Unblocking The Main Thread Solving ANRs and Frozen Frames
Live Audio Event Pitfalls to Avoid
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Pitfalls to Avoid When Broadcasting a
Live Audio Event
Presented by: Mike Smith @sacsmitty
Director of Solutions Engineering
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What’s Your Source
• Balanced versus Unbalanced
• External Audio Interface
• Adapters and Cables
• Be Prepared!!! You can text questions to me at any time
during the presentation
+1-916-773-1999
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Recommended Input Source
• Balanced Audio @ +4dB
• Balanced TRS Cables or XLR
• External Audio Interface
• Balanced versus Unbalanced
• Adapters and Cables
• Garbage In = Out
You can text questions to me at any time
during the presentation
+1-916-773-1999
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@MirrorImageDDN
A Word About Video and Audio
• The quality of the video rapidly deteriorates if the sound quality is poor.
Camera microphones are not good enough because they collect the sound
from the whole room, creating too much “noise” that is hard to filter out.
• Our ears can filter that noise out, but microphones can not.
You can text questions to me at any time
during the presentation
+1-916-773-1999
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Why Is Audio Important
• Listener fatigue (also known as listening fatigue) is a
phenomenon that occurs after prolonged exposure to an
auditory stimulus. Symptoms include tiredness, discomfort,
pain, and loss of sensitivity.
You can text questions to me at any time
during the presentation
+1-916-773-1999
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Introduction of Artifacts
• Musicality, especially on the radio, contains musical aspects and artifacts that arise
from non-musical aspects (dynamic range compression and sonic balance). The
introduction of these sonic artifacts affects the balance between these musical and
non-musical aspects.
• When the volume of music is higher, these artifacts become more apparent, and
because they are uncomfortable for the ear, cause listeners to "tune out" and lose
focus or become tired.
• These listeners may then unconsciously avoid that type of music, or the radio station
they may have heard it on.
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Using A DSP
• A Digital Signal Processor (DSP) is used for gain control,
dynamics processing and sound equalization..
RAW Audio Compression Sample 1 Compression Sample 2
Encoded Sample 32Kbps
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A Word About Balance
• Too much signal processing...
– Causes Listener Fatigue
– Degrades Encoded Audio Quality
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Codecs and Bitrates
• Know your target audience
• Device and App Compatibility
• Don’t confuse transport stream and codec
• Cost of bandwidth versus codec used and
bitrate
You can text questions to me at any
time during the presentation
+1-916-773-1999
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The Dreaded “B Word”
• Bandwidth
– Know your bandwidth
• Shared or Dedicated?
• Wired or Wireless?
• DSL, Cable or Fiber?
• Why
– Even though audio is
relatively low bandwidth,
you may need to encode
multiple versions from your
source encoder.
– Do you have enough
upstream to deliver to your
CDN?
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Reaching Your Target Audience
• No one content aggregator is alike.
– iHeart Media (Icecast/MP3 and HLS)
– TuneIn (RTMP and Icecast/MP3)
– iTunes Radio Directory (Icecast)