How to remove the audio track from a video made on an iPhone, using iMovie

Sometimes I take a video of something and on listening to it hear other noise or conversation that I don’t particularly want to include. Here’s how I get rid of it in ‘post-production’.

This may not be the best way of doing it and I’m certain it’s not the only way. However, it works and doesn’t involve downloading any extra apps or spending money, so it’ll be the method I’m likely to favour. If you know of a better way, others might be interested so please feel free to share your improvements and suggestions in the comments below.

This post assumes that you have an iPhone with the built-in camera, and iMovie apps. I’m running iOS 7.6 (if you’ve got a higher iOS then my screenshots might look a little different from yours, but hopefully not so much as to make the instructions unworkable).

Here are the basic instructions, repeated below with the addition of screenshots

1. Record your video
2. Open iMovie
3. Click the + at bottom right to create new project
4. Click Movie
5. Click Create Movie
6. Tap the icon to ‘insert media’
7. Select your chosen video, it goes yellow
8. Click the down arrow to insert
9. Your video appears as a panel of images, and the cursor leaps to the end
10. Click the video panel, it goes yellow
11. Audio is already selected, click the two dots below the dustbin, click detach
12. The audio track is now separated from the video and you can, if you wish, move it into a different position. It’s already selected (yellow) so press delete to remove it
13. Try out your now silent video, all the sound should have gone
14. To export it click on the back arrow at the top, then the upload icon for sharing options. Your options will depend on your phone and apps but I’ve got Facebook, YouTube, Vimeo etc. and if I scroll along there’s the email option at the end and WhatsApp. The save video, in the lower down (not brightly coloured) panel will save it to your camera roll, from which you can also email and send it other places etc.).

To share it on Twitter, note that it will need to be reduced in length to just a few seconds and you’ll need to save this ‘iMovie project’ to your camera roll to do so (and ensure that you’ve granted Twitter access to your iPhone’s camera roll [at some point I might add something about how to do this but it’s in Settings somewhere]), you can also email it to yourself.

You’ll end up with a much smaller, squarer version of your video, rather than the rectangular one you created. I’ve no idea why, nor how to make it larger. If you know a better way that will let you end up with a video that’s identical to the one you recorded minus the audio, please let me know. I’m less interested in costly professional tools though.

The same again but with added images

1. Record your video
2. Open iMovie (it was already installed on my phone)
3. Click the + at bottom right to create new project

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4. Click Movie (in blue, below)

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5. Click Create Movie (top right in pale blue, below)

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6. Tap the sprocketed film + musical note icon at the top to insert media

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7. Select your chosen video, it goes yellow – you can slide the yellow boundaries to make your clip shorter too.
8. Click the down arrow to insert

photo 1(5)
9. Your video appears as a panel of images, and the cursor leaps to the end

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10. Click the video panel, it goes yellow

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11. Audio is already selected, click the two dots below the dustbin, click Detach

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12. The audio track is now separated from the video and you can, if you wish, move it into a different position. It’s already selected (yellow) so press the dustbin icon to delete it

photo 1(5)

13. Try out your now silent video, all the sound should have gone
14. To export it click on the back arrow at the top, then the upload icon for sharing options. Your options will depend on your phone and apps but I’ve got Facebook, YouTube, Vimeo etc. and if I scroll along there’s the email option at the end and WhatsApp. The save video, in the lower down (not brightly coloured) panel will save it to your camera roll, from which you can also email and send it other places etc.).

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Above: Click the left-facing arrow in the top left to start the export process.

Below: you’ll see this screen, choose the upload icon in the middle to upload your silent film.

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Below: Mail is at the end of the list of things you can send the file to and you can also save it to your camera roll.

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How to do .@ replies on Twitter

How to open up a tweet or conversation thread to your public timeline without quote-tweeting it (which breaks any threading as that creates a new tweet).

Updated – whether or not your mobile phone app can or can’t do the .@ may depend on the version of your software (eg iOS) or whether or not you’ve updated the app.

Mobile phone users
Carry on as you were by clicking the start of the reply to position the cursor there and typing the . as normal (tested on Twitter for iPhone, Echofon for iPhone and Twitter for Android – I’m assuming other apps behave similarly but please let me know if not).

