Ultra-condensed version: I’m videoblogging now. To watch the videos online, you just need Flash 9 or later. To watch the downloaded videos, Linux users should install MPlayer, Windows users should install FFDSHOW and Media Player Classic, and Mac users should upgrade to QuickTime 7.
I recently started posting videos on my blog (It’s the Dive Into Mark show!; You make bunny cry; Waiter, there’s a fly in my studio). The videos are closed captioned for the hearing impaired. Herein lie the gory details of how to watch the videos and display the captions.
Briefly, all videos are encoded in a particular format (called a codec). To play a video, you need software that understands the video codec. To hear the audio while the video is playing, you need software that understands the audio codec. The video and audio (and captions) are stored in a single file (called a container), so your software needs to understand the container format too.
My videos use an MPEG-4 container with H.264 video, AAC audio, and 3GPP timed text captions. Contrary to popular belief, these are not QuickTime-specific or Apple-proprietary formats. They are all international standards that QuickTime happens to support (with some limitations, see below). Other players also support these standards, so you have plenty of choices.
Some players support all of these codecs natively, without installing additional software. Other players assume you have already installed the codecs separately. Some players support the video and audio but not the embedded captions (in 3GPP timed text format), but they can load captions from a separate file instead. For these players, I also make the captions available in a separate file in SubRip (.srt) format. If you put a foo.mp4 video file and a foo.srt captions file in the same directory, these players are smart enough to automatically load the separate captions file and display the captions while you watch the video.
I publish two versions of each video, a small one and a large one. Even with the proper software, the large version requires a relatively fast computer (by today’s standards). In my tests, a 1.5 GHz laptop stutters enough to make the large video unwatchable, but a 2 GHz laptop plays it without a hiccup. Your mileage may vary.
Apple’s QuickTime 7 (Mac OS X, Windows) can play the videos. It includes the standalone QuickTime Player and a browser plug-in so you can watch the videos in your browser. However, due to what I consider a bug, it will only display the embedded captions if the video file has a .3gp extension. If you want to watch the videos with captions, you will need to download the video and change the file extension from .mp4 to .3gp. Please note that QuickTime requires an extraordinary amount of CPU power to display captions — much more than playing the same video without captions. There is nothing I can do about this except recommend that you download a better video player.
The videos require QuickTime 7 or later; earlier versions of QuickTime do not have the necessary codecs. Mac users can check their QuickTime version by going to System Preferences → QuickTime → “About QuickTime…”. Windows users can go to Start → Control Panel → QuickTime → “About QuickTime…”.
Apple’s “5th generation” video iPod can play the small version, but it will not display the captions. The small video is already in an iPod-compatible format; just download it, import it into iTunes, and sync it to your video iPod. Better yet, have iTunes download it for you by selecting Advanced → “Subscribe to podcast” and pasting the address of my syndicated feed.
Democracy Player is a Free Software video aggregator that lets you subscribe to video podcasts and automatically download videos. It can play the videos, but it will not display the embedded captions (bug 3422) and does not support auto-downloading a separate captions file (bug 3423). Select “Add channel…” and paste the address of my syndicated feed.
Totem (Linux) is the GNOME media player. Totem does not support any particular video or audio codecs; it relies on you having already installed the necessary codecs. To install the codecs under Ubuntu Dapper, download EasyUbuntu and select “Free Codecs” in the Multimedia tab. Totem requires a separate captions file to display the captions.
MPlayer (all platforms, but I would only recommend it on Linux) can play the videos without installing any additional software. It requires a separate captions file to display the captions.
Ubuntu Dapper users can install MPlayer by enabling the universe and multiverse repositories and selecting MPlayer from Synaptic Package Manager (or typing sudo apt-get install mplayer). If you want to watch videos within Firefox, install the mozilla-mplayer package.
MPlayerOSX (B8r5) is a port of MPlayer to Mac OS X. It can play the videos but doesn’t support the embedded captions and doesn’t support loading captions from a separate file. (This is almost certainly a bug in the GUI, since you can manually find and run the mplayer executable within the MPlayerOSX.app folder and it will auto-detect and display the separate captions file.)
VLC (all platforms) 0.8.5 or later can play the videos and the embedded captions, without downloading a separate captions file or installing any additional software. Captions are off by default; to display them, select Video → Subtitles → “Track 1 [english]“.
Ubuntu Dapper ships with an older version of VLC that distorts the picture in certain frames. Install the latest version of VLC. If the picture is still distorted, go to Settings → Preferences → Input / Codecs → Other codecs → FFmpeg, check the “Advanced options” checkbox in the lower right corner, set “Skip the loop filter for H.264 decoding” to “All”, and restart VLC. (This tip epitomizes everything that is wrong with Linux.)
Media Player Classic (Windows) is a Free Software video player. It does not support any particular video or audio codecs; it relies on you having already installed the necessary codecs. FFDSHOW will install the necessary codecs (the default install options are fine).
Media Player Classic can display the embedded captions, without a separate captions file. To display the embedded captions, go to View → Options → Playback → Output, set “DirectShow Video” to “VMR9 (renderless)”, and restart MPC.
The Core Media Player (Windows) is a WinAMP-like video player. It can play the videos once you install FFDSHOW. It requires a separate captions file to display the captions.
Microsoft’s Windows Media Player can play the videos once you install FFDSHOW, but it doesn’t support the embedded captions and doesn’t support loading captions from a separate file.
Kaffeine is a media player for KDE. It can play the videos once you install libxine-extracodecs. It claims to be able to display captions, but selecting a “subtitle channel” from the menu does nothing for me.
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