Advice On Movie Playback On Gp2x

[caliarbor]

Hi Everyone,

I currently have a GP2X F200(B) and I am running the latest version of Open2x. I typically watch movies one time and then delete them from the SD card. I also normally watch on battery power, even though I do have an AC adaptor for flashing, etc.

My question is, is it worth it for me to take the time and re-encode movies to 320x240 before watching? I have a slighlty older PC (single core P4 3.0GHZ) but a decent internet connection (6mbit).

I'm using the MP2X player that's integrated into Open2x at the stock speed of 200MHz and I currently just download a movie, transfer, watch and then delete. I didn't know if by re-encoding if I would be able to lower the CPU on MP2X or possibly just have a better viewing experience?

Thanks!

 

[trooper]

Your best bet is to actually try it out and see what you think.

Some people prefer not to re-encode, And some do.

Pocket Divx Encoder is a free, Fast, Easy to use, All in one video encoder, Made mainly for converting videos for portable devices, And is pretty quick at converting even on old hardware.

You may already have a set of software to do the conversion, But PDE is definitely worth a try.

Trooper

 

[markiej]

I completely agree with the idea of using pocketdivxencoder to reencode movies for the gp2x.

• much smaller files
• better compatibiility
• eliminates most sound synch issues
• can zoom in a little on cinemascope movies (2:35-1 aspect ratio) so they're a little easier to see
• Can watch movies in low-power mode without any stuttering

 

[caliarbor]

so they're a little easier to see
[*]Can watch movies in low-power mode without any stuttering
[/LIST]

Thanks for the recommendations. Could you give me a recommended profile/settings to use when reencoding a 16:9 DVD with PDE? I would guess a 4:3 would be a 320x240 and a 16:9 would be something like 320x170?

I'm not so concerned with space as I am quality since I use my PC for long term storage.

 

[trooper]

I would personally use the PocketPc profile, Then just higher or lower the audio and video quality settings
via the sliders on the left hand side. It also give you a pretty good estimate of the final file size too.

Oh btw, You can re-encode more than one file at a time (batch mode) if you like.

Trooper

 

[christo930]

if you like.

Trooper

Does it work well with multi-core setups? Will re-encoding introduce compression artifacts into the video? I used to have that problem with creating vcd's from downloaded movies.

 

[trooper]

I would personally use the PocketPc profile, Then just higher or lower the audio and video quality settings
via the sliders on the left hand side. It also give you a pretty good estimate of the final file size too.

Oh btw, You can re-encode more than one file at a time (batch mode"] if you like.

Trooper

Does it work well with multi-core setups? Will re-encoding introduce compression artifacts into the video? I used to have that problem with creating vcd's from downloaded movies.[/quote]Converting from one format to another will always introduce artifacts and/or degradation of quality, Except when going from one lossless format to another. How much is introduced when going from lossless > lossy or lossy >lossy greatly depends on the quality of the file you wish to convert. There are many other permutations, Such as resolution, Bitrate, Audio quality/format etc. We won`t go in to that, But you get the picture.

Best thing to do is test it out.

Trooper

 

[Tag5]

Pocket Divx Encoder have always worked a treat for me as I used to convert movies for my smartphone. I wouldn't use anything else.

 

[pder]

If you are using Linux, I recommend looking for the "reencode" frontend script for mencoder in the archive. This will handle reencoding just about any video file you throw at it as long as mplayer can handle it.

Usually encoding a movie is as simple as

reencode -o gp2xmovie.avi -i movie.mpg

This will scale the movie down and reencode the audio to mp3.

I found that xvid seems to be much more reliable on the gp2x than divx so I pass -c xvid as well

Here are the other options you can pass in:

OPTIONS [default]:
-i | in Infiles (Has to be at the end or followed by a '-')
-d | dvd Encode from a DVD (specify titles)
-o | out Outfile or directory [<infile>-small.avi]

-c | codec Codec lavc,xvid [lavc]
-r | rate Bitrate [250]
-x | crop Try 'mplayer file.avi -vf cropdetect' to get dimentions
-s | scale Scale [320:-3]
-p | pass Passes [1]
-g | deint Use deinterlacing
-t | cartoon Use cartoon mode (xvid only)

-y | acopy Copy audio without recompressing
-a | audio Audio bitrate [64]
-m | arate Audio samplerate [22050]
-v | volume Audio volume gain (db) [0]

Note that you could probably also use cygwin to run this script with the mencoder port for windows.

 

[christo930]

I would personally use the PocketPc profile, Then just higher or lower the audio and video quality settings
via the sliders on the left hand side. It also give you a pretty good estimate of the final file size too.

Oh btw, You can re-encode more than one file at a time (batch mode"] if you like.

Trooper

Does it work well with multi-core setups? Will re-encoding introduce compression artifacts into the video? I used to have that problem with creating vcd's from downloaded movies.

Converting from one format to another will always introduce artifacts and/or degradation of quality, Except when going from one lossless format to another. How much is introduced when going from lossless > lossy or lossy >lossy greatly depends on the quality of the file you wish to convert. There are many other permutations, Such as resolution, Bitrate, Audio quality/format etc. We won`t go in to that, But you get the picture.

Best thing to do is test it out.

Trooper[/quote]When you convert from one format to another the end result usually sux (althoug dvd to svcd is usually very, very, good)
Converting down the bitrate within a codec though usually drops the video quality slightly, but doesn't introduce artifacts since the video isn't really recompressed. Anyhow, I want to try this out on my laptop when my wife lets me have it back What is a reasonable expectation for the file size of a 100 minute movie? Is 256MB a realistic expectation while keeping decent video quality?

Chris

 

[budweiser]

Has anybody made a gp2x f100/f200 template yet ?
Poket divx Beta version (0.4.5 - 2008.09.15)supports this now ...Bud



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