SRC yet again...

[taturana]

After using R8brain (free and pro) for a while for SRC, i decided to try SoX and really liked the results... the sound actually seems clearer ... especially hf... i think from the src comparison chart i would guess that it has to do with a better lpf algo...

it's a bit awkward since it's a command line program...the good thing is that it's multi platform ...mac, linux and windows and it's freeware...

does anyone have experience with it? or tips? or know of any interface to make it easier to work with?

[Cellotron]

The test results are certainly impressive with it. Thanks for the link - I hadn't heard of this before. Downloading now - it would certainly be nice to find a front end gui for it though.

Best regards,
Steve Berson

[taturana]

Originally Posted by Cellotron

The test results are certainly impressive with it. Thanks for the link - I hadn't heard of this before. Downloading now - it would certainly be nice to find a front end gui for it though.

Best regards,
Steve Berson

I am thinking of writing a simple Batch file... to make it easier... but haven't got down to it yet....

[evac]

they link to this GUI on the SOX site: Studio: Sound Editor
It's written in Tcl/Tk which will be easier to get working on Mac than Win, but I assume the latter is possible.

Tcl/Tk 8.0

[taturana]

found this one for win32 and going to install it to test...

t@b Media Converter (GUI for sox, mencoder) for win32 download page

[taturana]

i tried the gui but it does not work at least not for src..... too bad....

[Cellotron]

Originally Posted by taturana

I am thinking of writing a simple Batch file... to make it easier... but haven't got down to it yet....

Well if you came up with a front end for Windows that was functional for batching sample rate conversions using the SoX algoirthm I'd certainly would be willing to pay something for it. I figure many who would otherwise be ponying up for something like r8brain Pro would be willing to do the same.

Best regards,
Steve Berson

[sanddigger1]

Originally Posted by taturana

i tried the gui but it does not work at least not for src..... too bad....

Same here...

[neilwilkes]

Originally Posted by Cellotron

Well if you came up with a front end for Windows that was functional for batching sample rate conversions using the SoX algoirthm I'd certainly would be willing to pay something for it. I figure many who would otherwise be ponying up for something like r8brain Pro would be willing to do the same.

Best regards,
Steve Berson

Being an owner of R8Brain Pro, I can certainly say that if there was a better option, I would pay for it.
Not that there is anything wrong with what I am currently using, but if there actually was a better option I would be a fool not to look at it seriously.
Command line is too much of a PITA, and brings back far too many bad memories of early DVD-A days when all authoring was done to scripts as there was no GUI.....it makes me shudder to even remember it all.

[taturana]

I have found several guis for mac and linux but the only one so far for windows was the t@b one... and it does not work for that purpose... i guess it's more directed towards audio and video file conversion...


so far i've been dumping all files to be converted in the root directory of my computer and i cut and paste the command line command, just switching the names in the process... still it is a PITA!

i like the sound though... and i just about got used to using it that way... soon somebody is going to make a better gui for it... but SoX is quite cool...

the typical command line argument for src would be...

sox filename.wav -r 44100 filenamenew.wav

i still haven't found out if there is a way to change src quality in SoX, so if anybody knows that answer please chime in...

[Nordenstam]

Socks?

Originally Posted by taturana

the typical command line argument for src would be...

sox filename.wav -r 44100 filenamenew.wav

Created litterally thousands of .bat files when 4Dos ruled, can hardly remember anything now!

IIRC, the "parameter input" is "%1" "%2" etc.

If that is so, a src.bat with
"sox %1.wav -r 44100 %1new.wav"
would make it possible to type "src filename" without extension and have the rest filled in automatically.

Worth a try..

[taturana]

Originally Posted by Lupo

Socks?




Created litterally thousands of .bat files when 4Dos ruled, can hardly remember anything now!

IIRC, the "parameter input" is "%1" "%2" etc.

If that is so, a src.bat with
"sox %1.wav -r 44100 %1new.wav"
would make it possible to type "src filename" without extension and have the rest filled in automatically.

Worth a try..

Yeah... it's funny but every once in a while it's cool to know your DOS...

I used to have the old IBM DOS technical reference manual... from the time IBM had a building just for writing manuals... e.. i made me quite a few batch files too!

make that .bat like you said and create a shortcut in the desktop... not that hard really...thanks for the tip

And searching GS about SoX... i did learn a bit about the Red Sox... eh

[bandpass]

Originally Posted by taturana

so far i've been dumping all files to be converted in the root directory of my computer and i cut and paste the command line command, just switching the names in the process... still it is a PITA!

i like the sound though... and i just about got used to using it that way... soon somebody is going to make a better gui for it... but SoX is quite cool...

the typical command line argument for src would be...

sox filename.wav -r 44100 filenamenew.wav

i still haven't found out if there is a way to change src quality in SoX, so if anybody knows that answer please chime in...

