Here’s a column that talks about the requirement to perform both objective and subjective testing when evaluating different encoding techniques or comparing codecs. Here’s the first paragraph.
I spend a lot of time assessing video quality, sometimes to compare different codecs, but more frequently to identify the optimal encoding techniques. For example, does an I-frame interval of 3 seconds deliver substantially better quality than an interval of 1 second? How about VBR vs. CBR, or the very slow x265 preset compared to medium? The only way to know is to encode both ways and compare the results.
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