|
| MEMBERS ONLINE | | | Currently no members online. |
You are an anonymous user. You can register for free by clicking here
Lost password?
Get new password |
| |
|
|
|
| Author |
Message |
| |  |
eprepr
TV Newbie
Joined: Dec 03, 2007
Posts: 1
|
 Posted:
Dec 03, 2007 - 07:47 AM |
 
|
|
hello gurus,
i am new and might be asking very stupid questions, but please help out if you can. I did try to do my homework, as you can see from my questions bellow.
i just bought this camera yesterday, and so far it has been great. however, i do have some un-answered questions.
first, regarding avchd, from wikipeida, it is a format that favors blue-ray. because 'it can be played by BD players directly but not hd-dvd. this definitely is an issue for me becuase i have a xbox360 and i love it, no plan for a ps3. so does that mean i will never be able to play the avchd files created?
however, the software came with it did provide an option to convert my video into mpeg2. i wonder will that cause any downgrade in my video quality? ( i somehow got that hint since it says this is for 'burning dvd'.)
second, some basic question on the format war, so from wikipedia(again), it says both formats actually support the same encoding: H.264/MPEG-4 AVC / VC-1 / MPEG-2. can someone explain to me why they are still differnt format then?
third question, this is very specific to this machine, unlike the similar model from canon( which explicitly stated a 'newly developed high-def cmos sensor'), this one didn't say anything special about the sensor, could it be using some old sensor and doing 'upconverting' stuff?
thank you very much in advance for any comments.
(btw i will like post same question to some other forums i can find, and will report back my findings.)
Best.
epr |
|
|
|
|
-horn-
Secondary Master
Joined: Nov 19, 2003
Posts: 1519
Location: 49584 Fürstenau und Bremen
|
| Posted:
Dec 06, 2007 - 04:22 PM |
|
|
hi epr, and nice to have you here on board! 
| eprepr wrote: | hello gurus,
i am new and might be asking very stupid questions, but please help out if you can. I did try to do my homework, as you can see from my questions bellow.
|
no prob!  just feel free to ask anything you'd like to know!
| eprepr wrote: |
i just bought this camera yesterday, and so far it has been great. however, i do have some un-answered questions.
first, regarding avchd, from wikipeida, it is a format that favors blue-ray. because 'it can be played by BD players directly but not hd-dvd. this definitely is an issue for me becuase i have a xbox360 and i love it, no plan for a ps3. so does that mean i will never be able to play the avchd files created?
|
never say never! because the avchd standard is not directly connected to one of the format-war teams. right now, it should be playable with a lot of bd-players, but I think, that some avchd camera manufacturer or just anm avchd software programmer will create an programm to convert the m2ts files created on cams to hd-dvd comtable containerfiles (perhaps *.EVO) in their data structure, that can be recognized by the hd-dvd player. Keep in mind, that these homemade videos are not part in the format war battle so it could be alterted like you want to, because these files are just files. if you look to the core of an m2ts or an eveo file, there can also be an mpeg4 videofile, just the container ist different. so change the container and some other parts/streams et voila, it "should" work. and it should be done without major loss of quality.
but right now, I don't know any software to do that, because it is just too early. the best thing is to nicely "complain" to your cam manufacturer and demanding such a software.
BTW: which cam do you have?
| eprepr wrote: |
however, the software came with it did provide an option to convert my video into mpeg2. i wonder will that cause any downgrade in my video quality? ( i somehow got that hint since it says this is for 'burning dvd'.) |
it depends if your software supports shrinking the complete file onto on dvd chunk, or JUST splitting the file onto several dvd sized chunks, but keeping the bitrate.
but avchd cams record in mpeg4 and if you transform it to mpeg2 then their COULD be loss in quality, because mpeg2 is not that efficient, and it highly depends on the chosen bandwidth. eg the mpeg4 stream has 26mbits then the mpeg2 stream shouldn't be at least under this rate, better more, because mpeg4 is 25% more efficient and so the mpeg2 stream should have 25% more datarate to compensate this.
BUT the last factor in this chain is YOU. so if you can live with a lower datarate, because you can't see any differrence, than you are free to go!
| eprepr wrote: |
second, some basic question on the format war, so from wikipedia(again), it says both formats actually support the same encoding: H.264/MPEG-4 AVC / VC-1 / MPEG-2. can someone explain to me why they are still differnt format then? |
kay that's easier. both medias are using the same codecs, but just some are mandattory to one formate and not to the other and vice versa, and their is a different in the maximum limits to each codec, but these aren't so bad
the difference is inside the media itself. HDDVD was designed to be similar to the old dvd, so that it can be produced on the same manufacturing lines as dvds with only slight chances to the machines and some slight changes. this made the hddvd cheaper at the beginning. so the hddvd resembles the dvd in same points, so lies the data layer inside the dvd "cakesandwich" and the pits where the data is stored aren't as tight together as blu-ray pits.
the laser has to be focused so that the pits inside can be detected and the pits itself can be dected as seperated pits. you can think of glasses for your eyes which has to be formed according to you visus, in our case for a focus which lies deeper inside translucent plastic and the dots you want to see are seperated wider.
bd wasn't designed to resemble the dvd, so the datalayer is nearer to the open end to the cakesandwich, justz pürotected with a smaler layer of translucent plastic, but more resistent (Durabilis). and their pits are more packed. so theses "glases" have to focus on nearer distanced and more densed pits.
so, also both medias are using blue/violet lasers, they can't read the opposite media, because the first the hardware can't do that without expensive stuff, which is just done with some combo players right now. it's like using to glasses .
afterwards it's just a mater of software to read and understand the datastructure, but the hardest part is to handle the numerix apperature (the focus stuff).
but we can be lucky that both formats are using 12cm disks, because so there can be comboplayers, that wasn't realy possible with vhs, beta and v2000, because theses used different sized casettes. that was like putting an rectangle into cillindric hole, even babies do theses just twice .
| eprepr wrote: |
third question, this is very specific to this machine, unlike the similar model from canon( which explicitly stated a 'newly developed high-def cmos sensor'), this one didn't say anything special about the sensor, could it be using some old sensor and doing 'upconverting' stuff?
|
you have to really check these! because during the first hdv cam era, their had been some cams that couldn't record even in 1440*1080 because their sensors weren't that high resolving. so theses interpolated the missing pixels. I am not that AVCHD expert, but it could be the same there. you have to check the sensor datas. mostly they use sperated sensors for RGB and al of theses have to have 1920*1080 pixels. hmm, i think it was the jvc cam (not avchd, but recording on hdd but in mpeg2) that used a trick, where one of these sensors were placed somehow "outside" the other sensor area and because of this displacement they could calculate the massing resolution. but you are right, and you should check that.
| eprepr wrote: |
thank you very much in advance for any comments.
(btw i will like post same question to some other forums i can find, and will report back my findings.) |
I hope that I explained everything right . and I hope to have helped you.
It's a nice offer to post opther findings/answers in here, but then please be kind and post the authors names and the link to th eexternal thread as a credti to these persons.
I woul dlike to see you in here more often
greets, Andreas |
_________________
[1] = HDTVtotal.com : [2] = Private
------------------------------------------------
www.seniorenschule-recke.de
 |
|
|
|
|
| |
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Maximize
