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TICKET ARCHIVE -> Quicktime and Streaming (locally)
jbbevan - Jan 4, 2006 - 12:40 pm
I own an iMac G5, and iBook G4, and a Mac Mini -- all acquired over the past 15 mos. I have them all speaking to each other over an Airport network and I used the AirTunes feature liberally all over the house. That's background...
I have some video material(mp4)on an external HD connected to the G5. I have a projector connected to the Mac Mini. I would like to play the mp4 file "streamed" through Airport. This works for about 30 seconds then begins halting, yanking, jerking.
I can copy a 2 hour mp4 file over this network in less than 20 minutes so the problem should not be the data transfer rate. The problem does seem to be that Quicktime buffers Internet video but does not similarly buffer video being transferred locally.
There is no problem "seeing" the hard drive (as there was before Tiger). And, as I say, I can begin to watch the video.
Bottom Line: Is there a way to "stream" over Airport from a network hard drive that will work?
Oh, yes, and I have "fiddled" with the delay setting under QT Preferences which seems to affect the way it streams from the Internet but does nothing for the local issue.
Thanks,
Jim Bevan
I have some video material(mp4)on an external HD connected to the G5. I have a projector connected to the Mac Mini. I would like to play the mp4 file "streamed" through Airport. This works for about 30 seconds then begins halting, yanking, jerking.
I can copy a 2 hour mp4 file over this network in less than 20 minutes so the problem should not be the data transfer rate. The problem does seem to be that Quicktime buffers Internet video but does not similarly buffer video being transferred locally.
There is no problem "seeing" the hard drive (as there was before Tiger). And, as I say, I can begin to watch the video.
Bottom Line: Is there a way to "stream" over Airport from a network hard drive that will work?
Oh, yes, and I have "fiddled" with the delay setting under QT Preferences which seems to affect the way it streams from the Internet but does nothing for the local issue.
Thanks,
Jim Bevan
eddy264 - Jan 4, 2006 - 8:32 pm
I'm not sure if this is what you are looking for, but you can use the Darwin Streaming Server (http://developer.apple.com/darwin/projects/streaming/). This software allows you to have live streams, so it may be a little different from what you require, plus it takes a little bit of setup. This should, however, fix your problem.
Carl
Carl
jbbevan - Jan 5, 2006 - 1:33 pm
I checked out Darwin. It seems to be a solution that is more complicated than the problem. I'm not interested in streaming to the Internet; I only want to stream from a shared hard drive over an Airport network (all under one roof).
I've checked out the Apple support/discussions for Quicktime. Others have asked similar questions but none of those questions are getting answered.
It doesn't seem like it ought to be that difficult. Anyhow, I'm not facile enough "under the hood" to pursue Darwin.
Thanks,
Jim
I've checked out the Apple support/discussions for Quicktime. Others have asked similar questions but none of those questions are getting answered.
It doesn't seem like it ought to be that difficult. Anyhow, I'm not facile enough "under the hood" to pursue Darwin.
Thanks,
Jim
eddy264 - Jan 6, 2006 - 11:38 pm
I'm going to reopen your question, because I'm not sure exactly what the problem is.
Sorry,
Carl
Sorry,
Carl
jbbevan - Jan 7, 2006 - 1:05 am
The problem is that I'm not a good enough hacker to get the Darwin solution to work for me; it requires more knowledge than I have.
I want to play video material off of an Airport network hard drive and I want to do it as easily as playing audio over Airtunes.
I'm not sure how to make it clearer.
Thanks,
Jim
I want to play video material off of an Airport network hard drive and I want to do it as easily as playing audio over Airtunes.
I'm not sure how to make it clearer.
Thanks,
Jim
Drumhum - Jan 7, 2006 - 10:59 am
Jim,
I think I see your problem: you just want to "play" a movie thats stored on a disk on your wireless network. When you do this you find the playback stutters. The question is why?
just to confirm, have you tried playing this movie direct from your local drive on your mini - ie not from the network? make sure you test this via your projector. The reason I say this is that playing back a movie in full screen is harder for your computer than when its just in a small quicktime window. Your mini *should* be up to the job, but my G4 imac has had problems with some MP4 movies (H.264 codec is very processor demanding - my computer certainly struggles with high quality hi-def movies). Assuming all is well from your local drive, next, I would try connecting your external HD that stores your movie directly to your mini (I assume its firewire!). Its just to check the issue is not with your external HD - file transfer is different to streaming a movie so even if you find you can transfer a file quickly, it doesn't follow that movie playback is no problem! l just feel its important to rule out that the problem is not with your computer or hard disk, before we look to your network.
Thoughts re network...
Can you test with an ethernet, wired connection? You should be able to connect your mini to the "host computer" directly with an ethernet cross-over cable, if you don't have a router. If your movie doesn't stutter this way then at least you can conclude its associated with the wireless network. Its worth noting that ethernet is usually much much faster than wireless though.
as for wireless...
If you have just "airport" rather than "airport extreme" it is possible that its not really fast enough. Although airport is rated at 11Mb/s (thats 11 mega bits/second) the speed you actually get can be very much less and depends on how strong your received signal is and what else is going on with your network. Note that if you have Airport Extreme, if there is any device connected that is just Airport, then your "Extreme" speed will be reduced to airport speeds across the network. The first thing I would try is to disconnect/switch off all other network devices, including any internet connections. Make sure you are not running any other applications on either host computer or MacMini, that might access or try to access the network too (eg email software).
Also try the Mini located closer to the airport basestation to rule out wireless signal strength problems - if the signal is weak then your problem would be typical!
