Follow this guide to have the best settings for recorded videos before uploading to Castr's pre-recorded streams. If your video is not formatted to our suggested configuration, the stream might be stopped during live due to the video's settings.

For more details on how to get started with scheduled streams, please read this tutorial.

Castr Scheduler currently only accept mp4 video files for pre-recorded stream. Here are the full settings for recording videos:

  • Video Format: MP4

  • Rate Control: Constant Bitrate (CBR)

  • Keyframe Interval: 2 Seconds

  • Recommended Resolution: Full HD (1920x1080)

  • Recommended Frame Rate: 30 FPS

  • Recommended Bitrate: 4,000 Kbps (4.0 Mbps)

How to lower bitrate for videos and recordings

There are cases where the pre-recorded streams could not reach certain platforms, and the cause of the issue is usually the video's too high bitrate.

To avoid this, you can use an application called HandBrake to lower the bitrate and FPS on your videos/recordings.

  1. Download HandBrake from its website. The app is available for Max, Linux, and Windows.

  2. After finishing installation, open your video in Handbrake

  3. In Summary tab

  • Select Preset as Fast 720p30. Feel free to choose otherwise, but this is a decent output.

4. In Video tab

  • Video Codec should be set to H.264 (x264).

  • Select Framerate (FPS) as 30 and choose Constant Framerate.

  • Select Quality as Average Bitrate (kbps) with 2-pass encoding enabled. We recommend average bitrate between 1500 kbps to 2500 kbps to accommodate different platforms.

  • The above should be enough for your normal video but if your video is fluctuated a lot in bitrate, it's recommended to add the below line to Advanced Options:

    • The option in Advanced Options is separated by colon.

    • You can find deep explanation for each option here.

    • We recommend that you set vbv-maxrate = 1.25-1.5x of the average bitrate. Example: Average bitrate = 2500 kbps, then your vbv-maxrate is about 3500 kbps.

    • vbv-bufsize should be doubled the vbv-maxrate value. Example: your vbv-maxrate is 3500, then your vbv-bufsize should be 7000.

    • keyint is number of pictures within the current GOP (aka “keyframe interval”). It should be doubled the framerate number, in our setting, the framerate = 30, so the keyint = 60.

5. In Audio tab

  • On first track, select Codec as AAC (avcodec).

  • On first track, select a Bitrate between 128 and 320 Kbps. We recommend 128 Kbps if you plan to stream to Facebook and Youtube.

  • Ensure there is only 1 track. If there are multiple tracks of audio, remove the other tracks and leave one 1 track.

6. Click Start Encode, wait for encoding process to finish then upload your encoded video to Castr.

Please reach out to our 24/7 support if you have more questions.

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