{
  "id": 1162,
  "title": "Vdeo Decoding Hurdle",
  "url": "/competitions/GestureChallenge/discussion/1162",
  "author_name": "",
  "post_date": "2011-12-15T04:53:23.050Z",
  "votes": null,
  "comment_count": 6,
  "views": 4308,
  "content": "<p>I suspect no one has made a submission yet because unlike other contests, the data for this one is not readily accessible. I downloaded one of the ZIP files and double-clicked on a video, and Windows Media Player popped up with this message:</p>\r\n<p>Windows Media Player encountered a problem while playing the file. For additional assistance, click Web Help.</p>\r\n<p>I've worked&nbsp;with digital&nbsp;video before so I opened the AVI file in a hex editor and saw that the video codec is FMP4, something I never heard of before.</p>\r\n<p>I guess we can all download libavcodec and write&nbsp;our little video decoders, but&nbsp;is there a&nbsp;Visual C&#43;&#43; project out there already with all the external libraries included, that decodes&nbsp;FMP4 video to RGB or YUV buffers ?</p>",
  "messages": [
    {
      "id": "7166",
      "postDate": "12/15/2011 04:53:23",
      "content": "<p>I suspect no one has made a submission yet because unlike other contests, the data for this one is not readily accessible. I downloaded one of the ZIP files and double-clicked on a video, and Windows Media Player popped up with this message:</p>\r\n<p>Windows Media Player encountered a problem while playing the file. For additional assistance, click Web Help.</p>\r\n<p>I've worked&nbsp;with digital&nbsp;video before so I opened the AVI file in a hex editor and saw that the video codec is FMP4, something I never heard of before.</p>\r\n<p>I guess we can all download libavcodec and write&nbsp;our little video decoders, but&nbsp;is there a&nbsp;Visual C&#43;&#43; project out there already with all the external libraries included, that decodes&nbsp;FMP4 video to RGB or YUV buffers ?</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7183",
      "postDate": "12/15/2011 14:45:08",
      "content": "<p>I had the same thoughts. Using an older version of Matlab on WinXp to get started. Doesn't decode FMP4, even thought VirtualDub, WMP, etc. can use the FFMPEG codec I located and installed.\r\n<br>\r\nEnded up slicing the avis into pngs to move on while I solve this frustration by looking at Octave on Ubuntu or, drum roll please ..., the Kinects SDK. Bet that solves the problem for Windows. Anyone know?</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7185",
      "postDate": "12/15/2011 16:02:09",
      "content": "<p>Haven't tried this so not sure if it is of any help, but my wife is&nbsp;a videogrpaher and she uses\r\n<a href=\"http://www.any-video-converter.com/\">http://www.any-video-converter.com/</a> quite often to convert from different formats.&nbsp; Maybe you could use this to convert them into format that uses a more common codec?</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7187",
      "postDate": "12/15/2011 16:46:04",
      "content": "<p>Bo, what version of Windows are you using?</p>\r\n<p>I can play the files on Windows 7 fine with Windows Media Player; it required the codec from http://sourceforge.net/projects/ffdshow-tryout/files/latest/download to play via WMP on an old Windows XP machine I have. VLC player came with the codec as well.</p>\r\n<p>I have OpenCV 2.2 on OS X Lion, and it could decode the videos fine. Possibly you could use OpenCV on your machine to decode the videos? A quick test on the Python interface (once you have OpenCV compiled / installed) is:</p>\r\n<p style=\"padding-left:30px\"><span style=\"font-family:'courier new',courier\">import cv</span><br>\r\n<span style=\"font-family:'courier new',courier\">capture = cv.CaptureFromFile(&quot;K_1.avi&quot;)</span><br>\r\n<span style=\"font-family:'courier new',courier\">frame = cv.QueryFrame(capture)</span><br>\r\n<span style=\"font-family:'courier new',courier\">while frame:</span></p>\r\n<p style=\"padding-left:60px\"><span style=\"font-family:'courier new',courier\">cv.ShowImage(&quot;video&quot;,frame)</span><br>\r\n<span style=\"font-family:'courier new',courier\">frame = cv.QueryFrame(capture)</span><br>\r\n<span style=\"font-family:'courier new',courier\">cv.WaitKey(1)</span></p>\r\n<p>If you see the video, then everything worked fine.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7189",
      "postDate": "12/15/2011 17:10:00",
      "content": "<pre>The videos are formatted is a quasi-lossless compressed AVI format. The compression was performed with FFMPEG http://ffmpeg.org/, using:\r\nffmpeg -i original.avi -sameq compressed.avi\r\nCompressed file can be read with one of many readers available for free, including SMplayer http://smplayer.org/. From Matlab, you may use mmreader or mmread.</pre>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7222",
