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I finally managed to pickup an old copy of Premiere 5 cheaply and am playing around with it a little. I got some unexpected results which surprise me, and I hope someone can help me out.
I have some CCITT compliant test screen images (BMP's), copied directly from DVD, which are all in the 16-235 luma range. I used Premiere to turn one of these into a short HuffYuv AVI clip. After opening this AVI file in VirtualDub, I could verify that the luma range is still 16-235. So far, so good.
Then I wanted to export the same bitmap file as a short MPG clip,
for brightness/contrast calibration purposes on TV.
The following puzzling situation occurs. In the encoder (tMpeg 1.2 J) I select the option "export YUV data as basic YCbCr instead of CCITT", so the encoder is not allowed to change the luma levels.
I then opened this Mpeg file in VirtualDub. Guess what? Luma range is 0-255. What the heck is going on here? I see only two possibilities. Either the MPG-1 import filter in VirtualDub "stretches" the luma, or Premiere does so before passing the images to the encoder. Can anybody shed some light here?
I have some CCITT compliant test screen images (BMP's), copied directly from DVD, which are all in the 16-235 luma range. I used Premiere to turn one of these into a short HuffYuv AVI clip. After opening this AVI file in VirtualDub, I could verify that the luma range is still 16-235. So far, so good.
Then I wanted to export the same bitmap file as a short MPG clip,
for brightness/contrast calibration purposes on TV.
The following puzzling situation occurs. In the encoder (tMpeg 1.2 J) I select the option "export YUV data as basic YCbCr instead of CCITT", so the encoder is not allowed to change the luma levels.
I then opened this Mpeg file in VirtualDub. Guess what? Luma range is 0-255. What the heck is going on here? I see only two possibilities. Either the MPG-1 import filter in VirtualDub "stretches" the luma, or Premiere does so before passing the images to the encoder. Can anybody shed some light here?