Converting HD video for TiVoGoBack on a Mac

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Converting HD video for TiVoGoBack on a Mac

If you have a TiVoHD or Series 3 TiVo and a Mac, you've probably read tutorials like this about enabling the hidden TiVoGoBack feature on a Mac (last October's update to HD TiVos added the long-awaited feature). If you've tried it yourself, you've probably noticed that VisualHub's default TiVo mpeg profile converts everything to standard def output.

It's a great automatic feature, but it can be a drag if you're converting HD versions of shows and movies. You lose the full use of your widescreen TV because the standard def conversion adds black bars to the sides of output as well as black bars top and bottom within that area to display video at the proper aspect ratio. Zooming in on the video will exaggerate artifacts and show a fairly poor looking picture.

When the feature was first added, I spent a couple days experimenting and researching ways to use the full screen but couldn't find the right combination of settings. Thankfully, someone did finally figure it out. This guide to downloaded video playback on a HD TiVo covers the exact steps required for proper full use of the screen.

The pertinent settings are:

Select the mpeg tab in VisualHub
DON'T select the TiVo Profile
Hit the Advanced button
set the Video bitrate to 17000
Add -maxrate 17M -bufsize 1024k to the Video ffmpeg extra flags field
Click to enable Two-pass conversion

If you're crunching down 720p or 1080p video, it will take quite a while (especially being a two-pass process) but the results are worth it. Normal 1.85 aspect ratio movies and shows playback using the entire screen and 2.35 ratio movies work as well. My tests with 1.85 720p samples yielded good results (screenshot above of a LOST episode) and converted video was 1280x720 in size. 2.35 widescreen movies looked just as good with final output at 1280x544.

If you've got a HD TiVo and a Mac, and were considering buying an Apple TV to playback downloaded content, you might want to consider this approach and save yourself the money and added hardware. Note, for those on a PC wanting to do similar things, this guide at lifehacker covers the basics but not the full-aspect ratio HD conversion details (thanks for the tips, Phil!).

by Matt Haughey February 26, 2008 in TiVo

Comments

Thanks Matt! The video looks great. Is there any way to keep the 5.1 audio though? Visualhub seems to want to convert everything to stereo. I've tried using -acodec copy but the audio is extremely choppy.

Posted by: Chris at Feb 27, 2008 9:58:38 AM

Thanks for the summary. I had also discovered the aldoblog article. I have the same question as Chris: how do I pass 5.1 audio all the way from the DVD to my TivoHD? BTW, in my single test using VisualHub to directly transcode the VIDEO_TS folder (selects largest VOB), I got nonsense results. So I'm ripping to mp4 with Handbrake and then using VisualHub to produce .mpg for Tivo Desktop.

Posted by: John at Apr 19, 2008 4:25:51 PM

Help!

When I try to do this, I don't see the option in the drop down menu for the -maxrate 17m etc...

Any ideas why that is, or if I'm doing something wrong?

Posted by: Rob at May 10, 2008 3:03:08 PM