TPESystem/Media/VideoThumbnail: Difference between revisions

TPESystem/Media/VideoThumbnail (view source)

717 bytes added , 19 February 2014

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+This page is intended to have an overall summary of discussions in Bug#942078[https://bugzilla.mozilla.org/show_bug.cgi?id=942078] and webapi mailing list[https://groups.google.com/forum/#!topic/mozilla.dev.webapi/N9BW0V7MUHA].
 == Background ==
-Currently video thumbnail generation is not a good way and there are some room to improve as described as below.
+Currently video thumbnail generation is not a good method and there are some room to improve as described below.
-#Seek to 1/10th of the duration
+<OL>
-*1/10th may not be a good choice
+<LI><b>Seek to 1/10th of the duration</b>
-*Sometimes seeking takes time
+<OL>
-#Use Canvas to draw image and save it as a file
+<LI>1/10th may not be a good choice <br>
+A better way is to pick the biggest frame of the first 10 key frames as Android does. That frame should contain much information.
+<LI>Sometimes seeking takes time <br>
+Current seeking is a precise way which means it decodes from the closest key-frame to the requested seek frame. If the frame at 1/10 duration is far from key frame, it takes longer.
+</OL>
+<LI><b>Use Canvas to draw image and save it as a jpeg file </b><br>
+There is a full-size memory allocation used in Canvas to hold a decoded frame.
+</OL>
+== Possible Solutions ==