Its just worth bearing in mind that playing a high quality MP4 movie is not as easy for your computer as you might think. Coupled with the fact that the computer also has to sort out the networking side it could be that the demands are too much for your computer or the host computer for that matter. As lovely as the mini is, it is quite under-powered compared to other Macs. You don't mention what your host computer is. The amount of RAM you have will matter here too. Check that both host computer and your mini has enough. MacosX really needs more than 500MB to be properly happy. I typically advise folk to have 1GB or more for a new computer, these days!
I'll stop there for now. Have a think and a play and let me know how you get on. You are quite right in thinking this should be possible and there shouldn't be any need for fancy Darwin type software.
regards
Tom
I think I see your problem: you just want to "play" a movie thats stored on a disk on your wireless network. When you do this you find the playback stutters. The question is why?
just to confirm, have you tried playing this movie direct from your local drive on your mini - ie not from the network? make sure you test this via your projector. The reason I say this is that playing back a movie in full screen is harder for your computer than when its just in a small quicktime window. Your mini *should* be up to the job, but my G4 imac has had problems with some MP4 movies (H.264 codec is very processor demanding - my computer certainly struggles with high quality hi-def movies). Assuming all is well from your local drive, next, I would try connecting your external HD that stores your movie directly to your mini (I assume its firewire!). Its just to check the issue is not with your external HD - file transfer is different to streaming a movie so even if you find you can transfer a file quickly, it doesn't follow that movie playback is no problem! l just feel its important to rule out that the problem is not with your computer or hard disk, before we look to your network.
Thoughts re network...
Can you test with an ethernet, wired connection? You should be able to connect your mini to the "host computer" directly with an ethernet cross-over cable, if you don't have a router. If your movie doesn't stutter this way then at least you can conclude its associated with the wireless network. Its worth noting that ethernet is usually much much faster than wireless though.
as for wireless...
If you have just "airport" rather than "airport extreme" it is possible that its not really fast enough. Although airport is rated at 11Mb/s (thats 11 mega bits/second) the speed you actually get can be very much less and depends on how strong your received signal is and what else is going on with your network. Note that if you have Airport Extreme, if there is any device connected that is just Airport, then your "Extreme" speed will be reduced to airport speeds across the network. The first thing I would try is to disconnect/switch off all other network devices, including any internet connections. Make sure you are not running any other applications on either host computer or MacMini, that might access or try to access the network too (eg email software).
Also try the Mini located closer to the airport basestation to rule out wireless signal strength problems - if the signal is weak then your problem would be typical!
Its just worth bearing in mind that playing a high quality MP4 movie is not as easy for your computer as you might think. Coupled with the fact that the computer also has to sort out the networking side it could be that the demands are too much for your computer or the host computer for that matter. As lovely as the mini is, it is quite under-powered compared to other Macs. You don't mention what your host computer is. The amount of RAM you have will matter here too. Check that both host computer and your mini has enough. MacosX really needs more than 500MB to be properly happy. I typically advise folk to have 1GB or more for a new computer, these days!
I'll stop there for now. Have a think and a play and let me know how you get on. You are quite right in thinking this should be possible and there shouldn't be any need for fancy Darwin type software.
regards
Tom
jbbevan - Jan 7, 2006 - 12:11 pm
Thanks, Tom.
Yes, you understand what I'm trying to do.
To try to answer your queries:
The video will play from the Mini HD without a problem.
The External drive with the videos is connected to the Mini through Firewire 400. The video plays beautifully from the Ext HD through the Mini and projector. No problem.
The "other" machine is an iMac G5 that is about 15 mos. old.
The wireless network IS Airport Extreme.
My G5 is in a office where I also have a treadmill. I'm trying to play the video over the wireless network from my Mini (in a home theater room) to my G5 so I can watch while I "tread".
The real question in my head is why I can play even HDTV trailers off of the Internet (which is connected through Airport) with spectacular results, i.e. the system is downloading the H.264 and decoding on the fly (out of a buffer that is observable on the QT player as it happens). But pulling a video from that hard drive (which, to me, should be less of a challenge than playing an Internet stream) works for 30 seconds then yanks and jerks so badly that it won't proceed at all.
The problem seems to be that Quicktime does not "buffer" this when reading from the hard disk. If it would create the same kind of buffer that it does when playing an Internet stream, then I believe all would be well. So I guess I do need an Intranet streaming tool (as Carl suggested) but Darwin doesn't seem to be the answer.
Simplistically, I guess I believe that if I can play a "movie" (trailer) from the Apple site with Quicktime, I should be able to play similar material being dellivered through exactly the same "pipe".
PS: My original post elaborates on all my equipment and the "math" of the situation, i.e. a 2 hr. video transfers across the network in 20 minutes...thus it is delivering the information fast enough but the lack of buffer, I'm sure, is causing the problem.
Yes, you understand what I'm trying to do.
To try to answer your queries:
The video will play from the Mini HD without a problem.
The External drive with the videos is connected to the Mini through Firewire 400. The video plays beautifully from the Ext HD through the Mini and projector. No problem.
The "other" machine is an iMac G5 that is about 15 mos. old.
The wireless network IS Airport Extreme.
My G5 is in a office where I also have a treadmill. I'm trying to play the video over the wireless network from my Mini (in a home theater room) to my G5 so I can watch while I "tread".
The real question in my head is why I can play even HDTV trailers off of the Internet (which is connected through Airport) with spectacular results, i.e. the system is downloading the H.264 and decoding on the fly (out of a buffer that is observable on the QT player as it happens). But pulling a video from that hard drive (which, to me, should be less of a challenge than playing an Internet stream) works for 30 seconds then yanks and jerks so badly that it won't proceed at all.
The problem seems to be that Quicktime does not "buffer" this when reading from the hard disk. If it would create the same kind of buffer that it does when playing an Internet stream, then I believe all would be well. So I guess I do need an Intranet streaming tool (as Carl suggested) but Darwin doesn't seem to be the answer.
