Mercurial > cortex

     1 #+title: Capture Live Video Feeds from JMonkeyEngine

     2 #+author: Robert McIntyre

     3 #+email: rlm@mit.edu

     4 #+description: Capture video from a JMonkeyEngine3 Application with Xuggle, and use gstreamer to compress the video to upload to YouTube.

     5 #+keywords: JME3, video, Xuggle, JMonkeyEngine, youtube, capture video, Java

     6 #+SETUPFILE: ../../aurellem/org/setup.org

     7 #+INCLUDE: ../../aurellem/org/level-0.org

     8 

     9 

    10 * The Problem

    11 So you've made your cool new JMonkeyEngine3 game and you want to

    12 create a demo video to show off your hard work. Screen capturing is

    13 the most straightforward way to do this, but it can slow down your

    14 game and produce low-quality video as a result. A better way is to

    15 record a video feed directly from the game while it is

    16 running.

    17 

    18 In this post, I'll explain how you can alter your JMonkeyEngine3 game

    19 to output video while it is running. The main trick is to alter the

    20 pace of JMonkeyEngine3's in-game time: we allow the engine as much

    21 time as it needs to compute complicated in-game events and to encode

    22 video frames. As a result, the game appears to speed up and slow down

    23 as the computational demands shift, but the end result is perfectly

    24 smooth video output at a constant framerate.

    25 

    26 

    27 * Game-time vs. User-time vs. Video-time

    28 

    29 A standard JME3 application that extends =SimpleApplication= or

    30 =Application= tries as hard as it can to keep in sync with

    31 /user-time/.  If a ball is rolling at 1 game-mile per game-hour in the

    32 game, and you wait for one user-hour as measured by the clock on your

    33 wall, then the ball should have traveled exactly one game-mile. In

    34 order to keep sync with the real world, the game throttles its physics

    35 engine and graphics display.  If the computations involved in running

    36 the game are too intense, then the game will first skip frames, then

    37 sacrifice physics accuracy.  If there are particuraly demanding

    38 computations, then you may only get 1 fps, and the ball may tunnel

    39 through the floor or obstacles due to inaccurate physics simulation,

    40 but after the end of one user-hour, that ball will have traveled one

    41 game-mile.

    42 

    43 When we're recording video, we don't care if the game-time syncs with

    44 user-time, but instead whether the time in the recorded video

    45 (video-time) syncs with user-time. To continue the analogy, if we

    46 recorded the ball rolling at 1 game-mile per game-hour and watched the

    47 video later, we would want to see 30 fps video of the ball rolling at

    48 1 video-mile per /user-hour/. It doesn't matter how much user-time it

    49 took to simulate that hour of game-time to make the high-quality

    50 recording.

    51 

    52 * COMMENT Two examples to clarify the point:

    53 ** Recording from a Simple Simulation

    54 

    55 *** Without a Special Timer

    56 You have a simulation of a ball rolling on an infinite empty plane at

    57 one game-mile per game-hour, and a really good computer. Normally,

    58 JME3 will throttle the physics engine and graphics display to sync the

    59 game-time with user-time. If it takes one-thousandth of a second

    60 user-time to simulate one-sixtieth of a second game time and another

    61 one-thousandth of a second to draw to the screen, then JME3 will just

    62 sit around for the remainder of $\frac{1}{60} - \frac{2}{1000}$

    63 user-seconds, then calculate the next frame in $\frac{2}{1000}$

    64 user-seconds, then wait, and so on. For every second of user time that

    65 passes, one second of game-time passes, and the game will run at 60

    66 frames per user-second.

    67 

    68 

    69 *** With a Special Timer

    70 Then, you change the game's timer so that user-time will be synced to

    71 video-time. Assume that encoding a single frame takes 0 seconds

    72 user-time to complete.

    73 

    74 Now, JME3 takes advantage of all available resources. It still takes

    75 one-thousandth of a second to calculate a physics tick, and another

    76 one-thousandth to render to the screen. Then it takes 0 seconds to

    77 write the video frame to disk and encode the video. In only one second

    78 of user time, JME3 will complete 500 physics-tick/render/encode-video

    79 cycles, and $\frac{500}{60}=8\frac{1}{3}$ seconds of game-time will

    80 have passed.  Game-time appears to dilate $8\frac{1}{3}\times$ with

    81 respect to user-time, and in only 7.2 minutes user-time, one hour of

    82 video will have been recorded. The game itself will run at 500 fps.

    83 When someone watches the video, they will see 60 frames per

    84 user-second, and $\frac{1}{60}$ video-seconds will pass each frame. It

    85 will take exactly one hour user-time (and one hour video-time) for the

    86 ball in the video to travel one video-mile.

