4 Replies Latest reply: Jan 3, 2010 5:55 AM by Jon Walker
cps26 Level 1 Level 1 (0 points)
Hi there,

I've recently purchased a Sanyo Xacti HD2000, and I've got a question about playing back the highest resolution (full HD, 1080p at 60 fps) in Quicktime - basically, it doesn't work! I've posted a video of this symptoms here: http://www.vimeo.com/7999031

From reading some other posts here and on Vimeo, some people seem to suggest that this is because the computer doesn't have sufficient power to deal with this resolution of video, and you would need a quad core processor to play it back. Is this right? It seems a bit surprising - the computer doesn't seem to struggle to play it (other than all the weird artifacts!) and the CPU doesn't max out when I attempt to play the video.

I've also (I think) been able to use MPEG Streamclip to export the video into a .mov file at 60fps, and this seems to play back ok (though I'm not clear whether it is in fact playing back at 60fps properly).

Does anyone have any insights into this? Better yet, does anyone have any solutions?! (Other than not shooting in 1080p60 I guess...!)

Thanks,

Chris

iMac 24" 2.66 Intel Core Duo, Mac OS X (10.5.8), 4 Gb RAM
  • Jon Walker Level 6 Level 6 (17,940 points)
    From reading some other posts here and on Vimeo, some people seem to suggest that this is because the computer doesn't have sufficient power to deal with this resolution of video, and you would need a quad core processor to play it back. Is this right? It seems a bit surprising - the computer doesn't seem to struggle to play it (other than all the weird artifacts!) and the CPU doesn't max out when I attempt to play the video.


    This is a distinct possibility. Apple recommends a 2.0 GHz Core Duo or faster for 1080p @ 24 fps and you may be trying to process about 2 and a half times as much information at 60 fps dependent on the movie's actual data rate. As to computer struggling or not struggling here, QT automatically drops frames during playback if it can't keep up. Check the "actual" frame rate in the inspector during playback to see if platform is failing to "keep up." If they are in the 24-30 fps range, then QT is struggling and dropping frames to reduce processor workload.

    I've also (I think) been able to use MPEG Streamclip to export the video into a .mov file at 60fps, and this seems to play back ok (though I'm not clear whether it is in fact playing back at 60fps properly).

    Did you just save the original data to an MOV file container or did you "export" the movie? ()I.e., the latter re-compresses the data which likely changed the movie characteristics and possibly making it more QT playback compatible.)

    Does anyone have any insights into this? Better yet, does anyone have any solutions?! (Other than not shooting in 1080p60 I guess...!)

    Options are likely limited to a) not shooting in 1080p, b) shooting at a lower frame rate, or c) re-compressing files to lower data/frame/resolution combination after shooting movie. Sounds as if none of these options are what you would want to do.




  • David M Brewer Level 6 Level 6 (9,270 points)
    Both iMove and Final Cut Pro comes with the Apple Intermediate Codec. If you have either of these editing programs export from Quicktime Pro using the Apple Intermediate Codec. Apple's Intermediate Codec has less of a demand on the cpu for playback compared to the rest of Quicktime codecs/formats.
  • cps26 Level 1 Level 1 (0 points)
    Thanks Jon and David - this is very helpful. I can see that Quicktime is indeed only playing back at 30fps or under when playing the original 1080p files.

    In terms of exporting the file - using Quicktime Pro I can export to a .mov file using AIC as the compression technique, and this solves the artifact problem so the video is watchable - the frame rate then varies between 30 and 39 fps, so I guess the computer is still somewhat underpowered and can't hit the full 60fps even for AIC.

    Is AIC the 'easiest' compression option (in terms of processor use on playback) for an export from Quicktime Pro, or is there any other option which would blow out the file size even more, but allow true 60fps playback?

    In any event, I think what this shows is that I should shoot mainly at 1080p30! The only think I would like to use 60fps is to get some kind of 'overcranking' effect to slow down footage of skiing etc, but since I don't need sound for this I can get it anyway by using QT to export 60fps footage to an image sequence and then reimporting the sequence at 30fps - this seems to work quite nicely (unless anyone knows of a slicker one step way of doing this?)

    Thanks for all the help - much appreciated!

    Chris
  • Jon Walker Level 6 Level 6 (17,940 points)
    Is AIC the 'easiest' compression option (in terms of processor use on playback) for an export from Quicktime Pro, or is there any other option which would blow out the file size even more, but allow true 60fps playback?


    The Apple Intermediate Codec (AIC), as the name implies, was specifically designed as an "intermediate" editing compression format for the HDV work flow and has, more recently, been adapted/adopted by Apple video editing applications as the target format for the editing of AVCHD camcorder content. If your end goal is the editing of your content, then AIC is an acceptable choice but remember, for general viewing, what you gain in playback speed is paid for in terms of file storage space. If your primary goal is the viewing of HD content at the highest source quality and smallest storage space, then use the camcorder (or a dedicated compatible player of the same media type) connected directly your HDTV for playback. If your primary goal is the viewing of content at acceptable levels of quality on a computer or the internet, then re-compress your content to playback specific format(s) using dimensions and data rates tailored to your specific end use.

    In any event, I think what this shows is that I should shoot mainly at 1080p30! The only think I would like to use 60fps is to get some kind of 'overcranking' effect to slow down footage of skiing etc, but since I don't need sound for this I can get it anyway by using QT to export 60fps footage to an image sequence and then reimporting the sequence at 30fps - this seems to work quite nicely (unless anyone knows of a slicker one step way of doing this?)


    QT Pro, many video editing applications, and some video players have the ability to create/display slow/fast or even "stop" action effects but may require more work to achieve the results you want. A dedicated third party application like the JES Deinterlacer (free) would allow you to quickly create fast or slow motion movie segments at will. iMovie '09's "by reference" editing work flow would allow you to create a movie that plays the content at regular speed and then create a replay of any particular segment in either slow or fast motion and then export/share the content to a specific end use playback format. It all depends on what you are trying to achieve.