What's the benefit of ripping DVD to 800x480?

[Recercare]

I have a Galaxy S smartphone. A lot of guides recommend setting 800x480 resolution when ripping DVDs (720x576). Why is this? I mean, resizing from 720 to 800 AND from 576 to 480.......wouldn't that decrease the quality a lot and also give a very stretched picture? I know from photography that resizing will influence sharpness, so it seems much more logical to only resize the vertical resolution (720x480 or 720x436). Am I wrong here? What am I missing?

Kind regards
.lars

[guns1inger]

What am I missing?

Black bars.

Ideally you would not have to do this at all. Simply rip and convert, keeping the original aspect ratio of the footage. The player should then add whatever bars are required to maintain that aspect ratio. I suspect the guides are written by people who do not understand this, and who simply see that the phone has a resolution of 800 x 400 and assume the video must be the same resolution. Or they are happy to crop, mangle and bend their videos in unusual and unfortunate ways simply to fill the screen at all costs.

Some people do not like to have letterboxing on videos on small screens (personally, it doesn't bother me). If this is the case then you could do some cropping to get to the aspect ratio of the screen, however as the screen does not match the standard TV aspect ratio, any cropping you do would suit only the phone, and nothing else.

If it were me, I would simply rip and convert some testing footage preserving the correct aspect ratio, and see what it looks like on playback. If the phone's player cannot preserve the correct aspect ratio (by applying letterboxing or pillarboxing as required), you know you have to do something else.

[Recercare]

Thanks. Hmm, so when you're playing a 576 movie on a 480 display the smartphone has to decrease the vertical size to 480 and in order to keep the aspect ratio the horizontal resolution is therefore decreased to 600.

When reading the cover of a DVD it reads 1:2.35 16:9 PAL, which is 720x436. When inserting in a DVD ripper/converter the software states it's 720x576. So, the difference between 436 and 576 is filled by black bars......nothing weird about that, but is it then advisable to crop it as 720x436 is much closer to 800x480 in aspect ratio? If going full screen I assume it would be easier for the phone to do it?

Kind regards
.lars

[lordsmurf]

The 720x576 pixels are not square.

[Recercare]

Today I have tested different encoding resolutions and even though I am just as confused...the result was great. I tried 3 conversions of the same source, a DVD, PAL 1:2.35.

My video converter identifies source as 720 x 576, so I try the following:
1. Convert it without cropping or changing resolution.
2. Convert it using 800x480 in the videoconverter (the native res. of Galaxy S).
3. Convert it using 720x436 in the videoconverter, but the media file info reads 720x448 after conversion.

#3 gives the best result, no question. It's definately sharper than #1 and #2. I have no explaination for it though. It's possible that Galaxy is lousy at "resizing" 576 to 480 when playing the movie.

Kind regards
.lars

[guns1inger]

Using what software ? What resize filters ? What encoder ?

[Recercare]

I did it the simple way. I am using the Aura4you DVD-ripper + video converter. I am selecting
*.mp4, x264, 2-pass encoding, bitrate:1200, AAC: 160, 48000.

Sorry I can't provide more detailed info.
I am now trying the same test with another DVD-movie with PAL 1:1.78. It's going to be interesting to check if the same thing happens again. I will try original format, 800x480 and 720x405.

Kind regards
.lars

[guns1inger]

Crap software gives dubious results, sorry. Widescreen PAL should resize to 800 width without loss of quality if done properly. (Actually, it should go to 1024 width, which is what 16:9 PAL expands to during playback)

Personally, I would be using XmediaRecode for the encoding and resizing. I have been using it to convert DVDs to AVC MP4 format for storing on my media player, and the results are very good at 1020 x nnn

[lordsmurf]

Aura4you DVD-ripper + video converter

Standard crap Chinese software:

Shenzhen Hi-Tech Park
Shenzhen, Guangdong 519057
China

In most cases, candy-looking GUI on top of poorly butchered freeware.

[Recercare]

Hmm....I will try different software then. Thanks guys.

Kind regards
.lars

[Recercare]

I have now tested 4 converters (Handbrake included) and to be honest the result is pretty much equal regarding IQ. However, all these 4 converters gave much better results at 800x480 than Aura4You. The difference was so huge that I encoded it again in Aura4you just to double-check and this time the result was excellent. I guess something wrong happened the first time.

So, the conclusion is....when converting for 4" (Galaxy S) 7" (Galaxy Tab) and possibly 10" high resolution displays it's not necessary to become a encoding nerd/geek as most movies will look good anyway.

Kind regards
.lars