# Software for "cropping" mp3s



## mamascarlatti (Sep 23, 2009)

Does anyone know some easy to use free software for cropping mp3s - ie I want to extract about 9 seconds of an mp3 for a presentation I'm doing.


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## Ukko (Jun 4, 2010)

Audacity. More than you need, but easy enough.


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## mamascarlatti (Sep 23, 2009)

Thanks Hilltroll72. Worked fine.


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## Ukko (Jun 4, 2010)

Ah, that's great. After I posted, I began wondering about the 'easy enough'. I'm so used to that way of presenting the file - from using GoldWave - that I forget whether it's really obvious.


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## Huilunsoittaja (Apr 6, 2010)

I wish I had that... because I wanna clip a pre-screening recording I made so I just get the exposition of a movement, and not the whole thing.


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## Argus (Oct 16, 2009)

Huilunsoittaja said:


> I wish I had that... because I wanna clip a pre-screening recording I made so I just get the exposition of a movement, and not the whole thing.


Audacity is free.

:tiphat:


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## mamascarlatti (Sep 23, 2009)

Argus said:


> Audacity is free.
> 
> :tiphat:


Yes, it took me about 10 minutes from download to a cropped file.

Only problem was that I had to save it as .wav because i couldn't organise the re-encoder to work.


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## bassClef (Oct 29, 2006)

I like Goldwave - a bit dated now,but it does the job, and is simple to use.


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## Ukko (Jun 4, 2010)

mamascarlatti said:


> Yes, it took me about 10 minutes from download to a cropped file.
> 
> Only problem was that I had to save it as .wav because i couldn't organise the re-encoder to work.


My copy of Audacity lets me 'export' the file in several different formats, including LAME mp3. I don't remember now if I downloaded "plug-ins" to get that flexibility, but it's there.

I would respond to the GoldWave liking poster separately, but I'm trying to hold my post total under 100 (for personal reasons). Anyway, if you get the paid-for version of GoldWave it is not, I think, dated for audio work. The creators update the app rather frequently, and they heed their clients comments. I make all of my LP-to-CD-R transfers using it.


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## Nicola (Nov 25, 2007)

Hilltroll72 said:


> My copy of Audacity lets me 'export' the file in several different formats, including LAME mp3. I don't remember now if I downloaded "plug-ins" to get that flexibility, but it's there.
> 
> I would respond to the GoldWave liking poster separately, but I'm trying to hold my post total under 100 (for personal reasons). Anyway, if you get the paid-for version of GoldWave it is not, I think, dated for audio work. The creators update the app rather frequently, and they heed their clients comments. I make all of my LP-to-CD-R transfers using it.


I've used Audacity a lot. To be able to use MP3 or AAC or FLAC you have to download separately these codecs, as Audacity itself is not licensed to bundle it in with the main programme. To do this go to edit/preferences/libraries and follow the instructions. Once these codecs are incorporated in your file structure, you then "export" the file you are working on using whichever codec suits you. There are various others that are available which are already incorporated as standard.

If justified by the quality of the initial file, I generally export anything I'm working on using MP3 with the option set at 320kbps. That's because most other software works easily with it, and the quality is to all extents and purposes indistinguishable from CD.

As for snipping part of a file, the easiest way to do this is to highlight the relevant part of the file and then use "export selection". Before I export anything I always look carefully at the amplitude of the sound wave. If it looks too loud or soft for whatever the piece is, I use the "normalise" facility by going to effect/normalise. If normalisation is justified you should normalise the whole file first of all before any exporting any part of it. All that "normalise" does is find the highest part of the volume and then scales everything else to a corrected new maximum. It doesn't introduce any distortion as everything is linearly adjusted.

I use Audacity mainly for editing recorded music from radio and live concerts, e.g. to get rid of audience coughing and sundry other blemishes. For such material it's only worth using MP3 set at 160 kbps, given the limitations of DAB radio and live internet streams, but it's not bad. Overall Audacity is fantastic and I couldn't without it.


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## Nicola (Nov 25, 2007)

Hilltroll72 said:


> I would respond to the GoldWave liking poster separately, but I'm trying to hold my post total under 100 (for personal reasons).


An intriguing comment. Most people can't wait to get to 100 posts hence all the drivel you get here. Like you, I'm very parsimonious with my comments, and take "time out" in between appearances. I'm sure it does wonders for one's image not to over-do it, as that way one can continue for so much longer. The few mega-posters fizzle out sooner or later, and some are reputedly still only about 15 years of age. Quite a dreadful thought, isn't it, being "hooked" on a place like this when so young. Gosh, wait until they get into alcohol or even worse.