Simplistically, I guess I believe that if I can play a "movie" (trailer) from the Apple site with Quicktime, I should be able to play similar material being dellivered through exactly the same "pipe".
PS: My original post elaborates on all my equipment and the "math" of the situation, i.e. a 2 hr. video transfers across the network in 20 minutes...thus it is delivering the information fast enough but the lack of buffer, I'm sure, is causing the problem.
Drumhum - Jan 7, 2006 - 6:02 pm
Jim,
Most strange!
I got your set-up slightly wrong as I assumed you had the movie on your G5 imac and wanted to watch it via airport on your mini in your home theatre (can I have your house?). This means of course that my previous advice needs to be applied to your imac! Check to see if the movie file plays fine when on your imac HD and what its like from your firewire drive connected directly to your Imac. I suspect you've tried this (?)... I am just trying to establish exactly where the "bottle neck" is occuring. Something is slowing something down!
I've just tried playing a qt movie on a G5 imac from the drive of a G4 imac via an ethernet network and had no problems. The movie was not mp4/h.264 but a sorenson codec. It was a 2Mb/s stream though and I had no problems.
The buffering you see via the web is because the technology is implemented slightly differently. The buffering is to make up for the unpredictable nature of internet connections, which should not be a problem on a typical small home network and you are right to observe that the buffer preference settings of QT only relate to Internet use.
Just to be absolutely clear, you are accessing your mini's drive via your imac's Finder (eg clicking on the network icon in a finder window, locating the file on your mini's ext HD and just double clicking it to launch it in Quicktime player?
When the movie is playing (ie before it trips up) what is the data rate of the movie? You can find this by pressing apple key and "i" to get the movie info pane.
If this movie has a particularly high data rate, can you try a movie with a lower data rate to see if things improve? This will help establish if its an issue of network speed. Can you try a different movie of similar data rate but different codec (eg Mpeg1). I have seen some odd behaviour from H.264, especially using earlier versions of quicktime.
It is hard to diagnose these sort of issues without "being there". Sorry I can't just give you a quick fix. I do feel though that its not about buffering exactly. My guess is that it will either be down to:
1) an issue with your G5 set-up and how its playing movies
2) An issue with networking (make sure the network is free of other tasks - eg perhaps there's someone in the house using the net or your mac is checking email etc)
3) it's to do with the range of your wireless network - they can be fussy things wireless networks and it needs to be fast and solid for this application!
4) network software is slowing things down - do you have virus checking software, firewalls or anything else network related running on the imac or mini?
It would be worth trying the set-up via a wired connection (ethernet) to by-pass the airport, and see what happens
Have you tried reading the movie on your mini from your G5 (ie reverse the process)? Trying lots of different combinations can produce useful info into just what is going on!
Something isn't right. It should be possible to have a drive containing movies, music etc that can be accessed from any computer on the network, without having to transfer files first.
Again, sorry I can't provide a quick answer, I know these things can be a real frustration. If you are prepared to persevere we should be able to find some sort of answer!
Regards
Tom
Most strange!
I got your set-up slightly wrong as I assumed you had the movie on your G5 imac and wanted to watch it via airport on your mini in your home theatre (can I have your house?). This means of course that my previous advice needs to be applied to your imac! Check to see if the movie file plays fine when on your imac HD and what its like from your firewire drive connected directly to your Imac. I suspect you've tried this (?)... I am just trying to establish exactly where the "bottle neck" is occuring. Something is slowing something down!
I've just tried playing a qt movie on a G5 imac from the drive of a G4 imac via an ethernet network and had no problems. The movie was not mp4/h.264 but a sorenson codec. It was a 2Mb/s stream though and I had no problems.
The buffering you see via the web is because the technology is implemented slightly differently. The buffering is to make up for the unpredictable nature of internet connections, which should not be a problem on a typical small home network and you are right to observe that the buffer preference settings of QT only relate to Internet use.
Just to be absolutely clear, you are accessing your mini's drive via your imac's Finder (eg clicking on the network icon in a finder window, locating the file on your mini's ext HD and just double clicking it to launch it in Quicktime player?
When the movie is playing (ie before it trips up) what is the data rate of the movie? You can find this by pressing apple key and "i" to get the movie info pane.
If this movie has a particularly high data rate, can you try a movie with a lower data rate to see if things improve? This will help establish if its an issue of network speed. Can you try a different movie of similar data rate but different codec (eg Mpeg1). I have seen some odd behaviour from H.264, especially using earlier versions of quicktime.
It is hard to diagnose these sort of issues without "being there". Sorry I can't just give you a quick fix. I do feel though that its not about buffering exactly. My guess is that it will either be down to:
1) an issue with your G5 set-up and how its playing movies
2) An issue with networking (make sure the network is free of other tasks - eg perhaps there's someone in the house using the net or your mac is checking email etc)
3) it's to do with the range of your wireless network - they can be fussy things wireless networks and it needs to be fast and solid for this application!
4) network software is slowing things down - do you have virus checking software, firewalls or anything else network related running on the imac or mini?
It would be worth trying the set-up via a wired connection (ethernet) to by-pass the airport, and see what happens
Have you tried reading the movie on your mini from your G5 (ie reverse the process)? Trying lots of different combinations can produce useful info into just what is going on!
Something isn't right. It should be possible to have a drive containing movies, music etc that can be accessed from any computer on the network, without having to transfer files first.
Again, sorry I can't provide a quick answer, I know these things can be a real frustration. If you are prepared to persevere we should be able to find some sort of answer!
Regards
Tom
jbbevan - Jan 7, 2006 - 8:51 pm
You are being very patient with this. I appreciate it. Thank you.
