Changes between Version 4 and Version 5 of Encode/H.265


Ignore:
Timestamp:
Jan 17, 2015, 6:40:11 PM (4 years ago)
Author:
slhck
Comment:

minor improvements

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  • Encode/H.265

    v4 v5  
    11= FFmpeg and H.265 Encoding Guide =
    22
    3 H.265 (also known as HEVC) offers 50-75% compression efficiency compared to an H.264 video, while retaining the same quality. ffmpeg has support for HEVC encoding using the x265 encoder. '''Note:''' libx265 is under heavy development. The API may change.
     3H.265 (also known as HEVC) offers 50-75% more compression efficiency compared to H.264 video, while retaining the same visual quality. ffmpeg has support for HEVC encoding using the x265 encoder. '''Note:''' libx265 is under heavy development. The API may change.
    44
    55== Getting ffmpeg with libx265 support ==
     
    1313 Similar to x264, the x265 encoder has multiple rate control algorithms, including:
    1414
    15 * 1-pass constant bitrate
    16 * 2-pass constant bitrate
     15* 1-pass constant bitrate (by setting `-b:v`)
     16* 2-pass constant bitrate (see [[H.264#twopass]])
    1717* Constant Rate Factor (CRF)
    1818
    19 In this guide we are going with CRF encoding.
     19In this guide we are going to focus on CRF encoding.
    2020
    2121=== Constant Rate Factor (CRF) ===
    2222
    23 Use this mode if you want to retain good visual quality and don't care about the exact bitrate or filesize. The mode works exactly the same as in x264, so please read the [[H.264]] guide for more info.
     23Use this mode if you want to retain good visual quality and don't care about the exact bitrate or filesize of the encoded file. The mode works exactly the same as in x264, so please read the [[H.264]] guide for more info.
    2424
    2525In this example, we will use the following settings:
    2626* default CRF of 28. The CRF of 28 should visually correspond to libx264 video at CRF 23, but result in about half the file size.
    27 * `medium` preset. The preset determines how fast the encoding process will be – at the expense of compression efficiency. Put differently, if you choose `ultrafast`, the encode is going to run fast, but the file size will be larger when compared to `medium`. Valid presets are `ultrafast`, `superfast`, `veryfast`, `faster`, `fast`, `medium`, `slow`, `slower`, `veryslow` and `placebo`.
     27* `medium` preset. The preset determines how fast the encoding process will be – at the expense of compression efficiency. Put differently, if you choose `ultrafast`, the encoding process is going to run fast, but the file size will be larger when compared to `medium`. The visual quality will be the same. Valid presets are `ultrafast`, `superfast`, `veryfast`, `faster`, `fast`, `medium`, `slow`, `slower`, `veryslow` and `placebo`.
    2828* AAC audio at 128 kBit/s. This uses the ffmpeg-internal encoder, but under [[AAC]] you will find info about more options.
    2929
     
    3232}}}
    3333
    34 Generally, options are passed to x265 with the `-x265-params` argument. For fine-tuning the encoding process, you can therefore pass any option that is listed in the [http://x265.readthedocs.org/en/default/ x265 documentation].
     34Generally, options are passed to x265 with the `-x265-params` argument. For fine-tuning the encoding process, you can therefore pass any option that is listed in the [http://x265.readthedocs.org/en/default/ x265 documentation]. Keep in mind that fine-tuning any of the options is generally not necessary, unless you absolutely know what you need to change.
    3535
    3636== Further Info ==