2007-02-12 (03:00)

The Brando MP4 watch as seen here:

http://gizmodo.com/gadgets/gadgets/brando-mp4-watch--video-killed-the-mp3-star-212506.php

and here:

http://www.the-gadgeteer.com/review/brando_mp4_watch

... has Windows software for converting images and videos (it plays mp3s
natively).  I'm working on tools to avoid the need for Wine, or a Windows box.

I've sorted the conversion of images so far with the scripts in this directory,
messy but functional.  I started out making a ppmtosomething compatible perl
script, to maybe later port to C, but then just got bored.  I might even add in
system calls to the convert processes and just have the one perl script for it
all (probably should use CPAN ImageMagick libs).

I'm unsure if pnmdepth does fancier stuff than my division based averaging on
the 8 to 5 or 6 bit values.  If it does I can't tell so far, I might reverse
the process on larger images so I can get a better visual feel.  I had
considered running pnmdepth twice, once for 5 once for 6 bit and nabbing the
middle value of the 6bit one, but that would be an awfully messy way to do it
:)

I'm now looking at the video format, playing with two example ones I have now
and working on perl to extract the frames and mp3 so I can work towards
inserting back again.

This page helped greatly basically explaining exactly what to do.
http://wiki.multimedia.cx/index.php?title=NXV
So does elvis' hex view.  

update:

2007-02-18 (23:50)

I've uploaded a kludgy little perl script that will take a directory full of
.raw files (converted using the other scripts in this directory) and an mp3
(128kbps, JStereo, 44100Hz - lame default and seemingly what the watch likes)
and create a working .nxv file.  Hooray!

This should be portable to MacOSX too, so basically all main operating systems
should be able to create .nxv files now, not just Windows.

This is VERY much work in progress, you'll need to view the perl to see what
filenames it needs and creates.  It's hardwired in many places (this is why I
call it kludgy).  I've found that the first 21 bytes as described
http://wiki.multimedia.cx/index.php?title=NXV are not quite enough, but 112
bytes of the header from the .nxv that came with the watch seemed to do the
trick.  I pad with 0x00 in all of the other places that seemed to be random
data and the video played back fine.

I've created a video that plays back longer than the video that came with it,
confirming the bytes in the header don't limit play length.

To use this you'll need to do something like the following:

ffmpeg -sameq -deinterlace -i ./file.avi -f image2 -r 16.1 sample_000\%04d.jpg
ffmpeg -sameq -i ./file.avi -ar 44100 audio.wav
lame audio.wav
# (yes I could have just made ffmpeg make the mp3...)
cp audio.wav.mp3 sample.mp3
# (in previous tests, I was adding RIFF headers, with riffmp3_elf_intel)
for i in samp*jpg; do
sh ./convert-1.2.sh $X
end
perl createvid-1.2.pl

mount /dev/sdX /mnt/watch
cp sample.nxv /mnt/watch
umount /mnt/watch

Enjoy.

You need ImageMagick and ffmpeg if you want to create 100s of images from a
movie in the way I demonstrated.

I recommend checking/altering the ./convert-1.1.sh script.  I've recently
decided I prefer to crop to 128 rather than composite the correct aspect ratio
on to a 128x128 black square, as this leave letterboxing on an already tiny
screen.  One thing I can't stand is incorrect aspect ratio display though.

I've taken away the +0.5 averaging as this created incorrect looking colours.
I'm quite certain there is a correct 5:6:5 rgb display mode to
ffmpeg/imagemagick or something that could better automate this whole process.
Then again cedega could probably run the directx9 requiring nxv convertion tool
for native conversion under wine.

My estimates put the frame rate at 16.1 fps but I could have worked that out
incorrectly.  Also although I'm letting this loose to the public, it currently
doesn't produce video with the audio correctly in sync, I'm going to create
some longer videos with some obvious audio placemarks and see if I can do some
sort of padding in video or audio.  My aim is to put a 25-30minute video of
something like The Office or Friends for my wife to watch on the tube on the
way to work.

This was her b'day prezzy and it was 3 months late to be delivered so this is
the least I can do :)