HydrogenAudio

Hydrogenaudio Forum => General Audio => Topic started by: João13 on 2017-10-13 18:36:02

Title: Dynamic range of music decreased in conversion by foobar2000
Post by: João13 on 2017-10-13 18:36:02
Hello, I'm new to the forum.
I downloaded an album by bandcamp in .flac format, after downloaded I opened foobar2000 to convert to 320kbps CBR MP3. Before that I checked the dynamics of the album by foobar2000, gave DR8 in the three songs present in the album. After the conversion I checked the dynamics of the converted file and gave DR7 in the second song. Why has the momentum diminished? I used the following parameters in foobar2000: -m s -q 2 --noreplaygain -b 320 - %d

Dynamic Range Original Album In FLAC:

foobar2000 1.3.16 / Dynamic Range Meter 1.1.1
log date: 2017-10-13 14:12:19

--------------------------------------------------------------------------------
Analyzed: NONE / selftitled
--------------------------------------------------------------------------------

DR         Peak         RMS     Duration Track
--------------------------------------------------------------------------------
DR8       -0.10 dB    -8.99 dB     11:57 01-Cold
DR8       -0.14 dB    -9.42 dB      8:45 02-Wither
DR8       -0.16 dB   -11.68 dB      9:26 03-Suffer
--------------------------------------------------------------------------------

Number of tracks:  3
Official DR value: DR8

Samplerate:        44100 Hz
Channels:          2
Bits per sample:   16
Bitrate:           616 kbps
Codec:             FLAC
================================================================================

Dynamic Range Original Album Converted To MP3 320kbps CBR

foobar2000 1.3.16 / Dynamic Range Meter 1.1.1
log date: 2017-10-13 14:18:02

--------------------------------------------------------------------------------
Analyzed: NONE / selftitled
--------------------------------------------------------------------------------

DR         Peak         RMS     Duration Track
--------------------------------------------------------------------------------
DR8       -0.10 dB    -8.99 dB     11:57 01-Cold
DR7       -0.18 dB    -9.42 dB      8:45 02-Wither
DR8       -0.15 dB   -11.68 dB      9:26 03-Suffer
--------------------------------------------------------------------------------

Number of tracks:  3
Official DR value: DR8

Samplerate:        44100 Hz
Channels:          2
Bitrate:           320 kbps
Codec:             MP3
================================================================================
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: greynol on 2017-10-13 18:55:19
Easy: the DR meter is a complete and utter joke.

Have you tried the ABX comparator?  It's amazing what happens when you're no longer able to judge sound quality based on numbers.  After all, what it sounds like is all that matters!!!

Any reason why you're forcing the use of all stereo frames?
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: itisljar on 2017-10-13 19:00:27
Any reason why you're forcing the use of all stereo frames?

I'm guessing it's because it's pure stereo :)
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: saratoga on 2017-10-13 20:04:13
MP3 is a lossy format.  If you encode stuff in MP3 and compare to the lossless files, you will not necessarily get the same results.  This is normal.  You can possibly reduce this effect by not using bad settings with lame like the -m flag, but if you need lossless you should be  using flac.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: DVDdoug on 2017-10-13 21:12:15
It's unusual, but not totally surprising...   Usually MP3 boost (some) peaks, increasing the crest factor and making a higher apparent/calculated  dynamic range (without changing the perceived dynamic range). 

A similar thing happens if you make a vinyl record.    The vinyl recording/playback process also tends to "hide" clipping by changing the wave shape (without removing the distortion, of course).

MP3 compression changes the wave shape making some peaks higher and some peaks lower.    If the highest new-peak is higher than the highest old-peak, you've increased the crest factor.   The effect tends to more dramatic when the peaks have been "artificially" compressed & limited (i.e. most commercial recordings).

In your case the new (MP3) highest-peak was lower for two of the songs, decreasing the apparent dynamic range.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: João13 on 2017-10-14 19:48:43
Easy: the DR meter is a complete and utter joke.

Have you tried the ABX comparator?  It's amazing what happens when you're no longer able to judge sound quality based on numbers.  After all, what it sounds like is all that matters!!!

Any reason why you're forcing the use of all stereo frames?
How so forcing the use of frames? The -m s parameter is to convert to the right stereo? The default option converts to the Joint Stereo.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: lvqcl on 2017-10-14 19:58:00
From LAME help:
Code: [Select]
    -m <mode>       (j)oint, (s)imple, (f)orce, (d)ual-mono, (m)ono (l)eft (r)ight
                    default is (j) or (s) depending on bitrate
                    joint  = joins the best possible of MS and LR stereo
                    simple = force LR stereo on all frames
                    force  = force MS stereo on all frames.
So, -m j (default mode) is usually the best.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: greynol on 2017-10-14 20:37:33
How so forcing the use of frames?
How does it cripple the encoder's ability to make the best decision, you ask?

Because that's literally what using -ms does.

The -m s parameter is to convert to the right stereo? The default option converts to the Joint Stereo.
So do you actually know what the difference is, or are you simply ascribing your own meaning to the terms being used?

http://wiki.hydrogenaud.io/index.php?title=Joint_stereo

Anyway, it is not my intention to change the thrust of the discussion to your misguided choice to force L/R encoded frames; rather, it was to underscore just how far off the mark you are in going about determining audible sound quality in a useful and objective way.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: João13 on 2017-10-15 10:16:34
How so forcing the use of frames?
How does it cripple the encoder's ability to make the best decision, you ask?

Because that's literally what using -ms does.

The -m s parameter is to convert to the right stereo? The default option converts to the Joint Stereo.
So do you actually know what the difference is, or are you simply ascribing your own meaning to the terms being used?

http://wiki.hydrogenaud.io/index.php?title=Joint_stereo

Anyway, it is not my intention to change the thrust of the discussion to your misguided choice to force L/R encoded frames; rather, it was to underscore just how far off the mark you are in going about determining audible sound quality in a useful and objective way.
From LAME help:
Code: [Select]
    -m <mode>       (j)oint, (s)imple, (f)orce, (d)ual-mono, (m)ono (l)eft (r)ight
                    default is (j) or (s) depending on bitrate
                    joint  = joins the best possible of MS and LR stereo
                    simple = force LR stereo on all frames
                    force  = force MS stereo on all frames.
So, -m j (default mode) is usually the best.

I really bugged. I thought the Joint Stereo joined the channels to have the same sound. You stupid one! Many thanks to all for the tips !!
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: includemeout on 2017-10-15 12:48:46
What translates into "use the throughly tried-and-tested recommended settings (http://wiki.hydrogenaud.io/index.php?title=LAME#Recommended_encoder_settings)" and be as happy as a lark.

Anything else is just trying to reinvent the wheel.
Title: Re: Dynamic range of music decreased in conversion by foobar2000
Post by: greynol on 2017-10-15 17:19:17
Knee jerk response from me. Not the first time a new poster was making decisions based on unsound methods.

DR figures are extremely crude, calculated without any regard as to how the human auditory system functions.