@Flatsquid tells me that he can’t do this on his version of Twitter for iPhone (whereas I can) so this may be a version issue. I don’t have an option to update my version so can’t confirm, though I am using an older iOS.

Tablet users
Twitter for iPad can’t do .@

Twitter on Safari doesn’t work either but it seems that using Dabr on a browser does (thanks @medtek for checking). Open browser app, go to and log in by authorising with Twitter credentials. Click reply and place the . at the front. Possibly Echofon for iPad would work too.

Web users
Twitter dot com and Tweetdeck can’t do .@

1a. On Twitter dot com or Tweetdeck reply within the confines of the new system
1b. Then retweet your own tweet – this makes it available to all your followers and maintains the thread so people can click and see the conversation.


2. Dabr: Go to and log in by authorising with Twitter. Click reply and place the . at the front.

What’s this all about?
Twitter’s latest improvement meddling has removed the capacity to insert a . before the username of the person you’re replying to on the desktop / web browser version of Twitter (eg or Tweetdeck). The simple addition of the . before the @ did two things (a) it converted a reply (which has a more limited distribution to those involved in the conversation and people following both them and you) to a broadcast tweet (visible to anyone following you) so that more could see it while (b) maintaining the threading, letting people click and see the expanded tweet in context. [Note that any tweet sent is visible on your public timeline unless sent as a DM or you’ve locked your account.]

In the new format Twitter has removed the usernames from the text of the tweet (giving us more characters, a potential plus I suppose) but making all replies replies and not easily ‘surfaced’ to more people.

I think this ONLY affects people tweeting from Twitter dot com and Tweetdeck, phone apps appear to be unaffected (may depend on OS version or app version).

I have no idea why Twitter has done this. I’m assuming they want to make desktop Twitter as difficult as possible to use to force everyone onto mobile apps, though that doesn’t make sense since there are so many things you can’t do (in terms of settings) on mobile apps. People have suggested that it reduces the risk of people piling on in response to a more publicised tweet – that would only be true if .@ was also removed from mobile apps or you couldn’t retweet your own tweet (which serves the same purpose, but perhaps doesn’t cue people in the same way that seeing .@ does). Possibly this will change in future.

Removing / adding people in the conversation
The other annoyance with Twitter’s new replies is that it adds an extra hassle barrier in untagging people from the conversation. They have now added a ‘remove everyone other than the person I’m replying to from this conversation’ one-click option.

Clicking ‘reply’ has always meant ‘reply all’ but the previous system made it easy to select the usernames as a chunk of text and delete, now you have to go and look for them. To do this click reply, then click on the line above saying ‘Replying to @name, @name etc’ and choose the options to delete people. You can write the names of new additions within the tweet – so there’s one way to remove people but a different way to add them, which seems confusing.

Threads are now a mess and it’s not clear who’s replying to whom.

Further reading
The New Twitter @-Replies Are Giving Me an Ulcer (30 March 2017) by Sarah Jeong

Twitter search operators, for better search results

Screenshot of Twitter’s dedicated search page. It looks like ‘operators’ is a link
to another page but it’s just a pop-up and there’s no real useable link there.

Below are Twitter’s search operators. There doesn’t seem to be an actual page I can link to so instead I pinched them from the pop up window that appears when you click operators on Twitter’s dedicated search page (see picture above). Here’s the link for the Advanced Search where you can do even more. I haven’t tried all of them but the one at the end doesn’t seem to be working now.

Edit: Heh, note that WordPress dot com auto converts text smiley faces like : and ) into 🙂 so in the table below please remember that you’d need to write colons and brackets into your search terms. I’ve no idea if this even works though. I think some of these operators might be out of date.

It’s possible Twitter will make me take this down cos I have totally stolen their content (literally in fact, when the popup appeared I used Ctrl+U on Firefox to bring up the ‘page’ sourcecode and then collected the HTML which I pasted into the draft of this post, above. Beyond me why they don’t make it more shareable. Mind you having seen their latest fiddling with replies…

What do do with a QR code once you’ve created one

Following on from my post on How to create a QR code here’s the logical extension of that – what to do with one. Feel free to add suggestions in the comments or ping me on Twitter (@JoBrodie).

QR codes are a square barcode-like picture which can be scanned by the camera in a smartphone to open a document or web page. A QR code is a “machine-readable optical label that contains information about the item to which it is attached”. They are also known as 2D barcodes and look like this – it’s a “link you can click on in real life“.

