Streaming & Video Sync¶
OBS 4K Streaming Settings¶
When producing 3D live streams, setting the correct OBS settings will make your stream look significantly better than other streamers. Below are important OBS settings that can massively improve streaming graphics quality.
PC Requirements¶
These settings are based on the following PC specifications:
| Component | Specification |
|---|---|
| GPU | RTX4080 Super |
| CPU | Intel(R) Core(TM) i7-14700F 2.10 GHz |
| Internet | 100+ Mbps upload speed |
You may need a PC that is similar or better.
Best Resolution¶
Important OBS Setting
Make sure this setting is correct.
Streaming video is always transcoded (re-encoded) to VP9 WebM format to provide viewers with various resolution options. Therefore, viewers never see the source (original) quality.
For the best VP9 transcode results, you should always use Output Resolution = 3840x2160 in the OBS Video section, even if your Base (Canvas) Resolution is 1920x1080 / 2560x1440 / 3840x2160.
Example Settings A¶
For the best graphics quality, use 3840x2160 for both Output Resolution and Base (Canvas) Resolution. Downscale Filter will be automatically disabled.
Example Settings B¶
If your OBS Base (Canvas) Resolution is only 1920x1080 but you want 4K quality transcoding, set Base (Canvas) Resolution = 1920x1080 and Output Resolution = 3840x2160. OBS will output 3840x2160 for processing as 4K. You do not need a 3840x2160 monitor for this setup.
4K Upscale Effect
Even when viewers watch a 4K video on a 1920x1080 monitor, a 4K video provides much better visual quality than a 1080p video. If your PC and internet can handle it, always stream at Output Resolution = 3840x2160.
1080p Output Warning
If Output Resolution is 1920x1080, visual quality will always be degraded due to low-quality 1080p VP9/AVC transcoding, regardless of OBS encoding settings. Use at least 2560x1440 or 3840x2160.
Best Encoder¶
Important OBS Setting
Make sure this setting is correct.
Encoder significantly affects encoding performance and visual quality! Always use your GPU's hardware encoder: NVIDIA / AMD / QuickSync (Intel)
Select the highest available option from the list below:
| Encoder | Description |
|---|---|
| NVIDIA NVENC AV1 | Most modern GPU encoder, excellent performance and quality. Always select this if available. Requires RTX 40 series or higher |
| NVIDIA NVENC HEVC | GPU H.265, slightly inferior to AV1 but still good enough. Requires GTX 1650 rev 2 or higher |
| NVIDIA NVENC H.264 | Worse quality than AV1 or HEVC. Use only if above options are unavailable |
| x264 | Old CPU encoder, bad quality, slow for 4K60fps. Do not use |
| SVT-AV1 | CPU encoder, very high quality but too slow for 4K60fps. Do not use for streaming |
| AOM-AV1 | CPU encoder, best quality but too slow for 4K60fps. Do not use for streaming |
Visual quality comparison at the same bitrate:
[Best Quality] AV1 > HEVC (H.265) >>>>>>>>>>>>>>>> AVC (H.264) [Worst Quality]
Always avoid encoders with 264 in the name (e.g., H.264/x264/AVC) for streaming.
4K video quality comparison: H.264 vs. AV1 (10Mbps)
Best Bitrate¶
Important OBS Setting
Make sure this setting is correct.
For OBS 4K60fps streaming, it is recommended not to exceed 51000 Kbps (= 51 Mbps). Therefore, use approximately 50000 Kbps Bitrate for 4K60fps OBS live streaming.
Check Upload Speed
To determine the best Bitrate, first check your upload speed using SpeedTest. To stream at 50000 Kbps (= 50 Mbps) Bitrate, a stable upload speed of 75Mbps (= 50 Mbps x 150%) or higher is recommended for stable 4K60fps streaming.
VTuber Warning
Do not open SpeedTest while streaming. Your IP and location will be displayed in the browser!
