2012-01-21, 02:17
I have 2 jailbroken AppleTV2's and both of them have a slightly annoying issue.
I record a LOT of programming from a MythTV Box that I transcode using handbrake before putting the files on my fileserver (h264 video, ac3 audio). For motion-picture style content (shot at 24fps) that I've inverse telecined back to 23.976 fps; this content plays perfectly on both AppleTVs. However, anything that I've recorded from video-based sources (shot at 60i) that I've had to deinterlace down to 29.97fps exhibits an uneven judder. This is not the same as the regular loss of temporal-resolution (60Hz > 30Hz) that is quite normal when using any field-combination deinterlacer, but rather an additional uneven judder that is quite noticable. It occurs every 12-15 seconds or so.
(I can't wait until Handbrake implements a proper field-extention 60Hz deinterlacer. Note to Handbrake devs: ATSC/NTSC video is not 29.97 frames/sec, it is a mistake to even think in terms of frames. It is 59.94 FIELDS per second; the two fields of each frame are often stored together in digital media for simplicity but they have no-relation to each other. Treating them overwise by using any kind of clever blending/interpolation is completely wrong and destroys the temporal resolution/smoothness of ATSC/NTSC video. Fields need to be treated as completely independant snapshots in time (60Hz); which they are. But I digress.)
Both AppleTV's are connected via Cat6 to a Gigabit Ethernet router to my file server; Ubuntu Linux 64-bit using NFS protocol.
No matter what I do, I cannot get 29.97fps programming to run at an even framerate; the judder is always there. I've tried the various suggestions here such as turning on 16-bit audio, fiddling with almost every combination of syncing framerate to video, audio (resample), audio (drop/dupe), nothing works.
I transcode everything to 720p (1280x720) resolution files in mp4 containers. As I mentioned earlier, I have NO problems with film-sourced material at 23.976 fps, this just happens on deinterlaced 29.97fps sources.
One of the AppleTVs is running on 4.1.1 and the other on 4.3. One of the AppleTV's is running XBMC nightly from Sept 16th (the 4.3 one) and the other is Pre-Eden Beta 1. Is there something else I'm doing wrong?
I record a LOT of programming from a MythTV Box that I transcode using handbrake before putting the files on my fileserver (h264 video, ac3 audio). For motion-picture style content (shot at 24fps) that I've inverse telecined back to 23.976 fps; this content plays perfectly on both AppleTVs. However, anything that I've recorded from video-based sources (shot at 60i) that I've had to deinterlace down to 29.97fps exhibits an uneven judder. This is not the same as the regular loss of temporal-resolution (60Hz > 30Hz) that is quite normal when using any field-combination deinterlacer, but rather an additional uneven judder that is quite noticable. It occurs every 12-15 seconds or so.
(I can't wait until Handbrake implements a proper field-extention 60Hz deinterlacer. Note to Handbrake devs: ATSC/NTSC video is not 29.97 frames/sec, it is a mistake to even think in terms of frames. It is 59.94 FIELDS per second; the two fields of each frame are often stored together in digital media for simplicity but they have no-relation to each other. Treating them overwise by using any kind of clever blending/interpolation is completely wrong and destroys the temporal resolution/smoothness of ATSC/NTSC video. Fields need to be treated as completely independant snapshots in time (60Hz); which they are. But I digress.)
Both AppleTV's are connected via Cat6 to a Gigabit Ethernet router to my file server; Ubuntu Linux 64-bit using NFS protocol.
No matter what I do, I cannot get 29.97fps programming to run at an even framerate; the judder is always there. I've tried the various suggestions here such as turning on 16-bit audio, fiddling with almost every combination of syncing framerate to video, audio (resample), audio (drop/dupe), nothing works.
I transcode everything to 720p (1280x720) resolution files in mp4 containers. As I mentioned earlier, I have NO problems with film-sourced material at 23.976 fps, this just happens on deinterlaced 29.97fps sources.
One of the AppleTVs is running on 4.1.1 and the other on 4.3. One of the AppleTV's is running XBMC nightly from Sept 16th (the 4.3 one) and the other is Pre-Eden Beta 1. Is there something else I'm doing wrong?
