Limitations of iRecord & AV/C Browser

Despite the fact that they work quite well, there are a number of limitations to both of the programs that we looked at from the standpoint of being used as a DVR:
  1. Lack of Guide Functionality - while iRecord is able to record on a schedule, neither iRecord or the AV/C Browser have any knowledge of what's actually airing in your area. For this, you'll have to turn to TV Guide online or TitanTV. There is potential for this sort of functionality to get integrated; however, that would fall on a developer to build up enough interest to do so.
  2. No Preview while Recording – You have to be pretty confident that what you're recording is what you want to be recording because neither of these programs offer a preview of what you're recording. You can view the transport stream as it is being recorded, and Patrick Edson also has a plugin for VLC that lets you watch what's on a channel without actually recording it.
  3. No 5C Encryption Support - Content that has 5C encryption enabled will not be playable, although it will appear to record fine. This will vary from one cable area to the next, but this type of content should primarily be premium channels (e.g. HBO HD). Although, we have seen situations where SD channels also appeared to have 5C encryption enabled.
Other limitations are ones that are surmountable. The data size issue can be worked with as you can always transcode the MPEG-2 transport stream to a smaller format, e.g. DivX. If you are familiar with AppleScript, you can actually build off of the FireWire SDK to add more functionality, which is how many of the initial Virtual D-VHS projects were done.

Performance on the Mac mini

Recording performance is absolutely a non-issue on the mini, since there's no decoding going on. Just simply write the MPEG-2 transport stream to your hard disk. Even when recording the highest bitrate HD streams, we didn't see CPU utilization go higher than 3% on our 1.25GHz Mac mini.

The problem, however, is that we haven't been able to find any applications that offer hardware accelerated MPEG-2 transport stream playback. It seems that the best application for playing back these transport streams natively is VLC (also available for the PC), which doesn't have any sort of hardware decode acceleration support. The end result is that anything above a 13Mbps stream ends up dropping frames on the 1.25GHz Mac mini, meaning that basically all HD streams are unplayable on the mini even though they record fine. The only solution here is to transcode the transport stream to something playable (e.g. DivX) before using your mini as a playback device, which is obviously a lot more work. Another option is to use only the mini as a capture device, and send the transport stream to a fileserver elsewhere in your house for playback or transcoding. The ideal solution would be to have a player that properly took advantage of the hardware, as the 1.25GHz G4 should be enough to playback the MPEG-2 transport stream. Currently, such a solution doesn’t exist for OS X.

Regardless, as impressive as the development support has been around DVR enablement on the mini (and OS X in general), it's still far from complete and far from polished.

The Mac mini as a DVR The Mac mini as a DVD Player
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  • Stokestack - Monday, July 21, 2008 - link

    You picked one of the worst possible DVD sets to use for comparison. These discs are NOT from film. They are clearly crap-quality encodes from lame, interlaced VIDEOTAPE sources.

    You don't even have to freeze the images to see that.
    Reply
  • p0wermac - Wednesday, June 18, 2008 - link

    http://www.ammesset.com/downloads/firerecord/FireR...">http://www.ammesset.com/downloads/firerecord/FireR...

    download that and the newest FireWire SDK's from developer.apple.com

    ~p0wermac

    Reply
  • Squidlet - Sunday, January 15, 2006 - link

    After building my Media Center and showing it installed with all of it's Demo
    applications. Most people I have show it to where blown away by this version 1.01 application.

    GenieCommands is a unique programmable software application
    that allows you to control all your applications and media via simple
    menus, in a theatre or lounge room environment. The Media Center
    is a computer like the Mac Mini combined with the Geniecommands software that
    provides an all-in-one entertainment system for your entire family.

    While attached to your television screen it allows you to enjoy your
    favorite entertainment such as; watch DVDs, record TV or pause TV,
    listen to music, share your digital photos, access the internet and more

    We have provided a complete set of demo menus to get you started,
    with links on where to download additional software. These menus
    can then be edited to suit your lifestyle or create a new one.

    GenieCommands provides a kiosk push button environment
    where users can get easier access to the best of what the industry has
    to offer in software. This is achieved through simple user defined
    graphic menus, to access all the scripts and to control almost any
    application.

    www.Geniecommands.com
    Reply
  • Squidlet - Sunday, January 15, 2006 - link

    After buiding my Media Center and showing it installed with all of it's Demo
    appliactions. Most people I have shopw it to where blown away by this version 1.01 appliaction.