First, yes I'm playing this through the Finder. I navigate the the external drive on the Mini, double click the QT file, and it comes up in QT on the iMacG5.
I tried a reverse process, based on your suggestion. I moved an mp4 file to the G5 and opened the file on the Mini through the Air Express network. Guess what? It played fine and filled my projected screen with no problem and no stutters. The data rate was 1920Kb/s.
I then moved that file to an external drive on the G5 and tried it again. Same result. No problem.
I then went back to the reverse situation. I tried to open a movie on the G5 where the file was resident on the home drive of the Mini. It stuttered in the first 10 seconds. I repeated the process on the External drive of the Mini....same result.
Right now I'm still experimenting and trying to make sure the Mini is not being tied up in some other way. Don't respond to this report. I'll report again after I try some more things. Certainly if it plays in one direction it should also play in the other, I would think.
There are no firewalls or virus checkers in the stream in either direction.
Oh, yes, and incidentally the movies that are resident on the Mini or its external drive play without a hitch on the Mini itself. I have had problems in the past with files being fragmented and exhibiting this same jerkiness. However, all of the video files on the Mini are frag free and play smoothly in that environment.
More later...
Thanks for the tips.
Regards,
Jim
PS: It is very difficult to hardwire these computers together because of their locations. I don't have an Ethernet router. So I'll leave that option until all others are exhausted.
First, yes I'm playing this through the Finder. I navigate the the external drive on the Mini, double click the QT file, and it comes up in QT on the iMacG5.
I tried a reverse process, based on your suggestion. I moved an mp4 file to the G5 and opened the file on the Mini through the Air Express network. Guess what? It played fine and filled my projected screen with no problem and no stutters. The data rate was 1920Kb/s.
I then moved that file to an external drive on the G5 and tried it again. Same result. No problem.
I then went back to the reverse situation. I tried to open a movie on the G5 where the file was resident on the home drive of the Mini. It stuttered in the first 10 seconds. I repeated the process on the External drive of the Mini....same result.
Right now I'm still experimenting and trying to make sure the Mini is not being tied up in some other way. Don't respond to this report. I'll report again after I try some more things. Certainly if it plays in one direction it should also play in the other, I would think.
There are no firewalls or virus checkers in the stream in either direction.
Oh, yes, and incidentally the movies that are resident on the Mini or its external drive play without a hitch on the Mini itself. I have had problems in the past with files being fragmented and exhibiting this same jerkiness. However, all of the video files on the Mini are frag free and play smoothly in that environment.
More later...
Thanks for the tips.
Regards,
Jim
PS: It is very difficult to hardwire these computers together because of their locations. I don't have an Ethernet router. So I'll leave that option until all others are exhausted.
jbbevan - Jan 9, 2006 - 9:19 am
OK, the weirdness goes on...
The Mini plays movies fine that are resident on the G5 or on its external hard drive.
However, the reverse is still not true. I thought I had found a clue when I discovered that, somehow, I had three different versions of QuickTime on the G5. I deleted all but the most recent 7.0.3. But this made no difference to the outcome. The G5 still won't play movies resident on the Mini or its external drive. I even tried playing movies with VLC and with MPEG Streamclip; it made no difference.
To add still another variable, not that we need it, I tried playing video on the 3rd Mac (the iBook G4). It plays video from its local drive. It plays video from the G5. It will not play a video from the Mac Mini. BUT the Mac Mini will also not play a video resident on the iBook.
Sooo...there is something about the G5 that is providing bits and bytes at a higher rate of speed...something like that...such that the G4's (whether Mac Mini or iBook) can play the feed without "running dry".
Under that scenario, all of the video material I have should be stored on the G5 or its external drive because its only from that location that the video can be played anywhere in the network.
I don't know what 64 bit upstream feeding 32 bit downstream has to do with it, but it seems to have some effect.
That's about all I know right now having tried about every permutation and combination of the three machines I can think of.
Response?
Thanks,
Jim
PS: I'm out of town until Friday night and will not have access to any of my Macs until then
-- such is life in MS dominated corporate America.
The Mini plays movies fine that are resident on the G5 or on its external hard drive.
However, the reverse is still not true. I thought I had found a clue when I discovered that, somehow, I had three different versions of QuickTime on the G5. I deleted all but the most recent 7.0.3. But this made no difference to the outcome. The G5 still won't play movies resident on the Mini or its external drive. I even tried playing movies with VLC and with MPEG Streamclip; it made no difference.
To add still another variable, not that we need it, I tried playing video on the 3rd Mac (the iBook G4). It plays video from its local drive. It plays video from the G5. It will not play a video from the Mac Mini. BUT the Mac Mini will also not play a video resident on the iBook.
Sooo...there is something about the G5 that is providing bits and bytes at a higher rate of speed...something like that...such that the G4's (whether Mac Mini or iBook) can play the feed without "running dry".
Under that scenario, all of the video material I have should be stored on the G5 or its external drive because its only from that location that the video can be played anywhere in the network.
I don't know what 64 bit upstream feeding 32 bit downstream has to do with it, but it seems to have some effect.
That's about all I know right now having tried about every permutation and combination of the three machines I can think of.
Response?
Thanks,
Jim
PS: I'm out of town until Friday night and will not have access to any of my Macs until then
-- such is life in MS dominated corporate America.
Drumhum - Jan 9, 2006 - 10:11 am
Jim,
Your G5 is undoubtedly equipped with the fastest hardisk and has the fastest processor. Its not surprising its the best performer at delivering 2Mb/s movie streams.
Sounds like there is a problem with the G5 though. Its disk is clearly fast enough. If its playing the average QT movie from say the Apple movie trailer site its worth noting that these movies are typically much less than 2Mb/s - more like 300k-ish and seem to max out at 1Mb/s.
have you done the usual house keeping on your G5? Repair permissions (via DiskUtility), zap the PRAM (start-up while holding down the alt, apple, "p" and "r" keys - hold down till you've heard 2 or three start-up chimes). I'd also suggest you run utility software such as "yasu", "onyx", "cocktail". A quick google will find these.