Sox has a zillion options and sometimes more than one way of achieving the same thing, so hang on to your hats...

These two commands:

sox filename.wav -r 44100 filenamenew.wav
sox filename.wav filenamenew.wav rate 44100

behave the same but with the second version you can add a quality option, e.g.

sox filename.wav filenamenew.wav rate -v 44100

changes the quality from 'high' (for 16-bit mastering) to 'very high' (for 24-bit).

AFAIK, there is no GUI front end for sox :-( but, I think creating a batch file shouldn't be too hard; use notepad to create say 44100.bat:

cd %~dp0
mkdir converted
FOR %%A IN (%*) DO sox %%A "converted/%%~nxA" rate -v 44100
pause

Put this in the same folder as sox.exe, then you can drag and drop files onto the batch file; the converted files end up in a folder called converted.

FYI, a new version of sox with more SRC options (minimum phase, bandwidth setting, etc.) is imminent -- there's a release candidate available.

-bandpass

[taturana]

Originally Posted by bandpass

Sox has a zillion options and sometimes more than one way of achieving the same thing, so hang on to your hats...

These two commands:

sox filename.wav -r 44100 filenamenew.wav
sox filename.wav filenamenew.wav rate 44100

behave the same but with the second version you can add a quality option, e.g.

sox filename.wav filenamenew.wav rate -v 44100

changes the quality from 'high' (for 16-bit mastering) to 'very high' (for 24-bit).

AFAIK, there is no GUI front end for sox :-( but, I think creating a batch file shouldn't be too hard; use notepad to create say 44100.bat:

cd %~dp0
mkdir converted
FOR %%A IN (%*) DO sox %%A "converted/%%~nxA" rate -v 44100
pause

Put this in the same folder as sox.exe, then you can drag and drop files onto the batch file; the converted files end up in a folder called converted.

FYI, a new version of sox with more SRC options (minimum phase, bandwidth setting, etc.) is imminent -- there's a release candidate available.

-bandpass

Thank you very much.... coool stuff...

[bandpass]

Originally Posted by bandpass

FYI, a new version of sox with more SRC options (minimum phase, bandwidth setting, etc.) is imminent -- there's a release candidate available.

It's been released:

• *Processing chain:
  • *now supports any number of input files
    *now allows multiple effects chains, multiple input pipes and, in some cases, multiple output files
    *initial support for Mac OSX audio IO
    *better support for large (2G/4G) files.
  *New effects:
  • *(ISO 226) loudness control
    *RIAA vinyl EQ
    *pitch bending
  *Enhanced effects:
  • *rate: minimum/intermediate/linear phase, custom bandwidth
    *dither: noise shaping
    *mcompand: now with Linkwitz-Riley crossover.
  *Various other small fixes/improvements.

SoX-home: SoX - Sound eXchange | HomePage

-bandpass

[kjg]

Thank you bandpass.

[taturana]

thanks for that...

btw... really liked that batch file example...

[Nordenstam]

Finally did some tests with this little gem..

Can't hear a big difference to R8Brain and don't think it could stand a blind test.. But it sure makes for different measurements. Here's something like the graphs on the src.infinitewave.ca page, zoomed in on the 22-44kHz area:



Original file was a linear 1 to 96000 Hz sweep at 192000 Hz, downsampled to 44100. R8Brain settings are as indicated in pic, while Sox was left at default setting as used in the supplied drag'n'drop batch file. The original signal disappears above the 22050Hz ceiling where the orange area ends, the rest as seen in R8Brain file is aliasing which suddenly stops at 44100. (anyone knows more about that?)

Please notice that the signal level in this test is zoomed to absurdity! The aliasing on the R8Brain is around -160 to -170 dB, lower than just about any other gear or DSP processing. Have nothing against R8Brain, been a happy user and can't complain. Though when the choice is there and affordable, I'll always take the cleanest route.. It's surprising to find the free SOX utility to perform so well. Especially since it's screaming fast too!

Thanks for the excellent program.


Regards,

Andreas Nordenstam

[taturana]

Quite a great program... i agree...

i tested the new version with the linear phase and very HQ src and it's flawless... and as you pointed out... very quick...

one more for open source... very nice...

and thanks for the tests Lupo...

Originally Posted by Lupo

Finally did some tests with this little gem..

Can't hear a big difference to R8Brain and don't think it could stand a blind test.. But it sure makes for different measurements. Here's something like the graphs on the src.infinitewave.ca page, zoomed in on the 22-44kHz area:



Original file was a linear 1 to 96000 Hz sweep at 192000 Hz, downsampled to 44100. R8Brain settings are as indicated in pic, while Sox was left at default setting as used in the supplied drag'n'drop batch file. The original signal disappears above the 22050Hz ceiling where the orange area ends, the rest as seen in R8Brain file is aliasing which suddenly stops at 44100. (anyone knows more about that?)

