H.265

H.265 (also known as HEVC) is the successor to H.264, delivering roughly 40% better compression at the same visual quality. It is the codec of choice for 4K content and is well-supported across Apple devices, modern smart TVs, and streaming platforms. Transcodely uses the libx265 encoder.

Quick Start

{
  "type": "mp4",
  "video": [
    {
      "codec": "h265",
      "resolution": "2160p",
      "quality": "standard"
    }
  ]
}

H265Options Reference

Override defaults by passing the h265 object on a video variant:

{
  "codec": "h265",
  "resolution": "2160p",
  "quality": "premium",
  "h265": {
    "profile": "main10",
    "preset": "slow",
    "crf": 22,
    "tune": "grain"
  }
}

Key Differences from H.264

Property	H.264	H.265
CRF range	15-35	18-35
Tune options	film, animation, grain, stillimage, fastdecode	grain, fastdecode
Profiles	baseline, main, high	main, main10, main-still-picture
Level range	3.0-5.2	3.0-6.2 (8K support)
Encoding speed	Faster	Slower at same preset
Default CRF (standard)	23	26

Presets

Same naming convention as H.264, but H.265 is generally slower at each preset level:

Preset	Allowed	Notes
`ultrafast`	Yes	Very fast, poor compression
`superfast`	Yes
`veryfast`	Yes	Default for economy tier
`faster`	Yes
`fast`	Yes
`medium`	Yes	Default for standard tier
`slow`	Yes	Default for premium tier
`slower`	Yes
`veryslow`	Not allowed	Minimal gain at extreme cost
`placebo`	Not allowed

Default by quality tier:

Quality Tier	Default Preset	Default CRF
`economy`	`veryfast`	32
`standard`	`medium`	26
`premium`	`slow`	22

Profiles

Profile	Bit Depth	Use Case
`main`	8-bit	Maximum compatibility (default)
`main10`	10-bit	Better gradients, HDR content, higher quality at same bitrate
`main-still-picture`	8-bit	Single-frame encoding (screencasts, slideshows)

The main10 profile is recommended for premium-tier encodes and any content that will be graded or color-corrected. It produces smoother gradients and eliminates banding artifacts common in 8-bit encoding.

Levels

H.265 extends the level system to support 8K resolution:

Level	Max Resolution	Max Framerate	Max Bitrate
`3.0`	960x540	30 fps	6 Mbps
`3.1`	1280x720	33 fps	10 Mbps
`4.0`	2048x1080	30 fps	12 Mbps
`4.1`	2048x1080	60 fps	20 Mbps
`5.0`	4096x2160	30 fps	25 Mbps
`5.1`	4096x2160	60 fps	40 Mbps
`5.2`	4096x2160	120 fps	60 Mbps
`6.0`	8192x4320	30 fps	60 Mbps
`6.1`	8192x4320	60 fps	120 Mbps
`6.2`	8192x4320	120 fps	240 Mbps

Levels are auto-selected based on resolution and framerate. Override only when targeting specific device profiles.

CRF (Constant Rate Factor)

Allowed range: 18-35 (stricter than H.264).

CRF Range	Quality	Use Case
18-20	Near-lossless	Archival, mastering
21-24	High quality	Premium streaming
25-28	Good quality	Standard streaming (default: 26)
29-32	Acceptable	Mobile, previews
33-35	Lower quality	Low-bandwidth delivery

H.265 CRF values are not directly comparable to H.264. An H.265 CRF of 26 produces roughly the same visual quality as an H.264 CRF of 23, at a significantly smaller file size.

Tune

H.265 supports fewer tune options than H.264:

Tune	Best For	Effect
`grain`	Film grain, vintage footage	Preserves grain texture, reduces artifacts
`fastdecode`	Low-power playback	Disables computationally expensive features

The film, animation, and stillimage tunes from H.264 are not available in H.265. The encoder handles content adaptation automatically.

Advanced Parameters

Parameter	Range	Default	Description
`bitrate`	100-240,000 kbps	None (CRF mode)	Target bitrate
`maxrate`	100-240,000 kbps	None	Maximum bitrate for VBV
`bufsize`	100-480,000 kbps	None	VBV buffer size
`keyint`	1-600 frames	250	Maximum keyframe interval
`min_keyint`	1-60 frames	25	Minimum keyframe interval
`bframes`	0-16	Per preset	B-frames between I and P
`ref`	1-16	Per preset	Reference frames
`rc_lookahead`	0-250	Per preset	Rate control lookahead
`aq_mode`	0-3	1	Adaptive quantization mode
`aq_strength`	0.0-3.0	1.0	Adaptive quantization strength
`psy_rd`	`"str:trellis"`	Per tune	Psychovisual optimization

Example: 4K HDR-Ready Encode

{
  "codec": "h265",
  "resolution": "2160p",
  "quality": "premium",
  "h265": {
    "profile": "main10",
    "preset": "slow",
    "crf": 20,
    "ref": 6,
    "bframes": 8
  }
}

Example: Efficient Mobile Delivery

{
  "codec": "h265",
  "resolution": "720p",
  "quality": "economy",
  "h265": {
    "profile": "main",
    "crf": 30
  }
}

Container Compatibility

H.265 works with: MP4, MKV, MOV, TS, HLS, DASH

H.265 does not work with: WebM

#H.265

#Quick Start

#H265Options Reference

#Key Differences from H.264

#Presets

#Profiles

#Levels

#CRF (Constant Rate Factor)

#Tune

#Advanced Parameters

#Example: 4K HDR-Ready Encode

#Example: Efficient Mobile Delivery

#Container Compatibility