Also, how much RAM do you have in the G5? The stuttering you see can be produced easily by not having enough RAM.
Thing is, a movie in H.264 at 2Mb/s is pretty hard work for a computer to play. the codec is very demanding on a computer - probably the most demanding codec. Its a great codec because of the picture quality for the size of the file or bandwidth needed, but its not easy to decode and play these movies. I would expect my 1GHz G4 imac to trip up with H.264 with that sort of data rate. I'd expect a G5 imac to cope much better though.
I think we've worked out its not a network issue as such - probably more to do with computer processing resources. If you can make your computer work more efficiently you might see better results. quit any background tasks, any other running applications, reapir any OS issues. Of course finding where the issues are is a problem in itself!
I'll have a think over the next few days and try and come up with something else before you get back;-)
Tom
Your G5 is undoubtedly equipped with the fastest hardisk and has the fastest processor. Its not surprising its the best performer at delivering 2Mb/s movie streams.
Sounds like there is a problem with the G5 though. Its disk is clearly fast enough. If its playing the average QT movie from say the Apple movie trailer site its worth noting that these movies are typically much less than 2Mb/s - more like 300k-ish and seem to max out at 1Mb/s.
have you done the usual house keeping on your G5? Repair permissions (via DiskUtility), zap the PRAM (start-up while holding down the alt, apple, "p" and "r" keys - hold down till you've heard 2 or three start-up chimes). I'd also suggest you run utility software such as "yasu", "onyx", "cocktail". A quick google will find these.
Also, how much RAM do you have in the G5? The stuttering you see can be produced easily by not having enough RAM.
Thing is, a movie in H.264 at 2Mb/s is pretty hard work for a computer to play. the codec is very demanding on a computer - probably the most demanding codec. Its a great codec because of the picture quality for the size of the file or bandwidth needed, but its not easy to decode and play these movies. I would expect my 1GHz G4 imac to trip up with H.264 with that sort of data rate. I'd expect a G5 imac to cope much better though.
I think we've worked out its not a network issue as such - probably more to do with computer processing resources. If you can make your computer work more efficiently you might see better results. quit any background tasks, any other running applications, reapir any OS issues. Of course finding where the issues are is a problem in itself!
I'll have a think over the next few days and try and come up with something else before you get back;-)
Tom
jbbevan - Jan 19, 2006 - 12:55 pm
Well, they're asking for ratings and we're not exactly done yet, are we?
RAM: G5 has 512Mb; Mac Mini has 512Mb; iBook G4 has 728 (or is it 748)Mb.
Recently acquired Elgato EyeTV 500 for recording HD TV on a Mac. It works wonderfully, but the HD signal can only be processed on a dual processor PowerMac; BUT export of the feed to compressed formats works well. I've been exporting these programs to m4v files. I'm not sure what flavor of Mp4 that is, but they look pretty good. These files load directly into iTunes when they are complete (which I didn't know until this morning). I was loading up my iPod with an Audiobook and noticed these Video files sitting in the library. That library is on the hard disc of the Mac Mini. I was sitting at my iMac G5 and seeing these files across my Airport network. I clicked on one of them. It came up and played beautifully without any stutters.
I don't know if data rates are fundamentally different between mp4 and m4v or not. Lots of things have changed since we last corresponded: 10.4.4 is now running the boxes; iTunes was reved; Quicktime was reved; so I guess I need to go back and redo all the former experiments to see if the results change. Certainly this experience with iTunes is new since I was unable to play a video which was resident on the Mac Mini from the G5 before.
Question: does disc cache have anything to do with results in this sort of thing? I don't know what the comparative caches are between all the external hard drives involved.
Thanks,
Jim
RAM: G5 has 512Mb; Mac Mini has 512Mb; iBook G4 has 728 (or is it 748)Mb.
Recently acquired Elgato EyeTV 500 for recording HD TV on a Mac. It works wonderfully, but the HD signal can only be processed on a dual processor PowerMac; BUT export of the feed to compressed formats works well. I've been exporting these programs to m4v files. I'm not sure what flavor of Mp4 that is, but they look pretty good. These files load directly into iTunes when they are complete (which I didn't know until this morning). I was loading up my iPod with an Audiobook and noticed these Video files sitting in the library. That library is on the hard disc of the Mac Mini. I was sitting at my iMac G5 and seeing these files across my Airport network. I clicked on one of them. It came up and played beautifully without any stutters.
I don't know if data rates are fundamentally different between mp4 and m4v or not. Lots of things have changed since we last corresponded: 10.4.4 is now running the boxes; iTunes was reved; Quicktime was reved; so I guess I need to go back and redo all the former experiments to see if the results change. Certainly this experience with iTunes is new since I was unable to play a video which was resident on the Mac Mini from the G5 before.
Question: does disc cache have anything to do with results in this sort of thing? I don't know what the comparative caches are between all the external hard drives involved.
Thanks,
Jim
Drumhum - Jan 20, 2006 - 11:39 am
Jim,
Sorry if it looked like this subject had been closed - its an automatic feature that assumes the problem is solved after a few days of inactivity! I'll mention this to the site manager as I wasn't notified that you had added comments/questions! sorry for the delay in answering:-)
Any hoo...
M4v is just a bog standard MPeg4 (using the H.264 codec) really. Its just that it is specified to be perfect for ipod video use - ie it has a set resolution of 340x240 and a data rate that gives nice results on the ipod and acceptable results on a connected tv/comupter monitor. You'll note in quicktime pro that you can export to Mpeg4 as well as "movie for ipod" Though both are mpeg4, the "movie for ipod" is just a preset and no parameters (eg data rate) can be tweeked. Apple's just trying to keep things simple for the ipoders.
