Problem for Matrix Coefficient

[shinjico]

As I kown，mostly the Japanese anime DVD is ITU-R BT.601，but DGindex alway tells that it's ITU-R BT.709, I want to kown why.

Another question,when matrix coefficient info in MPEG2 header is wrong or missing, how can I konw whether it's ITU-R BT.601 or ITU-R BT.709 ?

[tritical]

Another question,when matrix coefficient info in MPEG2 header is wrong or missing, how can I konw whether it's ITU-R BT.601 or ITU-R BT.709 ?
If it's missing (sequence display extension not present), then the spec says to assume the default, which is BT.709. If it's present but incorrect, then you're out of luck... there's no way you could tell from the stream alone that it's wrong or that it should be something else.

As I kown，mostly the Japanese anime DVD is ITU-R BT.601，but DGindex alway tells that it's ITU-R BT.709, I want to kown why.
DGIndex just displays what the stream indicates the colorimetry is. So either the sequence display extension isn't present (so the default of BT.709 is assumed), or it is set as BT.709.

[Mug Funky]

As I kown，mostly the Japanese anime DVD is ITU-R BT.601

why would this be? the japanese use the same equipment the rest of the world uses.

certainly the tape masters are no different - often they're exactly the same source (at least when there aren't english titles overlayed).

now if a source is ex-HDTV that's a different story - colours can get a bit whacky then, depending on how the conversion was done.