    GenieCommands is a unique programmable software application
    that allows you to control all your applications and media via simple
    menus, in a theatre or lounge room environment. The Media Center
    is a computer like the Mac Mini combined with the Geniecommands software that
    provides an all-in-one entertainment system for your entire family.

    While attached to your television screen it allows you to enjoy your
    favorite entertainment such as; watch DVDs, record TV or pause TV,
    listen to music, share your digital photos, access the internet and more

    We have provided a complete set of demo menus to get you started,
    with links on where to download additional software. These menus
    can then be edited to suit your lifestyle or create a new one.

    GenieCommands provides a kiosk push button environment
    where users can get easier access to the best of what the industry has
    to offer in software. This is achieved through simple user defined
    graphic menus, to access all the scripts and to control almost any
    application.

    www.Geniecommands.com
    Reply
  • MrCoyote - Friday, March 25, 2005 - link

    INTERLACING...That's what you see in those DVD pictures. It's no specific problem to that box. It is occuring, because the software is not de-interlacing the video. It happens on PC's too. Hook the box up to a standard interlaced TV, and the "problem" will go away. Reply
  • fitten - Friday, February 18, 2005 - link

    #11, the Mac was not the original all-in-one. There were *many* machines from the late 70s and early 80s that beat it. Commodore64, Apple ][c, Atari XE, heck, even the TRS80s. Reply
  • michael2k - Thursday, February 17, 2005 - link

    "it's similar to how apple disable's the dual display screen spanning on a perfectly capable radeon 9200 to segment the iBooks from the Powerbooks. there's no good functional reason to not have this sort of stuff enabled."

    Well, I can think of two functional reasons not to have this stuff enabled:

    1) No need to test this feature before distribution
    2) No need to support this feature in the field

    Those two aspects of manufacturing and tech support probably saves Apple some money :)

    By extension, that also saves consumers some money too.
    Reply
  • Childs - Thursday, February 17, 2005 - link

    H.264 will probably be the next preferred codec for htpc on the Mac. I've been meaning to test it out on my Mini, but haven't had the time.
    Reply
  • triadone - Wednesday, February 16, 2005 - link

    a liked the review. i'm unclear as to whether a TV or monitor was used for the DVD playback. if a TV would resolve the interlacing issues it would be nice to know. most ppl interested in using it as a HTMac probably wouldn't want it hooked up to their monitor, but their TV for playback.

    it is good that Anand is pointing out the limitations of OS X's hardware handling of video. it's similar to how apple disable's the dual display screen spanning on a perfectly capable radeon 9200 to segment the iBooks from the Powerbooks. there's no good functional reason to not have this sort of stuff enabled. i hope that apple is ready to take on their effort to expand their marketshare with the mini. i.e.-a traditionally PC-oriented site like Anandtech starts covering Mac products and giving them some recognition as well as constructive feedback...let's hope they listen instead of just doing their own thing. they'll have to learn how to "think different" and integrate the feedback from reviewers to better their product. it will be interesting if apple will be as responsive to their product reviews in similar fashion to how video and motherboard vendors are. i.e.-poor review = swift delivery of new firmware or drivers. i hope that apple can do this as i feel it will have everything to do with bettering the already solid product that the mini is.

    btw, USB 2.0 isn't a good option for Mac as of yet, unless u r a powermac user. specifically i'm referring to el gato's eyetv USB 2.0 product. it requires a baseline dual G4 system to handle the USB processor overhead along with on the fly video compression. not cool for my 1.2Ghz iBook. =(

    like others i would have liked to see divx/mpeg-4 evaluations. i use mpeg-4 and divx streamed wirelessly from my 250GB PC drive to my ibook without issue. simply due to the HD limitation, one would think that the primary function of the HTMac would be to act as a front end for media stored on the network, or at least that's how i use my iBook around the house. :)
    Reply
  • jsbhburg - Wednesday, February 16, 2005 - link

    The combination of the new 10.3.8 OS update, the QuickTime MPEG2 Playback Component and the EyeTV 1.7 software has tested out great on an eMac G4 1.25 GHz with the same 9200 Radeon video card. No dropped frames on 720p and very little, if any, on 1080i.

    Try out EyeTV 1.7 from elgato. It is dramatically better than VLC.

    Joe
    Reply

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