Saturday, April 18, 2009

Mac Mini bitrate max for 1080p and DTS Pass Thru

The Mac Mini 1.83ghz and Plex (0.7.13) have trouble playing anything with a bit rate over 40mps. while it can handle small spikes into the 30s, it will soon drop frames as well as cause audio drop outs and sync issues when peaking in the 40s. So any Blu-ray with bitrates that climb over 40mps will need to be re-encoded with a cap on bitrate. Understand that there are many other factors that come into play when playing back video, biterate is just one of the many factors im focusing on.
(note: Plex 0.7.14 has introduced issues with playback of some blu-ray 1080p material.)

After working with AnyDVD HD and TSmuxer to get the full quality m2ts ripp, see if you can play it. If the movie has bitrates that don't climb over 30mps you may not need to re-encode. But if you have issue..

Capping the bitrate:
Handbrake is the app I use to encode video. The only problem with Handbrake is that there is currently no DTS pass Thru, although AC3 passthru works just fine. (update the next release of Handbrake will include DTS pass thru for MKV containers)
No worries, I have discovered my own DTS pass thru workaround that seems to work like a charm! See the DTS work around below.
Back to capping bit rate. In the advanced settings in Handbrake add the following to the h264 settings:
On the main video page select Average bitrate and set it between 14000 - 24000

While this is not a "fix all" for all sources, its works a lot of the time. My last option is to re-encoded with plain MPEG-4 (part 2) Under Video Codec: MPEG-4(ffmpeg) please note using this method will not allow my DTS passthru trick.

DTS Pass Thru work around:
You have already created your muxed m2ts file that contains the original video and audio.

1. Put the muxed m2ts back into TSMuxer. You should have two sources, the video and the audio. uncheck the video and "mux out the audio" saving with the name DTS Audio.m2ts.

2. Back to the original m2ts. Bring that file into Handbrake. What your doing here is re-encding the file without the audio. So go into the audio prefs and de-select any audio source. Set you encoding prefs and save as a MKV with the name Video.mkv

3. Open TSMuxer and add both Audio.m2ts and Video.mkv and mux them back together saving with the name of the movie. That it!

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