Context
Hello everyone. I recently started using Infuse to play 4K HDR videos streaming from my NAS. I mostly use two devices right now to stream these videos:
- MacBook Pro 14" M2 Pro with Liquid Retina XDR display
- macOS version: Sequoia 15.3.1
- Infuse version: 8.1.1 (8.1.5107)
- iPad Pro 11" M4 with the XDR Display Tandem OLED
- iPadOS version: 18.3.1
- Infuse version: 8.1.1
I started looking into Infuse because the Plex client apps on my MacBook and iPad played the 4K HDR videos with lower brightness than the SDR versions of the same videos. I was elated to see that the MacBook version of the Infuse app played the 4K HDR videos without any issues and reached much higher brightness than the Plex player. However, when I play the videos with Infuse on the iPad, I get the same dimmed effect as when playing through the Plex client app. I tested four video files so far (metadata info at the end of this post) and they all had the same reduced brightness issue. The only exception is File 2, the only HDR I can play at the expected brightness through Infuse on the iPad.
As reported in this and this other Infuse posts, I also noticed that activating screen recording on the iPad increases the video’s brightness, but the brightness is still lower than what I get with an SDR version of the same video.
Questions
I am pretty confused about why the iPad is struggling so much with playback of HDR content. After many hours of searching for an answer, I understand there isn’t a simple fix. I’m mostly looking to understand better the situation and would be thankful for any insight anyone would like to share.
- The only difference between File 1 and File 2 seems to be the Mastering display color primaries (BT.2020 vs Display P3). Can this cause the difference in playback brightness between the two files?
- If the mastering display color primaries have anything to do with this, why would File 3 be played back at lower brightness? File 2 and 3 both have Mastering display color primaries set to the same Display 3.
- Are these issues related to the player app (Infuse, Plex, VLC, etc,) or to iPadOS?
Files
I tested video playback on the iPad with four different files. Here are the metadata shown by Mediainfo:
File 1—Dimmed
| Property | Value |
|---|---|
| Format | HEVC |
| Format/Info | High Efficiency Video Coding |
| Format profile | Main 10@L5.1@High |
| HDR format | SMPTE ST 2086, HDR10 compatible |
| Codec ID | V_MPEGH/ISO/HEVC |
| Bit rate | 51.2 Mb/s |
| Width | 3 840 pixels |
| Height | 2 160 pixels |
| Display aspect ratio | 16:9 |
| Frame rate mode | Constant |
| Frame rate | 23.976 (24000/1001) FPS |
| Color space | YUV |
| Chroma subsampling | 4:2:0 (Type 2) |
| Bit depth | 10 bits |
| Bits/(Pixel*Frame) | 0.257 |
| Stream size | 19.0 GiB (93%) |
| Writing library | ATEME Titan File 3.9.12 (4.9.12.4) |
| Language | English |
| Default | No |
| Forced | No |
| Color range | Limited |
| Color primaries | BT.2020 |
| Transfer characteristics | PQ |
| Matrix coefficients | BT.2020 non-constant |
| Mastering display color primaries | BT.2020 |
| Mastering display luminance | min: 0.0001 ca/m², max: 1000 cd/m² |
| Original source medium | Blu-ray |
File 2—Expected brightness
| Property | Value |
|---|---|
| Format | HEVC |
| Format/Info | High Efficiency Video Coding |
| Format profile | Main 10@L5.1@High |
| HDR format | SMPTE ST 2086, HDR10 compatible |
| Codec ID | V_MPEGH/ISO/HEVC |
| Bit rate | 67.8 Mb/s |
| Width | 3 840 pixels |
| Height | 2 160 pixels |
| Display aspect ratio | 16:9 |
| Frame rate mode | Constant |
| Frame rate | 23.976 (24000/1001) FPS |
| Color space | YUV |
| Chroma subsampling | 4:2:0 (Type 2) |
| Bit depth | 10 bits |
| Bits/(Pixel*Frame) | 0.341 |
| Stream size | 49.3 GiB (92%) |
| Language | English |
| Default | No |
| Forced | No |
| Color range | Limited |
| Color primaries | BT.2020 |
| Transfer characteristics | PQ |
| Matrix coefficients | BT.2020 non-constant |
| Mastering display color primaries | Display P3 |
| Mastering display luminance | min: 0.0000 cd/m², max: 1000 cd/m² |
| Original source medium | Blu-ray |
File 3—Dimmed
| Property | Value |
|---|---|
| Format | HEVC |
| Format/Info | High Efficiency Video Coding |
| Format profile | Main 10@L5.1@High |
| HDR format | Dolby Vision, Version 1.0, Profile 7.6, dvhe.07.06, BL+EL+RPU, compatible no metadata compression, Blu-ray compatible / SMPTE ST 2086, Version HDR10, HDR10 |
| Codec ID | V_MPEGH/ISO/HEVC |
| Bit rate | 56.1 Mb/s |
| Width | 3 840 pixels |
| Height | 2 160 pixels |
| Display aspect ratio | 16:9 |
| Frame rate mode | Constant |
| Frame rate | 23.976 (24000/1001) FPS |
| Color space | YUV |
| Chroma subsampling | 4:2:0 (Type 2) |
| Bit depth | 10 bits |
| Bits/(Pixel*Frame) | 0.282 |
| Stream size | 74.1 GiB (94%) |
| Language | English |
| Default | No |
| Forced | No |
| Color range | Limited |
| Color primaries | BT.2020 |
| Transfer characteristics | PQ |
| Matrix coefficients | BT.2020 non-constant |
| Mastering display color primaries | Display P3 |
| Mastering display luminance | min: 0.0001 cd/m², max: 1000 cd/m² |
| Maximum Content Light Level | 2755 cd/m² |
| Maximum Frame-Average Light Level | 400 cd/m² |
| Original source medium | Blu-ray |
File 4—Dimmed
| Property | Value |
|---|---|
| Format | HEVC |
| Format/Info | High Efficiency Video Coding |
| Format profile | Main 10@L5.1@High |
| HDR format | Dolby Vision, Version 1.0, Profile 7.6, dvhe.07.06, BL+EL+RPU, no metadata compression, Blu-ray compatible / SMPTE ST 2086, Version HDR10, HDR10 compatible |
| Codec ID | V_MPEGH/ISO/HEVC |
| Bit rate | 56.3 Mb/s |
| Width | 3 840 pixels |
| Height | 2 160 pixels |
| Display aspect ratio | 16:9 |
| Frame rate mode | Constant |
| Frame rate | 23.976 (24000/1001) FPS |
| Color space | YUV |
| Chroma subsampling | 4:2:0 (Type 2) |
| Bit depth | 10 bits |
| Bits/(Pixel*Frame) | 0.283 |
| Stream size | 23.2 GiB (95%) |
| Language | English |
| Default | No |
| Forced | No |
| Color range | Limited |
| Color primaries | BT.2020 |
| Transfer characteristics | PQ |
| Matrix coefficients | BT.2020 non-constant |
| Mastering display color primaries | BT.2020 |
| Mastering display luminance | min: 0.0001 cd/m², max: 1000 cd/m² |
| Maximum Content Light Level | 996 cd/m² |
| Maximum Frame-Average Light Level | 64 cd/m² |
| Original source medium | Blu-ray |