ray discs, the HDMI output of your PS3 is just about the least likely culprit that might be causing it. Your speakers are the biggest determining factor in the sound quality that you hear. If your speakers can't reproduce the full frequency range of a Blu-ray soundtrack, replacing the Blu-ray player will do nothing for you. Upgrading your speakers will improve the sound quality of all sources you listen to. After the speakers, the next most important factor is your receiver, and the quality of its Digital-to-Analog Conversion and amplification. Again, if your receiver has poor DAC or amp components, those will limit the quality of anything that passes through them, no matter how pure the signal.
It's also extremely important that you calibrate you speaker levels and bass crossover settings with a sound level meter and calibration disc, if you haven't already. Many receivers these days offer auto calibration tools such as Audyssey MultEQ, in which you place an included microphone at various points throughout your room and let the receiver calculate its own optimal settings. In my experience, these generally work pretty well for a quick-and-dirty calibration. However, you can probably fine-tune your results more accurately (or more to your own personal preferences) by doing your own measurements.
Any of these things will have a more immediate and substantive impact on the sound quality of your system than your Blu-ray player's HDMI output.
The HD Advisor knows many things, but he doesn't know everything. Some questions are best answered with a consensus of opinions from our readers. If you can help to answer the following question, please post your response in our forum thread linked at the end of this article. Your advice and opinions matter too!
Resume Play Function on Java Discs
Q: I know it's been mentioned that the "resume" function is not possible on a BD-Java enabled disc. What I would like to understand is why isn't it possible? With all the technological advances in multimedia, I cannot understand why it's not possible to fix this with a simple firmware update. Is the limitation the hardware?
JZ: You've got me. It bothers me as well that such a seemingly-simple feature has been eliminated from a significant number of Blu-ray titles. Can any of our other readers shed some light on the real reasons (technical or otherwise) why Resume Play doesn't work on Java-enabled discs? Was this just an oversight in the format specs, or is there really an insurmountable hurdle that prevents it from working with Java?
Check back soon for another round of answers. Keep those questions coming.
Joshua Zyber's opinions are his own and do not necessarily reflect those of this site, its owners or employees.
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