Which MP4 video codec for Car DVD player

[WorriedNoodle]

hi Guys.

I'm not experienced with this so was wondering if someone could help?

The wife's fitted in a Touch Screen DVD player (DAV-U595 - looks like some generic Thai built thing) into one of her cars and was hoping it would play mp4 videos for the kids to watch from either the DVD drive, USB slot or SD card slot. (SD Card slot seems easiest).

However despite playing sound (mp3) and video (avi) files, whenever she tries mp4 the message is unsupported codec despite the player advertised as mp4 compatible. Now many files we get these days off net are mp4 so that's why she bought it. So how do we know what codecs the device supports and what codecs are needed by the mp4 files she has on storage? The device user manual is very basic and just says "The system can read DVD/VCD/SVCD/CD/MP3/WMA/MPS4/AVI etc." with no clues about the etc part!

* Is there a PC tool that will reformat a mp4 file of car player unreadable codec to a more generic readable mp4 format? Would the process be painfully slow for a 2 hour movie?

[WorriedNoodle]

Ok this is what I have found out so far. The car players CPU is slow vs a PC, so a less complex video rendering technique is needed. This means converting all existing mp4, mkv files etc to something like DVX. A guy here mentions how its done using free DivX converter. I tried it on a 90 minute movie and the conversion took about 12 minutes. Output resolution is reduced but good enough for the car.

Other methods I am keen to hear of too.

[RichCor]

Did it play back in the Distinct CarAudio DAV-U595 car deck?

As you have surmised, MP4 is a container specification for grouping together encoded digital streams of Audio, Video, Pictures, and Text.

I tried googling your car deck for playback specifications but found nothing going into any details.

It would be nice to know supported codec format, encoding rates, resolutions, etc, etc.

nice to know you've found DivX works.

the DOOM9 website has an interesting FAQ page on MP4

3) How can i create spec compliant MP4 files?
easy answer: have a look at Doom9's MP4 Guide or Nero Recode2 Guide

detailed answer:
1) To create MP4 files you should preferably use audio/video formats covered by the MPEG-4 Standard:
- MP4 video formats: MPEG-4 SP/ASP: XviD, DivX5, 3ivx, ffmpeg/ffdshow, NeroDigital ASP... and MPEG-4 AVC/H.264: x264, NeroDigital AVC, Apple... and MPEG-2, MPEG-1 (not DivX3/MS Mpeg-4, WM9, RV9 or VP6) - doom9's quality comparisons: 1 2
- MP4 audio formats: Advanced Audio Coding (AAC FAQ): Quicktime/iTunes, Nero, Psytel, FAAC (binary)... (rjamorim's quality comparisons: 1 2) and (E)AC3 (free specifications), MP3, MP2, MP1, CELP (speech), TwinVQ (very low bitrates), SAOL (midi), ALS (lossless)
- MP4 subtitle/text format: MPEG-4 Timed Text (see question 7)
- MP4 picture formats: JPEG, PNG

[WorriedNoodle]

Yes, mp4 to DivX output played OK on the deck after using DivX Converter. I used a low res output suitable for mobile phone, but that looks good enough on the deck screen. I will create a folder of Car Only videos like the guy on YouTube.

I suppose a more expensive deck might have more mp4 decoding options, but this is a cheap deck I understand. It's just to keep the kids quiet on long journeys. I cannot find any info about formats in the user manual that comes with it.

Another thing I found out was the deck gave an unintelligible error message plugging in an USB stick with movies on it. I then remembered some Linux systems need FAT32 format sticks, and so I changed from NTFS to FAT32 and then it worked on the deck.