5 Replies Latest reply: Feb 20, 2013 5:04 AM by Terry Duschinski
Terry Duschinski Level 2 Level 2 (155 points)

Trying to get away from Flash video, I've used QT with h.264 encoding but in both FireFox and Safari my 29-minute video plays only about the first minute. Meanwhile, another video encoding exactly the same way plays fine. They're both on the same page (and both autoplay, another problem).

 

http://www.terrydvideo.com

 

Any ideas about a fix?

 

Thanks,


Terry D


MacBook Pro, Mac OS X (10.6.8), A1260 2.4GH 2GB Ram 750GB HD FCE4
  • Jon Walker Level 6 Level 6 (17,905 points)

    Trying to get away from Flash video, I've used QT with h.264 encoding but in both FireFox and Safari my 29-minute video plays only about the first minute. Meanwhile, another video encoding exactly the same way plays fine. They're both on the same page (and both autoplay, another problem).

     

    http://www.terrydvideo.com

    Thanks for posting the URL. All too often users post questions to a forum but fail to provide required information or provide the actual content for examination. Have downloaded and examined the first two file and am still in the process of downloading the third file from the upper area of the web page for examination.

     

     

    Any ideas about a fix?

    alli-jas.mov

    Recompress the project file. Something went wrong with your work flow. Although the "alli-jas.mov" file claims to have a duration of 29 minutes 22.29 seconds and "weigh in" as a 1.20 GB file, it is, in reality, only 1 minute 26.34 seconds long and physically only 77.7 MBs in size.  If I attempt to download the file directly to my QT 7 Pro player, the download terminates when the file runs out of data. Attempts to play the file as linked on your web paqe or as downloaded, the file plays normally while there is data. However, when all all data has played, the playhead continues to move since the movie atoms insist there is still supposed to be almost 27 more minutes of content to be played but the display remains unchanged and silent since there are no more video frames or audio to be played. In other words, the currently referenced file cannot be fixed.

     

    In addition, this file was encoded at an incorrect aspect ratio. (I.e., the file is encoded as a 720x480 non-anamorphic file rather that as a 720x480 (640x480) anamorphic or 640x480 non-anamorphic file.) Not sure if you did this intentionally or if you lost the anamorphic settings accidentally due to your work flow. You also encoded your audio at 5 to 10 times the data rate I would have used. In any case, I corrected your file to a 640x480 H.264/AAC non-anamorphic encode so you can see the difference this makes to the combined total average data rate which reduced your 77,7 MB file segment down to only 17.5 MBs. Here is a link to my version of your file:

     

    alli-jas.mov

     

    Duggan.mov

    This file was encoded correctly as a QVGA 320x240 non-anamorphic H.264/AAC file (although I would have probably used a higher quality AAC audio settings). I would not, however, normally autostart playback on the web page (or default preload) with a second video capable of being played simultaneously on the page. (I.e., even though I stopped playback on this file to manually speed up caching of the second file on the page to my computer, this file continued preload and, thus, slowing the download.)

     

    seq-Duggan-WEDDING-2.mov

    Like the file just above, this file was also correctly encoded as QVGA 320x240 non-anamorphic H.264 video but once again you failed to use the more efficient AAC audio codec which reduces your 380.9 MB file down to on 83.7 MBs. Here is a link to my version of your file:

     

    seq-Duggan-WEDDING-2.mov

     

    SJAUG.png

  • Terry Duschinski Level 2 Level 2 (155 points)

    Wow!!! Way over the top in generosity with your time and attention to this.

     

    Thanks VERY much for the fix...and the lesson.

     

    Much appreciated.

     

    Terry D

  • Terry Duschinski Level 2 Level 2 (155 points)

    Jon:

     

    And if I may ask, how do you autopsy my video files to know my encoding?

     

    Thanks,

     

    Terry D

  • Jon Walker Level 6 Level 6 (17,905 points)

    Jon:

     

    And if I may ask, how do you autopsy my video files to know my encoding?

    I may use a number of differe apps and/or utilities depending on the information gleaned from the player. For instance, in the case of the "alli-jas.mov" file, I started with the QT 7 Pro "Inspector" window.

     

    Screen Shot 2013-02-18 at 7.04.42 PM.png

     

    The "Format:" entry tells me the audio was on of the 16-bit PCM codecs (Stereo L/R sampled @ 48.0 KHz) and the video was encoded non-anamorphically using the H.264 (aka MPEG-4 AVC) codec at 720x480.

     

    NOTE: At this point I began to wonder if the file was really a custom 3:2 file (an aspect ratio not normally used for video but often used by cameras) of if the file was supposed to be an anmorphic 720x480 (640x480) file that had been missencoded—i.e., the latter be a common occurence in some work flows when editing and/or converting NTSC DV or MPEG-2 file content. Based on some video tracking error and and seeing the 320x240 (4:3) encode of the of the same content, it became obvious that this file was encoded at the wrong aspect ratio.

     

    The "Data Size:" entry told me the file should contain at least 1.20 GBs of compressed data for the active audio and video tracks specified in the "Format:" entry while the "Data Rate:" entry indicated a combined total data rate for these two tracks averaging 5827.64 Kbps.

     

    Screen Shot 2013-02-18 at 7.48.53 PM.png

     

    I next decided to open the "Properties" if there were any inactive data tracks about which I should know, check on the distribution of date between active audio and video tracks, as well as, check the individual durations of the various data tracks. Everything still looked normal dispite what I considered a waste of data rate/space for encoding the audio and video. (I.e., there still was still no apparent reason for the limitation on playback.)

     

    Screen Shot 2013-02-18 at 9.43.11 PM.png

     

    Since I remembered the file size had not increased as rapidly as I had expected while monitoring the download, at this point I opened the Finder "Info" window to see how much physical space the file was taking up on my hard drive. To my surprise, the Finder only indicated 77.7 MBs of file space as opposed to the 1.20 MBs of data plus normal file overhead expected. It was obvious that only a fraction of the file data was present in the file. While I did use Atom Inspector and Dumpster to verify the track durations, time scales, and presence of various valid data tables, the data itself was physically absent (as demonstrated by the physical file size) and this was not a case of modified in and out play points preventing QT-based apps from accessing the data.

     

    I also used the MediaInfo utility to check on the Profile and Level used to encode your files, but this had no real bearing on your main playback problem.

     

    SJAUG.png

  • Terry Duschinski Level 2 Level 2 (155 points)

    Wow. You really know your stuff.

     

    Again, a million thanks.

     

    TD