If you want to improve the quality then you'll need to increase data rate or resolution. Of course if you do this it will be more taxing for your computer/disk drives/network and you'll have a bigger movie file. The fact the m4v movies play well will be down to their relatively low requirement for processing power (they have to run on ipods!)
Itunes will play m4v's automatically as its an ipod thing but you should find that any quicktime movie will work via itunes (ie .mov, mpeg4, mpeg 1 etc). pretty handy way of working in your case I think as iTunes will also display media from other machines on a network. Note that if you drag a movie into itunes it will typically be copied to the itunes library like audio files are. I mention this as you could end up with duplicate movies which could eat up a lot of disk space!
If you find m4v only just "acceptable" try exporting the elgado files as mpeg4 with a higher data rate (i think ipods movies are about 700kbs so perhaps try about 1.4Mb/s or more). Also try increasing the resolution to 640x480. You may have to juggle the data rate vs resolution vs frame rate to find the best you can get that works.
Note you will get no benefit recording HD if your broadcast tv is standard def. HD is VERY demanding on computers! Your elgato thing records to Mpeg2 I think and that is a tricky codec to play back at the best of times! Mpeg2 at HD is even harder and at the data rates that would display HD properly I'd be surprised if a normal home network, like yours would cope. It would depend on the data rate of the encoding though.
Could be that all the up-dates you've done have "optimised" certain things that will provide better performance - certainly worth trying to see if things have improved.
Disk cache is important to how well a drive performs. Like everything, the higher the better. In your case however, I would expect the RPM speed of the disk is more crucial. Big disk caches prove useful when the drive has to access lots of different files quickly (say in video editing) - the cache gives the drive breathing time to find other files etc. To be honest it all merges as the "better" drives will have high RPM AND large disk caches. For video use it is normally advisable to use 7200RPM drives as a minimum. There are many factors that affect how a drive performs but it typically all comes down to "you get what you pay for". I use 7200rpm Lacie firewire 400 drives for video editing and I've not had any problems (yet!).
If you want to examine the performance of your drives have a look at Xbench...
http://www.xbench.com/
This will test the speed/performance of your drive (and other things). Could prove useful when you're trying to find what is causing slowdowns/bottle necks.
Hope all that helps. feel free to get back to me. If you find anything else new let me know.
regards
Tom
Sorry if it looked like this subject had been closed - its an automatic feature that assumes the problem is solved after a few days of inactivity! I'll mention this to the site manager as I wasn't notified that you had added comments/questions! sorry for the delay in answering:-)
Any hoo...
M4v is just a bog standard MPeg4 (using the H.264 codec) really. Its just that it is specified to be perfect for ipod video use - ie it has a set resolution of 340x240 and a data rate that gives nice results on the ipod and acceptable results on a connected tv/comupter monitor. You'll note in quicktime pro that you can export to Mpeg4 as well as "movie for ipod" Though both are mpeg4, the "movie for ipod" is just a preset and no parameters (eg data rate) can be tweeked. Apple's just trying to keep things simple for the ipoders.
If you want to improve the quality then you'll need to increase data rate or resolution. Of course if you do this it will be more taxing for your computer/disk drives/network and you'll have a bigger movie file. The fact the m4v movies play well will be down to their relatively low requirement for processing power (they have to run on ipods!)
Itunes will play m4v's automatically as its an ipod thing but you should find that any quicktime movie will work via itunes (ie .mov, mpeg4, mpeg 1 etc). pretty handy way of working in your case I think as iTunes will also display media from other machines on a network. Note that if you drag a movie into itunes it will typically be copied to the itunes library like audio files are. I mention this as you could end up with duplicate movies which could eat up a lot of disk space!
If you find m4v only just "acceptable" try exporting the elgado files as mpeg4 with a higher data rate (i think ipods movies are about 700kbs so perhaps try about 1.4Mb/s or more). Also try increasing the resolution to 640x480. You may have to juggle the data rate vs resolution vs frame rate to find the best you can get that works.
Note you will get no benefit recording HD if your broadcast tv is standard def. HD is VERY demanding on computers! Your elgato thing records to Mpeg2 I think and that is a tricky codec to play back at the best of times! Mpeg2 at HD is even harder and at the data rates that would display HD properly I'd be surprised if a normal home network, like yours would cope. It would depend on the data rate of the encoding though.
Could be that all the up-dates you've done have "optimised" certain things that will provide better performance - certainly worth trying to see if things have improved.
Disk cache is important to how well a drive performs. Like everything, the higher the better. In your case however, I would expect the RPM speed of the disk is more crucial. Big disk caches prove useful when the drive has to access lots of different files quickly (say in video editing) - the cache gives the drive breathing time to find other files etc. To be honest it all merges as the "better" drives will have high RPM AND large disk caches. For video use it is normally advisable to use 7200RPM drives as a minimum. There are many factors that affect how a drive performs but it typically all comes down to "you get what you pay for". I use 7200rpm Lacie firewire 400 drives for video editing and I've not had any problems (yet!).
If you want to examine the performance of your drives have a look at Xbench...
http://www.xbench.com/
This will test the speed/performance of your drive (and other things). Could prove useful when you're trying to find what is causing slowdowns/bottle necks.
Hope all that helps. feel free to get back to me. If you find anything else new let me know.
regards
Tom
Drumhum - Jan 22, 2006 - 9:23 am
please ignore this - I accidently placed the question back in the "open pool" - putting it back where it should be:-)
jbbevan - Jan 24, 2006 - 8:12 pm
Tom
I'm having a new issue that is clouding my ability to evaluate the original one. Ever since installing QT 7.0.4 my (mostly) mp4 and m4v files are losing synch. They start off with the lips perfectly synched and with 30 seconds they look like foreign language over dubs...nothing synchs. BUT if I pause and start again, everything takes off in synch again.