QR_code_for_mobile_English_Wikipedia.svg.pngQR code for the URL of the English Wikipedia Mobile main page

I’ve only ever used QR codes that point to websites, but that could include YouTube videos or links to Word or PDF documents, or surveys etc.

Table of Contents

  1. QR scanners for your phone
  2. Example of using QR codes at an event to collect survey data
  3. Classroom use
  4. Teaching staff use
  5. Research posters
  6. Marketing for events
  7. Museums
  8. Language learning / supermarkets
  9. Downsides, or things to be aware of
  10. Dynamic QR codes and short URLs

1. QR scanners for your phone

I have several QR code scanners on my phone – I think they were all free: Scan-Life (it just opens the page so watch out if you’re not sure about the page), Kaspersky’s QR Scanner and RedLaser. They all also scan supermarket barcodes, though unless the product is listed in its library the scanner doesn’t really know what to do with them.

2. Example of using QR codes at an event to collect survey data
A recent example from my work with computer science teachers: we’ve just had our annual conference for teachers supported by Computing At School (CAS) London and we wanted to find out what the delegates thought of the sessions and conference overall. At the final plenary we included massive QR codes on the slides (and a short link written in full for those sitting in the audience without QR-enabled phones) and people were able to point and click, or type the address, and complete the short survey there and then.
Pro-tip: if you want to compare use of QR codes with typing in (short) links, create two short links (one for each) that point to the same page.

3. Classroom use

Eleni Kyritsis has used QR codes cubes, each side posing a different question, to encourage her pupils to reflect on their learning (there’s a template on her page).

I also asked my primary school teacher chum Jane for her thoughts on the use of QR codes in primary classrooms and, paraphrasing, she said…

“One of the requirements in early education is to be creative with computing (not just programming) and for us to get kids using tech and building up their IT skills through fun activites (if it is not fun it does not happen – or at least not without huge disruption and pain).

QR codes are used in all sorts of ways.

We can make interactive displays (we LOVE displays of children’s work – gives the children an audience/purpose and better motivation/quality of work) – so children create little presentations as well as a piece of artwork or writing – so they are augmenting their physical artefacts with e-artefacts – they make a QR code and put it next to their work and then peers and other year groups (and visitors) use their mobile device (which many primary schools have a small batch of) and the viewer can access this other piece of work.

Interactive displays are also used by teachers to create displays that teach, so you might have a display about volcanos – that also has a link to a website or presentation etc..

QR codes are used for differentiation (this tends to be for schools where they have class sets of mobile devices) so if I have 3 core ‘sets’ High ability/ Middle/ developing plus a couple of children with special educational needs or who speak English as an additional language then I create a differentiated task for the lesson – and rather than photocopying the task – they scan the red QR code, blue QR code etc…

QR codes are used for assessment – this is getting to be a very popular idea. Kids are each given their own QR code as a little laminated square – with their photo on the back and say a colour on each edge of the QR code so red can be top, blue can be top, yellow can be top or numbers can be used 1,2,3 4 for orientation. The orientation of the QR code – gives a up to 4 different answers from a pupil. So you have 30 little mites all sitting on the carpet, or at tables if a bit bigger mites…. and you ask what is the correct spelling for the word (say a word) and show 4 spellings marked 1,2,3,4 They all show the relevant bit of their card. You use your mobile device hooked up to some app – can’t remember the name and it instantly records who got it right/wrong and what the wrong answers were. We are big into this kind of fast formative assessment. Normally we used whiteboards – but this captures the data longer term and is more accurate than scanning by eye.

Primary teachers are very creative and you never quite know what they get up to make their classroom more interesting, teach concepts in quirky fun ways or just help them work quicker and smarter.”

4. Teaching staff use 
This post highlights a kind of game which encouraged teachers to share useful resources with one another while also getting them using QR codes and getting a sense of how they might use them in their classrooms. There’s a picture of a QR code on the blog, so I scanned it and a message came up which said “10. Find and share a parent communication resource” – they used to do this.

5. Research posters
A QR code pointing to a web page containing your contact details, publications, PDF of the poster and whatever else might be useful would seem quite handy. Don’t forget that you can update the page during or after the conference too. Marianne’s using them on research posters to point people to a short video about cancer research.

