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    Categories: How To

How to Encode Video for a Podcast

It’s occurred to me that some of you may be interested in how to create your own high quality web video. I’ve already explained how I create a widescreen movie without an HD camera, but that article did not go into depth about exactly how I encode my video for internet delivery. Much of video encoding is considered a “black art” because different video genres require different levels of data, as well as the dizzying amount of options that most video codecs (or coder/decoders) have. Constant motion through a forest would require a higher rate of data per second than someone talking in front of a stationary background, for example. Creating web video doesn’t have to be difficult, though. Here’s a brief look at how a byteful video is dealt with after its edited.

The Platform: Blip.TV

In the early 21st century as I write this, there are a vast array of places available for content creators to upload their video. The most obvious choice would be YouTube because of its popularity. There is a Byteful Video account on YouTube, but while YouTube is strong in its community, its video quality and flexibility are inferior to many other services.

Byteful Video’s primary video distribution site is Blip.TV because it provides a wonderful and free way to publish and syndicate your own video podcast, what I refer to as a netshow. Blip.TV refers to itself as “blip”, so henceforth I will refer to it as such.

Blip’s strength lies in its flexibility. When a new video is uploaded, Blip automatically creates a Flash video version of the content which is the same format YouTube uses. Flash video is preferred because Flash video works on a wide range of computers. Blip also allows for a customizable show player, which is featured on the Byteful Video page, and even provides a sidebar widget. However, the most important feature is blip’s easy to use RSS syndication. As mentioned in The Importance of RSS, the video feed provides an easy way to be notified of new videos from Byteful Video, and if you add the RSS address to a podcast aggregator such as iTunes or Miro player, new videos will be automatically downloaded as they are released — the basis for the podcasting revolution.

Some of the internet’s best netshows use blip, including Wallstrip, and Mahalo Daily. Even one of my very favorite netshows Beachwalks.tv, who recently featured this site in an episode, uses blip to host its shows. And once again, I’d like to thank Beachwalks for their support. If you want to experience a bit of the Aloha Spirit, I suggest you check them out.

The Key Ingredient for Quality

To ensure quality in online video, the key is understanding how to properly compress the video. With the sheer complexity of most video codecs, there are plenty of technical settings to consider. Many people sidestep this complexity by using iMovie 6’s “Share” menu presets because the resulting video is actually quite good. However, to get the best quality per bit, there is an “expert” option as well. The main issue at hand, and the reason codecs were invented, is to balance a small file size with quality. Finding the sweet spot between a small file size and great quality takes time. Here is how a byteful video is exported: In Quicktime player or iMovie (both use the same encoder), export the movie as “Movie to MPEG-4”. This container is preferred because compatible over a wide range of devices. Then click the “options” button and set these settings:

Byteful Video Settings

– In the “Video” tab –

Video Format: h.264 (most efficient video codec for the web)
Data Rate: 1500 Kbps, Optimized for Download
Image size: 640×360 for widescreen, 640×480 for fullscreen
Frame rate: Current
Key frame: automatic (best to choose auto with h.264, it’s very smart)

• Click the Video options button and choose:

Encoding Mode: Best Quality (multi-pass) (which looks much better)
Restrict profiles to: Baseline (which makes it compatible with all iPods, as long as you’re using 1500kbps data rate and not much higher)

• Click “OK”

– In the “Audio” tab –

Audio Format: AAC-LC (music)
Data Rate: 128kbps (can be set it lower if there is no music)
Channels: Stereo
Output Sample Rate: 44.100khz
Encoding quality: Best

– In the “Streaming” tab –

• Check “Enable Streaming” and leave the numbers as they are (this allows your movie to download as it’s playing. this is also known as “hinting.” go figure.)

Encoding Takes Time

Click “Okay”, click “Save”, and go make a banana smoothie or something as this will probably take a while. On a 1.5ghz Powerbook, it takes about 4-5 hours to compress a 22 minute movie with these settings, so you’ll definitely want to experiment with a short clip of perhaps 10 seconds. However, make sure that clip contains a lot of variety so you can see how the settings affect different situations. If you want to have chapter markers in your video, you must use Apple’s Compressor program to preserve the chapter markers in the final file. Thanks to Steve and the other guys at Revision3 for their help in figuring this out.

Experiment for Yourself

I’ve reached these settings after much experimentation, and so far these are the best upload settings I’ve found. They work best for Byteful Video because they’re completely compatible with all video iPods, Apple TVs, devices that play MPEG-4 video, as well as all computers with Quicktime 7 installed; and more importantly, the settings are a great balance between a small file size and sharp high quality video. However, depending on how you want to use your video, these settings may not be the best choice for you. As I said before, finding the sweet spot between a small file size and great quality takes time. When you export, just make sure you experiment with only a short piece of your work. You can choose only a small portion of video in iMovie by checking “export selected clip only” when you go to “export” in the “share” menu.

Edit: If you decide to export H.264 video with Quicktime, you may find that your video becomes washed out. Read “How to Fix Washed-Out H.264 Video” for instructions on how to counteract this.

As always, experiment and learn.

Did this tutorial help you? How could I have improved it?
Leave a comment below and let me know.

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