These are proven files that worked perfectly well on 7.0.3. AND they still stay synched just fine if I play them with VLC instead. However, QT Pro has the "Present Movie" feature which I like because I can project the file at less than full screen but still have the image surrounded by black. Any other player (including iTunes) leaves a less than full screen window in the middle of a desktop. That's probably no big deal when you're "computing" using a standard LCD display but with a projected image (as I am using right now)(an image that is 72" horizontal across the bottom) controlling the display window size against a black background (as only QT does) is very important.
Anyhow, any ideas about the synch issue? I tried downloading QT again, trashing the old version and reinstalling, but to no avail.
Thanks,
Jim
I'm having a new issue that is clouding my ability to evaluate the original one. Ever since installing QT 7.0.4 my (mostly) mp4 and m4v files are losing synch. They start off with the lips perfectly synched and with 30 seconds they look like foreign language over dubs...nothing synchs. BUT if I pause and start again, everything takes off in synch again.
These are proven files that worked perfectly well on 7.0.3. AND they still stay synched just fine if I play them with VLC instead. However, QT Pro has the "Present Movie" feature which I like because I can project the file at less than full screen but still have the image surrounded by black. Any other player (including iTunes) leaves a less than full screen window in the middle of a desktop. That's probably no big deal when you're "computing" using a standard LCD display but with a projected image (as I am using right now)(an image that is 72" horizontal across the bottom) controlling the display window size against a black background (as only QT does) is very important.
Anyhow, any ideas about the synch issue? I tried downloading QT again, trashing the old version and reinstalling, but to no avail.
Thanks,
Jim
Drumhum - Jan 25, 2006 - 11:06 am
Sync issues can be difficult to solve!
I recall a situation dating back to an earlier quicktime version where movies with sound tracks encoded at sample rates other than the standard 32kHz, 44.1KHz, 48kHz etc would go out of sync. Apple correctly pointed out that these movies did not comform to the QT spec. QT would play the audio at the standard rates and so the audio went out of sync.
Might be worth comparing the information shown when you press Apple key - "I" for "get movie info" in both QT and VLC and see if there are any discrepancies.
Of course it could be a bug in QT 7.0.4 too.
I really don't have a solution as such. I suggest you do the usual "repair permissions" in DiskUtility (always do this after installing software) and see if deleting QT preferences in you Home->Library->preferences folder helps at all.
Does this problem exist on your other computer?
Might be worth trying the movie under a different "user" on the same computer.
Its just trying to find out if its a problem with QT 7.0.4 per se or a problem with your particular set-up.
If 7.0.3 does what you need then perhaps going back to that version is your best bet. the latest version does not mean the best version!
I suspect the movies are pretty large but if you can put it up in some web space/ftp I'll have look and see if it does the same on my system. Or if you cut the movie down to a minute or two you could try emailing it to me at
thomas@spam.macosx.com
(remove the "spam." from that address).
Just for the record, as this correspondence is now getting rather long it is getting cumbersome if I need to place the question back into the "open pool". In the Open pool it is accessible to others that might have more direct experience of the issue. If you'd like this question accessible to other techs may I suggest you start a new query?
I am not discouraging you from getting back to me of course - Its just I have to accept there may be some other tech who knows better than me:-)
regards
tom
I recall a situation dating back to an earlier quicktime version where movies with sound tracks encoded at sample rates other than the standard 32kHz, 44.1KHz, 48kHz etc would go out of sync. Apple correctly pointed out that these movies did not comform to the QT spec. QT would play the audio at the standard rates and so the audio went out of sync.
Might be worth comparing the information shown when you press Apple key - "I" for "get movie info" in both QT and VLC and see if there are any discrepancies.
Of course it could be a bug in QT 7.0.4 too.
I really don't have a solution as such. I suggest you do the usual "repair permissions" in DiskUtility (always do this after installing software) and see if deleting QT preferences in you Home->Library->preferences folder helps at all.
Does this problem exist on your other computer?
Might be worth trying the movie under a different "user" on the same computer.
Its just trying to find out if its a problem with QT 7.0.4 per se or a problem with your particular set-up.
If 7.0.3 does what you need then perhaps going back to that version is your best bet. the latest version does not mean the best version!
I suspect the movies are pretty large but if you can put it up in some web space/ftp I'll have look and see if it does the same on my system. Or if you cut the movie down to a minute or two you could try emailing it to me at
thomas@spam.macosx.com
(remove the "spam." from that address).
Just for the record, as this correspondence is now getting rather long it is getting cumbersome if I need to place the question back into the "open pool". In the Open pool it is accessible to others that might have more direct experience of the issue. If you'd like this question accessible to other techs may I suggest you start a new query?
I am not discouraging you from getting back to me of course - Its just I have to accept there may be some other tech who knows better than me:-)
regards
tom
jbbevan - Jan 25, 2006 - 6:52 pm
Tom,
Thanks for your prompt reply, as usual. I did the Apple-I thing and couldn't see anything wrong, though I was't absolutely clear what I was looking for. I believe my files are all encoded "to spec" however, so I didn't have much confidence in that step to reveal anything tell tale.
However, I deleted QT Preferences per your instructions. I noticed that the file had been created 9/25/05 which is before I bought my Mac Mini. So it was a factory setting. After deleting that file I reopened an mp4 in QT which played perfectly even after 30 seconds (and beyond). Victory ! Thank you.
