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

The problems with streaming HD video content

I recently participated in a study which looked at a number of different ways to stream HD encoded video. It was headed by Edgar Huang and the results of which were presented to the New Media Consortium summer conference in Princetown University a few days ago. You can find background details of the study, including the methodology, here.

The study seemed to be focussed around a series of tests which sought to compare and contrast a number of different video codecs dealing with the same footage and assess how well they streamed. It was thought that some of the codecs may find it a little difficult to strike the balance between full size 1280 x 720-pixel screen ratio data delivery whilst maintaining a decent image quality and whilst also maintaining a decent frame rate (30fps). What good is fantastic video quality if you need to wait around 5 minutes to watch a 1 minute clip? Similarly, constant buffering of data makes for a distinctly unpleasant viewing experience. Finding a happy balance is tricky

It was with those thoughts in mind that I'd thought I'd take part. I was a little skeptical as to the usefulness of my contribution given that I was sat at my iMac at work which seemed to fail the required 5MBps connection speed. This just happened to be during term time when the denizens of the student piracy party were clogging up the pipes with their BitTorrent traffic, meaning that my connection speed was a little compromised to say the least. I cannot really complain though - it is usually very speedy:

Can you see the speed of that baby? How can you tell the seeders/leechers have gone?

Another issue I feared was that my media player plugins would let me down. Perian and Flip4Mac were installed and managed to deal with most of the codecs but there was one which got in the way of the study in that it forced me to open VLC outside of the browser (Safari) in order to play it.

So, which codecs were tested?

• Adobe Flash HD
• Apple QuickTime HD
• DivX HD
• Microsoft Windows Media HD
• Vividas HD

At first I thought I knew exactly what the winner of this contest was going to be as I've played around with most of these codes whilst using Handbrake, the open source cross platform DVD to MPEG-4 converter. DivX is widely used but tends to produce artefacts in its SD incarnation. The Windows Media codec always seemed to suffer from a lack of consistent development. I figured that the QuickTime H.264/MPEG-AVC codec would be the winner due to its history and excellent results in Handbrake. I knew little about Vividas... As for Adobe HD, I suspected their 97% market share of the SD streaming world would give them an advantage, despite its relatively short life to date.

Personally, I favoured the QuickTime encode for vividness of colour and speed although there were some visible artifacts in fast moving sequences. The Adobe codec was more impressive in its ability to capture fine detail, although it did give the footage a washed out feel. It was very hard to decide which was better as they both had their negatives and positives. The Vividas codec caused me the VLC headache I mentioned earlier.

You can view Edgar's findings here. There are a number of interactive results tables allowing for a useful explorations of the results. In terms of image quality, it seemed most participants also favoured the QuickTime codec with Adobe coming a close second. Adobe came out ahead for initial start-up speed with QuickTime placed third. Other variables were also accounted for and Adobe ranked highest overall (by average) with QuickTime in second place. Unsurprisingly, the worst performer was Window Media HD, as Edgar points out:

Informed customers may make their decisions based on the fact that MSNBC, a Microsoft company, even uses Adobe Flash video, not Windows Media Video, to stream videos.

I was pretty shocked at the price difference though: $995 for the Adobe codec compared to $29.99 for QuickTime. I'm not so sure I'd be willing to stump up that kind of cash for marginal performance improvements.