Adding audio level stat that can be used to compute averages. #221
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webrtc-stats.html
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| for each audio sample sent/received for this object (and | ||
| counted by <code><a>totalSamplesSent</a></code> or | ||
| <code><a>totalSamplesReceived</a></code>), add the square of | ||
| the sample's value divided by the highest-intensity encodable |
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Is this too ambiguous? It's meant to mean square(sample/max), not square(sample)/max.
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Is the expression below and the explanation in the text here in sync?
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My bad, I think I get what you mean.
The first paragraph is about how totalAudioEnergy is computed. And the second paragraph is how it could be used by an application.
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I think it's clear but you could clarify with a formula at the end of the sentence, (sampleEnergy^2/maxEnergy)*sampleDuration.
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webrtc-stats.html
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| for each audio sample sent/received for this object (and | ||
| counted by <code><a>totalSamplesSent</a></code> or | ||
| <code><a>totalSamplesReceived</a></code>), add the square of | ||
| the sample's value divided by the highest-intensity encodable |
| <code>Math.sqrt(totalAudioEnergy/totalSamplesDuration)</code> | ||
| becomes <code>Math.sqrt(0.0026/0.02) = 0.36</code>, which is | ||
| the same value that would be obtained by doing an RMS | ||
| calculation over the contiguous 20ms segment of audio. |
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nit: Can you change this example to include two getStats calls so that people don't get confused about where to do the sqrt?
webrtc-stats.html
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| This can be used to obtain a root mean square (RMS) value | ||
| that uses the same units as <code><a>audioLevel</a></code>, | ||
| using the formula | ||
| <code>Math.sqrt(totalAudioEnergy/totalSamplesDuration)</code>. |
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nit: Can you also have the RFC reference here? (Same as the audioLevel reference)
webrtc-stats.html
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| for each audio sample sent/received for this object (and | ||
| counted by <code><a>totalSamplesSent</a></code> or | ||
| <code><a>totalSamplesReceived</a></code>), add the square of | ||
| the sample's value divided by the highest-intensity encodable |
There was a problem hiding this comment.
I think it's clear but you could clarify with a formula at the end of the sentence, (sampleEnergy^2/maxEnergy)*sampleDuration.
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@taylor-b if you can make the changes (and merge) in the forthcoming days, I will make a new editor's release. |
Fixes w3c#220. It's slightly different than most of the stats of this sort, since the application needs to compute "sqrt(a)/b", not just "a/b". But the concept is the same.
This now takes a sample's duration into account when adding it to `totalAudioEnergy`, which prevents higher-frequency samples from being weighted more significantly than lower-frequency samples.
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Updated and fixed merge conflicts. |
Fixes #220.
It's slightly different than most of the stats of this sort, since the
application needs to compute "sqrt(a/b)", not just "a/b". But the
concept is the same.