Mac mini HDTV playback thread

[madpoet]

I admit I don't have one, but I'm interested ;). There's a lot of conflicting reports about whether it can or can't play back HD streams, and how people get them to play. Can we get some consolidated info? If you've managed to get your mini to play back 720p or 1080i/1080p streams, how did you do it? If you've tried and it didn't work, what did you try? What software did you use? How are you connected to your display (firewire, component, DVI, etc)? I just want to get to the bottom of the HDTV playback mystery ;)

Thanks,
MP

[edesilva]

I've got a 1.4 GHz/1 GB mM connected to a Panny plasma via DVI. The mM played some .avi feeds fine fwithout any apparent dropped frames using both VLC and QT (after DLing the 3ivx plug in from www.3ivx.com (http://www.3ivx.com)). Did not fare so well with respect to the 1080i .ts files--dropped frames and some combing during motion, although I gather the latter may be curable by tweaking the VLC settings.

The 720p files were from: www.divx.com/hd (http://www.divx.com/hd)

The 1080i files were from: www.dvico.com/hdtv/download.asp (http://www.dvico.com/hdtv/download.asp)

[anthonymoody]

I too had success with 720p as described above with my mini (1.42/512) and also had dropped frames with 1080i. However, it has been posted elsewhere that you can convert the .ts into a different format and import it into iMovie where it will play fine. However, doing so seems to increase the (already large) file size about 3x.

TM

[HD2005MM]

1) Is there a fix for the dropped frame issue at 1080i?
2) What are the settings for VLC to address the combing issue?

I'd be wary of using a plasma as a computer display due to burn-in issues.

[HD2005MM]

anthonymoody...do you happen to know the tools to convert the .ts file and how to do it?

[edesilva]

I think the poster in the other thread said he dropped a .ts file into iMovie to do the conversion--he also indicated that it took 70 minutes to do a 17 min. clip...

I was told in the other thread that the combing might be eliminated if it set VLC to ignore interlacing.

[amanpatel]

Originally posted by HD2005MM
1) Is there a fix for the dropped frame issue at 1080i?
2) What are the settings for VLC to address the combing issue?

I think that other than a faster CPU the only 'fix' for dropped frames is for Apple to open the API's that would allow third party programs to use the video card for decoding. However, I don't know if any video cards have anything other than MPEG-2 decoding built-in.

For VLC, I use the Bob deinterlacing method. Of course, this will require an even faster CPU to get it all done. I think a Bob & Force Weave setting is preferred by many, but VLC doesn't seem to offer it, unless that is the same thing as the Bob setting.

-Aman

[bdraw]

I was able to play 1080i on the 1.2 mini at the store, by converting to mpeg first and then importing into iMovie HD. The playback was perfect. It did seem to take some time to import. I ordered one after that. I don't know enough about Mac's to figure out a way to get the Mini to play the ts file directly.

[xmltok]

When you imported the MPEG into iMovie HD it converted the video to the Apple Intermediate Codec. As was referred to above, I have done some experimenting with this. The file sizes are a several degrees larger and do indeed playback smoother. This is because AIC is composed entirely of I-frames and is not heavily compressed.

After watching the DivX sample HD videos I also experimented converting my transport streams to DivX. Unfortunately, what you do not see on the DivX videos is what happens to film noise when compressed with the codec. It chunks up badly in all OTA streams I have tried even at very high bitrates.

Right now I believe our best hope is that Apple opens the hardware MPEG2 decoding on our video cards and that this can also be used to decode H.264. I have also tested x264, the VideoLAN opensource codec. I will refrain from reviewing its performance since it is in such an early stage of development, but it leads me to expect high CPU requirements from H.264.

[Further]

Well, first of all, I'm doing this on a G5, not a mini, and secondly, I don't have an HDTV (I'm using an Apple Cinema display). I downloaded a sample from the site referenced above (1080i samples). Why do all the samples have a .tp extension while you guys refer to .ts? Well, IAC, I also downloaded the new ffmpeg X, installed the other files it requested and opened the (renamed) hdtv_demo file I had downloaded.

OK, this is not a mini, but the file was converted (to avi dixv, IIRC) in about 1 minute and instead of being larger, it was smaller. The original was 71MB, the converted was 27MB. The new ffmpeg offered to play the original (which it did successfully) and then played the converted. As I don't have an hdtv, there was not much difference I could see.

The only problem was no sound, however, there may have been a setting I missed as I charged ahead without reading the docs;)

[Joseph S]

MyHD records .tp files, HiPix and others record .ts. Virtual DVHS records .mts. EyeTV records .mpg....


At least we can assign this stuff to VLC and not worry why they can't all just figure out an extension to settle on. :D

[Further]

Correct. I opened the original in VLC and it actually played better than in ffmpeg X (although still no sound).

[jsb_hburg]

Originally posted by Further
(snip)

The only problem was no sound, however, there may have been a setting I missed as I charged ahead without reading the docs;)

I ran into the same thing but got distracted playing with my daughter's new toy, the iPod shuffle.

I recall reading the other day on the divx doctor site about the repairing the sound issue. I will try again this evening.

[pale]

Joe,
Any luck with the sound issue? I got a Mini this weekend and have been playing with iMovieHD to create some intros for the HT.

However when I try to "Share" them and then convert them to an MPEG-TS with FFmpegX I get great video for 720p but no audio. I have tried everything Passthrough, MP2, MP3 no luck at all. I get the two files, .mpv and .mp2 but the .mp2 is a zero byte file.

I know this is a little off topic but I can not find anything out there on the FFmpegX forums about it at all.

As for 1080i playback on the Mini I have seen some real chop and drop when trying to play 1080i with only 512Meg. I also noticed that when connected to a ADC 23" Apple Cinema Display there are "noise" problems at 1920X1200. :) Yes I know why use the Mini to drive that screen, because I had the screen on my PC and always wanted to see a MAC logo on it.

Thanks

[WiFi-Spy]

solution!

go buy a messed up JVC 30K DVHS recoder from Ebay (most likley wont play tapes correctly)

the just play your Transport streams in Virtual DVHS (with Macmini hooked to the JVC via firewire)

the Jvc has a Hardware Mpeg2 decoder, HDTV component outputs and Optical audio

:)

[tartan_guru]

Still only at an alpha stage (requires compiling), but someone has managed to reverse engineer the Apple hardware acceleration API. Not tried it myself but others are reporting major decreases in processor loading:-

defyne.org/dvb/accellent.html

From the developers forum:-

"Rough timings from my initial tests with 720p on one 1.25GHz G4 CPU are:
MPlayer OS X 2 b6: 75% CPU
iTele v0.5.8b1: 47% CPU
Accellent v0.1: 25% CPU"

If these are true then things look promising (just hope that Panther doesn't break this)