    87 

    88 ** Recording from a Complex Simulation 

    89 

    90 *** Without a Special Timer

    91 You have a simulation of a ball rolling on an infinite empty plane at

    92 one game-mile per game-hour accompanied by multiple explosions

    93 involving thousands of nodes, particle effects, and complicated shadow

    94 shaders to create realistic shadows. You also have a slow

    95 laptop. Normally, JME3 must sacrifice rendering and physics simulation

    96 to try to keep up.  If it takes $\frac{1}{120}$ of a user-second to

    97 calculate $\frac{1}{60}$ game-seconds, and an additional

    98 $\frac{1}{60}$ of a user-second to render to screen, then JME3 has

    99 it's work cut out for it.  In order to render to the screen, it will

   100 first step the game forward by up to four physics ticks before

   101 rendering to the screen. If it still isn't fast enough then it will

   102 decrease the accuracy of the physics engine until game-time and user

   103 time are synched or a certain threshold is reached, at which point the

   104 game visibly slows down. In this case, JME3 continuously repeat a

   105 cycle of two physics ticks, and one screen render. For every

   106 user-second that passes, one game-second will pass, but the game will

   107 run at 30 fps instead of 60 fps like before.

   108 

   109 *** With a Special Timer

   110 Then, you change the game's timer so that user-time will be synced to

   111 video-time. Once again, assume video encoding takes $\frac{1}{60}$ of

   112 a user-second.

   113 

   114 Now, JME3 will spend $\frac{1}{120}$ of a user-second to step the

   115 physics tick $\frac{1}{60}$ game-seconds, $\frac{1}{60}$ to draw to

   116 the screen, and an additional $\frac{1}{60}$ to encode the video and

   117 write the frame to disk. This is a total of $\frac{1}{24}$

   118 user-seconds for each $\frac{1}{60}$ game-seconds. It will take

   119 $(\frac{60}{24} = 2.5)$ user-hours to record one game-hour and game-time

   120 will appear to flow two-fifths as fast as user time while the game is

   121 running. However, just as in example one, when all is said and done we

   122 will have an hour long video at 60 fps.

   123 

   124 

   125 * COMMENT proposed names for the new timer

   126 # METRONOME

   127 # IsoTimer

   128 # EvenTimer

   129 # PulseTimer

   130 # FixedTimer

   131 # RigidTimer

   132 # FixedTempo

   133 # RegularTimer

   134 # MetronomeTimer

   135 # ConstantTimer

   136 # SteadyTimer

   137 

   138 

   139 * =IsoTimer= records time like a metronome

   140 

   141 The easiest way to achieve this special timing is to create a new

   142 timer that always reports the same framerate to JME3 every time it is

   143 called.

   144 

   145 

   146 =./src/com/aurellem/capture/IsoTimer.java=

   147 #+include ../../jmeCapture/src/com/aurellem/capture/IsoTimer.java src java

   148 

   149 If an Application uses this =IsoTimer= instead of the normal one, we

   150 can be sure that every call to =simpleUpdate=, for example, corresponds

   151 to exactly $(\frac{1}{fps})$ seconds of game-time.

   152 

   153 * Encoding to Video

   154 

   155 Now that the issue of time is solved, we just need a function that

   156 writes each frame to a video.  We can put this function somewhere

   157 where it will be called exactly one per frame.

   158 

   159 The basic functions that a =VideoRecorder= should support are

   160 recording, starting, stopping, and possibly a final finishing step

   161 there it finilizes the recording (such as writing headers for a video

   162 file).

   163 

   164 An appropiate interface describing this behaviour could look like

   165 this:

   166 

   167 =./src/com/aurellem/capture/video/VideoRecorder.java=

   168 #+include ../../jmeCapture/src/com/aurellem/capture/video/VideoRecorder.java src java

   169 

   170 

   171 JME3 already provides exactly the class we need: the =SceneProcessor=

   172 class can be attached to any viewport and the methods defined therein

   173 will be called at the appropriate points in the rendering process.

   174 

   175 However, it is also important to properly close the video stream and

   176 write headers and such, and even though =SceneProcessor= has a

   177 =.cleanup()= method, it is only called when the =SceneProcessor= is

   178 removed from the =RenderManager=, not when the game is shutting down

   179 when the user pressed ESC, for example. To obtain reliable shutdown

   180 behaviour, we also have to implement =AppState=, which provides a

   181 =.cleanup()= method that /is/ called on shutdown.

   182 

   183 Here is an AbstractVideoRecorder class that takes care of the details

   184 of setup and teardown.

