Your studio accepts H.264 or H.265 (HEVC) with AAC sound in MPEG-TS over SRT. Practically every SRT app sends that by itself. The details matter all the same: an even bitrate, a keyframe every 2 seconds and a bitrate that fits your link.
The values below are our recommendation. They apply to every source, whether OBS, a phone app, ffmpeg or a hardware encoder. What the fields are called differs from app to app.
The settings at a glance
| Setting | Recommendation | Why |
|---|---|---|
| Video codec | H.264, with a tight bitrate H.265 (HEVC) | The studio accepts both. Every device can do H.264. H.265 shows the cleaner picture at 2–4 Mbit/s if your device encodes it in hardware. |
| HDR | off | The studio does not convert an HDR picture; the colors then look pale. |
| Resolution | 1080p or 720p | More is not needed. 720p saves bitrate when the link is tight. |
| Frame rate | up to 60 frames per second | 60 for movement and gameplay; for calm pictures 30 is enough. |
| Rate control | constant bitrate (CBR) | An even data rate is easier to carry over a mobile or internet link than one with peaks. |
| Video bitrate | 3–4 Mbit/s on shaky mobile data, 6 Mbit/s on good 5G, Wi-Fi or fiber | The bitrate has to be safely below what your link manages in upload. More than 6 Mbit/s only on a link you know to be good. |
| Keyframe interval | 2 seconds | After a lost packet the picture stays faulty until the next keyframe comes. At 2 seconds an error is gone again quickly. |
| Audio codec | AAC | The format the studio expects. |
| Audio bitrate | 128–160 kbit/s, stereo | Enough for speech and music. |
| Sample rate | 48 kHz | The studio works at 48 kHz. Other common sample rates work too. |
| Container | MPEG-TS | The normal case with SRT, usually not even a setting. |
| SRT mode | Caller | Your studio waits for the connection, the app sets it up. |
| Passphrase | leave empty | The inputs work without encryption. A passphrase that is entered prevents the connection. |
Bitrate: rather too low than too high
The most common cause of a stuttering picture is a bitrate the link does not manage for long. SRT can ask for lost packets again, but it cannot produce bandwidth that is not there. A clean picture at 4 Mbit/s looks better than a disturbed one at 8.
This is how you go about it:
- Measure the upload where you are going to send from, and count on only a part of it. On mobile data the value varies a lot.
- Set the bitrate according to the table and send for a few minutes as a trial.
- In the studio, look at the link quality display on the “Eingänge” (inputs) tab. Packets that arrived as a retransmission were repaired by SRT in time; that is fine. Packets that never arrived you see as picture errors and hear as gaps in the sound. If that number rises, lower the bitrate or raise the SRT latency.
On the road the data volume counts too: 6 Mbit/s are about 2.7 GB per hour, 4 Mbit/s about 1.8 GB.
Keyframes: in seconds or in frames
Some apps ask for the distance in seconds, others for the number of frames (often called “GOP”). 2 seconds are:
- 120 frames at 60 frames per second
- 100 frames at 50 frames per second
- 60 frames at 30 frames per second
If the setting is on “automatic”, the distance can be much longer. Then it takes correspondingly longer until a picture error disappears. So enter the value as a fixed one.
What the studio makes of it
Your source's settings only determine the stretch from you to the studio. The program that goes to Twitch, YouTube or Kick is encoded anew by the studio. So you do not have to send different values for every platform. What your source does not bring along in quality, however, the studio cannot add.
Checklist before the stream
- The codec is set to H.264 or H.265 (HEVC), HDR is off.
- The bitrate is constant and safely below your upload.
- The keyframe interval is fixed at 2 seconds.
- The sound is AAC, stereo, 48 kHz.
- The passphrase is empty.
- The address matches the one on the “Eingänge” tab.