[libbluray-devel] BD Specifications

[Petri Hintukainen]

Luca Wehrstedt wrote:
> First of all, I have some questions about the CPI part in the Clip
> Information File.
> What's the use of these information about the clip?

Basically it just maps time stamps (PTS) to packet offsets in the file.
It is used for seeking and angle changes.

> What does CPI stand for?

Characteristic Point Information

> What's the EPMap? (and what does EP stand for?)

EP = Entry Point ?

EPMap contains (PTS,SPN) pairs for single stream.

Points are guaranteed to fullfit some properties:
video: sequence header + I frame or SPS + I / IDR frame
audio: PES packet start
PG/IG: PCS/IGS segment following with complete display set

i.e. those are points where it is possible to start decoding.

There are also flags for for possible angle change points.

> What does SPN stand for? (I guess something like Stream Packet Number)

Yes, Source Packet Number.


- Petri