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Master Mi

Do streaming platforms like Youtube compress/worsen your soundtracks once again

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Hey, guys.

I just want to know if streaming platforms like Youtube do a further compression on your uploaded sountrack content if you have already exported your video from your video cutting program with the best settings Youtube allows.

The problem is >>> with my built-in video cutting program Movie Maker from Microsoft (in which I load my uncompressed WAVE audio file from my music project) I can only export videos (I use WMV format for videos) with a maximum audio bitrate of 192 kbit/s.

Seems to be no problem because Youtube obviously allows only max. 192 kbit/s for the audio stuff in the video.

Or is it still a disadvantage for the sound quality and does Youtube make a further compression on the uploaded 192 kbit/s stuff which would justify buying a more professional video editing software where you can export videos with uncompressed WAVE audio quality before you upload your soundtrack/video content?

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It seems like the audio compression is to about 126 ~ 128 kbps AAC in an MP4 container. This link analyzes the video for the bitrate:

https://www.h3xed.com/blogmedia/youtube-info.php

Look for "audio/mp4;" under "type" and then locate the bitrate on the far left in "bps" (bits per second). As far as I can tell, even some of my old videos back in 2007 have retroactively-revised bitrates to be about the same as one of my more modern videos (rendered at 720p HD with 320 kbps audio, iirc). If you were wondering, after 2013, video resolution chosen on YouTube no longer affects audio bitrate.

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Hm - but somehow the streaming quality on Youtube seems to be slightly better than on Soundcloud - and Soundcloud already allows just 128 kbit/s. You can often hear the slightly worse sound quality on Soundcloud by listening to the higher drum sections like cymbals (cymbals often sound a bit raspy, distorted, less defined and less full in their whole frequency spectrum).
On Youtube cymbals still sound pretty clean - even the reverb of those.

Just compare my solo drums track on these two streaming platforms:

Soundcloud >>> https://soundcloud.com/master-mi/drum-grooves-lvl-2-composed-by-master-mi
Youtube >>> https://www.youtube.com/watch?v=P9MIzC_oe38

In addition to that I've converted some videogame remixes on Youtube into MP3 files - and most of them come up with an audio bitrate of 192 kbit/s.
Don't know if this alone gives a small hint on the real streaming audio bitrate on Youtube.

But just by listening to soundtracks on both platforms I get the impression Youtube seems to have a slightly better streaming audio quality than Soundcloud.

But to get back to my question...
What do you think?
Is there a difference of the sound quality between uploading a video with 192 kbit/s audio stuff (if that would be the maximum audio bitrate Youtube allows) and a video with uncompressed wave audio stuff on Youtube or will these two options result in the same audio streaming quality - or.. will the upload with the just 192 kbit/s audio stuff get compressed once again a little bit which could lead into a slightly worse audio streaming quality after uploading the file (compared to the file before the upload)?

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tldr; you get out what you put in.

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A good way to verify this is to rip audio using Audacity's "Windows WASAPI" audio host, and then render as WAV; then, encode using WinLAME into an MP3 using VBR1 on the "High" Encoding Quality setting. That should be enough to allow for what should be the highest bit rate based on the current time in the song, rather than providing a flat bitrate for the song (like you would get with CBR).

[I do think that youtube is more efficient in its audio compression than soundcloud. I always hear a slight, or sometimes quite noticeable fidelity issue with the upper treble on soundcloud.]

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Here is an MP3 based on the steps described above, of the first video from 2007 I showed, a raw AVI recorded of a 160 x 144 dimension video:

https://app.box.com/s/r750tyd1hxufw6vda13j500qsanbewfw

The most prominent bit rate range it has in WinAmp is 112 ~ 160 kbps; it goes no higher than 160 kbps.

I think that sounds pretty accurate... it is just an emulation of a GBA game.

Here is an MP3 for the second video from 2016 I showed rendered using Adobe After Effects and Sony Vegas on the highest settings possible, with the audio stream before uploading being the original VBR1 MP3 file that would be distributed on OCR:

https://app.box.com/s/ytv60g8s766ban58qrx3iehjl3n3xr9c

The most prominent bit rate range it has in WinAmp is 192 ~ 320 kbps; it goes no lower than 192 kbps. The actual MP3 I put in, for comparison, can be found here.

Based solely on bit rate, these are nearly identical, with a few flashes of 160 kbps in the ripped MP3 above. Based on an explicit A/B comparison, I can tell that the actual MP3 sounds slightly better in the upper treble. But I think youtube did a pretty good job at keeping it sounding good, even if it's not identical.

And for good measure, here's a third test with a third video, this time from 2009 processed through Sony Vegas (instead of uploaded as a raw AVI) into 720p HD, but recorded in the same way of a 160 x 144 dimension video. The MP3 that resulted is:

https://app.box.com/s/bgq8bnn9as35tzyq7igpulgub5x87eh1

The most prominent bit rate range it has in WinAmp is 128 ~ 160 kbps, occasionally making it to 224 kbps and occasionally flashing 112 kbps; it goes no higher than 224 kbps.

This is fairly consistent because the recording input was the same as in the first video, so it makes sense that the bit rate ranges are similar, but the bit rate is slightly better because it was rendered at a higher audio quality ceiling instead of being uploaded as a raw AVI.

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So yes, the audio quality ceiling that you feed into youtube does "change" what bit rate you get out... because you get out the bit rate that you put in (more or less). I'd say, oh, about 95 ~ 98% of the original quality stays. I'd approve!

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