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## Huilunsoittaja (Apr 6, 2010)

Yep, I got it now. Thanks for the suggestion!


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## Ukko (Jun 4, 2010)

*Rats; thwarted by the need for courtesy*



Nicola said:


> An intriguing comment. Most people can't wait to get to 100 posts hence all the drivel you get here. Like you, I'm very parsimonious with my comments, and take "time out" in between appearances. I'm sure it does wonders for one's image not to over-do it, as that way one can continue for so much longer. The few mega-posters fizzle out sooner or later, and some are reputedly still only about 15 years of age. Quite a dreadful thought, isn't it, being "hooked" on a place like this when so young. Gosh, wait until they get into alcohol or even worse.


Well, this requires me to 'burn' another post.

If I am 'parsimonious' with my posts it would normally be because I want them to be informative - or at least humorous. This forum adds the 'Senior Member' incentive. Those 15 year old members may get a kick from being 'senior'; I do not. I'm already plenty senior enough.

BTW, your explanatory post about Audacity is very well done. I was once a technical writer, so I recognize that sort of thing. (I wanted to tell you this in a private message, but couldn't figure out how that is done. Sorry if I embarrass you.)

:tiphat:


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## mamascarlatti (Sep 23, 2009)

It's taken me a couple of attempts to download, install and connect the plug-in to allow Audacity to export MP3s, but this is the page with the instructions for success

http://audacity.sourceforge.net/help/faq?s=install&item=lame-mp3

At the risk of bumping up everyone's post count past the permissible level, can you now recommend a good free programme for capturing streaming radio? I've got Freecorder but I find it very capricious - it only works half the time.

To send PMs, go to the brown menu bar at the top of this page, select User ControlPanel, navigate down to "Private Messages" - Click on "Send New Message". Enter the username of your recipient and your text, and send.


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## 151 (Jun 14, 2010)

Normalising actually makes the waveform as loud as possible without distorting, I wouldn't recommend it, all it does it remove the dynamic range.

Are you talking about an .m3u stream or just recording the audio, mamascarlatti?

Depending on the quality of your soundcard, you could get decent results using a freeware recorder like the aforementioned Audacity or alternately, Wavepad by NCH, which comes with an MP3 codec.

You need to set the program to record your soundcard by clcking the red record button and selecting "Stereo Mix" on Audacity.


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## Ukko (Jun 4, 2010)

*Well jeez*



151 said:


> Normalising actually makes the waveform as loud as possible without distorting, I wouldn't recommend it, all it does it remove the dynamic range.


Normalization has zero effect on dynamic range. The process finds the loudest point in the file, calculates the change needed to make that point 'zero decibels' (just lower than distortion), and uses that datum to change the entire file by that amount. For the listener it is equivalent to turning a volume knob on a preamp. The difference is that normalization, while it will raise the noise floor in the file along with the music, it doesn't affect the noise floor of your preamp.


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## Nicola (Nov 25, 2007)

mamascarlatti said:


> It's taken me a couple of attempts to download, install and connect the plug-in to allow Audacity to export MP3s, but this is the page with the instructions for success
> 
> http://audacity.sourceforge.net/help/faq?s=install&item=lame-mp3


I'm surprised it took two attempts. If you had read what I wrote (largely for your benefit) in my post # 10 you would see in paragraph 1 that I wrote: "_.... To do this go to edit/preferences/libraries and follow the instructions._" (first paragraph) If you click on the the "download" button at this place it takes you straight to the page above, after which it's dead easy to implement the instructions.


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## Nicola (Nov 25, 2007)

151 said:


> Normalising actually makes the waveform as loud as possible without distorting, I wouldn't recommend it, all it does it remove the dynamic range.


I'm afraid you are are completely wrong. Normalisation has no effect whatsoever on dynamic range. It merely shifts the maximum volume up or down, but everything else is held in the same ratio, hence there is no effect on dynamic range.

Dynamic range would be affected only if a fixed arithmetic addition or subtraction of volume was made at all points along the sound wave, but this is not how normalisation is applied as it's a geometric filter not an arithmetic filter. Applying normalisation is simply like adjusting the volume control on a properly regulated amplifier.

