Codec discussion-Idea [mythtv-users] Leadtek WinFast TV 2000
phreaki at earthlink.net
Tue Feb 24 14:53:58 EST 2004
Quite easy I must say, but it will be implemented by me, I do volunteer
if there is
interest (those submitting samples) in such a tool and web program.
Given the number of video codecs available for the Mythtv system,
it's no large feat to simply choose a range of video to export
from what's in your database already.
Since everyone has the basic structure to start with, I intended to create
a program that will let you choose the recording, then will output to disk,
or alternate to actually uploading it. Obviously not everyone is keen on
that last part, so I won't leave something open to abuse: it probably won't
work that exact way unless consent says it is ok.
Doing an 'offline' recording would introduce even more noise and possible
signal fade that would ruin the real test. This all needs to stay digital in
any possible way.
There is not a huge difference in systems when it comes to your normal
Video cards in doing whatever type of accelerated playback of a movie
it be Linux, Win32 or Mac all appear very close in quality. This even
with Ati, NVidia, Matrox, but there is going to be some difference,
What is important, the real test, is how does your signal decoder look?
Given the same codec to compress, likewise with the resolution to capture,
your pentiumIII will produce the same quality of a conversion if the
exactly the same.
The part of your system that really makes the video stink, or shine is
signal converters, that take Composite, Svideo, Coax, lock onto the video
feed, then throw it into your I/O and out pops a video on the other side.
The codec will have some bearing here but all those variables can be worked
around, ensuring that the real thing we all care about is easy to expose.
So to recap, it's all about using what transcoding utilities are already
-in- Mythtv to
start with. When you level the playing field by hoping that everyone
being that you don't have to recompress the clip, merely cut at the
the real meat is exposed.
Thanks again for your interest.
>>What does the quality look like?
>>So far, I have seen wonderful pictures of actual systems that were
>>built, but one thing
>>is always lacking: actual video clip samples from various boards.
>Maybe I'm dumb, but I'm missing one thing: how do you do the video clip
>of what your system actually _outputs_ ?
>Will you put a camera in front of your monitor/TV/projector wall/whatever
>and record the movie?
>Then digitize the tape and make the video clip?
>I believe this would degrading the video quality (not to mention
>multi-channel audio), and even if your camera could record
>both audio and video at the same quality that my system outputs,
>will other people be able to play it at the same quality?
>I mean, if one has a system which quality is better than mine,
>then he can play the movie and know that my system is worse;
>however, if one has a system worse than mine, he won't be able
>to play the movie at a quality better than his system allows,
>so he will never know my system is better :-)
>Please correct me if I have misunderstood something.
>>If at least 5 people say they would
>>submit a clip and hardware specs with inputs
>_WHEN_ my system will be completed I'll be glad to
>post pictures, clips, and whatever will be found useful,
>as a little contribute to this mailing list and to all
>people who helped me with their suggstions (thanks again).
>But you have to explain me how do I do the clip! :-)
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