Re: concat problem

[Glenn English <ghe2001@gmail.com>]

On Sat, Sep 23, 2017 at 12:33 PM, Jan Stary <hans@stare.cz> wrote:
> On Sep 22 16:36:39, ghe2001@gmail.com wrote:
>> Debian Jessie, Supermicro box, SoX 14.4.1, SoX noob.
>
> The current version is 14.4.2

Not on Debian Jessie it's not.

>> I ask SoX to concatenate AIFFs, and Mac Air stops at the end of first file.
>> I've written a Python script (first use of SoX)
>
> If you are new to SoX, learn it by running SoX,
> not by writing Python scripts.

In Python, you just create a list of the command and the options and
stuff, and it's passed to the kernel. There was only one point where
that didn't work -- the concatenation to aiff. And besides, I did try
running things by hand when there were problems.

> What happens if you play the file with SoX's own play(1)?
> What does 'play --ignore-length output.aiff' do?
> What does soxi(1) say about the file?

Dunno.

> Also, you can contatenate the original mp3's just as easily,
> so why are you converting them to aiff first?

Because there is sometimes a need for a lossless file, and I don't
trust anything to process mp3s properly. (I've run into that with
different software.)

> We don't know what 'big' computer is that and what a 'sneaker net' is
> and how it relates to your aiff problem.

The 'big computer' is a Supermicro server type -- it doesn't play music.

'Sneakernet', IIRC, is a term used at Apple back in the dark ages.
When you wanted to give a colleague some bits, you wrote them onto a
floppy and carried the floppy to where it had to go. By hand, walking
on sneakers.

And neither seemed to have anything to do with the aiff problem. Both
machines displayed the same trouble.

> It would also be easier to do audio work
> on a comupter wich has sound. Duh.\

I like to check a generating/processing program on several computers
to look for bugs. The failure was pretty obvious -- when I 'ran' the
sound file on the silent computer, it came back in a few seconds.

The noisy computer is an Apple MacBook Air running VLC. I consider it
a reliable reproducer of audio.

> $ soxi file.aiff

I don't know soxi. I'll try to become familiar with it...

> Why are you converting the mp3s to aiff,
> then concating the aiffs to aiff, and then reconvert to mp3?
> Why don't you just concat the mp3 files as they are
> if that's what you eventually want to have?

See above. And there was to be an additional step (and still is) where
the whole lossless file was normalized, equalized, and compressed.

> In that case, the aiff outout you are creating is probably too big.

No, It wasn't. I thought of that, and cut the size down to very small.
Same result.

> What exactly was the command line and what exactly was the error message?

I sent the command in a response to Eric (see below), and there was no
error message. Eric solved my last week's problem last week.

> 316M of flac is a lot. What exactly are you doing here and why?

What? I'm trying to convert audiobook CDs into a single file on a
computer disk. Last week, I was working with a collection of mp3s that
a friend of mine had already processed from CD, into a million mp3s.
This week, it's a million wav files ripped by cdparanoia from live CDs
of a Tom Clancy novel.

Why? Because I don't have a CD changer attachment on my computer. And
the Air doesn't even have a CD player.

> Are you _concatenating_ hornet parts to create a rendition of a song?
> How long is that song that it takes 316M of flac?

Like I said, the source was a reading of 'The Girl Who Kicked the
Hornet's Nest'. Big, real big. But there's plenty of space on my disk.

>> > What's the exact command?
>> ['sox', '--multi-threaded', '--combine', 'concatenate',
>> 'flacs/1-01HornetIntro.flac', 'flacs/1-02Hornet01a.flac',
>> 'flacs/1-03Hornet01b.flac', 'flacs/1-04Hornet01c.flac',
>> 'flacs/1-05Hornet01d.flac', 'flacs/1-06Hornet01e.flac',
>> 'flacs/1-07Hornet02a.flac', 'flacs/1-08Hornet02b.flac',
>> 'flacs/1-09Hornet02c.flac', 'flacs/1-10Hornet02d.flac',
>> 'flacs/1-11Hornet02e.flac', 'flacs/2-01Hornet02f.flac',
>> 'flacs/2-02Hornet03a.flac', 'flacs/2-03Hornet03b.flac',
>> 'flacs/2-04Hornet03c.flac', 'flacs/2-05Hornet03d.flac',
>> 'flacs/2-06Hornet03e.flac', 'flacs/2-07Hornet04a.flac',
>> 'flacs/2-08Hornet04b.flac', 'flacs/2-09Hornet04c.flac',
>> 'flacs/2-10Hornet04d.flac', 'flacs/2-11Hornet04e.flac',
>> 'flacs/2-12Hornet04f.flac', 'big_file.flac']

> What "subprocess"?

See Python dox. It's a class/module Python uses to interact with the kernel.

>> Like I said, I've tried that.
>
> And?

Same result.

>> FLAC works.
>
> Meaning what?

The conversion to flac and the concatenation generates a file that
plays past the first 6 or 7 seconds.

> You can create a flac output that long,
> as opposed to an aiff output that long?

Well, pretty much. The are both lossless files containing all the
data, but the flac is way shorter that the aiff. And it works.

--
Glenn English

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