No Audio on Chromecast with Allcast? [Protip]

If you pirate bootleg torrent borrow movies or every House of Cards episode in 1080p and beam it directly to your Chromecast-equipped TV using either your computer or directly from your Android phone using Allcast, you may have been dismayed once or twice to discover that while the video was fine you had no audio. Ouch.

The technical explanation, and sorry to be so verbose, is that your Chromecast doesn’t understand all the major audio codecs or whatever, something like that.

So when encountering this situation, instead of scrambling to download a dozen different copies of the same video hoping one will work while popping a fistfull of Xanax and downing it with a bottle of Maker’s you acquired before the Japanese bought the company, all you gotta do is download FFmpeg which literally runs on every platform (except probably Windows Phone) and convert the audio of the video (but not the video of the video) to the AAC codec — you with me?

So here’s what worked for me on a DOS-like command line:

C:stash> ffmpeg –i houseofcards-s02e13.mkv –vcodec copy -acodec aac –strict experimental –ab 640k houseofcards-s02e13.mkv

That was a 1080p 3.4GB file that I was able to transcode with zero perceptible audio loss in a relatively short period of time on my six year old computer, a 59 minute clip crunched in about 14 minutes. On my Nexus 5, not so fast, a 720p video I’m testing, about 1350 bitrate, is transcoding only 16 seconds per minute. Slow, but if I were stranded, good enough. Well, no, because it would, even if plugged in, be brutal on my battery’s longevity and CPU.

I imagine the same exact command would work on Linux and OS X. You may need to substitute “aac –strict experimental” with “libfaac” or maybe not. I don’t know if it will work but right now I’m trying a run with FFmpeg Media Encoder for Android. Here’s the official but less user-friendly source of the Android ffmpeg.

Or if I wanted to waste a lot of time I could simply git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg and compile FFmpeg on any platform that can compile something – maybe even Windows Phone (if you can transfer and execute programs and play movies on those things yet). Good luck finding a Windows Phone Chromecast app clone though.

FFmpeg is the most powerful media encoder/transcoder/demuxer/player/server/whatever in the world and could blow your head clean off if you’re not feeling lucky. It’s one of those godsend pieces of software, like VLC, that is free, open source and the best at what it does. This is just one specific use of many others that might interest you, so instead of bootlegging Adobe Media Encoder (which would not have worked for my House of Cards mkv season finale, I tried), just man up and use FFmpeg. Or use iTunes and an iTV to watch it legally, you girly-man.

House of Cards is really good by the way. Seriously. All this transcoding nonsense was just a pretext to recommend the show.

Doug Simmons