Quicktime, MP4 and MPEG-4 User-Data filter, mp4, structure, library, produce

andy

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.

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

Thanks for the reply. Can anyone suggest a site (FTP/from) 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.

Hi Jamie,

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

member.php?u=1704Cheers

/upload_withuserdata.mp4

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

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

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 quot;atomquot; in the mp4 or even another track isn't really feasible.

What do you guys think?

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 amp; co goes to the decoderspecificinfo or how its called

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.