jocelyntremblay wrote:Absolutely. It is either, uncompressed or compressed using lossless or lossy compression.
However, which one is "visually lossless" compression ?
Lossless is lossless. Period.
Absolutely, but you didn't look much in it, did you ?
The thing is that I actually understand the terminology, so I'm not going to waste my time spewing it mindlessly.
If you were a developing a software that reads CinemaDNG, you would dig deeper. You would have found that CinemaDNG is a image sequence where each video frame is independently encoded using the DNG (Digital Negative) image format. The video stream is stored either as a picture track in an MXF (Material Exchange Format) file or as a sequence of individual frame files.
Yes, it's spelled out pretty clearly on the web site, and it's orthogonal to the question you asked.
You would also found that the DNG image file must be one of the following :
- Uncompressed
- JPEG compressed data, either baseline DCT JPEG, or lossless JPEG compression
- Deflate compression (ZIP)(Lossless compression)
- Lossy JPEG
Lossy compression is JPEG only.
JPEG compression is available only in 8bits.
None of that contradicts anything I wrote. It's true that JPEG is an 8-bit codec, but the list you cite clearly states that CinemaDNG also supports lossless compression.
I'm asking again, is "visually lossless" compression lossy or lossless ?
Lossless is lossless. That's it. If it's not lossless, then obviously it's lossy. What I said is that CinemaDNG support lossless compression at whatever bit rate you prefer, and with all the jargon that you're regurgitating without any apparent understanding you've found nothing to contradict that, and you won't no matter how hard you try.
For a definitive answer about what compression method BMD is using on the Pocket Cinema Camera, we'll have to wait until BMD decides to share that information with us. For all we know they're still working on a compression implementation that meets the constraints of the limited bandwidth available on an SD card and don't even know for sure yet. It's also possible that they're working on a Cineform RAW implementation. I suspect that a lot of people would like that quite a bit, and it obviously works quite well given the image quality of the Black Edition of the Hero 3.