<div dir="ltr">To fix this all you need to do is attenuate the floating-point output of the decoder by a couple or few dB before you convert to fixed. The playback will be a little quieter but the listener can compensate by adjusting the volume up. The same attenuation is applied to all material at all times so there's no anticipation or other monkey business. For efficiency, this adjustment can be combined with the loudness normalization adjustment.<div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Kevin Gross - AVA Networks</div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr">On Sun, Oct 14, 2018 at 7:23 PM Bob Katz <<a href="mailto:bobkatz@digido.com">bobkatz@digido.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p>Dear Kevin: Admittedly, there is no one size fits all encoding
level. But if content producers (mastering engineers) shoot for
iTunes' MFIT (high bit rate) codec, the vast majority of clipping
in all streaming will be handled fairly well in my opinion. I
personally don't shiv a git if it's occasionally too hot for
Spotify if we cover MFIT in our coding of a master. Spotify
deserves what they get with such a low bit rate codec they use,
and that will improve in due time. As a mastering engineer I do
not want to shoot for lowest common denominator. And most of my
sensibly-mastered material will play fine on Spotify with possibly
only occasional one hit clips. As I've said before, it's
impractical to make and control too many masters. We're currently
lobbying for all distributors to send the 2444 MFIT master and
send it to all the streaming customers. We'd like to see the 1644
originally intended to send to CD die a quick death. That's often
a dB hotter than the MFIT master. <br>
</p>
<p>As for attacking both ends and dealing with clipping on the
decode side I'd like to hear an explanation as to how a streaming
service's player can deal with (anticipate) a clipping situation
and attenuate post decoder.... from a moving bitstream. Please
start by telling us how you would deal with a song that has a clip
two minutes after the song has already begun... <br>
</p>
<br>
Best wishes,<br>
<br>
<br>
<br>
Bob<br>
<br>
<br>
<div class="m_-2823499860786167807moz-cite-prefix">On 10/14/18 6:54 PM, Kevin Gross wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr"><br clear="all">
<div>
<div dir="ltr" class="m_-2823499860786167807m_2960190518890253103gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">On Sun, Oct 14, 2018 at 8:32 AM Bob Katz <<a href="mailto:bobkatz@digido.com" target="_blank">bobkatz@digido.com</a>> wrote:<br>
</div>
</div>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"><br>
In our recent conversations, I pointed out that it's
totally impractical to expect or even talk about any
streaming player applying attenuation to avoid overs just
post the decode stage. Therefore even though the clipping
is not baked into a well-made encoder, it has to be the
responsibility of the mastering engineer to prevent
decoder clipping by reducing the level that will be
applied to the encoder if necessary. Mastering engineers
have to bake that level into the fixed point file that we
supply to the distributors. <br>
</div>
</blockquote>
<div><br>
</div>
<div>If you want to fix this pre-encoder, you're going to get
content producers to comply with something like Spotify's -2
dBTP suggestion. That means bringing peaks down 4-6 dB
compared to where they currently stand at 0 dBFS. I don't
see mastering engineers getting behind this. I don't know if
we even want to recommend it either because it will result
in more squashing.</div>
<div><br>
</div>
<div>We should also be raising awareness of the potential for
clipping post-encoder and advocating for more robustness in
players in this regard. You're right, we're not going to be
able to get all decoders fixed. We're also not going to be
able to get all masters fixed. If we work both ends, we'll
make the most meaningful progress.</div>
<div><br>
</div>
<div>Kevin</div>
</div>
</div>
</blockquote>
<br>
<div class="m_-2823499860786167807moz-signature">-- <br>
<div class="m_-2823499860786167807moz-signature">
<div class="m_-2823499860786167807moz-signature">
<div class="m_-2823499860786167807moz-signature">
<div class="m_-2823499860786167807moz-signature">
<div class="m_-2823499860786167807moz-signature">
<div class="m_-2823499860786167807moz-signature">
<pre class="m_-2823499860786167807moz-signature" cols="80"><font face="Courier">
If you want good sound on your album, come to
Bob Katz 407-831-0233 </font><font face="Courier">DIGITAL DOMAIN MASTERING STUDIO
Author: <b>Mastering Audio </b></font><font face="Courier">
<a href="http://www.digido.com/" target="_blank">Digital Domain Website</a>
No trees were killed in the sending of this message. However a large number
of electrons were terribly inconvenienced.<font color="#ff0000">
</font></font></pre>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote></div>