sox-users@lists.sourceforge.net unofficial mirror
 help / color / Atom feed
From: "Måns Rullgård" <mans@mansr.com>
To: Martin Ratinaud <martinratinaud@gmail.com>
Cc: sox-users@lists.sourceforge.net
Subject: Re: Wav to Mp3 leads to an mp3 file that has a longer duration
Date: Mon, 16 Dec 2019 13:30:16 +0000
Message-ID: <yw1xmubswg7r.fsf@mansr.com> (raw)
In-Reply-To: <CAKy7tYhrv0+H_5_twwaz+1x_Q_E7Nvv9e2dpwibdcMDWy0c+XQ@mail.gmail.com> (Martin Ratinaud's message of "Mon, 16 Dec 2019 16:02:56 +0400")

Martin Ratinaud <martinratinaud@gmail.com> writes:

> Hi Måns and thanks very much
>
> Though it seems the resulting file is 7939544 samples
>
> and 7939544 / 1152 = 6891.965277777777
>
> So it's not a multiple of 1152 unless I'm missing something ?

That difference is due to a rounding error in the stream length
calculation.

> On Mon, Dec 16, 2019 at 3:48 PM Måns Rullgård <mans@mansr.com> wrote:
>
>> Martin Ratinaud <martinratinaud@gmail.com> writes:
>>
>> > Hi all,
>> >
>> > I'm converting a file called vocals.wav to vocals.mp3
>> >  vocals.wav
>> > <
>> https://drive.google.com/file/d/1he1eCJag1G8iGkgL932jy_mXuLT_khGM/view?usp=drive_web
>> >
>> > For this I'm using this command
>> >
>> > ```
>> > sox vocals.wav vocals.mp3
>> > ```
>> > and here is the result of the corresponding files
>> >
>> > - original file
>> > ```
>> > soxi /Users/martin/Downloads/split-test/vocals.wav
>> >
>> > Input File     : '/Users/martin/Downloads/split-test/vocals.wav'
>> > Channels       : 2
>> > Sample Rate    : 44100
>> > Precision      : 16-bit
>> > Duration       : 00:03:00.00 = 7938000 samples = 13500 CDDA sectors
>> > File Size      : 31.8M
>> > Bit Rate       : 1.41M
>> > Sample Encoding: 16-bit Signed Integer PCM
>> > ```
>> >
>> > - converted file
>> > ```
>> > soxi /Users/martin/Downloads/split-test/vocals.mp3
>> >
>> > Input File     : '/Users/martin/Downloads/split-test/vocals.mp3'
>> > Channels       : 2
>> > Sample Rate    : 44100
>> > Precision      : 16-bit
>> > Duration       : 00:03:00.04 = 7939544 samples = 13502.6 CDDA sectors
>> > File Size      : 2.88M
>> > Bit Rate       : 128k
>> > Sample Encoding: MPEG audio (layer I, II or III)
>> > ```
>> >
>> > You can see that the duration is not the same which is weird and the number
>> > of samples also changed.
>> > In fact, 1544 samples have been added to the beginning of the file
>> >
>> > If I try to launch `sox -V vocals.mp3 vocals-trimmed.mp3 trim 1544s` it
>> > does not work
>>
>> MP3 files have to have a multiple of 1152 samples.  This can't be
>> avoided.  If the input isn't such a multiple, it will be padded by the
>> encoder.
>>
>>
>
> _______________________________________________
> Sox-users mailing list
> Sox-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/sox-users
>

-- 
Måns Rullgård


_______________________________________________
Sox-users mailing list
Sox-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sox-users

  reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-11 14:26 Martin Ratinaud
2019-12-11 17:18 ` Jeremy Nicoll - ml sox users
2019-12-12  4:18   ` Martin Ratinaud
2019-12-12 17:05     ` Jeremy Nicoll - ml sox users
2019-12-16  5:10       ` Martin Ratinaud
2019-12-16 11:48 ` Måns Rullgård
2019-12-16 12:02   ` Martin Ratinaud
2019-12-16 13:30     ` Måns Rullgård [this message]
2019-12-16 13:36       ` Martin Ratinaud
2019-12-16 17:44         ` Måns Rullgård
2019-12-17 10:04           ` Martin Ratinaud
2019-12-17 10:50             ` Måns Rullgård
2019-12-18  4:00               ` Martin Ratinaud
2019-12-18  7:43                 ` Mikko Olkkonen
2019-12-18  9:06                   ` Martin Ratinaud
2019-12-19  9:52                     ` Mikko Olkkonen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-list from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://lists.sourceforge.net/lists/listinfo/sox-users

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=yw1xmubswg7r.fsf@mansr.com \
    --to=sox-users@lists.sourceforge.net \
    --cc=martinratinaud@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

sox-users@lists.sourceforge.net unofficial mirror

Archives are clonable: git clone --mirror https://public-inbox.org/sox-users

Example config snippet for mirrors

Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.audio.sox
	nntp://ou63pmih66umazou.onion/inbox.comp.audio.sox
	nntp://news.gmane.io/gmane.comp.audio.sox

 note: .onion URLs require Tor: https://www.torproject.org/

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git