Talkback for article: 204, May2001

Real-time mp3 recording, part II

Back to: http://cgi.linuxfocus.org/English/May2001/article204.shtml

From: celelettin <c_altinpinar(at)yahoo.com> [ date: 2001-05-06 ]
Hi!I have some advise to you. you use difficult word and tecniques so I hardly undestood your article. If you want that more people benefit from your articles keep it simple.

From: Peter [ date: 2001-05-07 ]
Hi celelettin,
I have no problems with the text. Not every article needs to be
one for beginners on this subject.
From: Johan [ date: 2001-05-12 ]
Nice, but I would like to use OGG.
From: Aaron Bentley [ date: 2001-05-12 ]
Joint stereo does have an impact, it just doesn't make the files smaller.
When you specify 128 kbits per second, you get 128 kbits per second, no
matter what. This shouldn't be too surprising, and in fact, is quite
important, when you need to predict file sizes in advance.

What Joint stereo gives you is improved quality. Many aspects of the
sound in a stereo recording are similar for both left and right channels.
In the extreme case, a stereo recording of a mono source, joint stereo will
produce a 128-kbit mono stream and send it to both speakers, while a normal
stereo process will produce two identical 64-kbit streams, and send one
to each speaker. The benefits of joint-stereo are rarely this spectacular,
but they are real.
From: Philip de Groot <philipg(at)authors.linuxfocus.org> [ date: 2001-05-13 ]
Hello,


Thank you for the additional information on joint-stereo. I did not know this...

By the way. I received an email of someone pointing to a Linux-program that is capable of splitting large mp3-files in smaller chops. Below, i have quoted a piece from this email


[quote]
Second to editing MP3 files or more precisely chopping them up. There is
a Linux option for this but you have to look hard. Anyway look on freshmeat
for mpgtx. It is aimed a video MPEG files, but *will* happily chop up
audio MP3 files.
[/quote]


And yes, I know that the quote things between square brackets will remain visible, but at least it is clear that I quoted this text.



Regards,

Philip de Groot
From: _Death_ <dw_death_(at)hotmail.com> [ date: 2001-05-13 ]
I once made radiorecordings too, 3 minute long cronned recordings, from a short comedy at the end of late night program.
Naturally i didnt want to decode, edit and reencode again, realising that mp3 is frame based.
So after some digging i stumbled over Olli Fromme his mp3asm.
It allows for ppl to cut and paste mp3s at the frame level.
Sadly the development stopped in oct 97, leavin this nice gem in a bad state since it needs empty frames to exist in the stream in case it needs to insert one in the stream.
Ive rewritten it and am currently waiting for the hosting of the site before i put it on fm.
I am workin on a gtk version, which will have the ability to change the gain of the granules.
And from testing, i can say that editing mp3s on framelevel is kinda crude, at 26-27ms per frame, but its hard to spot the place where theres a slight mismatch in timing.
But imho its better removing a frame cleanly than reencoding and passing all those filters again.
When editing a radio recording u would like to fade in and out, for which mp3asm will be perfect as soon as i get the gtk version runnin.

So check fm for it, i will put it on there as soon as the site is up. Or mail my behind for it now.

And btw; mp3stream lenghts r always a function of bitrate and actual lenght of audio.
A layer stream has almost 38 frames per second, that coupled with ~418 bytes for 128kbps will always give u a set filesize.
JS does allow for certain signals to be stored only once instead of once for each channel.
Which saves alot on datasize, and in turn allows for higher quality in the available space thus better compression.
But, as always, the encoder's psycho acoustics decides how it all is encoded.
From: Arne Flones <flonesaw(at)rot13(ybatfuvc).net> [ date: 2001-05-13 ]
Here's another MP3 file editor (called Mpcut):

http://minnie.cs.adfa.edu.au/Programs/Mpcut/index.html

It has some bugs, but it does work fairly well.


From: Nathan Myers <ncm(at)nospam.cantrip.org> [ date: 2001-05-13 ]
Isn't it a bit irresponsible to be still making MP3s now that
the format is encumbered with patent restrictions, and a better
Free alternative (Ogg/Vorbis) is well-supported everywhere?
From: Philip de Groot <philipg(at)authors.linuxfocus.org> [ date: 2001-05-14 ]
Hello,

Vorbis/Ogg is not really finished yet. Furthermore, It is comparable to maximally 128 kbps/channel mp3 encoding (see: http://www.ogg.org/ogg/vorbis/faq.html ), which is not enough for the REAL audiophiles. But apart from that, mp3 is nowadays generally accepted and a lot of mp3 decoding software and mp3-PLAYERS are available. I have never heard of a hardware-based Ogg-player to be honest. This is probably just a matter of time, but an important reason for me not to switch to Ogg. Off course, things will change if private users will be charged for using mp3-encoding software, but this is not the case (yet).

