GPAC MP4Box Information, Feature Requests & Discussions [No bug reports]

[SeeMoreDigital]

Hi Kurt,

Have there been any reported issues with MP4Box 0.4.3_20061115?

It does not seem to handle VOBsubs as reliably (ie: muxing and de-muxing and playing in MediaPlayer Classic) as your previous MP4Box 0.4.3 build, dated 2006-08-28....


Cheers

[Drachir]

Originally Posted by SeeMoreDigital

Hi Kurt,

Have there been any reported issues with MP4Box 0.4.3_20061115?

It does not seem to handle VOBsubs as reliably (ie: muxing and de-muxing and playing in MediaPlayer Classic) as your previous MP4Box 0.4.3 build, dated 2006-08-28....

Yes, there is a report.
http://sourceforge.net/forum/forum.p...orum_id=287547

Like mentioned in GPAC's changelog, there may be some trouble, introduced through the porting to symbian.

[Lele-brz]

Hi all,
I'd like to use mp4box to set the header at the beginning, is it possible, generally I have a aac audio track and h264 track then I mux them but no always the header is at the beginning so when opening the file I have to go at the end or the middle of the file preventing me from streaming that.
thanks for any tips on that
Bye

[Drachir]

By default the moov box/atom is placed at the beginning in mp4/3gp files created by MP4Box. Only if you use -flat you will find this box/atom at the end of the file.
Your goal seems to be progressive download not streaming. A short comparison can be found here:
http://www.streamingmedia.com/articl...56&page=1&c=11

[Lele-brz]

yes, you're right, and I found that using mp4creator -optimize it's possible to move it at the beginning if you have non Mp4box file

[Lele-brz]

Hi all,
I'm trying to use the -frag oprion of mp4box, my intention is to have a smaller header size.
But when I mulptiplex using this option with MP4Box the file is not readable, what can I do?
thanks
bye

[Drachir]

Originally Posted by Lele-brz

Hi all,
I'm trying to use the -frag oprion of mp4box, my intention is to have a smaller header size.
But when I mulptiplex using this option with MP4Box the file is not readable, what can I do?
thanks
bye

Did you try to play the file with Osmo4? I don't know if fragmented MP4 files are supported by other players.

You will get a smaller moov box/atom, but you will get also a moof box/atom every 0.500 seconds(MP4Box default).

An other alternative could be a streaming server like the Darwin Streaming Server.

[bond]

fragmented mp4 files indeed need special parsers (iirc also 3ivx' mp4 directshow splitter supports it) and i kinda doubt that they are having smaller headers/overhead as drachir mentioned

[Drachir]

Originally Posted by bond

fragmented mp4 files indeed need special parsers (iirc also 3ivx' mp4 directshow splitter supports it) and i kinda doubt that they are having smaller headers/overhead as drachir mentioned

I didn't said that there will be less overhead for the complete mp4 file. I only said that the moov box will be smaller, because there will be no tables entries in the Sample Table Box[stbl].

But you will also get a moof box every x time.

[SeeMoreDigital]

Please refer to Drachir's thread: -

http://forum.doom9.org/showthread.php?t=126453

[mcka]

What do you think about implementing a pasp atom in mp4box as described in Amendment 1 of ISO/IEC 14496-12 (MP4 standard)?

Currently I cannot use any tools using mp4box (like staxrip or megui), for encoding.

I have added a Feature Request to the tracker, but no reply there:
http://sourceforge.net/tracker/index...01&atid=571741

Something like that has been requested in two other feature requests and in the sf.net forum too. I don't think the solution is very complicated, but I have problems to identify the exactly affected sourcecode from GPAC. In my feature request I've described my problem. Perhaps you could give me some hints so that we can find a solution together?

best regards
mcka

[Drachir]

@mcka to rephrase the same question, again and again, probably won't help. You did a feature request, wait some time if Jenlf will do something in this regard.
Maybe there is something we do not see.

About the other feature request you mentioned there, was asked about implementing the use of the transformation matrix for anamorphic video. The transformation matrix isn't used in the MP4 File Format(ISO/IEC 14496-14).
This is a diffrent feature request, probably with the same goal.
The use of transformation matrix to deform a video elementary stream in MP4 files is not standard conformance.

[mcka]

pasp is a new feature specified in MP4 file format (ISO/IEC 14496-14) which makes the transformation matrix obsolete, because latest Quicktime Applications already understand pasp in MP4. So anamorphic encoded video streams could be implemented in a standard conformance way, which is understood by nearly all client applications.

