frame diagnosis

[Zeul]

i am looking to parse the mpeg stream directly with in the vob. This is no problem in itself, but what I need to know is how to determine how many b,p frames there are in each packet. Ie at the specified address the bit code (from mpucoder site) will state whether the frame is I,B,P or D (what is a D frame?). But if you open up a vob in vobedit you will see that often a video pack is BBPB etc. Now by studying the video pack I see that each frame is listed. Where in the video pack is the offset to start reading the frame details and where does it state how many frames are in that video pack (above BBPB would be 4 frames).

Need your help mpucoder - please.

Zeul

[Guest]

>what is a D frame?

A D frame is an intra-coded picture with only DC coefficients. They can be used in MPEG-1 but not in MPEG-2. They are used (rarely) in MPEG-1 to allow efficient display of a low-resolution image when doing fast forward or fast rewind.

There are no stored offsets to pictures (it is correct to refer to pictures rather than frames, because there can be field pictures). You have to parse for the appropriate start codes. The MPEG-2 specification describes start code processing and is available at my website in the Library section.