In fact, use of Audacity's "amplify" effect is an alternative procedure which achieves much the same effect. Use of normalisation is preferable if there is "dc ofset" (i.e, if the centre of the sound wave not on zero) and when you wish to normalise multiple audio channels (which are related to each other) at once. If "amplify" was used in these circumstances, each track would have the same maximum volume, which would not necessarily be required. "Normalise" preserves the relativities in terms of maximum volume between tracks, which is often what is required.

I was also careful to point out that I only use the normalise facility in Audacity when I consider it appropriate. I don't normalise everything, only when there seems to be something peculiar about the recording from the appearance of the sound wave and the kind of music under consideration. Moreover, I normalise to -3db.


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## mamascarlatti (Sep 23, 2009)

Nicola said:


> I'm surprised it took two attempts. If you had read what I wrote (largely for your benefit) in my post # 10 you would see in paragraph 1 that I wrote: "_.... To do this go to edit/preferences/libraries and follow the instructions._" (first paragraph) If you click on the the "download" button at this place it takes you straight to the page above, after which it's dead easy to implement the instructions.


Thank you. I found the instructions on the page I quoted easier to follow, as you used a word I was previously unfamiliar with (codec). Also the page I quoted gave a direct link to the necessary internet page which I thought I had found on my first google attempt but proved not to contain the required programme.

All this is very new to me and my needs are specific but much more limited than what you described in your post, as I merely want to crop sentences out of a dialogue for teaching ESL.


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## mamascarlatti (Sep 23, 2009)

151 said:


> Are you talking about an .m3u stream or just recording the audio, mamascarlatti?


There, you've lost me. I'm just talking about streaming something like internet radio on my PC and recording it so I can listen to it at a convenient time. Freecorder 3 records anything that's playing through your sound card but not reliably - the software freezes at regular intervals (maybe probs with Windows 7?)



151 said:


> Depending on the quality of your soundcard, you could get decent results using a freeware recorder like the aforementioned Audacity or alternately, Wavepad by NCH, which comes with an MP3 codec.
> 
> You need to set the program to record your soundcard by clcking the red record button and selecting "Stereo Mix" on Audacity.


I found the record button on Audacity but how do you select "Stereo Mix"?


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## Nicola (Nov 25, 2007)

mamascarlatti said:


> Thank you. I found the instructions on the page I quoted easier to follow, as you used a word I was previously unfamiliar with (codec). Also the page I quoted gave a direct link to the necessary internet page which I thought I had found on my first google attempt but proved not to contain the required programme.
> 
> All this is very new to me and my needs are specific but much more limited than what you described in your post, as I merely want to crop sentences out of a dialogue for teaching ESL.


I didn't address your query about how to record internet streams. It's definitely worth learning how to do this.

Since you have already gained some experience with Audacity, I suggest you stick with this. As you know, you start the recording process by clicking the red button. If all is well you will see the creation of a sound wave of what is being recorded. The blue button pauses the process, and the yellow button stops it. To be on the safe side, I suggest you set the "input slider" control initially to 0.9. This slider is in the top row to the right of the spot where you will see a picture of a microphone. You might need to adjust the level later in the light of experience.

If you don't see the wave card being created, then your PC is not correctly configured for the purpose. Go to edit/preferences/devices. Use the drop down menus to select "mme" for host. For playback and record, select your sound card. You should be able to home in quite quickly on the relevant set of options, by experimentation.

With experience you will find that the input volume tends to vary a lot according to different source material. Often I find that the sound from you tube videos, for example, is way to loud, as they are mostly amateur recordings. But even commercial recordings can vary significantly. You will be able to identify excessive input by observing red vertical lines on the sound wave where the "clipping" occurs. It is highly desirable to avoid clipping, so you need to adjust the input volume slider accordingly until it is just avoided. Generally speaking, rather than fiddle around constantly with the input volume control from source to source, I set it fixed at 0.9 and then use the "normalise" facility if things don't look right. Judging the latter is something you acquire by experience.

You can arrange for timed recordings (e.g. to record a radio programme while you are out) by selecting transport/timer record.

A word on your PC's sound card. If it's the original card, as shipped with the PC, it's likely to be worth upgrading if you are serious about using a PC as a music recorder/player. There are lots of options which I won't go into, but if you don't want to spend much and and yet obtain a significant improvement over the normal card then Creative Labs make a range of cards of varying quality. A good cheap one is the Audigy SE (it's an internal card), which should work easily and doesn't normally create a load of hassle as one often experiences installing new sound cards. This sound card comes shipped with Creative Labs own media player/recorder which is what I actually use for recording and playback. I use Audacity only for editing. If you decide to upgrade your sound card, this can be fiddly as you have to go through a process of uninstaling the driver for the old card, etc. I would suggest you get some help if you are unsure.

