Extracting Time Data from Mpeg2 Stream (Hard Disk Cam)

[gallion311]

Whats up guys,

I'm working on a method, using a couple pieces of software to be able to extract the TimeStamp from Mpeg2 footage, and re-display it once the file has been transferred to PC. (by converting the data to subtitles, and using subtitle program to display that data)

I was at a dead end for the longest time, as all the software I found was for DV Avi files, but I recently had some success using a small utility I found here on the forums.

As I understand it, the Mpeg2 stream from a Sony Hard Drive cam comes in 3 streams: Video, Audio, and Private. The Private stream includes some various metadata, including the time and date stamp info.

This utility I found was written using PAL 25 fps, so it looks for a frame every 12 frames, instead of 15.

So it does work, but it ends up cutting off 20% of the time stamp data.

How does this Utility work? Does anyone have any experience in this who would be able to write a similar utility that would work with NTSC footage?

Here's a link to the Utility:

http://dl.free.fr/rx5Dz7U7E

Here's the authors description:

The mpg file generated by Sony HDcamcorders includes 3 streams

a video stream (0x00)
an audio stream (0x80)
and a private stream (0xFF) which contains the info
For each I frame, all the data is stored within a data structure

[Baldrick]

Where did you find this? Maybe possible to contact the author?

[gallion311]

Yeah I found the utility after some Google searching on a thread in this forum.

I've contacted the author a couple times, but am having limited success because of the language barrier. I also don't want to bother him too much (which I already feel like I have). I work in a software company, and if we could figure out how this type of data extraction is accomplished we'd love to be able to develop a tool in-house.

It's like the old "feed a man fish/teach a man to fish" saying...