Thanks for the review Chris, you did a supurb job at it.
It's like to use this space to explain a little bit more on what screenrating is made for, and what it means for users of older handhelds.
Screenrating adjusts the framerate based on the limitations of your device.
more technical information, as well as testfiles can be found on
http://www.pocketdvd.ca/screenrating.htm
but in short, it's basicaly doing the following.
During testing An Ipaq 2210, a NEC MP900 and a Jornada720 were used.
These devices differ greatly in age, size and screen capabilities.
The 2210 IPAQ has a smaller screen, TFT and an OS thats optimized for its processor.
The Jornada720 has a 640x240 screen, based upon the older DSTN technology, and uses HPC2000 as os, which is basicaly optimized for the StrongArm206mhz of the device.
The NEC MP900 has also a 640x240 DSTN screen, similair specifications to the IPAQ, but does not have an OS thats optimized for its processor.
After testing, we came to the result that for TFT screens with a low resolution, 320x240 basicaly the IPAQ is capable of playing any amount of frames that are being thrown at it.
It showed some tearing when going over 20 frames per second when watching a high speed movie, but this is barely noticable.
Before the NEC arived, we found out that the best playback bitrate on a J720 for DIVX is around 160kbps, so I started converting a bunch of files already on this bitrate to get started when the NEC arived.
The files were a mixture of widescreen and fullscreen movies, and when the NEC finaly arived, they all looked bad. Ghosting was terrible, and it just looked like a slideshow due to the frames that were being skipped to keep up with the sound.
On pause, they look good, but when in motion it was unwatchable.
After some fiddling with the framerate, a framerate of 8 came to be the best framerate for playback a movie on the full 640x240 resolution.
(this is different then normal widescreen
). Converting a few movies
(full/wide/ultrawide
) using this framerate resulted good results for the ultrawide files, but the others still looked bad.
With this information, Screenrating has been calculated, and after testing with lowbitrate files, it proves to show its quality on DSTN screens.
8frames per second might sound low, but due to the limitations of an older screen this does not look like a slideshow presentation.
A DSTN screen takes a longer time to fadeout a frame when a new one is being send to the screen, and thus it's limitations actually make playback smoother then it actually is.
Looking at files encoded for these devices on a desktop computer is however not recommended.
On the screenrating section of the www.pocketdvd.ca website, are some encoded files for testing. They are all encoded on 100kbps to minimize the influence of the processor speed of your device, but do provide a full screen playback for the resolution you download it for.
The left/right offset has been used to modify them to an exact fit, but the files are not really intended to showoff the capabilities of PocketDVD.
The files give you an impression of what kind of screenrating setting would result in the best playback on your device, and after you have found your proper screenrating, just download the trial version
(or enter the contest and hope you win
) and try a few movies/dvd's of your own, using your screenrating.
When testing these files you will notice that the lower fps files will provide a better picture quality as well when compared to files using the same settings and higher fps.
The bitrate quality is directly influenced by the amount of frames these bits need to be distributed on.
in basic english, a file encoded on 160 kbps with 8 frames per second will have a same picture quality per frame as a 16 frames per second file on 320 kbps.
If you have multiple devices, you can save profiles for each device, and if you have found the perfect setting for your device, feel free to submit them to me. We are currently working on a list of devices with screenrating for on the site.
Sincerly,
PocketDVD