Doom9's Forum - View Single Post - BDSup2Sub - convert and tweak bitmap subtitle streams (VobSub,BD-SUP,BDN XML,HD-SUP)

Rectal Prolapse · 7th April 2009, 05:12

0xdeadbeef, for your reference:

http://forum.doom9.org/showthread.ph...51#post1175551

and

http://forum.doom9.org/showpost.php?...postcount=4045

My tests were done using a screenshot of MPC (not MPC-HC) and the eyedropper color tool in irfanview or Photoshop to check the accuracy of the YCbCr->RGB conversions.

Technically, you should be using BT709 - as that is the color space used by all hidef material (all hidef broadcasts, all Blu-ray discs, and all HD-DVDs), and is also the default color space used by the typical computer monitor (BT.709 is the same as SRGB).

Supread I think uses BT601 and also expands to PC levels (white at 255, black at 0) instead of the technically correct white at 235 and black at 16. It is up to the user's player to do the proper expansion when rendering.

This is not a criticism of your tool (in fact I think it is a great idea - I was thinking of making a similar tool, but assumed there was a resolution limitation) - just want to give you basis for your tests. As you can see, I am anal about adhering to standards as closely as possible.

7th April 2009, 05:12	#218 \| Link
Rectal Prolapse Registered User Join Date: Mar 2005 Posts: 433	0xdeadbeef, for your reference: http://forum.doom9.org/showthread.ph...51#post1175551 and http://forum.doom9.org/showpost.php?...postcount=4045 My tests were done using a screenshot of MPC (not MPC-HC) and the eyedropper color tool in irfanview or Photoshop to check the accuracy of the YCbCr->RGB conversions. Technically, you should be using BT709 - as that is the color space used by all hidef material (all hidef broadcasts, all Blu-ray discs, and all HD-DVDs), and is also the default color space used by the typical computer monitor (BT.709 is the same as SRGB). Supread I think uses BT601 and also expands to PC levels (white at 255, black at 0) instead of the technically correct white at 235 and black at 16. It is up to the user's player to do the proper expansion when rendering. This is not a criticism of your tool (in fact I think it is a great idea - I was thinking of making a similar tool, but assumed there was a resolution limitation) - just want to give you basis for your tests. As you can see, I am anal about adhering to standards as closely as possible.