Automatic Streaming

The system/heuristics used to determine settings in automatic live streaming mode is described below. These are determined in 4 steps which are evaluated every time you go live using automatic mode:

Step 1: An initial resolution will be set depending on your computer’s proximity to the nearest streaming server. Using different approaches and depending on the streaming service provider, XSplit Gamecaster will connect to a server location as close to you as possible and set a resolution of 720p if your ping time (network round trip delay) is 100ms or less, otherwise it will be set to 540p. A frame rate of 30 FPS will always be used in automatic mode.

The reason for setting 720p as the maximum resolution in automatic mode is that higher resolution streaming can be associated with technical complications. For some users, 1080p may work fine while others may experience lag or other problems. Higher resolution streams usually work better if the ping time to the target server is less than 100ms.

Step 2: Using the initial resolution and frame rate of step 1, the capabilities of your CPU and GPU will be tested to select the best encoder among several options internally supported. XSplit Gamecaster will use the world’s best H.264 software encoder called x264 as the default option to achieve the best possible quality of video at low bitrates. If XSplit Gamecaster’s internal simulation shows that your computer has 60% or less total CPU utilization when encoding with x264 at the resolution set in step 1, then x264 will remain as the encoder for the session. If your computer uses more than 60% total CPU at the time of the test, then any of the supported hardware encoders will be selected if available.

The reason to switch to a supported hardware encoder if excessive CPU usage is detected is to offload the encoding process from the CPU. With a hardware encoder, there will be little or no CPU usage for the encoding process.

Step 3: If the total estimated CPU usage after completing step 2 is less than 60%, then no further adjustments are made in this step. If the CPU usage is still too high, the resolution is lowered until the maximum CPU usage limit of 60% has been achieved. (The minimum resolution used is 240p)

Lowering the resolution will usually result in less CPU usage, particularly if XSplit Gamecaster was not able to find a supported hardware encoder after completing step 2.

Step 4: An internal bandwidth test is performed to determine if your connection can maintain the default preferred bitrate required for the resolution that has been set after completing steps 1 to 3. If the bandwidth test proves successful then your stream is started and you will go live. If the bandwidth test shows that your internet connection to the service provider is unable to handle the default preferred bitrate for the given resolution, the resolution is lowered until the bandwidth test succeeds.

Resolution

240p

426 x 240

102k

360p

640x360

230k

480p

854x480

410k

540p

960x540

518k

720p

1280x720

921k

1080p

1920x1080

2 M

Default bit rate

350kbps

650kbps

1100kbps

1350kbps

2300kbps

4500kbps

Minimum bit rate

200kbps

400kbps

600kbps

750kbps

1300kbps

2850kbps