mpeg5 / xeve

eXtra-fast Essential Video Encoder, MPEG-5 EVC (Essential Video Coding)
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A few questions regarding documentation/help #96

Open Selur opened 10 months ago

Selur commented 10 months ago
  1. Defaults. Not all options have defaults. Does this mean they are not used or that the defaults are simply not listed.
  2. The command line help mentions:
    --preset [STRING] (optional) [medium]
    : Encoder PRESET     [fast, medium, slow, placebo]
    --tune [STRING] (optional) [None]
    : Encoder TUNE   [psnr, zerolatency]

    but it does not mention how those settings change the defaults. (I assume 'medium' correlates to the defaults.)

  3. most options that have integer as type have no min and max info. Can you share those?
  4. Profile&levels: are profile&level restrictions, regarding feature sets, vbv etc. enforced? Are there warnings on violation if not? So if I select profile main and level 4.1, can I be sure the resulting output is compatible to the selected profile&level restrictions for vbv&co?
  5. Rate control. Does "--rc-type 0" mean that constant quantizer encoding will be used? Does '--qp' have any influence for 'rc-type' 1&2 ?
  6. Does 'codec-bit-depth' 'just' set the internal calculation precision, or is does it also set the output bit depth. (or is output = input bit depth) ?
  7. When encoding to H.265, I assume the output is always Main Tier, is that correct?
Selur commented 10 months ago
  1. STRING vs INTEGER Looking at:

    --videoformat [STRING] (optional) [None]
    :  0-component, 1-pal, 2-ntsc, 3-secam, 4-mac. 5-unspecified
    --range [STRING] (optional) [None]
    : black level and range of luma and chroma signals as 1- full or 0- limited
    --colorprim [STRING] (optional) [None]
    : 1- bt709, 2-unspecified, 3- reserved, 4- bt470m, 5- bt470bg, 6- smpte170m,         7- smpte240m, 8- Generic film, 9- bt2020, 10-smpte428, 11-smpte431, 12-smpte432,          22-EBU Tech. 3213 Default 2-unspecified
    --transfer [STRING] (optional) [None]
    : 1- transfer characteristics from bt709, 2-unspecified, 3-reserved, 4-bt470m, 5-bt470bg, 6-smpte170m,         7-smpte240m, 8-linear, 9-log100, 10-log316, 11-iec61966-2-4, 12-bt1361e, 13-iec61966-2-1,         14-bt2020-10, 15-bt2020-12, 16-smpte2084, 17-smpte428, 198-arib-std-b67. Default 2-unspecified
    --matrix-coefficients [STRING] (optional) [None]
    : 0-gbr, 1-bt709, 2-unspecified, 3-reserved, 4-fcc, 5-bt470bg, 6-smpte170m, 7-smpte240m, 8-ycgco, 9-bt2020nc, 10-bt2020c, 11-smpte2085, 12-chroma-derived-nc, 13-chroma-derived-c, 14-ictcp, 15-255 reserved}; 

    Is STRING really correct for those and one should use something like for example '--colorprim "22-EBU Tech. 3213"' or it be Integer and one should use '--colorprim 22' ?

  2. Frame rate:

    -z, --fps [INTEGER]
    : frame rate (frame per second)

    is this correct that only whole frame rates are supported? (Double or better fraction support would be nice)