x265 --input source.y4m --output compressed.hevc --preset medium --crf 22 --profile main10 --no-sao --no-strong-intra-smoothing --aq-mode 3 --aq-strength 1.2 --deblock -2:-2
At the heart of shrinking a video file with x265 are two essential parameters: the Constant Rate Factor (CRF) and the encoder preset. These are the primary levers you will pull to control the relationship between file size, encoding speed, and visual quality.
To reduce file size, you must remove redundant or imperceptible information. Here are the five levers you can pull.
While many converters exist, is widely considered the industry standard for this task because it is free, open-source, and provides deep control over HEVC parameters. Handbrake (Recommended): Excellent x265 tuning options. FFmpeg: Command-line powerhouse for advanced users. shrinking x265
Despite all these techniques, some content resists shrinking:
Ironically, modern playback devices make things worse. Smart TVs, phones, and tablets have excellent upscalers and noise reduction. A shrunk x265 file can look passable on a small screen—until you cast it to a 65-inch OLED. Then the compression artifacts bloom like digital cancer.
Audio can take up substantial space. Re-encode 7.1 DTS-HD MA to 5.1 AC3 or AAC. x265 --input source
The encoder preset determines how hard your CPU works to find compression algorithmic efficiencies. The scale ranges from Ultrafast to Placebo .
placebo offers negligible gains for massive time costs; ultrafast creates significantly larger files. Recommended Tools
Shrinking x265 is not about slapping a "256 kbps" bitrate limit on a video. It is a surgical process: Here are the five levers you can pull
"Shrinking" also applies to the output file size.
In the era of 4K streaming, high-resolution surveillance, and massive media libraries, storage space is a premium asset. While the codec is already highly efficient—offering up to 50% better compression than its predecessor, H.264—there are many scenarios where you need to shrink these files even further.
The ultimate guide to focuses on maximizing compression efficiency using tools like HandBrake and FFmpeg without sacrificing visual quality.