Quicktime, MP4 and MPEG-4 User-Data

[Jamie_T]

Hey All,

We're using an ATEME encoder to produce MPEG-4 MP4V video and also embedding extra data in the frame using the user data structure (GOV aka. 000001B2 followed by the data).

The problem is that when I embed this MPEG-4 with the user data in an MP4 file (using the excellent MP4V2 library) it breaks quicktime. I have to filter out the user data before writing my MPEG-4 sample.

Having the .mp4 files playable in a widely used player is a requirement for us - so that means either WMP or Quicktime, as WMP doesn't do .mp4 as standard that means Quicktime.

Can anyone confirm the above and maybe suggest a way I could keep the user-data and keep quicktime happy?

Thanks,
Jamie.

[SeeMoreDigital]

Unfortunately QuickTime player is very weak and is not very open to the inclusion of erroneous data.... It can't even cope with ASP implementations

Can you provide a short clip, so we can check to see if your encodes will work with other players/filters?


Cheers

[Jamie_T]

Thanks for the reply. Can anyone suggest a site (FTP/HTTP) which I could upload my .mp4 files to? 2 x 10MB.

I have confirmed that with the user data it plays in VideoLAN Media Player and also in Nero.

[SeeMoreDigital]

Hi Jamie,

One of our forum moderators, Richard Berg, has offered some temporary ftp space. A link to it can be found in his "sig", which in-turn can be found here: -

http://forum.doom9.org/member.php?u=1704


Cheers

[Jamie_T]

Cheers thanks for that, the files are below.

Doesn't work with quicktime:

ftp://avisynth.org/upload_withuserdata.mp4

Works with quicktime (i've removed any user data):
ftp://avisynth.org/upload.mp4

[SeeMoreDigital]

May I ask... What is your user-data for?


Cheers

[Jamie_T]

Well the clips above are actually from an Axis IP Camera which embeds the cameras date/time as user data - this doesn't bother me too much.

Soon we'll be including some proprietery data which needs to be bound to each frame - user data seems the obvious place to put it, as it needs to survive both the mp4 file format and RTP streaming - so using a user data "atom" in the mp4 or even another track isn't really feasible.

What do you guys think?

[bond]

iirc you are not allowed to store userdata, vol, vosh or whatever together with the video data

video data goes to the mdat atom
userdata & co goes to the decoderspecificinfo or how its called

[Esc]

I have a problem with user data.

I have a number of videoclips. All made by different people. They are all mp4 with x264+aac inside. I have reports that 2 of them do not play on some computers while others do. The only difference that I found was that those 2 files (and only them) have some gibberish in [user] tags (see attachment).

The questions are: how could such user data be created, how can those tags affect the playback and how can I stop them from doing so?

We do recommend CCCP to our viewers and most of them do not have any problems. But I still would like to increase the playability of all files to the maximum.