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Old 5th February 2018, 09:56   #19  |  Link
jonatans
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Join Date: Oct 2017
Posts: 56
Thank you Selur for the comments.

The only level of progress indication right now is with "-verbose 1" and it is done on SubGop level (and not frame level) since the print-out is coupled with the delivery of encoded data from the encoder lib to the command line application.

You are completely correct in that there is no multi-threading support on the encoder yet. This is of course a desirable feature that we would like to see support for soon (together with other speed improvements) but so far we are still more focused on producing really high quality with no specific encoding time limitations.

You are right in that "-qp" stands for "quantization parameter". In general terms, a higher qp gives coarser quantization steps (lower quality) and a lower qp gives finer quantization steps (higher quality). However, internally xvc will use the "-qp" as input for calculating which base qp to use for different pictures, depending on the SubGop length and the current picture's position in the SubGop. Furthermore, within a picture, different blocks will use different qp depending on the local energy.

The range of "-qp" is -64 to 63. There is no mathematical lossless mode in xvc and depending on the internal bitdepth it might actually make sense to use qp below 0, although in general I would say that "-qp" should probably be between 15 and 45 in order to produce useful result.

Did you get a chance to compare your encoded result to some other codec? Any comments on the quality?
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