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Silverlight 3 MediaElement - Mac Progressive Download problem with playing full movies

    Question

  • I am developing a video asset manager for clips and full movies using Silverlight 3. It plays many different flavors of clips and everything works fine on the PC. This problem is strictly a problem when on a Mac using Leopard and/or Snow Leopard with current updates. It has been a problem on several types of Mac machines, from a beast of a Mac Pro, to a standard Mac Mini, to a MacBook Pro that is relatively new. I tested with Safari 4 and Firefox 3. Both had the issue. We have an issue using progressive download for full movies, yet shorter clips of 10 minutes or less are fine. This is only with a Mac; there are no problems at all on the PC. The details on the file we are currently using to test with are at the end of this entry. The problem is: when the movie is played, it plays fine. It starts downloading, but once it hits a certain point (roughly 80% to 98.8%) the downloading stops and the player will no longer play or do anything. The silverlight app is not frozen on a fast machine though and I can navigate to other screens within the app and go back to the player, but the same problem still exists. We were streaming it from a server in that was not local, then tried streaming on a local network machine (which was much faster to test) but still had the problem. I did notice that the % that is loaded before the player freezes is pretty constant for each instance of browser used; i.e. if I open Firefox, it will download to 80% 9 out of 10 times. Then if I close Firefox and re-open it will download to 89% 9 out of 10 times. Tested on a Mac Pro with 8 cores at 3GHz, 12 GB RAM and OS X (10.5.8), the silverlight app does not freeze. Tested on a Mac Mini with 1.83 GHz Duo, 1 GB RAM and OS X (10.5.8) the silverlight app crashed in safari, but not in firefox, though firefox performance was very bad when the problem occurred. I have searched all over the net for some data on this problem without any luck. I tried disabling the download status update, but the video still froze. Has anyone encountered this or have any guidance? Regards, Justin -- File info: General Format : MPEG-4 Format profile : Apple TV Codec ID : M4VH File size : 1.24 GiB Duration : 1h 54mn Overall bit rate : 1 556 Kbps Encoded date : UTC 2010-03-16 04:44:42 Tagged date : UTC 2010-03-16 04:45:58 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : Main@L3.0 Format settings, CABAC : No Format settings, ReFrames : 2 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 1h 54mn Bit rate mode : Variable Bit rate : 1 430 Kbps Width : 640 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate mode : Constant Frame rate : 23.976 fps Resolution : 8 bits Colorimetry : 4:2:0 Scan type : Progressive Bits/(Pixel*Frame) : 0.194 Stream size : 1.14 GiB (92%) Language : English Encoded date : UTC 2010-03-16 04:44:36 Tagged date : UTC 2010-03-16 04:45:58 Color primaries : BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M Transfer characteristics : BT.709-5, BT.1361 Matrix coefficients : BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M Audio ID : 2 Format : AAC Format/Info : Advanced Audio Codec Format version : Version 4 Format profile : LC Format settings, SBR : No Codec ID : 40 Duration : 1h 54mn Bit rate mode : Constant Bit rate : 121 Kbps Nominal bit rate : 128 Kbps Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 44.1 KHz Stream size : 99.4 MiB (8%) Language : English Encoded date : UTC 2010-03-16 04:44:37 Tagged date : UTC 2010-03-16 04:45:58
    Wednesday, April 14, 2010 2:38 AM