I realise that you only want to record something quite simple to start with, but learning how to do this properly - and having the equipment to make a reasonably good job of it - is worth acquiring. Just to mention one very useful classical music internet stream, the BBC's Radio 3 (its largely classical music station) offers some good stuff including live concerts. For example, the entire Proms was available online, and during its last week the BBC made available an experimental link which provided the stream at the very high quality level of AAC 320 kbps, which is way above the maximum quality level that MP3 can achieve. (AAC is a more advanced codec than MP3).


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## mamascarlatti (Sep 23, 2009)

Thanks for all your help and information, Nicola. Very useful.


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## Ukko (Jun 4, 2010)

Nicola said:


> If you don't see the wave card being created, then your PC is not correctly configured for the purpose. Go to edit/preferences/devices. Use the drop down menus to select "mme" for host. For playback and record, select your sound card. You should be able to home in quite quickly on the relevant set of options, by experimentation.
> 
> With experience you will find that the input volume tends to vary a lot according to different source material. Often I find that the sound from you tube videos, for example, is way to loud, as they are mostly amateur recordings. But even commercial recordings can vary significantly. You will be able to identify excessive input by observing red vertical lines on the sound wave where the "clipping" occurs. It is highly desirable to avoid clipping, so you need to adjust the input volume slider accordingly until it is just avoided. Generally speaking, rather than fiddle around constantly with the input volume control from source to source, I set it fixed at 0.9 and then use the "normalise" facility if things don't look right. Judging the latter is something you acquire by experience.
> 
> ...


Good stuff, Nicola. I would like to get the internet stream/sound card relationship straight though. The card is not required when _recording_ the stream, right?

I ask this because if that is so, and the processed file is intended to be exported to another device, the sound card is not in the game. I am not being facetious here. I use Audacity only to process wav or mp3 files, not raw input.

BTW, I prefer the M-Audio 'Audiophile 24/96' to anything that Creative Labs makes.

BTW2, you are accruing posts nearly as fast as I am. And I am becoming discouraged about avoiding the 'senior' classification.


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## Nicola (Nov 25, 2007)

Hilltroll72 said:


> Good stuff, Nicola. I would like to get the internet stream/sound card relationship straight though. The card is not required when _recording_ the stream, right?
> 
> I ask this because if that is so, and the processed file is intended to be exported to another device, the sound card is not in the game. I am not being facetious here. I use Audacity only to process wav or mp3 files, not raw input.
> 
> ...


I'm not posing as any kind of expert on Audacity, but merely a fairly experienced user.

As far as I understand the situation, Audacity needs a sound device for recording, as well as playback if appropriate. It doesn't matter what's being recorded, whether it's streamed audio or audio from any other source.

Audacity's default sound device for both recording and playback is "Windows Sound Mapper", but this is neither a physical device, nor a driver, but a virtual device (which is part of Windows) that results in Audacity using whatever default device has been selected in the "Sound" section of Windows Control Panel.

Audacity should, therefore, in principle utilise the PC's sound card if everything is set up correctly. But sometimes things can go awry, and the default sound device, as set in Control Panel, may by accident be set incorrectly, e.g. the sound side of a webcam, in which case "Windows Sound Mapper" will select that device as the recorder/player for Audacity. To avoid any such problems it is better to select the PC's sound card directly in the drop down menus of edit/preferences/devices.

Regards an alternative sound card, I only mentioned the Creative Labs Audigy as an example of cheap one that's been around for years, is easily available, is well tried and tested, and which generally causes little if any trouble upon installation. Some internal sound cards, with more exotic performance specs, can be difficult to get running properly, and may also be incompatible with some motherboards. It's definitely a big improvement of the kind of sound card normally hard-wired into most cheap/middle of the road desktops.

On your last point, I'm getting worried about my post count too. I'd hate to be a "senior member". How tacky. If you glance at my previous "form", you will see that this is my third manifestation on T-C. I've been far too "factual on this occasion. I usually like blowing "over-blown" egos out of the water, but it usually lands me in trouble. Hence, I don't think the Mods like me much so I may be pushing off soon. On the other hand, I might just be tempted to spring a few more jokes before leaving. If not, it's been nice knowing you. Don't overdo it!


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## 151 (Jun 14, 2010)

Nicola said:


> I'm afraid you are are completely wrong. Normalisation has no effect whatsoever on dynamic range.


