[0:00] video encoding plays an important part
[0:02] in live streaming it's the process of
[0:04] converting a raw video signal from a
[0:06] camera into a compressed digital format
[0:09] for efficient delivery across the
[0:11] internet the encoder might be integrated
[0:13] directly into a camera or even take the
[0:16] form of computer software or a mobile
[0:19] app
[0:19] often the encoder as a studio tool is
[0:22] used to both apply a codec that
[0:24] compresses the video signal and
[0:26] implement a protocol to transport that
[0:28] stream over the internet
[0:30] while this process often includes audio
[0:33] and video encoding we'll focus on the
[0:35] video aspect for simplicity
[0:37] codec is short for compress decompress
[0:40] when it comes to video there's a ton of
[0:42] information contained in just one second
[0:44] so in order for data to be transferred
[0:46] the stream of video needs to be tightly
[0:48] compressed different codecs achieve this
[0:51] in different ways but most codecs remove
[0:53] information to make the bitrate small
[0:55] enough for live streaming
[0:57] visual algorithms are used to eliminate
[1:00] data that'll go unnoticed by the human
[1:02] eye and motion compensation techniques
[1:04] are used to reduce redundant data
[1:06] between frames
[1:08] once the video has been compressed to a
[1:09] suitable bitrate for the available
[1:11] bandwidth it's streamed using a protocol
[1:14] these streaming protocols take the data
[1:17] and reorganize it as needed breaking it
[1:19] up into optimized chunks for delivery
[1:22] some streaming protocols employ
[1:23] standards used by computer networks they
[1:25] do error checking to ensure nothing gets
[1:28] lost or placed in the wrong order and
[1:30] other protocols use standards made for
[1:33] servers and clients they apply more
[1:35] modern methods used by browsers today
[1:38] when the live video stream reaches its
[1:40] final destination for playback the
[1:41] receiving device unpacks the protocol
[1:44] and then decompresses the codec if the
[1:46] device can't do one or the other then it
[1:48] won't be able to play back the stream
[1:50] now when it comes to codecs h.264 also
[1:53] known as avc is most widely used that's
[1:57] because it's been around for so long
[1:59] most devices can play it back
[2:01] the newer h.265 also known as hevc
[2:06] works better for compressing higher
[2:07] resolutions but royalty concerns have
[2:10] limited its adoption by devices
[2:12] vp9 is royalty free and works great for
[2:15] 4k streaming so it's gaining more
[2:17] traction into devices but av1 is the
[2:21] most current and highly optimized open
[2:24] source option
[2:25] however it does require more processing
[2:27] power to get the job done
[2:29] when picking the right codec you still
[2:31] need to consider the protocol encoder
[2:33] software is mainly designed to stream
[2:35] rtmp but from the prior list rtmp can
[2:39] only handle h.264
[2:41] that's why more encoding software now
[2:43] supports srt which can handle noisy
[2:46] networks better and is codec agnostic so
[2:49] any codec can be used
[2:51] both rtmp and srt are generally not used
[2:54] for playback so that's where a streaming
[2:57] platform like wires of streaming cloud
[2:58] comes in it can take the original stream
[3:01] and repackage it into different playback
[3:03] protocols now this might be hls which
[3:06] supports both h.264 and h.265 or
[3:11] mpeg-dash which like srt is codec
[3:14] agnostic
[3:15] or even webrtc which handles h.264 and
[3:20] vp9
[3:21] av1 support is also on the horizon
[3:24] alright so that's it for how video
[3:26] encoding works in the world of live
[3:28] streaming if you'd like to learn more to
[3:30] help pick the right codecs and protocols
[3:32] for your live streaming needs please
[3:34] contact us at wowza