      "postDate": "12/16/2011 05:43:51",
      "content": "<p>For the files, I would recommend VLC player. Actually in general, I would recommend VLC player. Never had a problem with it not being able to open any video file.&nbsp;</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "7449",
      "postDate": "12/23/2011 04:43:26",
      "content": "<p>If anyone else is struggling to deal with the video files in python, here's how I finally got my environment set up correctly: http://mattscsproblems.blogspot.com/2011/12/installing-opencv-with-python-and.html</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 7183,
      "author_name": "autoauto",
      "author_url": "",
      "post_date": "12/15/2011 14:45:08",
      "content": "<p>I had the same thoughts. Using an older version of Matlab on WinXp to get started. Doesn't decode FMP4, even thought VirtualDub, WMP, etc. can use the FFMPEG codec I located and installed.\r\n<br>\r\nEnded up slicing the avis into pngs to move on while I solve this frustration by looking at Octave on Ubuntu or, drum roll please ..., the Kinects SDK. Bet that solves the problem for Windows. Anyone know?</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 7185,
      "author_name": "bradpreston",
      "author_url": "",
      "post_date": "12/15/2011 16:02:09",
      "content": "<p>Haven't tried this so not sure if it is of any help, but my wife is&nbsp;a videogrpaher and she uses\r\n<a href=\"http://www.any-video-converter.com/\">http://www.any-video-converter.com/</a> quite often to convert from different formats.&nbsp; Maybe you could use this to convert them into format that uses a more common codec?</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 7187,
      "author_name": "benhamner",
      "author_url": "",
      "post_date": "12/15/2011 16:46:04",
      "content": "<p>Bo, what version of Windows are you using?</p>\r\n<p>I can play the files on Windows 7 fine with Windows Media Player; it required the codec from http://sourceforge.net/projects/ffdshow-tryout/files/latest/download to play via WMP on an old Windows XP machine I have. VLC player came with the codec as well.</p>\r\n<p>I have OpenCV 2.2 on OS X Lion, and it could decode the videos fine. Possibly you could use OpenCV on your machine to decode the videos? A quick test on the Python interface (once you have OpenCV compiled / installed) is:</p>\r\n<p style=\"padding-left:30px\"><span style=\"font-family:'courier new',courier\">import cv</span><br>\r\n<span style=\"font-family:'courier new',courier\">capture = cv.CaptureFromFile(&quot;K_1.avi&quot;)</span><br>\r\n<span style=\"font-family:'courier new',courier\">frame = cv.QueryFrame(capture)</span><br>\r\n<span style=\"font-family:'courier new',courier\">while frame:</span></p>\r\n<p style=\"padding-left:60px\"><span style=\"font-family:'courier new',courier\">cv.ShowImage(&quot;video&quot;,frame)</span><br>\r\n<span style=\"font-family:'courier new',courier\">frame = cv.QueryFrame(capture)</span><br>\r\n<span style=\"font-family:'courier new',courier\">cv.WaitKey(1)</span></p>\r\n<p>If you see the video, then everything worked fine.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 7189,
      "author_name": "challengeadmin",
      "author_url": "",
      "post_date": "12/15/2011 17:10:00",
      "content": "<pre>The videos are formatted is a quasi-lossless compressed AVI format. The compression was performed with FFMPEG http://ffmpeg.org/, using:\r\nffmpeg -i original.avi -sameq compressed.avi\r\nCompressed file can be read with one of many readers available for free, including SMplayer http://smplayer.org/. From Matlab, you may use mmreader or mmread.</pre>",
      "votes": null,
      "replies": []
    },
    {
      "id": 7222,
      "author_name": "",
      "author_url": "",
      "post_date": "12/16/2011 05:43:51",
      "content": "<p>For the files, I would recommend VLC player. Actually in general, I would recommend VLC player. Never had a problem with it not being able to open any video file.&nbsp;</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 7449,
      "author_name": "mmolek",
      "author_url": "",
      "post_date": "12/23/2011 04:43:26",
      "content": "<p>If anyone else is struggling to deal with the video files in python, here's how I finally got my environment set up correctly: http://mattscsproblems.blogspot.com/2011/12/installing-opencv-with-python-and.html</p>",
      "votes": null,
      "replies": []
    }
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