Vmoox: Cross-platform Video Publishing Solution ... - pace university

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VEDA uses ffmpeg in order to transcode flash videos to H.264/AVC videos. Below is the implementation of generateChapter(final String inputFile- Name,final Integer from, final Integer duration) method. This method as input receives the path to the original flash video file, the from and duration of the transcoding. As output this method returns the path to the new H.264/AVC video file. private String generateChapter(final String inputFileName, final Integer from, final Integer duration) { ArrayList cmdList = new ArrayList(); cmdList.add(h264Transformation+"./h264_h"); cmdList.add(localMediaPath + inputFileName); cmdList.add(duration.toString()); cmdList.add(from.toString()); cmdList.add(h264MediaPath + inputFileName.replace(".flv", "") + "_" + from + "_" + duration + "." + fileOutPutExtension); Runtime rt = Runtime.getRuntime(); Process proc = rt.exec(cmdList.toArray(new String[0])); // any error message? StreamGobbler errorGobbler = new StreamGobbler(proc .getErrorStream(), "ERROR"); } // any output? StreamGobbler outputGobbler = new StreamGobbler(proc .getInputStream(), "OUTPUT"); errorGobbler.start(); outputGobbler.start(); return inputFileName.replace(".flv", "") + "_" + from + "_" + duration; This method uses Java's RunTime and Process classes in order to execute a shell script that class the ffmpeg program. Below is the implementation of the h264_h shell script: /opt/local/bin/ffmpeg -y -threads 0 -i $1 -vcodec libx264 -s 480x272 -flags +loop -cmp +chroma -deblockalpha 0 -deblockbeta 0 - - 46 -
crf 24 -bt 256 -refs 1 -coder 0 -me_range 16 -subq 5 -partitions +parti4x4+parti8x8+partp8x8 -g 250 -keyint_min 25 -level 30 -qmin 10 -qmax 51 -trellis 2 -sc_threshold 40 -i_qfactor 0.71 -acodec libfaac -ab 96k -ar 48000 -ac 2 -t $2 -ss $3 $4 This script as an input receives the original flash video file name (i.e.,-i $1), the duration of the transcoding to perform (i.e., -t $2), the time stamp to start the transcoding from (i.e., -ss $3) and the output file name (i.e., $4). The video codec that is being uses is specified in the -vcodec flag (i.e., -vcodec libx264). The Transformation class use the singleton design pattern. The single design pattern insures that only one instance of a class is created, provides a global point of access to the object and also allow multiple instances in the future without affecting a singleton class's clients [48]. Below is the first few lines of Transformation.java that illustrates the singleton design patten in action. public class Transformation { private Properties properties; private String localMediaPath; private String h264MediaPath; private String h264Transformation; private String fileOutPutExtension; private Integer chaptherDuration; } private static Transformation instance = null; public static Transformation getInstance() { if (instance == null) { instance = new Transformation(); } return instance; } protected Transformation() { //implementation... } The constructor visibility of this class is protected, this insure that clients of this class are able to access it only through its static getInstance() method. As described above the VPSI module uses the Transcoding class to perform an initial transcoding. If a video duration is less then three minutes then the - 47 -
Page 2 and 3: Vmoox cross-platform video publishi
Page 4 and 5: 5. Web Service/ API 21 a. Featured
Page 6 and 7: List of Figures Figure 1: Pre-iPhon
Page 8 and 9: Figure 1: Pre-iPhone: BellSouth/IBM
Page 10 and 11: 4. It's Not Me, It's You - The Flas
Page 12 and 13: II. H.264/AVC Smartphone Support Th
Page 14 and 15: Palm Pre MPEG-4, H.263, H.264 [27].
Page 16 and 17: implement several end-points to you
Page 18 and 19: (d) Content Update An existing clie
Page 20 and 21: (a) Fully Transcoded Videos Videos
Page 22 and 23: capabilities), or both. The basic t
Page 24 and 25: 2. VPSI retrieves content from the
Page 26 and 27: 2. VPSI - Design The Vmoox Publishe
Page 28 and 29: 3. Transcoder - Design Vmoox perfor
Page 30 and 31: Figure 10: VEDA Chapter Name Creati
Page 32 and 33: imported into the system. This help
Page 34 and 35: Figure 12: Services Vmoox Web Servi
Page 36 and 37: 8. Front End Application - Design T
Page 38 and 39: (c) The View Objects: (Web Based ap
Page 40 and 41: Figure 16: Video Object UML Video p
Page 42 and 43: Vmoox Web Service uses the Ad objec
Page 44 and 45: } if (n == -1) break; baOut.write(b
Page 48 and 49: transcoding interface transcode the
Page 50 and 51: private List getVideoChaptersAndSta
Page 52 and 53: (c) Ad DBProxy class uses Hibernate
Page 54 and 55: public void insertNewVideos(List vi
Page 56 and 57: s":false,"duration":245,"networkId"
Page 58 and 59: } } videos = criteria.list(); if (k
Page 60 and 61: 7. iPhone Native and Web App The la
Page 62 and 63: } This method builds the request pa
Page 64 and 65: public void loadFeaturedView(List v
Page 66 and 67: Figure 23: Video View This view is
Page 68 and 69: Figure 24: A Video is Being Played
Page 70 and 71: X. References [1] http://www.vmoox.
Page 72 and 73: [25] BlackBerry Storm Specification

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