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Generation Loss in the digital world?
For the past 10 years this question comes to mind, but I’ve never remembered to ask it. Weird I know. Until now… is generation loss a factor in the digi-world? I don’t mean if you convert an HD file down to a smaller format. I mean as long as you’re trying to stay true to the source , does generation loss even need to be a concern like it was in the analog days?
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I don’t have any charming or witty things to put in my signature. So as Peter Griffen says, “That’s may mama!” -
4 Replies
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SOrry for 2 posts at once, when I came to this forum all the sudden this post kept coming up when I would select, “Create new post” The message body of this one would appear like I had not posted it. I don’t know what happened or why.
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I don’t have any charming or witty things to put in my signature. So as Peter Griffen says, “That’s may mama!” -
We can talk about generation lost when reproducing a picture.
The possible quality lost when up/down-scaling a picture can’t be considered “generation lost”.The only way to avoid generation lost in digital, is using Uncompressed formats and high quality processes.
Every compression/decompression cycle degrades the picture as when in Analog the Composite signal is separated to Components and back to Composite.
In digital will depend of the quality of the RAW material and the quality and number of rendering processes that your stuff undergoes.
rafael -
Bit-for-bit transfers do no damage. Areas where rendering takes place may create some degradation, but this is minor compared to analogue. Videos that keep getting re-compressed suffer more degradation each time becasue the comperssion is achieved by throwing out some bits and averaging others. A guy with more patience than I have took this to an intersting extreme…he digitized and re-digitized the same footage in a loop a hundred times (100 generations down) to see what the compression artifacting would do to it, and it turned his sample footage into abstract art. I’ll try to find a link to that, but my google-fu-is weak on this one.
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You are right Mark.
Of the current FC codecs, the only you can re-compress forever without loss would be 8 and 10b 422 Uncompressed.
When you process in FC, any YUV stuff is “deployed” as 444 YUV.
The missed Chroma samples are filled, but back to 422, the same Chroma samples that are filled, are discharged (downsampled).
You end up with the original 422 picture.
rafael
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