HEVC (H.265) and AV1
Updated 11 Oct 2026HEVC and AV1 give the same picture quality with less bitrate than H.264 — usually 30–50 % less — so less bandwidth for the same viewers. From Castreon 1.4.0 they are included in all plans. Encoding on the graphics card and multiple qualities (ABR) still depend on the plan.
You choose them in the profile, under Codec, for each video quality — see Transcoding profiles.
Who can play them
| Codec | Played by |
|---|---|
| H.264 | every player, browser, TV and set-top box |
| HEVC | Safari (Mac, iPhone, iPad), Chrome and Edge on computers with hardware HEVC decoding, most TVs and Android boxes; Firefox only on some systems |
| AV1 | Chrome, Edge, Firefox and Android; Safari only on devices with hardware AV1 decoding; among TVs, only recent ones |
Our recommendation: a profile with several qualities, one of which is H.264 (for example HEVC 1080p + H.264 720p). The player picks by itself what it can play, so no viewer is left without a picture. The profile editor shows you this information and warns you when an H.264 quality is missing.
Which outputs they work on
| Output | HEVC | AV1 |
|---|---|---|
| HLS, DASH, LL-HLS | yes — in fMP4 (CMAF), chosen automatically, with the tag Apple players require | yes — in fMP4 (CMAF) |
| HTTP-TS, UDP, SRT, RIST (MPEG-TS) | yes | no — AV1 cannot be carried in MPEG-TS: receivers see it as data, not as a picture. Castreon stops these outputs and writes why in the log; select an H.264 or HEVC quality on them |
| RTMP push | yes, via Enhanced RTMP, if the platform accepts it | yes, via Enhanced RTMP, if the platform accepts it |
| WebRTC | re-encoded to H.264 (extra CPU) | no — add an H.264 quality and select it on the WebRTC output |
| DRM | yes | no |
RTMP push next to HLS / DASH: the same HEVC quality cannot go both over RTMP and over HLS / DASH (each needs a different picture tag). Castreon then stops only the RTMP output, with a note in the log. The fix: an H.264 quality in the profile, selected on the RTMP output (Quality sent).
The archive currently keeps only TS segments, while HLS with HEVC or AV1 uses CMAF — a channel with HEVC or AV1 is not archived yet. Keep H.264 for the archive.
On the graphics card or on the CPU
| Codec | NVIDIA (NVENC) | Intel (Quick Sync) | CPU |
|---|---|---|---|
| H.264 | every card with NVENC | yes | x264 |
| HEVC | GTX 10xx and newer | yes (newer generations) | x265 — heavy load |
| AV1 | only RTX 40 and newer | Arc cards and recent processors | SVT-AV1 — very heavy load |
At startup, Castreon tries every encoder on your server. The profile editor tells you if a codec does not work on the chosen card — for example AV1 on NVENC on a GTX 10xx, RTX 20 or RTX 30 card — before you save. If a channel still starts with an encoder the card does not have, the log explains what happened and what to choose.
AV1 on the CPU (SVT-AV1): in the Capped variable and Constant modes the encoder does not accept the Maximum peak — Castreon uses the target bitrate with a buffer. The peak only applies with Constant quality. The Constant mode uses the encoder's low-delay structure.
10-bit and HDR
For HDR sources (HLG, PQ), choose the 10-bit pixel format under Advanced. Castreon keeps the HDR information when transcoding to HEVC and AV1. Not every graphics card encodes 10-bit — the editor warns you.
What players learn about the stream
Castreon automatically writes into the HLS playlist and the DASH manifest the exact codec of each quality (profile, level, 8 or 10 bits), based on resolution and frames per second. This way players pick only the qualities they can play.