The Ultimate Guide to VOD Video Renditions & Bitrates on Dacast

As a broadcaster, it is important to understand that not all viewers will have the same internet speed. Why is this important, you might ask? It is important to acknowledge the variation in internet speeds so that you are providing files with the optimal bitrate to reduce buffering or lagging. In this article, we will be covering video bitrate, multi-bitrate streaming, the value of providing multiple VOD renditions, and suggested video rendition settings.

Table of Contents

What is Bitrate?

Bitrate is the measure of how many bits per second are transferred. A video with a higher bitrate would transfer more data at one time than a video with a lower bitrate. When it comes to broadcasting, bitrate is often measured in megabits per second (Mbps). Faster internet connections can handle larger bitrate streams. Please keep in mind that the higher the bitrate you use, the more bandwidth your stream will consume. In order to create multiple renditions of your video, which would be copies that are a variety of sizes, you must transcode the video. Dacast uses cloud transcoding on uploaded videos.

What is Multi-Bitrate Streaming?

As we mentioned, higher internet speeds can handle streaming at a higher bitrate. On the flip side, lower internet speeds may destroy the quality of a high bitrate stream. A solution to varying internet speeds is multi-bitrate streaming. Multi-bitrate streaming uses multiple video renditions at different bit-rates. Some video players that use multi-bitrate streaming allow users to choose the rendition they’d like to stream. There are also adaptive bitrate video players that automatically choose the best rendition for each viewer based on their internet speed.

Suggested VOD Rendition Settings

Below is a table that documents the full details of the output for each VOD rendition.

Name	Description	Long	Short	FPS (Round Down)	Max Video Bitrate	Max Audio Bitrate	Container	Video Codec	Profile	Audio Codec
4k – 2160p	UHD (Ultra High Definition)	3480	2160	25/30/50/60	10 Mbps	128	MP4	H264	High	AAC
2k – 1440p	QHD (Quad High Definition)	2560	1440	25/30/50/60	7.7 Mbps	128	MP4	H264	High	AAC
FHD – 1080p	FHD (Full HD)	1920	1080	25/30/50/60	6.1 Mbps	128	MP4	H264	High	AAC
HD – 720p	SHD (Standard HD)	1280	720	25/30/50/60	3.2 Mbps	128	MP4	H264	High	AAC
SD – 480p	FWVGA (Full Wide Video Graphics Array)	960	480	25/29.97/30 /50/59.54/60	2 Mbps	128	MP4	H264	Main	AAC
LD – 360p	NHD (Ninth of High Definition)	640	360	25/30/50/60	1.5 Mbps	128	MP4	H264	Main	AAC
ULD – 240p	WQVGA (Wide Quarter Video Graphics Aray)	426	240	25/30/50/60	0.5 Mbps	128	MP4	H264	Main	AAC

Other Required Live Encoder Settings

Since bitrate goes and in hand with some other aspects of videos, now is a good time to touch upon encoder settings for streaming on Dacast. The following live encoder settings are required for live streaming with Dacast, regardless of your selected resolution and bitrate:

VIDEO CODEC	H.264 (x264 may work)
FRAME RATE	25 or 30
KEYFRAME INTERVAL	3 secs (or 3x frame rate)
SCANNING	Progressive
ENCODING BITRATE	Constant (CBR)
AUDIO CODEC	AAC
AUDIO BITRATE	128 kbps
AUDIO CHANNELS	2 (Stereo)
AUDIO SAMPLE RATE	48 kHz (48,000 Hz)

Any questions or need help/access to this feature? Please contact us. Not yet a Dacast user, and interested in trying Dacast risk-free for 14 days? Sign up today to get started.

get started for free

Rich Jenkins

Director of Product at Dacast with experience in enterprise, start-ups and everything in-between. Believes coffee and kale do compete and enjoys consuming both.