Introduction To Live Transcoding

 

To ensure your transcoded live stream is stable and fully functional, you MUST configure your encoder to use the settings defined on this page. These settings have been chosen to ensure maximum compatibility with the Dacast platform. Failure to follow these settings may result in your live stream’s renditions having a wide variety of playback issues. In this article you will find:

  1. Recommended live encoder settings
  2. Best Resolution & Bitrate Settings
  3. Unsupported Settings that must not be used

1. Required Live Encoder Settings

The following settings are required for live streaming with Dacast, regardless of your selected resolution and bitrate:

VIDEO CODECH.264 (x264 may work)
FRAME RATE30
KEYFRAME INTERVAL3 secs 
SCANNINGProgressive
RATE CONTROLConstant (CBR)
AUDIO CODECAAC-LC
AUDIO CHANNELS2 (Stereo)
AUDIO SAMPLE RATE48 kHz (48,000 Hz)

2. Resolution & Bitrate Settings

When creating multiple renditions using a single input, you will want to be sure your input is of high quality to create lesser renditions at acceptable quality levels. While we accept inputs at varying degrees of quality, you must stick to one of the following preset options. An important note: Upon ingesting a stream, we will use that input to create 5 lesser renditions. If you were to stream at a quality that is less than one of these created renditions, then the viewer’s experience in the player will be subpar as each of the created renditions will be far lower quality than they are meant to be.  We suggest sending us a Full HD (FHD) stream with the following settings for best results. 

Video Bitrate (kbps)4000
Resolution Width (px)1920
Resolution Height (px)1080
H.264 ProfileHigh
AUDIO BITRATE192 kbps

If you struggle to support an FHD stream reliably, you may prefer to stream using an HD channel and use the following settings. 

Note – A new HD channel will require provisioning. Please contact us to get this started.

Video Bitrate (kbps)2400
Resolution Width (px)1280
Resolution Height (px)720
H.264 ProfileHigh
AUDIO BITRATE192 kbps

Although we do not recommend it, you can send us an SD stream to be transcoded using these settings.

If you struggle to support an HD stream reliably, you may prefer to stream using an SD channel and use the following settings. 

Note – A new SD channel will require provisioning. Please contact us to get this started.

Video Bitrate (kbps)1800
Resolution Width (px)1024
Resolution Height (px)576
H.264 ProfileHigh
AUDIO BITRATE128 kbps

3. Unsupported Settings

Note that the following settings are unsupported and will break your stream:

  • Baseline H.264 Profile
  • Interlaced Scanning

Please make sure FPS is not a decimal value on both your camera and your encoder.
Tip: If your FPS is a decimal value, you can use a decimator to convert it, we recommend FPS value of 30.

Harmonie Duhamel

Harmonie is a Senior digital marketer with over 6 years in the Tech Industry. She has a strong marketing and sales background and loves to work in multilingual environments.