As said I'd like to help implementing it, but I ran into some problems and I'm looking for help. It does not need to be implemented in official gpac source (though this would be the best). With some help I could create a patch, so anybody who would like to use StaxRip or MeGUI to create anamorphic video files which should work with most players could compile mp4box by oneself.

An alternative could be to create a small tool, which only adds the pasp atom to a completed mp4 file. This way I could avoid to understand all the GPAC internals, but I'd need to write a lot more code...

[SeeMoreDigital]

Originally Posted by mcka

...An alternative could be to create a small tool, which only adds the pasp atom to a completed mp4 file. This way I could avoid to understand all the GPAC internals, but I'd need to write a lot more code...

Adding or amending the "aspect ratio signalling" values of MPEG-4 part-2 or part-10 video streams is pretty simple to do (for .AVI and .MP4 contained files). And works in just about every software and hardware player I have

Personally, I don't see much point in being able to add or amend pasp values at the container level, when (as far as I know) only Quicktime player supports them anyway...

[mcka]

Originally Posted by SeeMoreDigital

Personally, I don't see much point in being able to add or amend pasp values at the container level, when (as far as I know) only Quicktime player supports them anyway...

But it doesn't hurt either if it's done in a standards compliant way. On the other hand it would make a lot of people happy. It's not because I love to play mp4 files on my PC using Quicktime, but I'd like to play them with AppleTV, where I cannot simply change the player. I really don't like the limitations from Quicktime, but if I don't use anamorphic encoding everything works fine. So this is the only problem which could be solved by adding pasp to mp4box.

Since I'd like to encode my videos on Windows, I'd like to use StaxRip or MeGUI, at the moment anamorphic encoding only works with Quicktime pro or a SVN Version of Handbrake.

[SeeMoreDigital]

Originally Posted by mcka

... but I'd like to play them with AppleTV, where I cannot simply change the player. I really don't like the limitations from Quicktime, but if I don't use anamorphic encoding everything works fine.

So your saying AppleTV has the same limitations as QT7 player at not recognising aspect ratio signalling at the MPEG-4 video stream level.... Jeez that's lame!

On that basis your proposed suggestion would indeed be useful...


Cheers

[mcka]

Originally Posted by SeeMoreDigital

So your saying AppleTV has the same limitations as QT7 player at not recognising aspect ratio signalling at the MPEG-4 video stream level.... Jeez that's lame!

Indeed! Before QT 7.1 you had to use a on standard compliant transformation matrix, that's what Handbrake people did. But since QT 7.1 it supports pasp which is standard compliant. So I looked at the specification and at gpac source-code to write a patch to add pasp to mp4box, I already added a proposal how to add a PixelAspectRatioBox structure in isomedia_dev.h. But I could not figure out how to add the PixelAspectRatioBox into the file creation process. If someone who knows more details about mp4box source code could give me some advice, I could come up with a patch which could be integrated in the source or which could make it possible for Apple TV users to patch mp4box and create an own mp4box binary to create anamorphic movies which work on their Apple TVs.

Originally Posted by SeeMoreDigital

On that basis your proposed suggestion would indeed be useful...

I think so. It would help every Apple TV / iPhone / iPod user, who likes to use encoding guis based on mp4box. Thanks to Awkwardtv community we can turn Apple TV into a really nice device for watching our encoded movies on TV (up to 720p H.264 @ 5Mbit). The only missing thing is support for anamorphic encoding in encoding guis. Since Apple TV was made to watch your movies (which can be stored on a PC or NAS) on HD screens, it definitly matters if you use anamorphic encoding or resize the movies.

[Kurtnoise]

Jean Lefeuvre, the main developper of GPAC, is going to introduce the pasp support into the framework. So, wait & see...

or check out the code in the cvs tree.

[mcka]

That's great news!

Looking at the cvs commits I think I'd never got this working on my own ;-)

Thanks a lot! Looking forward to test this great new feature!

@Kurtnoise13: Is your mp4box-dev build a CVS checkout from 2007-Jun-25? If so, the patch does not seem to be complete yet (or needs a special command line switch...) - for those who'd like to test it (like me ;-)). But from now on I'll wait patiently...

[Kurtnoise]

Yes, not complete yet. That's why I said "wait & see"...