In Short: I think that Ogg/Vorbis has a high potential, but is unattractive at the moment.

About the mp3-editing software. I will keep an eye on them and try them out when they become available.

Regards,

Philip de Groot
From: philippe [ date: 2001-05-14 ]

Hi

>In short, you need a program that is capable of editing the mp3-files THEMSELVES!
>Such programs do exist, but not (for the moment) for Linux.

I think it 's wrong :)
have you try broadcast 2000 ?
dont look very nice but very usable for mp3 editing :)
(no need to uncompress all, but need to render into wav what you have selected)
I do that regularly, recording from radio as in your first article, then
editing with broadcast select what i want , render into wav then reencode it
in batch mode

From: Rick Holbert [ date: 2001-06-22 ]
I've modified my recording script to use oggenc in place of lame.

A sample script follows:

#!/bin/sh
/usr/bin/aumix -L
/usr/local/bin/wavrec \
-r 22050 \
-l 3600 | \
/usr/bin/oggenc \
--bitrate 32 \
--title "Title of Show Here" \
--album "Album Name Here" \
--date `date +%d %b %Y` \
--comment="Copyright (c) `date +%Y` Owner Name" \
-o test.ogg \
-


From: Philip de Groot <philipg(at)lauthors.inuxfocus.org> [ date: 2001-06-25 ]
Thanks
From: lcdtastatur <lcdtastatur(at)web.de> [ date: 2002-01-10 ]
Hello

I want record an mp3-stream in C-language.


I have bild an LCD with keys and that should controll te record.

you can find it under :

http://members.tripod.de/MASE5/linux/lcd/

Pleas help me

P.S. Sorry for my bad english i speak German.

From: Mario Sonka <mario.sonka(at)web.de> [ date: 2002-07-05 ]
Neither can't find Mann's Mp3 (site not available) nor a reasonble working mp3cutting software for Linux.
Could you please support?
From: dan <carlos(at)lopes.freeserve.co.uk> [ date: 2002-08-16 ]
i downloaded your program windows version buth i cannot install this ........please help me as i am not a computer expert ...the file i downloaded is -mpegrec-1.0.src+bin.win32.tar- what i have to do to install this program under windows platform (to unzip...does not work ...to rename ..does not work )......?????please help .thank you
From: Philip de Groot (original author) <philipg(at)authors.linuxfocus.org> [ date: 2002-08-25 ]
Hello,

Mann's MP3-software can be downloaded from my (Dutch) site. Here is a direct link:
http://www.loostad.com/linux/overige_updates/mp3/MannsMp3Edit_1.0.0.9.zip


Sorry for the late respons. Usually, I should be automatically notified regarding an added comment on the Talkback pages. This did not happen and I just found out by checking this page... Regards, Philip de Groot
From: Chris Holt [ date: 2002-12-04 ]
Have you tried MP3 DirectCut? It's very fast, as it does not load and decode the MP3. It is very quick and easy to make cuts and split up large files. The latest version is at:
http://www.rz.uni-frankfurt.de/~pesch
Totally free. Good stuff.

Chris
From: Anthony G [ date: 2006-04-22 ]
I came across this page while searching for resources on how a GNU/Linux user might edit a MP3 encoded audio file without having to decode the file, edit the PCM with audacity and re-encode. I wanted to split MP3 audio files so as to remove the long stretch of silence encoded in audio files that included the "hidden" track that often appears at the end of the last track on a CD.

After further searching, I came across mpgedit - "an MPEG 1 layer 1/2/3 (mp3), MPEG 2, and MPEG 2.5 audio file editor that is capable of processing both Constant Bit Rate (CBR) and Variable Bit Rate (VBR) encoded files. mpgedit can cut an input MPEG file into one or more output files, as well as join one or more input MPEG files into a single output file. Since no file decoding / encoding occurs during editing, there is no audio quality loss when editing with mpgedit." - from http://www.mpgedit.org/mpgedit/

It's licensed under the GPL and once I had read the man page, I found it quite easy to use.

18 talkbacks in English
Other talkbacks:   Portugues Francais




Due to the increased amount of web spam we have deciced to removed the talkback posting possibility. You can read old talkbacks but you can no longer post new ones.

Back to http://cgi.linuxfocus.org/English/May2001/article204.shtml

Please contact webmaster(at)linuxfocus.org if you have any questions with regards to this talkback

lftalkback version 3.10