|
|
Posted by Frank on 02/14/07 22:43
On Wed, 14 Feb 2007 12:01:14 -0800, in 'rec.video.desktop',
in article <Re: MPEG4 Camcorders - any good?>,
"PTravel" <ptravel@travelersvideo.com> wrote:
>A couple of points:
>
>1. Some HD TVs do a good job up-converting 640i (standard definition
>video), and some do an absolutely atrocious job, while looking good with HD
>material.
>
>2. All transcodes (the process of converting non-mpeg2 source material to
>mpeg2) are not created equal. DVD camcorders, entry-level editing packages
>and dedicated software transcoders all produce DVD-compliant mpeg2.
>However, the differences in resulting video quality will be dramatic. DVD
>camcorders do single-pass, on-the-fly transcodes and result in the worst
>quality. Entry-level editing packages (and even some mid-range to prosumer
>packages) usually compromise on transcode quality and optimize for short
>transcode time. These will produce better DVDs than a DVD camcorder, but
>they're stll not the best. The highest video quality will be achieved by
>using a stand-alone transcoder program that can do 2-pass, 10-bit, maximum
>motion search transcodes. There are inexpensive solutions for this -- I use
>tmpgenc -- but transcode time with this product is measured in tens of hours
>(transcoding a 2-hour video can take up to 24 hours on my 3 GHz P4). More
>expensive (much more expensive) software transcoders can achieve equal
>quality in somewhat less time, though I'm not aware of any that can do a
>quality real-time transcode, i.e. 2 hours to transcode a 2 hour video. The
>differences in video quality between a DVD camcorder, an entry-level
>all-in-one package and a properly-produced stand-alone transcode are obvious
>on a good standard definition television. On an HD TV that has good
>upscaling capability, the differences will be very dramatic.
>
>3. I'm strictly a hobbyist. I produce video for myself, my wife and my
>in-laws, along with the occassional Youtube upload (and I do have my own
>non-commercial website on travel video just for fun). As you note, everyone
>has their own standard for what is "good enough." I don't know your
>standard, but I can tell you this: I wouldn't expect anything remotely
>acceptable from the Sanyo. The focus of its design is a gimmick, i.e. a
>small form factor and tapeless video. I see many, many posts in these ngs
>from people asking, "why does my video look so bad?" The answer will vary
>depending on how the video was produced, but often the answer is: "you used
>a lousy camera with crappy glass that produces video at high-compression
>rates and with low data bandwidth." No amount of post-processing can "fix"
>video like that. As they say in the computer field, "garbage in, garbage
>out." Because my videos are important to me, I strive for the best quality
>I can (within reason). The DVDs that I can produce come pretty close to
>commercial quality, but I use a prosumer camcorder, edit with prosumer
>software (Premiere Pro), transcode for highest quality and author the DVD
>with a high-end consumer/prosumer package (Encore). That may be more
>trouble than it's worth for you, but my feeling is that the memories I
>preserve this way will be something I want to see for the rest of my life.
>
>With all that said, if you're still interested in the Sanyo, I'd suggest
>trying it hands on in a store that will output the video to a decent monitor
>(don't rely on the camera's lcd or viewfinder). Try it under a variety of
>lighting conditions, particularly low-light. Do some quick pans to see how
>it handles motion artifacts. If you're satisfied with what you see, you'll
>probably be satisfied with a DVD produced from the video. Bear in mind
>that, regardless of how impeccable your technique, the video quality on the
>DVD will be degraded from what you see. The 1080i television issue is a red
>herring. A good up-converting 1080i television will hand a DVD as well or
>better than a standard def television. A poor-upconverting 1080i set will
>not. Finally, remember that commercial DVDs of films are not good sources
>to judge the 1080i upscaling ability for home video. Because of the
>difference in film and video frame rates, televisions (both SD and HD) have
>to do 3/2 pull-down -- showing some frames longer than other frames. This
>is complicated by having to handle interlace issues (that's what the "i" in
>1080i stands for). Because most people want to watch DVD movies on their HD
>set, a lot of attention is paid to the 3/2 pull-down system, with less paid
>to displaying 640i (standard definition) video material.
In the above post, please change all occurrences of "640i" to "480i"
(576i in PAL-land).
Thank you!
--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/
Navigation:
[Reply to this message]
|