6. Marketing for events
You can play around with different sizes – smaller QR codes on an A5 flyer work fine (you can test before printing by pointing a QR-enabled phone at your onscreen code with the document sized at 100%).

7. Museums
Museums are adding QR codes to some of their exhibits which take visitors to a page with additional information. The Broolyn Museum is doing some interesting stuff in this area. QR codes should never replace the normal text-based information of course. If you’re adding QR codes can I recommend sending someone round to check them periodically – if the link dies it’s a bit disappointing. See bit on dynamic QR codes below.

8. Language learning / supermarkets
Multi-language shopping labels: a Canadian supermarket gave customers a device which pronounced the names for various products in the indigenous language – Grocery stores bring Indigenous languages to the aisles

It would be quite handy if a supermarket used QR codes for “how do I cook and eat this obscure looking vegetable” (I’ve got no idea what celeriac is for) or gave recipe ideas.

9. Downsides, or things to be aware of
QR codes are not intuitive and people often need to be shown how to use them, and what the point of them is. If the technology (eg wifi) doesn’t work then have a back up plan. In most cases they should never replace other text-based instructions but only be used to augment.

Just like clicking on a link that ends up taking you to a dodgy site be careful what QR codes you ‘bip’. If in doubt use RedLaser or QR Scanner instead of Scan-Life because they tell you what the page is going to be.

Dynamic QR codes and short URLs
You can create a single QR code and change the link that it goes to by having an intermediary link which then redirects it. That service is available from and they have a very good page explaining what it’s for and how it works. I generally create static QR codes (can’t change what it points to) as it suits my purposes.

You can create a QR code based on a full length website link, or on a shortened link that points to it (I use and log in with Twitter so that I can customise the links). If you want to compare visits to a page from QR codes or from some other method (eg typing the address in, or via social media) you can create multiple aliases in and have one link for your QR code and one written out and can compare which is used more.

See How to create a QR code as well.



How to create a QR code

QR codes are a square barcode-like picture which can be scanned by the camera in a smartphone and open a web page. A QR code is a “machine-readable optical label that contains information about the item to which it is attached”. They are also known as 2D barcodes and look like this.

QR_code_for_mobile_English_Wikipedia.svg.pngQR code for the URL of the English Wikipedia Mobile main page

Opinion is divided on QR codes. The people who dislike them have perfectly good reasons for doing so, in that almost no-one has the faintest idea what they are, and it’s certainly not obvious if you’re seeing one for the first time, most people probably don’t have an app on their phone that will let their camera respond to them, and even if you do know what they are and how to interact with them you’ve still no idea where you’re phone’s browser is going to end up(1) as QR codes are not human readable (well, you can learn but they’re not as immediately informative as a web link).

Having said that I’ve always been rather smitten with them – they save so much time compared with typing in an address. Just open the app, point and ‘ping’ – the website opens. To be honest the excited ‘ping’ made by the app I use (Scan-Life) is part of the fun. It’s like living in the future.

(1) Presumably someone could invent a phone app that tells you where the QR code is trying to take you, perhaps this already exists. That would probably eliminate that particular problem. Kaspersky QR Scanner and RedLaser both tell you what URL you’ll be taken to (and invite you to decide if you want to) but don’t seem to give any warning about malicious links.

Here’s how I make a QR code from a web address
(Go to 3. if you just want a message to pop up, no websites)

1. You will need a web address (aka link, URL etc)
If you want your QR code to point to a document you’ll need to save it with a public link. My preference for that would be to upload the document to Dropbox and copy the file’s public link. Remember that if anyone finds the link they can access that file so if privacy is a big issue be aware of that.

2. Consider shortening the URL – tinyurl,, etc will all give you a shortened version and will also let you customise it to something human-readable and it will also tell you how often the link is visited. See bit in (3) about long-term use though.
It is probably quite good practice (in publicity contexts) to include the full original link, as well as the QR code and short URL, so that people can type that in if they’re wary (and don’t have an app or an idea of what to do with your QR code). If you’re doing this at a conference you can probably assume a degree of trust.

