Trying to change aspect ratio from 19:9 to 4:4 for mp4 iPod Docking System

[llee782]

I bought a new device to give me a bigger screen to view video from my 5th Generation iPod:

Philips DCP851 8.5" Portable DVD Player & iPod Docking System

This device has a 16x9 screen. It plays anamorphic DVDs just fine, but the 16X9 mp4 files played from my docked 5th Generation iPod aren't treated correctly. They are stretched, leaving black bars at top and bottom. The files all play with the correct aspect ratio in VLC, on the iPod screen, and through the video out when connected to a widescreen TV. When the mode of the Phillips device is set to 4x3, the movies are played with the correct aspect ratio, but with both black bars and pillar bars, a huge waste of screen real estate. This happens even when I'm playing iTunes purchased movies, but I don't have too many of those because I usually do my own conversions.

I'm going to call for help from manufacturer support, but I doubt that will do any good. However, before sending the device back, I want to try converting a 16X9 mp4 to 4X3, just to see if I can trick the device into playing it correctly while it's set for 16X9 playback format. Is there a way to convert these files from 16X9 to 4X3 without re-encoding? I tried something called MKVtools to change pixel aspect ratio, but the edited version of the file still plays by default at 16X9 in VLC, so I'm assuming that the change didn't accomplish what I wanted. Is there a simple way to truly change that aspect ratio from 16X9 to 4X3 in my mp4 videos without re-encoding? I have MP4Box, so if that will do it, please supply a command line to try.

Thanks.

[Baldrick]

See https://forum.videohelp.com/topic364240.html#1940070

And can't you set any output video settings on the ipod also? Because I guess it's it that actually plays the mp4.

[llee782]

Thanks, Baldrick.

"mediainfo -f" for a typical file I want to convert yields:

Pixel aspect ratio : 1.000
Original pixel aspect ratio : 1.327
Display aspect ratio : 1.333
Display aspect ratio : 4/3
Original display aspect ratio : 1.770
Original display aspect ratio : 16/9

So the values I used for par were "1:1", which appear to yield the intended results.

I don't have the player to test at the moment, but VLC plays the output of that conversion at 4X3. I'll try to report back after I test the player.

Thanks again!

[llee782]

It works for the Phillips player, too, and the same command works for both 16X9 and 2.35:1 movies the sources for which are already cropped to contain no black bars. To give credit to the manufacturer, though, the tech support rep I talked to believes that the problem is caused by a defective unit rather than a design flaw, so they are shipping a replacement at no cost to me. I'll be amazed if the problem was caused by a defective unit.