May have found possible way to play files without transcoding

[annafil]

Hi all, this is pretty much my first time posting here, but I had to given the weight of what I've discovered.

The awesomely light creative zen (2,4,8,16,32gb variants) is actually capable of playing videos without transcoding. This info comes from a user in Singapore who pre-ordered his Zen (8gig) before it was officially released. He has a 1.00 firmware (yikes) and I've actually seen that it played do any file he gave it - big, small, unencoded what have you. Yes I'm sure it's the same kind of zen, and yes I'm sure it's not a trick, and yes i know everyone else who has bought one and ever said anything on the issue says you need to transcode stuff. Humour me.

I've got a 2gig version with me until tomorrow (fixing it up for a friend), and it got me thinking why is that the off the shelf versions don't support videos in the same way? Half the time, I get video size errors. So I thought - it must be the firmware.

Until I took a look at the firmware files - there's nothing there at all that indicates any sort of file restrictions.

And then I saw the DeviceInfo.xml file (the very same file you get when you say mount the players internal memory using mtpfs on linux - sorry don't know how this works on Windows). Yes i know the general consensus is that this file tells windows what works and what doesn't work on the player.. but what if?

The zen 2gig has this

<?xml version="1.0"?>
<DeviceInfo>
<Creative display="320x240">
<!-- Hints for various profiles -->
<Profile property="Consumable" size="2147483648"/>
<Profile icodec="JPG Progressive" size="973616" width="320" height="240"/>
<Profile vcodec="WMV3" level="MP@LL"/>
</Creative>
</DeviceInfo>

I couldn't get my hands on the amazing 8gig that plays everything to verify, but I did look at the Zen Vision M 30gig that DOES support all video types - and the JPG width and height are VERY different on the Vision M. Something like 2400 and 1900.

At first the JPG thing threw me, but I tried putting a large jpeg wallpaper on the zen 2gig, and that loads fine, so that can't be a JPG file restriction, unless its a video restriction (don't those values just look fishy to you too??)

I'm willing to bet that this file actually controls what size video the player can and cannot play, and that it's not really a codec or firmware issue at all!

Here's the problem - I haven't figured out a way to modify this file. Though I can freely view it, any attempts to edit give me permission errors. Probably because the file is locked during an mtp event, and i'm using an mtp mount method.

If someone knows how to mount the internal memory in a way that doesn't use mtp (and hopefully means the .xml file is editable) - could you either post it here, or try to edit this file and see if that helps videos play better??

I only have the 2gig zen with me until tomorrow before I give it back to its owner, but I wanted to throw this out there anyway, and see if anyone is willing to pick it up and go from here. If we can just figure out how to edit that file!!

In the meantime, I'm gonna run a reverse test - try to give the zen vision M a file that is bigger than that listed in the .xml specifications and see if it throws me the same size error.

Fingers crossed!

[rapasoft]

it would be fantastic if anyone found that out!!!

i tried to do that to - mounted via mtpfs in linux and tried to edit that file, but it won't save...

[LuckyStrike]

This is very interesting. Thanks for checking this out.

[mc.p2]

<?xml version="1.0"?>
<DeviceInfo>
<Creative display="320x240">
<!-- Hints for various profiles -->
<Profile property="Consumable" size="2147483648"/>
<Profile icodec="JPG Progressive" size="973616" width="320" height="240"/>
<Profile vcodec="WMV3" level="MP@LL"/>
</Creative>
</DeviceInfo>

I suspect this is just to tell programs connecting to the zen what files it supports, but I might be wrong.

If you are getting permission errors you could try running your filebrowser as root using:

gksudo nautilus

(if you have a different filebrowser enter its name instead of nautilus)

Also, where did you hear about the person who has this player?

EDIT: I tried editing this myself and I get

Error writing DeviceInfo.xml: Function not implemented

when I try to save.

[annafil]

I didn't HEAR about this guy. I know this guy and I've talked to him about this - my boyfriend's elder brother who recommended i get the 2gig for my friend in the first place because his plays anything.

And yes, I tried editing the file with sudo permissions. Like I said in my first post - it can't be edited because the file is in use by an mtp process - it needs to be mounted without mtp but I can't figure out how to do that.

I know it seems like it doesn't make sense that this file controls it, but its like i said - there's nothing in the firmware, its more than theoretically possible that the zen can play other stuff, and the zen vision M has an entirely different set of sizes for those values.

Hopefully someone with more raw access experience can figure this one out

[msa]

hm, arent there a lot of firmware-hacks for wallpaper-editing?
you download the firmware and unpack it - i guess this is where you can edit the files.
then you pack it again and install the edited firmware.
maybe that will work...

[BobbyRS]

I'm sorry to be the bearer of bad news here, but the limitation on the supported resolution is hardware based from the STMP3700's ARM CPU. The STMP3700 line of SoC's support QVGA at 30 FPS.

Check out this PDF; section 2.2 titled Multimedia Processing and Display.

320MHz ARM926EJ-S™ processor: 16K+16K caches enable software-based video decode at QVGA resolution at 30 fps

The DeviceInfo.xml:

Originally Posted by mc.p2

I suspect this is just to tell programs connecting to the zen what files it supports, but I might be wrong.

Exactly..... An MTP DeviceInfo dataset rendered in XML structure that defines the device information supported codes/settings which can enable the device to be recognized as supporting certain formats and metadata transferring within MTP.

[annafil]

I'm sorry to be the bearer of bad news here, but the limitation on the supported resolution is hardware based from the STMP3700's ARM CPU. The STMP3700 line of SoC's support QVGA at 30 FPS.

I get that.. But then how is it that a limited batch of prereleased zens can play higher res videos? I find it hard to believe that creative would roll out a batch of players with higher spec hardware (for cheaper) during a prerelease sale and then decide to lock it down to a lower processor?

Something strange is going on here, that's all I know. You can either doubt me, or try it and prove me wrong... Doesn't matter to me all that much, I don't actually own a zen I'm just trying to do the guys who bought one a favour based on what I found out...

Have fun all The rest is up to you

[BobbyRS]

But then how is it that a limited batch of prereleased zens can play higher res videos? I find it hard to believe that creative would roll out a batch of players with higher spec hardware (for cheaper) during a prerelease sale and then decide to lock it down to a lower processor?

You got me.... I've never heard of that before. Maybe a test batch they tried. Perhaps there is a variant of the STMP70XX series that is capable of higher than QVGA resolution. Hell, perhaps the STMP3700 can decode higher than the stated QVGA, just not at 30fps. QVGA may be the max for 30fps. I don't really know.... either way, it should be hardware defined/restricted and not by an MTP generated DeviceInfo dataset file (which gets its settings from the device). I'm not sure if the 16k instruction and data cache would be the issue as much as the low single core clock rate of 300mhz of the STMP3700.