# What's the difference between 'hvc1' and 'hev1' HEVC codec tags for fMP4?
**URL:** https://community.bitmovin.com/t/whats-the-difference-between-hvc1-and-hev1-hevc-codec-tags-for-fmp4/101
**Category:** Support
**Tags:** hevc, codec, container, mp4, fmp4
**Created:** [December 29, 2021, 3:57pm UTC](https://community.bitmovin.com/t/whats-the-difference-between-hvc1-and-hev1-hevc-codec-tags-for-fmp4/101 "2021-12-29T15:57:19Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Monycky](https://community.bitmovin.com/u/Monycky)
#### Post date: [December 29, 2021, 3:57pm UTC](https://community.bitmovin.com/t/whats-the-difference-between-hvc1-and-hev1-hevc-codec-tags-for-fmp4/101/1 "2021-12-29T15:57:19Z")
HEVC video can be muxed into fMP4 using different codec tags.
According to `8.4.1 HEVC video stream definition` of [`ISO/IEC FDIS 14496-15:2019(E)`](https://webstore.iec.ch/preview/info_isoiec14496-15%7Bed5.0%7Den.pdf) there are `hvc1` and `hev1`.
But what’s the difference between the two?
---
### Author:  [@anon80868541](https://community.bitmovin.com/u/anon80868541)
#### Post date: [December 29, 2021, 3:57pm UTC](https://community.bitmovin.com/t/whats-the-difference-between-hvc1-and-hev1-hevc-codec-tags-for-fmp4/101/2 "2021-12-29T15:57:58Z")
It’s related to the placement of parameter sets (SPS, PPS, VPS) in the fMP4 file.
Section `8.3.2` of `ISO/IEC FDIS 14496-15:2019(E)` states:
> Parameter sets: A parameter set to be used in a picture must be sent prior to the sample containing that picture or in the sample for that picture. For a video stream that a particular sample entry applies to, the video parameter set, sequence parameter sets, and picture parameter sets, shall be stored only in the sample entry when the sample entry name is ‘hvc1’, and may be stored in the sample entry and the samples when the sample entry name is ‘hev1’.
### Conclusively:
- `hvc1` parameter sets are stored _out-of-band_ in the sample entry (i.e. below the Sample Description Box ( `stsd` ) box)
- `hev1` parameter sets are stored _out-of-band_ in the sample entry and/or _in-band_ in the samples (i.e. SPS/PPS/VPS NAL units in the bitstream/ `mdat` box)
### Side Notes:
- It seems not every platform/decoder supports both tags
- Apple QuickTime player on Mac only supports `hvc1`
- [Apple prefers `hvc1`](https://developer.apple.com/documentation/http_live_streaming/hls_authoring_specification_for_apple_devices#2969487) for HLS on Apple devices