Video Size

bacter · 08-08-2006, 13:09

Hello, i have a other question for ALL you
I have a IAUDIO A2 Rocks
The standar size for a movie is 700 mb, for example, i wanna have many movies, but i have other files to, if possible to get a movie with the same quality, but less mb, a hundred o 2 hundred for example. ok that it all
Thank, and sorry for the english , i dont speak english good.

NACHO.

eric3a · 08-08-2006, 13:45

Quote:

if possible to get a movie with the same quality, but less mb

Not possible.
You have to make a compromise on quality to have smaller files than already compressed 700mb movies.
Eric

dan_uk · 08-08-2006, 14:58

I find that using the JetAudio software with the default A2 option is fine in terms of picture quality.

I find the sound becomes a little too quiet which requires the movies to be watched at near full volume but that's no big deal.

A 750Mb file usually reduces to about 500Mb or so which is great IMO.

eric3a · 08-08-2006, 16:58

Yes the loss in quality is more than bearable considering the gain in space.
Eric

epaludo · 08-09-2006, 08:02

Quote:

Originally Posted by dan_uk

I find that using the JetAudio software with the default A2 option is fine in terms of picture quality.

I find the sound becomes a little too quiet which requires the movies to be watched at near full volume but that's no big deal.

A 750Mb file usually reduces to about 500Mb or so which is great IMO.

I notice that too.
It reduces quality because of the video resolution reduction. It reduces to the A2 pixels screen size: 480x272. You'll get good results to watch on the A2 screen, but not that good using AV-out mode ...

MCSmarties · 08-09-2006, 10:10

Do you want to watch the movies on the A2 only or on TV?
If you use the AV/OUT, you won't be able to reduce the movie size by much.

However if you watch only on the A2, you don't need to have such a high quality.
Using AutoGK or a similar encoding program, a quality level of 35% at a forced width of 480 will still give excellent results.

Having said that, I have watched many movies at 50%, 480x on a projected screen (80")
before and it's still tolerable - but not "DVD-like" quality anymore.

Tithis · 08-09-2006, 15:34

Its very easy to do what your saying. All you need is some video conversion software like VirtualDubMod. Like the people above me said if you just want to watch the movie on the A2 converting the video to match the A2's resolution. If you want to output them to TV you should keep it as it is.

I'm not sure if you can obtain the size's you want and still have a good quality movie. I have a 2 hour anime movie that is over 700mb. This is after I spent over an hour converting it.

doniago · 08-09-2006, 15:39

I think the general guideline is that movies under 2 hours can be safely compressed to 700 megs or so, while for anything over 2 hours you shouldn't compress beyond 1400 megs. Obviously this is just a guideline.

MCSmarties · 08-10-2006, 10:53

The "compressibility" of a movie varies greatly.
The only way I know to accurately take it into account is to use Gordian Knot (not AutoGK) and manually run a compressibility test first,
then decide on the parameters to use based on this result.

Here a few rules of thumb I am more or less following (not saying they are 100% correct):

- in general (with a high standard deviation!), 5 MB/min of a theatrical widescreen movie (2.35:1)
will give you ~ 40-50% quality at 480x width using MP3 VBR 128kbps soundtrack.

- full screen movies (1.33:1) require a bit more since the relative area occupied on the A2's screen is bigger

- 16/9 movies (1.78:1 to) require the most as it fills the screen completely

- the "older" the movie (= the more grainy), the worse it will compress

- "darker" movies compress in general better ("The Matrix" is astonishingly compressible!)

- transcoding a movie ALWAYS results in loss of quality.
For example, resizing an 800MB movie to 700MB will result in worse quality than if it had been ripped straight to 700MB in the first place.

- As an aside, the same is true for lossy AUDIO codecs!
(a 256kbps MP3 converted to 128kbps will sound worse than a "straight" 128kbps encode)

- if you are using AutoGK, learn about the "hidden" functions (accessible by pressing CTRL+F9).

- I always check "force ITU resize method" "check color" (fast) "enable standalone" (ESS)

- cartoon mode is only useful for "american"-styled cartoons (ex: the Simpsons), not necessarily for anime
(never use this setting with Hayao Miyazaki movies!)

- if you are encoding a vintage movie, remember to force mono sound and encode the entire movie as "credits"
(starting frame 0, 100% quality and check "grayscale") since otherwise you'll be wasting a lot of space
generating data that doesn't even originally exist...

- specify different settings for credits. 20% will look perfect, at 15% you'll start to see traces.
Also, check "grayscale" if your credits are in black and white (or could be satisfactorily watched in black & white)

- remember to check for a hidden bonus at the end of the credits first though!

- I find that if you are going to watch movies on TV, a higher resolution is usually better than a higher compression percentage for a given file size
(this greatly depends on the movie though andis only valid within limits - I'd never go below 35% quality)

Whoe else has some "rules of thumb" to share?
I'd be greatly interested in them!

mssx · 08-10-2006, 11:05

for movies that i plan to watch on the A2, i go for a 480 x 272 resolution at 700-900 kbps video bitrate. i looks good on a 21 inch TV as well. when i plan to watch movies on the TV, i go for something greater than a 640 x 480 at 1200 kbps video bitrate. for audio, i always do 128kbs CBR MP3. for friends series, i go for a 480 x 272 @700 kbps vid and 128 kbps CBR audio. for south park i am happy with 550 to 600 kbps of video and 112 kbps audio CBR. the animation sucks but the series RRRROOOOOCCCKKKSSSS!

bacter · 08-11-2006, 16:03

Thank you very much very much very much very much very much , a group of nice people. I read all you answers, a good advice for me. Thank again.