It does have an effect on dynamic range because the waveform's peaks will be raised and possibly clipped and the quiet parts will be closer to the peak. Thus, the dyanmic range of the waveform is reduced, making the body of sound perceived to be louder, as well as the peaks. Not only does this bring up the noise floor, as you mentioned, but there can be aliasing, due to full integer translation, especially with the shoddy algorithms that come with audacity and wavepad.

Turning up the volume is not like normalising a waveform, that's not how the gain is applied to the speakers. If you have a decent preamp, you may as well keep the headroom and boost at the source; turn the speakers up, or if you really need it, apply soft clipper or limiter in a good program or mixer.

Get a good copy of the recording and you shouldn't need to meddle with it at all. Let the excerpt sound as true as it can be.


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## Very Senior Member (Jul 16, 2009)

151 said:


> It does have an effect on dynamic range because the waveform's peaks will be raised and possibly clipped and the quiet parts will be closer to the peak. Thus, the dyanmic range of the waveform is reduced, making the body of sound perceived to be louder, as well as the peaks. Not only does this bring up the noise floor, as you mentioned, but there can be aliasing, due to full integer translation, especially with the shoddy algorithms that come with audacity and wavepad.
> 
> Turning up the volume is not like normalising a waveform, that's not how the gain is applied to the speakers. If you have a decent preamp, you may as well keep the headroom and boost at the source; turn the speakers up, or if you really need it, apply soft clipper or limiter in a good program or mixer.
> 
> Get a good copy of the recording and you shouldn't need to meddle with it at all. Let the excerpt sound as true as it can be.


You are wrong. This is not just a matter of opinion but plain fact.

Dynamic range is the difference between the loudest and softest parts of a recording. Applying normalization to a recording affects these parts equally, and therefore leaves the difference between them unchanged. It is the same as applying a simple volume change that moves everything up or down in level by the same amount.

Possibly you are confusing "compression" with "normalisation". The former does affect dynamic range because it changes the relationship between loud and soft parts of a music file, but normalisation does not do this because the relationship is unchanged.


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## HarpsichordConcerto (Jan 1, 2010)

Nicola said:


> I usually like blowing "over-blown" egos out of the water, but it usually lands me in trouble. Hence, I don't think the Mods like me much so I may be pushing off soon. On the other hand, I might just be tempted to spring a few more jokes before leaving. If not, it's been nice knowing you. Don't overdo it!


Nicola, you might like to consider using enriched grade plutonium on your torpedoes when aimed at blowing those rather large egos out of the water. For instance, my vessel is made out of unearthly compound materials that are virtually indestructible. :tiphat:


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## Ukko (Jun 4, 2010)

*Flames have limited range and a lousy sight picture*



HarpsichordConcerto said:


> Nicola, you might like to consider using enriched grade plutonium on your torpedoes when aimed at blowing those rather large egos out of the water. For instance, my vessel is made out of unearthly compound materials that are virtually indestructible. :tiphat:


Nicola may not realize the unlikelihood of hitting a target on a forum. Long experience at rec.music.classical.recordings (usenet) has shown me a lot of shooters and very few hits that were more than grazes. Flaming is childish activity at the pre-school level.

Some of the members here at TC may be thinner skinned than usenet folk, but putting out flames and flamers is one of the jobs moderators do.

On the other hand, a figurative finger-poke in the ribs disguised as, say, a comment about mode changes, can be a thing of beauty.


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## 151 (Jun 14, 2010)

Very Senior Member said:


> You are wrong. This is not just a matter of opinion but plain fact.
> 
> Dynamic range is the difference between the loudest and softest parts of a recording. Applying normalization to a recording affects these parts equally, and therefore leaves the difference between them unchanged. It is the same as applying a simple volume change that moves everything up or down in level by the same amount.
> 
> Possibly you are confusing "compression" with "normalisation". The former does affect dynamic range because it changes the relationship between loud and soft parts of a music file, but normalisation does not do this because the relationship is unchanged.


But normalisation is not just a gain function, it uses peak or RMS detection to maximise the volume. The dynamics are affected although there is a constant ratio because of the problems I mentioned. Dynamics is not all you'll lose, I may be stressing the wrong word in 'range,' it just won't sound good, no matter what your internet sources have you believe.


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## Ukko (Jun 4, 2010)

*Debate Derailed*

Aha! member 151 has invoked the dreaded proverb D3 (Damned Digital Distortion).

Further discussion is thus contraindicated.


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