Showing posts with label video editing. Show all posts
Showing posts with label video editing. Show all posts

Tuesday, 24 January 2012

Miro Video Converter dimension settings explained

Anyone who has used the great Miro Video Converter (ver 2.6) tool for transcoding video into a format that can be viewed in any browser you may care to use might find the encoder settings a little opaque. There's no intuitive way of finding out exactly what dimensions the video you want to process will come out at other than by being familiar with the encoder settings.

The encoder settings are handily listed under the following categories:

Android Devices
 Nexus One
 Dream / G1
 Magic / myTouch
 Droid
 Eris / Desire
 Hero
 Cliq / DEXT
 Behold II

Apple Devices
 iPhone
 iPod Touch
 iPod Nano
 iPod Classic
 iPhone 4 / iPod Touch 4
 iPad
 Apple Universal

Other Devices and Formats
 Playstation Portable (PSP)
 Theora
 WebM (vp8)
 MP4
 MP3 (Audio only)

For some people, these settings may be fairly self explanatory. However, it's still not exactly clear which of the settings will give the best quality output.  What I intend to do in this post is explain what these settings equate to when using a real world example. I'm going to take a piece of video freely available and run it through each of these presets and then post the details of the file size and the dimensions. The video I have chosen is to use is entitled Liquid Skies by Annis Naeem:



The reason I have chosen this video is mainly due to its relatively short length (1 minute 36 seconds)  - encoding video files can take a long time especially when the original file is long and necessarily large as a consequence.

Annis has enabled downloading of the video from his Vimeo page and it comes out as 29.1 MB Flash (.f4v) file. Using the Inspector tool within Quicktime we can see that the actual video dimensions of the file are 960 x 540 pixels, and it is encoded with the AVC Coding codec. We can also see other pieces of information such as the audio codec, frame rate and data rate. This file will be used as the starting point when trying all of the different presets.

Helpfully, when converting the files Miro appends the name of the preset to the new file name. However, there are times when this goes wrong - the Apple presets for the various iPod models all omit the specific device they are intended for so if you want to make multiple copies for different platforms it is advised that you add "nano" or "touch" to the file name to help distinguish between the conversions.

The Android Settings

Below is a list of the video conversion presets followed by the resulting file size of the newly converted video as well as the video dimensions


Android Devices
 Nexus One - 17.5 MB - 800 x 480 (853 x 480 actual)
 Dream / G1 - 8.9 MB - 480 x 320 (568 x 320 actual)
 Magic / myTouch - 8.9 MB - 480 x 320 (568 x 320 actual)
 Droid - 18.8 MB - 854 x 480 (853 x 480 actual)
 Eris / Desire - 8.9 MB - 480 x 320 (568 x 320 actual)
 Hero - 8.9 MB - 480 x 320 (568 x 320 actual)
 Cliq / DEXT - 8.9 MB - 480 x 320 (568 x 320 actual)
 Behold II - 8.9 MB - 480 x 320 (568 x 320 actual)

All of the Android presets came out as .mp4 files using the H.264 video codec, but the audio codec remained unchanged along with the frame rate (29.97). There appears to minimal (if any) difference between the settings for Dream / G1, Magic / myTouch, Eris / Desire, Hero, Cliq / DEXT, and Behold II.

The Apple Settings

Again, below is a list of the video conversion presets for Apple devices followed by the resulting file size of the newly converted video as well as the video dimensions

Apple Devices
 iPhone - 15 MB - 480 x 320 (568 x 320 actual)
 iPod Touch - 15 MB - 480 x 320 (568 x 320 actual)
 iPod Nano - 15 MB - 480 x 320 (568 x 320 actual)
 iPod Classic - 15 MB - 480 x 320 (568 x 320 actual)
 iPhone 4 / iPod Touch 4 - 15.1 MB - 640 x 480 (853 x 480 actual)
 iPad - 15.1 MB - 1024 x 768 (1365 x 768 actual)
 Apple Universal - 15.1 MB - 1280 x 720 (1280 x 720 actual)

As with the Android presets, all the Apple conversions came out as .mp4 files using the H.264 video codec, with the frame rate and audio codec remaining unchanged. The iPhone, iPod Touch, Nano and Classic all outputted the same video file. However the iPhone 4 and iPad outputs varied in video dimensions whilst the file size was slightly larger than the older Apple devices. It looks like the iPhone and iPad presets are optimised for those individual devices (the 'Retina Display'?) whilst the Apple Universal setting seems more geared towards an Apple TV device with its 720 output.

The Other Settings

As above, here's a list of the video conversion presets for the non-Apple/non-Android outputs. Not all the presets were able to convert the original file and the audio and video codecs were sometimes converted to fit the platforms they were expected to work on

Other Devices and Formats
 Playstation Portable (PSP) - file could not be converted
 Theora - 31.7 MB - 960 x 540 - video codec: Theora - audio codec: Vorbis
 WebM (vp8) - 4.4 MB - 960 x 540 - video codec: V_VP8 - audio codec: Vorbis
 MP4 - 17.3 MB - 960 x 540 - video codec: AVC - audio codec: AAC
 MP3 (Audio only) - 1.47 MB

Screengrab of WebM conversion
These presets produced a mixed bag of results. The Theora preset produced the biggest file out of all the presets available and the video footage looked sharp. The opposite can be said for the WebM conversion which produced a blocky and pixelated image, but it did compress the file down to 4.4 MB - the smallest size on test. It was truly awful when dealing with any onscreen motion. The Playstation Portable preset simply refused to work with any video I've thrown at it to date.

Conclusion


It certainly seems that Miro Video Converter contains a number of presets that do much the same thing as others. This is most likely due to the diversity of users with different platforms looking to make video specifically for their device (as in the case of the Android and Apple settings). Given that the generic Android and Apple presets put out video at 480 x 320 it's fair to say that the smaller file sizes reduce the amount of visible detail available, but then they are nearly half the size. This is an expected trade-off in quality.

Miro Video Convertor is a free tool with a tidy interface. If you are looking for a quick and simple  drag-and-drop tool then it will more than likely meet your needs. Just don't expect much in the way of control over the conversions you run through it. For that, you'll want to use something like Handbrake

Monday, 28 March 2011

The basics of video editing

Over on Lifehacker, Adam Dachis has been putting together a batch of easy to follow introductory '101' sessions using non-linear video editing tools as part of their Night School series. These are aimed squarely at those people who have little to no knowledge of big software packages like Avid, Adobe Premiere and Final Cut Pro but would like to know more.  These are some of the packages we use at the University of Sunderland so these videos might help function as simple intros for any of our students out there.

I've embedded all the videos below for ease of use, and included links to the original posts in the title:

#1 - Getting to know your work environment



#2 - Creating a project from start to finish



#3 - Effects and colour correction



#4 - Preparing and encoding your video for delivery



#5 - Additional resources

No video for this segment, I'm afraid.  However, there are some useful things provided in this post, such as a .pdf of all the lesson notes, and some hand links.  Go ahead and click the links and watch the vids.