We analyzed the loudness of YouTube videos in Japan

We analyzed the sound pressure of the YouTube video in Japan .

On YouTube, loudness normalization is introduced. Loudness normalization on YouTube lowers the volume of the video whose sound pressure is too high, but does not raise the volume of the movie whose sound pressure is too low.

If you have lots of videos with too little sound pressure on YouTube, you can increase the volume played on YouTube by raising the sound pressure to the extent that sound quality is not impaired.

Question

How much movie is too small sound pressure on YouTube?

As mentioned above.

Does the sound pressure drop if the YouTube video length is long?

As the length increases, the probability that the peak of the waveform will increase by chance will increase. If you use a limiter, you can suppress those peaks, but if you do not use a limiter, the sound pressure may decrease as the length increases.

From this, if you examine the relationship between length and loudness, it seems to be a material to judge whether the limiter is used or not. There are other factors related to length and loudness, so we can not make a judgment alone, but once we examine the relationship between length and sound pressure.

Analysis target video

A. Japan's Top YouTuber

Almost all videos of "Hajime" channel

B. Japanese music channels

Almost all videos of "Lantis Channel" channel

C. Japanese TV station channel

Almost all videos of "AbemaTV Official YouTube" channel

* Videos before 2018/12/8

※ Because almost all of the movies have failed analysis

※ The video list is described in Appendix

Analysis measures

Loudness

It is an indicator of the sound pressure. Calculated with ITU-R BS.1770-3.

Loudness Range

It is an indicator of dynamic range. We calculated and calculated the window length and overlap length of EBU TECH 3342. Window length 0.4 s, overlap length 0.3 s.

Analysis Result

Loudness

Loudness histogram

Loudness cumulative density distribution

Loudness time series

Loudness Range

Loudness range histogram

Loudness range cumulative density distribution

Loudness range time series

Relationship between loudness and loudness range

Loudness vs Loudness range scatter plot

Loudness vs. Loudness average and standard deviation

Length

Length Histogram

Length cumulative density distribution

Length time series

Relationship between length and loudness

Length vs Loudness Scatter plot

Length vs Loudness average and standard deviation

Discussion

How much movie is too small sound pressure on YouTube?

Looking at "Loudness cumulative density distribution", except for "Lantis", the loudness of 90% or more of the video is -14 dB or less.

Since the loudness calculation formula used this time is different from that of YouTube, I can not show the line that loudness normalization is applied any more, but if I refer here , I think that -14 dB is sufficiently small, so sound pressure other than Lantis If you raise it, there seems to be a possibility that the volume at the time of playing on YouTube will rise.

Does the sound pressure drop if the YouTube video length is long?

According to "Loudness vs Length Average and Standard Deviation", such a fact is unlikely.

Appendix

YouTube video analysis result in Japan (tsv)

Summary

I analyzed the sound pressure of the YouTube video in Japan.