I guess I don't know HOW to properly update. The QT 7.0.4 came down on the system update the day after the Mac World keynote. I assumed Mac software update took care of all the tidying up. I guess not. But since there is not an Uninstall function, if I want to delete an application (QT or anything else), how can one know when it has been properly accomplished?
I agree this is getting a bit long. Perhaps we should close this entire chain and after I've tried some things I'll re-ask the question if necessary. My email is jbbevan@yahoo.com if you care to comment on the last question.
PS: Elgato offers a system called EyeHome which is meant to convey Mac video data to distant TV's (on a home network). I may buy and experiment with that. I'm interested to know if it does anything special to buffer the video flow to avoid the stuttering that this whole thread started with.
Thanks for your prompt reply, as usual. I did the Apple-I thing and couldn't see anything wrong, though I was't absolutely clear what I was looking for. I believe my files are all encoded "to spec" however, so I didn't have much confidence in that step to reveal anything tell tale.
However, I deleted QT Preferences per your instructions. I noticed that the file had been created 9/25/05 which is before I bought my Mac Mini. So it was a factory setting. After deleting that file I reopened an mp4 in QT which played perfectly even after 30 seconds (and beyond). Victory ! Thank you.
I guess I don't know HOW to properly update. The QT 7.0.4 came down on the system update the day after the Mac World keynote. I assumed Mac software update took care of all the tidying up. I guess not. But since there is not an Uninstall function, if I want to delete an application (QT or anything else), how can one know when it has been properly accomplished?
I agree this is getting a bit long. Perhaps we should close this entire chain and after I've tried some things I'll re-ask the question if necessary. My email is jbbevan@yahoo.com if you care to comment on the last question.
PS: Elgato offers a system called EyeHome which is meant to convey Mac video data to distant TV's (on a home network). I may buy and experiment with that. I'm interested to know if it does anything special to buffer the video flow to avoid the stuttering that this whole thread started with.
Drumhum - Jan 26, 2006 - 8:45 am
Jim,
Glad QT is working now. Deleting the preference file often works when software starts to "play up". I'm not sure exactly why, other than the Prefs file is regularly updated by the application (regardless of what that modified date says!) and it is vulnerable to corruption - which can mess things up! Its a potential fix for all software.
(as is repairing permissions - a task that should be done regularly)
You are updating software correctly. Your computer does, on the whole, manage its files perfectly well automatically. To uninstall an application its typically just a matter of dragging the application (and its folder if there is one) to the trash. There is usually a preference file to locate and trash too but that is typically all there is to it. You can/should do a finder search to make sure there is nothing left to be sure (eg "quicktime" in Spotlight should locate all relevant QT files). Macs don't tend to have lots of files hidden away like Windows.
That EyeHome thing looks pretty cool. I doubt there will be any "buffering" as such but you may find it works well like it did when you played the movies from your G5. I'm not sure exactly why you are having the streaming problems. The network connection speed should not be an issue, your hard disks should be fast enough and both computers should be fast enough to decode the movie data. This is looking at aspects individually though. How your computer assigns priorities to network tasks is a possible cause of problems. You have a basic network here that is not really designed for intensive tasks. In a professional environment where large files need transferring or high data rates will be used, then the network will have a "server". This is where a computer is assigned to do nothing else than be a central storage hub and manage the network. Apple have MacOS X Server to manage a server. The specifics of of doing this is a bit out of my experience but it might be worth investigating. You may also find using an old second hand powermac - but with fast hard disks, would do a better job at delivering your media over a network. Bear in mind the Mac Mini is more like a laptop in terms of internal design and is not perhaps the best solution as a speedy media hub.
Although your application is domestic, you are asking quite a lot from your network. There's good reason why networks distributing multi-media in a pro environment would use a more sophisticated set-up. Thats not to say you wont get things working, but you may find you need to tweak a bit - such is life, living on the cutting edge of technology!
I wish you luck with your multi-media home!
regards
Tom
Glad QT is working now. Deleting the preference file often works when software starts to "play up". I'm not sure exactly why, other than the Prefs file is regularly updated by the application (regardless of what that modified date says!) and it is vulnerable to corruption - which can mess things up! Its a potential fix for all software.
(as is repairing permissions - a task that should be done regularly)
You are updating software correctly. Your computer does, on the whole, manage its files perfectly well automatically. To uninstall an application its typically just a matter of dragging the application (and its folder if there is one) to the trash. There is usually a preference file to locate and trash too but that is typically all there is to it. You can/should do a finder search to make sure there is nothing left to be sure (eg "quicktime" in Spotlight should locate all relevant QT files). Macs don't tend to have lots of files hidden away like Windows.
That EyeHome thing looks pretty cool. I doubt there will be any "buffering" as such but you may find it works well like it did when you played the movies from your G5. I'm not sure exactly why you are having the streaming problems. The network connection speed should not be an issue, your hard disks should be fast enough and both computers should be fast enough to decode the movie data. This is looking at aspects individually though. How your computer assigns priorities to network tasks is a possible cause of problems. You have a basic network here that is not really designed for intensive tasks. In a professional environment where large files need transferring or high data rates will be used, then the network will have a "server". This is where a computer is assigned to do nothing else than be a central storage hub and manage the network. Apple have MacOS X Server to manage a server. The specifics of of doing this is a bit out of my experience but it might be worth investigating. You may also find using an old second hand powermac - but with fast hard disks, would do a better job at delivering your media over a network. Bear in mind the Mac Mini is more like a laptop in terms of internal design and is not perhaps the best solution as a speedy media hub.
Although your application is domestic, you are asking quite a lot from your network. There's good reason why networks distributing multi-media in a pro environment would use a more sophisticated set-up. Thats not to say you wont get things working, but you may find you need to tweak a bit - such is life, living on the cutting edge of technology!
I wish you luck with your multi-media home!
regards
Tom
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