Please notice that the signal level in this test is zoomed to absurdity! The aliasing on the R8Brain is around -160 to -170 dB, lower than just about any other gear or DSP processing. Have nothing against R8Brain, been a happy user and can't complain. Though when the choice is there and affordable, I'll always take the cleanest route.. It's surprising to find the free SOX utility to perform so well. Especially since it's screaming fast too!

Thanks for the excellent program.


Regards,

Andreas Nordenstam

[bandpass]

Originally Posted by taturana

i tested the new version with the linear phase and very HQ...

Just worth pointing out that the previous version of SoX had the filter steepness fixed at 'steep' (=99% bandwidth); with the new version, the default is 95% bandwidth but you can still have steep by adding -s (or steeper still with -b percentage). But of course, too much steepness can cause excessive filter ringing -- hence the change to a slightly more conservative default.

If you know anything about filter impulse responses and want to see how some of the options affect this, there's a page here with some graphs.

-bandpass

[taturana]

Originally Posted by bandpass

Just worth pointing out that the previous version of SoX had the filter steepness fixed at 'steep' (=99% bandwidth); with the new version, the default is 95% bandwidth but you can still have steep by adding -s (or steeper still with -b percentage). But of course, too much steepness can cause excessive filter ringing -- hence the change to a slightly more conservative default.

If you know anything about filter impulse responses and want to see how some of the options affect this, there's a page here with some graphs.

-bandpass

I just converted a bunch of files with the -L option.. apparently from the graphic it appears to be the best option... the results were great...

What would you consider to be the best setting for SRC in a mastering situation ? (the very best quality conversion...)

[idylldon]

What's the best command to change a 48, 88.1, or 96K 24-bit file to 44.1/16 bit and retain the highest quality? I know, RTFM, and I will unless some kind soul who knows a LOT more about this stuff than I do takes pity on me.

Cheers,
--
Don

[taturana]

Originally Posted by idylldon

What's the best command to change a 48, 88.1, or 96K 24-bit file to 44.1/16 bit and retain the highest quality? I know, RTFM, and I will unless some kind soul who knows a LOT more about this stuff than I do takes pity on me.

Cheers,
--
Don

I think it would be best to convert to 24bit 44.1 and then dither to 16bit... theorywise...that is.

i am currently using the supplied batch file with the -L command (linear phase), any other suggestions?

[luiztornaghi]

Hi,
I used R8b for quite a while. But Izotope RX advanced is the winner for me now.

Has anyone compared SoX with Izotope?

[taturana]

Originally Posted by luiztornaghi

Hi,
I used R8b for quite a while. But Izotope RX advanced is the winner for me now.

Has anyone compared SoX with Izotope?

They are probably both really good and the difference is very small if there's one... but if you want you can send me a small file to convert and compare...

fala luiz... já masterizei um disco na Visom contigo...quando ainda era na barra, vários anos atrás... do BRAU... eu até levei o computador... vc deve lembrar... e ...abs....

[UnderTow]

Originally Posted by taturana

i am currently using the supplied batch file with the -L command (linear phase), any other suggestions?

From the manual: "By default, all algorithms have a ‘linear’ phase response". So I guess for most purposes, the -v option should be enough.

Alistair

[bandpass]

Originally Posted by taturana

I think it would be best to convert to 24bit 44.1 and then dither to 16bit... theorywise...that is.

i am currently using the supplied batch file with the -L command (linear phase), any other suggestions?

Resampling is a series of compromises so there's no one true answer for all situations, but the following rules of thumb should cover most people's needs for 99% of the time:

Phase setting: if resampling to < 40k, use intermediate phase (-I), otherwise use linear phase (-L, or don't specify; linear phase is the default).

Quality setting: if resampling (or changing speed, as it amounts to the same thing) at/to > 16 bit depth (i.e. most commonly 24-bit), use VHQ (-v), otherwise, use HQ (-h, or don't specify).

Bandwidth setting: don't change from the default setting (95%).

If you're mastering to 16-bit, you also need to add 'dither' (and maybe noise-shaping) after the rate.

Time for some examples:

sox any-file -b 16 outfile rate 44100 dither
(mastering for CDDA)

sox any-file -b 16 outfile rate -I 22050 dither

sox 24-bit-file outfile rate -v 88200
(outfile bit depth unchanged at 24-bit)

Lesson over for today

-bandpass

[idylldon]

Thanks for the help!

Cheers,
--
Don

[taturana]

thanks for that...

[thedug]

I thought I would open up this old thread to see what folks are thinking on this topic lately.

The R8BrainPro graphs sure do "look" alot better than others.

Also, the new wavelab crystal converter looks like a close 2nd.