3a. Use to create your QR code from your long or short URL (though for longer-term use better to use the real full-length URL in case the URL shortener goes off line)


3b. Use to create a QR code that just shows a piece of text or instruction on-screen

4. A QR image is automatically generated from either of the sites above. Check that the on-screen code works with your scanning app (I use Scan-Life for iPhone) then print it / save a copy / take a screenshot of it.

5. Open the picture in image editing software, I use Paint (free on Windows) or PowerPoint, and add a text box with the short or long URL on it for archiving purposes.
It’s a kindness to the end-user, and to yourself, to include the URL in a QR code so people know where they’re going to end up, and also it’s handy three years from now when you find the code stuck in a filing cabinet.

I have written might write the accompanying Part Two to this post – What do do with a QR code once you’ve created one 😉 I use them at work to provide people who come on our courses or events with a quick way of accessing the feedback surveys. The people who come on our courses etc are computing teachers and I understand that QR codes are much used among computing teachers.

If you stick a + at the end of a bitly link you can see how often it’s been clicked

This is one of those things that I tend to assume that everyone already knows, but then I remember the surprise I felt on learning that everyone doesn’t use or know about ‘Ctrl+F’ or its equivalents to find text in a document quickly (as opposed to scrolling and visually scanning). So I thought I might share it.

Bitly is a free URL shortening tool that lets you get some basic analytics about number of clicks and, if you register for an account or authorise with Twitter etc, also lets you customise the ‘end bit’ of the address. There might be a paid version that does more but I’ve never investigated or needed it.


Adding a + symbol to the end of any bitly link and then pasting it into an address bar will (a) show you what URL it’s linked to and (b) show you how often that link has been clicked. I’ve emphasised the ‘then’ in the last sentence because you can’t enter the bitly URL and click enter because then you’ll just be taken to the page that it points to.

If you see a bitly link on Twitter or Facebook, or wherever, you’ll need to copy the link first (don’t just click on it) and then add the + before loading the page. The + symbol doesn’t incorporate itself successfully into a clickable link by the way, you have to add it manually.

Note that someone else might also shorten the same long link, so there can be several bitly links for one web page – theirs might have had clicks and yours might not, or vice versa. Here’s one I’ve just created (without logging in, so I’ve not customised it) – see the bits circled in green for the salient information.


Handy tip – you can create more than one customised bitly link for the same URL yourself. You could post one to Facebook, one to email and one to Twitter and see which option brings you more visitors.




Capturing / sharing voice memos from iPhone and WhatsApp

I discovered yesterday that you can send an audio message through WhatsApp, I think it’s probably always been possible but I only just noticed. You can also save a copy separately (by emailing it to yourself), and I thought I’d write up how to save / email voice memos from iPhone too, so I added that at the end.

This post was prompted by thinking about Andy Mabbett’s (@pigsonthewing) post about the Wiki Voice Intro Project (#wikivip), while noticing that audio messages could be shared via WhatsApp. WikiVIP is about inviting people who have a Wikipedia page about them to record and share a short audio introduction (“Hi I’m X and have been doing Y since Z”, sort of thing), you can see an example on Ralph Fiennes’ Wikipedia page.


1. Here’s a redacted WhatsApp voice recording (you can make new ones by clicking on the remarkably obvious blue microphone icon at the bottom of the screen which I only spotted yesterday). If you press and hold anywhere inside the pale green box you’ll bring up the options window

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2. “Forward” is the option you’re after, to email it etc

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3. Then it’s the upload icon (bottom right in the picture below) and choose email option as before, the file is in an .opus format – I’ve never handled those before but there are file conversion tools [Zamzar – file converter (no download required)]

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iPhone voice memo app

This lets you record audio for as long as you have enough space on your phone to accommodate it. I’ve recorded several things longer than an hour, though I tend to split them up. Obviously longer recordings are bigger files than shorter ones but you can email any file to yourself [and it might be simpler to use a USB connection and iTunes for the really large ones – iPhone: Transfer Voice Memos from iPhone to Computer] by doing the following.

1. Choose the voice memo you want to share, click on it in the list to bring up the play, upload, edit and delete icons

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2. Click on the upload icon which brings up the ways to share, then choose the email option

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3. The file is an .m4a format (if recorded with an iPhone) but you can use software tools to convert to other formats [NCH Switch MP3 Converter software (download required)] [Zamzar – file converter (no download required)]

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