Changes between Version 9 and Version 10 of Encode/H.264


Ignore:
Timestamp:
Aug 14, 2012, 4:03:55 AM (7 years ago)
Author:
llogan
Comment:

revert confusing statement about lossless parameters; remove additional x264opts example since private options are already mentioned

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  • Encode/H.264

    v9 v10  
    4040The range of the quantizer scale is 0-51; where 0 is lossless, 23 is default, and 51 is worst possible. A lower value is a higher quality and a subjectively sane range is 18-28. Consider 18 to be visually lossless: it should look the same as the input but it isn't technically lossless. Increasing the CRF value +6 is roughly half the bitrate while -6 is roughly twice the bitrate. General usage is to choose the highest quality that still provides an acceptable quality. If the output looks good then try a higher value and if it looks bad then choose a lower value.
    4141
    42   '''Note:''' The CRF quantizer scale mentioned applies to 8-bit x264 (10-bit x264 quantizer scale is 0-63). You can see what you are using with `x264 --help` listed under `Output bit depth`.
     42  '''Note:''' The CRF quantizer scale mentioned on this page only applies to 8-bit x264 (10-bit x264 quantizer scale is 0-63). You can see what you are using with `x264 --help` listed under `Output bit depth`. 8-bit is more common amongst distributors.
    4343
    4444=== 2. Choose a preset ===
     
    7878
    7979== Lossless H.264 ==
    80 You can use `-qp 0` or `-crf 0` to encode a lossless output.  Despite being lossless, other parameters still matter.  Only two of the presets are generally useful though: `ultrafast` or `veryslow` since either a fast encoding speed or best compression are usually the most important factors.
     80You can use `-qp 0` or `-crf 0` to encode a lossless output.  The two useful presets are `ultrafast` or `veryslow` since either a fast encoding speed or best compression are usually the most important factors.
    8181
    8282=== Lossless Example (fastest encoding) ===
     
    104104}}}
    105105
    106 or
    107 {{{
    108 -x264opts vbv-bufsize=3600:vbv-maxrate=1800:crf=23
    109 }}}
    110 though these are somewhat redundant to other "standard" ffmepg settings, and can also be specified each separately.
    111 
    112106----
    113107