Best Encoder Settings¶
Other settings that affect visual quality and performance:
| Setting | Recommended Value |
|---|---|
| Rate Control | CBR |
| Keyframe Interval | 2 |
| Preset | Try P7:Slowest (Best Quality) first; use P6~P5 if limited by performance |
| Tuning | High Quality |
| Multipass Mode | Two Passes (Full Resolution); use Quarter Resolution if limited by performance |
| Profile | main (use high for H.264) |
| Look-ahead | On; use Off if limited by performance |
| Psycho Visual Tuning | On |
| GPU | 0 (set according to your PC) |
| Max B-frames | 4 (reduce to 2 if Look-ahead is Off) |
Recording Override Settings
When recording instead of streaming, override these 3 settings:
- Rate Control = Use CQP instead of CBR (VBR is also acceptable)
- CQ Level (CQ): 15 (lower for higher quality, but larger file size)
- Bitrate and Max Bitrate (VBR): 40,000 / 60,000. Increase to 100,000 / 200,000 for higher quality
OBS Settings Reference¶
Typical OBS settings for 4K60fps 3DLive. Assumes an RTX40xx GPU with NVIDIA NVENC AV1 encoder and stable 80+ Mbps upload speed.
NVIDIA NVENC OBS Guide¶
For a detailed explanation of recommended settings for 4K60fps streaming and recording:
Streaming Platform Differences¶
The above settings target 4K60fps live streaming only. They will not work for other streaming platforms!
(Last updated: 2025-10-01)
YouTube¶
| Item | Specification |
|---|---|
| Max bitrate | 51Mbps (68Mbps for 4K60fps HDR AV1 input) |
| Encoder | H.264, HEVC (H.265), AV1 |
| Max output resolution | 4K60fps |
| Notes | Transcodes to VP9 WebM for viewer delivery. Goal is to upload the highest bitrate stream |
Twitch¶
| Item | Non-Affiliate | Affiliate | Partner |
|---|---|---|---|
| Max bitrate | 8Mbps | 15Mbps | 25Mbps |
| Max resolution | 1080p60fps | 1440p60fps | 4K60fps (beta) |
| H.264 | Yes | Yes | Yes |
| HEVC (H.265) | No | No | Yes |
| AV1 | Beta testing | Beta testing | Beta testing |
Twitch Note
At the non-affiliate 8Mbps limit, consider 720p-900p for fast-motion games. Viewers can select Source quality, receiving the stream without quality loss.
Bilibili (China)¶
| Item | Specification |
|---|---|
| Max bitrate | 20Mbps (25Mbps for verified/partnered streamers) |
| Encoder | H.264, HEVC (H.265), AV1 |
| Max output resolution | 4K60fps (1080p60fps for non-verified) |
SOOP (Korea)¶
Formerly AfreecaTV, rebranded to SOOP in 2024 and expanding internationally.
| Item | Specification |
|---|---|
| Max bitrate | 12Mbps (20Mbps for partners/BJ Star rank) |
| Encoder | H.264, HEVC (H.265) |
| Max output resolution | 1080p60fps (1440p60fps for top-tier partners) |
| Notes | Low latency streaming (1-3 seconds) |
VideoPlayer & Recorder Sync Problem¶
If you find that VideoPlayer playback is not in sync when recording with Unity Recorder, there are two solutions.
KlakHap (Recommended)¶
(Recommended, works with Timeline Preview)
Instead of Unity's VideoPlayer, use HAP codec .mov videos with KlakHap. KlakHap supports perfect recording with Recorder and allows real-time preview playback in Timeline in edit mode (drag in Timeline to instantly preview video on RenderTexture, greatly boosting productivity for MV/cutscene work).
How to use KlakHap:
- Install KlakHap via Package Manager (instructions)
- KlakHap only supports HAP, HAP Alpha, HAP Q codec .mov files. Use Shutter Encoder to convert videos to HAP codec .mov
- Place the HAP codec .mov in your Unity project's Assets/StreamingAssets
- Add a HapPlayer script to a new game object
- Set the HapPlayer script's Path Mode to Streaming Assets
- Set the HapPlayer script's File Path to the HAP codec .mov filename (e.g., myVideo.mov)
- Set the HapPlayer script's Target Texture or Target Renderer to display the video result
- Enter Play Mode and verify the video playback result
- For Timeline control, add a new Control Track to Timeline, then drag the HapPlayer script object onto the Control Track
VideoPlayer Nilo Script (Not Recommended)¶
(Not recommended, does not work with Timeline Preview and is not user-friendly. Use KlakHap when possible)
- Attach the script VideoPlayerForceSyncWithRecorder from the NiloToonURP folder to the VideoPlayer component
- Ensure the script's fps setting correctly matches the Recorder's fps setting (e.g., 60)
- Only enable VideoPlayerForceSyncWithRecorder during recording; do not enable during normal gameplay
Audio Note
Neither solution outputs video audio. You need to play a separate audio track in Timeline.