This is from a PM with peer:
peer,
I understand your reasoning, but I do believe it is possible. I recall reading a document a while back that states that this is one 'benefit' of using the BD+ VM.
Also, picture the following transform: "toggle whether luma values are to be inverted on every closed GOP boundary". This wouldn't hurt compressability much. It would be quite annoying to somebody trying to remove BD+ though.
peer said:phigment said:Hi peer,
I'm curious if any of the BD+ titles that you have encountered have code that modifies the decoded bitstream? This question has been bothering me for a while. Wouldn't bitstreams from such disks be useless unless the BD+ code was still in tact to properly transform the decompressed bitstream to something visually correct?
I.e. studio transforms original RAW video, then applies compression, then puts BD+ code on disk to apply reverse transform on decoded RAW video.
Let me know if I'm not making any sense.
No they don't - don't think it's possible or even practical.
Think of the production path - hi quality video being recorded and compressed would have to get decoded, modified and re-encoded which would most definitely have a significant negative effect on quality.
Also severe modifications (the type that is desired by BD+) would have a very negativ impact on compressibility itself.
But: why didn't you ask this question in the forum? I'm sure others would like you to share your thoughts...
peer,
I understand your reasoning, but I do believe it is possible. I recall reading a document a while back that states that this is one 'benefit' of using the BD+ VM.
Also, picture the following transform: "toggle whether luma values are to be inverted on every closed GOP boundary". This wouldn't hurt compressability much. It would be quite annoying to somebody trying to remove BD+ though.