2 video streams in some BDs (i.e. National Treasure 2)


I’ve noticed that some Blu Ray movies have a small low res video embedded in the same m2ts file as the main movie ( see BDinfo below for National Treasure 2)

Codec Bitrate Description

MPEG-4 AVC Video 23245 kbps 1080p / 23.976 fps / 16:9 / High Profile 4.1
MPEG-4 AVC Video 179 kbps 480p / 23.976 fps / 16:9 / High Profile 3.2

The second movie appears to be all black but occasionally briefly displays an image when played. When I play the original stream I don’t see these images in the movie. For example, the small video displays a picture of Abraham Lincoln about 44 seconds into play; that image does not show up when I watch the original m2ts file.
I’ve seen this in several movies - anyone know why it’s there? If I use Clown_BD or TSmuxer and just grab the main video stream or if I grab both, it appears fine (Haven’t watched all the way through)



It’s “picture in picture” video commentary. Go through the menu system and turn it on. I’ve tried it on National Treasure 2 myself, it shows clips of the special effects shoots (for example, when the room fills with water at the end it shows the set flooding).

NT2 was the first Blu-Ray to have this feature, which was new with BD-Live 1.1 and was heralded as one of the “nails in the coffin” of HD-DVD since HD-DVD had it all along. It was a complete tempest in a teapot, I don’t think this functionality turned out to be much of a selling point in either format.