08-08-2006, 13:09	#1
bacter Junior Member Join Date: Aug 2006 Posts: 7	Video Size Hello, i have a other question for ALL you I have a IAUDIO A2 Rocks The standar size for a movie is 700 mb, for example, i wanna have many movies, but i have other files to, if possible to get a movie with the same quality, but less mb, a hundred o 2 hundred for example. ok that it all Thank, and sorry for the english , i dont speak english good. NACHO.

08-09-2006, 15:39	#8
doniago I, Like, Do Stuff Here. Join Date: Jun 2005 Location: Burlington, VT Posts: 4,651	I think the general guideline is that movies under 2 hours can be safely compressed to 700 megs or so, while for anything over 2 hours you shouldn't compress beyond 1400 megs. Obviously this is just a guideline. __________________ DonIago Iron Mod "When you do things right, people won't be sure you did anything at all."

08-10-2006, 10:53	#9
MCSmarties Senior Member Join Date: Nov 2005 Location: Pittsburgh, PA Posts: 677	My own rules of thumb The "compressibility" of a movie varies greatly. The only way I know to accurately take it into account is to use Gordian Knot (not AutoGK) and manually run a compressibility test first, then decide on the parameters to use based on this result. Here a few rules of thumb I am more or less following (not saying they are 100% correct): - *in general* (with a high standard deviation!), 5 MB/min of a theatrical widescreen movie (2.35:1) will give you ~ 40-50% quality at 480x width using MP3 VBR 128kbps soundtrack. - full screen movies (1.33:1) require a bit more since the relative area occupied on the A2's screen is bigger - 16/9 movies (1.78:1 to) require the most as it fills the screen completely - the "older" the movie (= the more grainy), the worse it will compress - "darker" movies compress in general better ("The Matrix" is astonishingly compressible!) - transcoding a movie ALWAYS results in loss of quality. For example, resizing an 800MB movie to 700MB will result in worse quality than if it had been ripped straight to 700MB in the first place. - As an aside, the same is true for lossy AUDIO codecs! (a 256kbps MP3 converted to 128kbps will sound worse than a "straight" 128kbps encode) - if you are using AutoGK, learn about the "hidden" functions (accessible by pressing CTRL+F9). - I always check "force ITU resize method" "check color" (fast) "enable standalone" (ESS) - cartoon mode is only useful for "american"-styled cartoons (ex: the Simpsons), not necessarily for anime (never use this setting with Hayao Miyazaki movies!) - if you are encoding a vintage movie, remember to force mono sound and encode the entire movie as "credits" (starting frame 0, 100% quality and check "grayscale") since otherwise you'll be wasting a lot of space generating data that doesn't even originally exist... - specify different settings for credits. 20% will look perfect, at 15% you'll start to see traces. Also, check "grayscale" if your credits are in black and white (or could be satisfactorily watched in black & white) - remember to check for a hidden bonus at the end of the credits first though! - I find that if you are going to watch movies on TV, a higher resolution is usually better than a higher compression percentage for a given file size (this greatly depends on the movie though andis only valid within limits - I'd never go below 35% quality) Whoe else has some "rules of thumb" to share? I'd be greatly interested in them! Last edited by MCSmarties; 08-10-2006 at 10:57..

08-10-2006, 11:05	#10
mssx Senior Member Join Date: Apr 2006 Location: Coventry, United Kingdom Posts: 510	for movies that i plan to watch on the A2, i go for a 480 x 272 resolution at 700-900 kbps video bitrate. i looks good on a 21 inch TV as well. when i plan to watch movies on the TV, i go for something greater than a 640 x 480 at 1200 kbps video bitrate. for audio, i always do 128kbs CBR MP3. for friends series, i go for a 480 x 272 @700 kbps vid and 128 kbps CBR audio. for south park i am happy with 550 to 600 kbps of video and 112 kbps audio CBR. the animation sucks but the series RRRROOOOOCCCKKKSSSS! __________________ Cowon A2 + Sennheiser IE6

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08-08-2006, 14:58	#3
dan_uk Junior Member Join Date: Jul 2006 Location: Nottingham, UK Posts: 29	I find that using the JetAudio software with the default A2 option is fine in terms of picture quality. I find the sound becomes a little too quiet which requires the movies to be watched at near full volume but that's no big deal. A 750Mb file usually reduces to about 500Mb or so which is great IMO.

08-08-2006, 16:58	#4
eric3a Senior Member Join Date: Dec 2005 Posts: 545	Yes the loss in quality is more than bearable considering the gain in space. Eric

08-09-2006, 10:10	#6
MCSmarties Senior Member Join Date: Nov 2005 Location: Pittsburgh, PA Posts: 677	Do you want to watch the movies on the A2 only or on TV? If you use the AV/OUT, you won't be able to reduce the movie size by much. However if you watch only on the A2, you don't need to have such a high quality. Using AutoGK or a similar encoding program, a quality level of 35% at a forced width of 480 will still give excellent results. Having said that, I have watched many movies at 50%, 480x on a projected screen (80") before and it's still tolerable - but not "DVD-like" quality anymore.

08-09-2006, 15:34	#7
Tithis Member Join Date: Jun 2006 Posts: 49	Its very easy to do what your saying. All you need is some video conversion software like VirtualDubMod. Like the people above me said if you just want to watch the movie on the A2 converting the video to match the A2's resolution. If you want to output them to TV you should keep it as it is. I'm not sure if you can obtain the size's you want and still have a good quality movie. I have a 2 hour anime movie that is over 700mb. This is after I spent over an hour converting it.

08-11-2006, 16:03	#11
bacter Junior Member Join Date: Aug 2006 Posts: 7	Thank you very much very much very much very much very much , a group of nice people. I read all you answers, a good advice for me. Thank again.