Every H.264 file we create in Sorenson Squeeze 7 (PC) has elevated black levels and reduced contrast. If I didn't know better I would have thought it was a RGB vs. 709 issue -- but I think we've disproved that.
We have exported test files from Avid (PC) using three different types of uncompressed QuickTime RGB (0-255) files -- Same as Source, Avid Codecs and Avid 1:1x.
And to check them for "unity" -- we re-imported them back into Avid as RGB -- and they match perfectly with the timeline.
Then we imported those uncompressed QuickTime files into Squeeze and compressed them using three different types of H.264 codecs -- MainConcept, Apple and Sorenson.
We have viewed all of these compressed files in QuickTime, Windows Media Player, VLC, Firefox, Chrome and Internet Explorer -- and they all have the same black and contrast problem.
The we imported all of the H.264 files back into Avid as RGB -- and they exhibit the exact same problem -- and do not match the timeline.
Finally, we exported an H.264 file directly out of Avid -- which I believe uses QuickTime codecs -- and the video levels are fine. And then we re-imported that Avid H.264 file back into Avid as RGB -- and the levels match the timeline perfectly.
I realize H.264 colorspace is different -- but the black level and contrast differences we are seeing are significant. More confusing -- is that the Avid H.264 export matches the timeline perfectly.
And, lastly, the "Black Normalization to 16" checkbox in Squeeze 7 -- has had absolutely no affect in any of our tests.
Anyone else see this problem -- or have a solution?
Thanks in advance.
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