x265 supports the following -tune options: psnr, ssim, grain, zerolatency, fastdecode. By default, this is disabled, and it is generally not required to set a tune option. Ignore placebo as it provides insignificant returns for a significant increase in encoding time. Use the slowest preset you have patience for. Valid presets are ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, and placebo. The preset determines compression efficiency and therefore affects encoding speed. CRF works just like in x264, so choose the highest value that provides an acceptable quality. The default is 28, and it should visually correspond to libx264 video at CRF 23, but result in about half the file size. The mode works exactly the same as in x264, except that maximum value is always 51, even with 10-bit support, so please read the H.264 guide for more info.Īs with x264, you need to make several choices: Use this mode if you want to retain good visual quality and don't care about the exact bitrate or filesize of the encoded file. In this guide we are going to focus on CRF and Two-Pass encoding, as 1-pass target bitrate encoding is not recommended. 1-pass target bitrate (by setting -b:v).Similar to x264, the x265 encoder has multiple rate control algorithms, including: You can list private options available in this encoder with ffmpeg -h encoder=libx265. You can also download a static build, all of which bundle libx265. The Compilation Guides show you how to do that.
See HWAccelIntro for information on supported hardware H.265/HEVC encoders.įfmpeg needs to be built with the -enable-gpl -enable-libx265 configuration flags and requires x265 to be installed on your system. These gains will be most pronounced at resolutions of 1080p and higher. This guide focuses on the encoder libx265 which can offer around 25–50% bitrate savings compared to H.264 video encoded with libx264, while retaining the same visual quality. Final Cut and Apple stuff compatibility.
0 kommentar(er)