   185 

   186 =./src/com/aurellem/capture/video/AbstractVideoRecorder.java=

   187 #+include ../../jmeCapture/src/com/aurellem/capture/video/AbstractVideoRecorder.java src java

   188 

   189 If you want to generate video from Java, a great option is [[http://www.xuggle.com/][Xuggle]]. It

   190 takes care of everything related to video encoding and decoding and

   191 runs on Windows, Linux and Mac.  Out of all the video frameworks for

   192 Java I personally like this one the best.

   193 

   194 Here is a =VideoRecorder= that uses [[http://www.xuggle.com/][Xuggle]] to write each frame to a

   195 video file.

   196 

   197 =./src/com/aurellem/capture/video/XuggleVideoRecorder.java=

   198 #+include ../../jmeCapture/src/com/aurellem/capture/video/XuggleVideoRecorder.java src java

   199 

   200 With this, we are able to record video!

   201 

   202 However, it can be hard to properly install Xuggle. For those of you

   203 who would rather not use Xuggle, here is an alternate class that uses

   204 [[http://www.randelshofer.ch/blog/2008/08/writing-avi-videos-in-pure-java/][Werner Randelshofer's]] excellent pure Java AVI file writer.

   205 

   206 =./src/com/aurellem/capture/video/AVIVideoRecorder.java=

   207 #+include ../../jmeCapture/src/com/aurellem/capture/video/AVIVideoRecorder.java src java

   208 

   209 This =AVIVideoRecorder= is more limited than the

   210 =XuggleVideoRecorder=, but requires less external dependencies.

   211 

   212 Finally, for those of you who prefer to create the final video from a

   213 sequence of images, there is the =FileVideoRecorder=, which records

   214 each frame to a folder as a sequentially numbered image file. Note

   215 that you have to remember the FPS at which you recorded the video, as

   216 this information is lost when saving each frame to a file.

   217 

   218 =./src/com/aurellem/capture/video/FileVideoRecorder.java=

   219 #+include ../../jmeCapture/src/com/aurellem/capture/video/FileVideoRecorder.java src java

   220 

   221 

   222 * /Really/ Simple Video Recording

   223 

   224 The most common case for recording a video is probably to just capture

   225 whatever is on your screen exactly as you see it.  In this case, this

   226 method will do.

   227 

   228 #+begin_src java

   229 public static void captureVideo(final Application app, 

   230 				final File file) throws IOException{

   231     final AbstractVideoRecorder videoRecorder;

   232     if (file.getCanonicalPath().endsWith(".avi")){

   233 	videoRecorder = new AVIVideoRecorder(file);}

   234     else if (file.isDirectory()){

   235 	videoRecorder = new FileVideoRecorder(file);}

   236     else { videoRecorder = new XuggleVideoRecorder(file);}

   237     

   238     Callable<Object> thunk = new Callable<Object>(){

   239 	public Object call(){

   240 	    ViewPort viewPort = 

   241 	    app.getRenderManager()

   242 	    .createPostView("aurellem record", app.getCamera());

   243 	    viewPort.setClearFlags(false, false, false);

   244 	    // get GUI node stuff

   245 	    for (Spatial s : app.getGuiViewPort().getScenes()){

   246 		viewPort.attachScene(s);

   247 	    }

   248 	    app.getStateManager().attach(videoRecorder);

   249 	    viewPort.addProcessor(videoRecorder);

   250 	    return null;

   251 	}

   252     };

   253     app.enqueue(thunk);

   254 }

   255 #+end_src

   256 

   257 This will select the appropiate backend =VideoRecorder= class

   258 depending on the file name you specify, and insturment your

   259 application to record video to the file.  You should still set the

   260 game's timer to an =IsoTimer= with the desired fps.

   261 

   262 This example will record video from the ocean scene from the

   263 jMonkeyEngine test suite.

   264 #+begin_src java

   265 File video = File.createTempFile("JME-water-video", ".avi");

   266 captureVideo(app, video);

   267 app.start();

   268 System.out.println(video.getCanonicalPath());

   269 #+end_src

   270 

   271 

   272 I've added support for this under a class called

   273 =com.aurellem.capture.Capture=. You can get it [[http://hg.bortreb.com/jmeCapture/][here]].

   274 

   275 

   276 * Hello Video!

   277 

   278 I've taken [[http://code.google.com/p/jmonkeyengine/source/browse/trunk/engine/src/test/jme3test/helloworld/HelloLoop.java][=./jme3/src/test/jme3test/helloworld/HelloLoop.java=]] and

   279 augmented it with video output as follows:

   280 

   281 =./src/com/aurellem/capture/examples/HelloVideo.java=

   282 #+include ../../src/com/aurellem/capture/examples/HelloVideo.java src java

   283 

   284 The videos are created in the =hello-video= directory

   285 

   286 #+begin_src sh :results verbatim :exports both

   287 du -h hello-video/*

   288 #+end_src

   289 

   290 #+results:

   291 : 932K	hello-video/hello-video-moving.flv

   292 : 640K	hello-video/hello-video-static.flv

   293 

   294 And can be immediately uploaded to youtube

   295 

   296 - [[http://www.youtube.com/watch?v=C8gxVAySaPg][hello-video-moving.flv]]

   297 #+BEGIN_HTML

   298 <iframe width="425" height="349" 

   299 	src="http://www.youtube.com/embed/C8gxVAySaPg" 

   300 	frameborder="0" allowfullscreen>

   301 </iframe>

   302 #+END_HTML

   303 - [[http://www.youtube.com/watch?v=pHcFOtIS07Q][hello-video-static.flv]]

   304 #+BEGIN_HTML

   305 <iframe width="425" height="349" 

   306 	src="http://www.youtube.com/embed/pHcFOtIS07Q" 

   307 	frameborder="0" allowfullscreen>

   308 </iframe>

   309 

   310 #+END_HTML

   311 

   312   

   313 * Summary 

   314 It's quite easy to augment your own application to record video,

   315 almost regardless of how complicated the actual application is.  You

   316 can also record from multiple ViewPorts as the above example shows.

   317 

   318 The process for adding video recording to your application is as

   319 follows:

   320 

   321 Assuming you want to record at 30 fps, add:

   322 

   323 #+begin_src java :exports code

   324 this.setTimer(new IsoTimer(30));

   325 #+end_src

   326 

   327 Somewhere in the initialization of your Application.

   328 

   329 If you want to record from the game's main =ViewPort= to a file called

   330 =/home/r/record.flv=, then add:

   331 

   332 #+begin_src java :exports code

   333 Capture.captureVideo(app, new File("/home/r/record.flv"));

   334 #+end_src

   335 

   336 Before you call =app.start()=;

   337 

   338 * More Examples

   339 ** COMMENT Hello Physics

   340 =HelloVideo= is boring. Let's add some video capturing to =HelloPhysics=

   341 and create something fun!

   342 

   343 This example is a modified version of =HelloPhysics= that creates four

   344 simultaneous views of the same scene of cannonballs careening into a

   345 brick wall.

   346 

   347 =./jme3/src/test/jme3test/helloworld/HelloPhysicsWithVideo.java=

   348 #+include ./jme3/src/test/jme3test/helloworld/HelloPhysicsWithVideo.java src java

   349 

   350 Running the program outputs four videos into the =./physics-videos=

   351 directory.

   352 

   353 #+begin_src sh :exports both :results verbatim

   354 ls ./physics-videos | grep -

   355 #+end_src

   356 

   357 #+results:

   358 : lower-left.flv

   359 : lower-right.flv

   360 : upper-left.flv

   361 : upper-right.flv

   362 

   363 The videos are fused together with the following =gstreamer= commands:

   364 

   365 #+begin_src sh :results silent

   366 cd physics-videos

   367 

   368 gst-launch-0.10 \

   369  filesrc location=./upper-right.flv ! decodebin ! \

   370  videoscale ! ffmpegcolorspace ! \

   371  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   372  videobox border-alpha=0 left=-640 ! \

   373  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   374  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   375  jpegenc ! avimux  ! filesink location=upper.flv \

   376  \

   377  filesrc location=./upper-left.flv ! decodebin ! \

   378  videoscale ! ffmpegcolorspace ! \

   379  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   380  videobox right=-640 ! mix.

   381 #+end_src

   382 

   383 #+begin_src sh :results silent

   384 cd physics-videos

   385 

   386 gst-launch-0.10 \

   387  filesrc location=./lower-left.flv ! decodebin ! \

   388  videoscale ! ffmpegcolorspace ! \

   389  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   390  videobox border-alpha=0 left=-640 ! \

   391  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   392  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   393  jpegenc ! avimux  ! filesink location=lower.flv \

   394  \

   395  filesrc location=./lower-right.flv ! decodebin ! \

   396  videoscale ! ffmpegcolorspace ! \

   397  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   398  videobox right=-640 ! mix.

   399 #+end_src

   400 

   401 #+begin_src sh :results silent

   402 cd physics-videos

   403 

   404 gst-launch-0.10 \

   405  filesrc location=./upper.flv ! decodebin ! \

   406  videoscale ! ffmpegcolorspace ! \

   407  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   408  videobox border-alpha=0 bottom=-480 ! \

   409  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   410  video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \

   411  jpegenc ! avimux  ! filesink location=../youtube/helloPhysics.flv \

   412  \

   413  filesrc location=./lower.flv ! decodebin ! \

   414  videoscale ! ffmpegcolorspace ! \

   415  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   416  videobox top=-480 ! mix.

   417 #+end_src

   418 

   419 #+begin_src sh :results verbatim

   420 du -h youtube/helloPhysics.flv

   421 #+end_src

   422 

   423 #+results:

   424 : 180M	physics-videos/helloPhysics.flv

   425 

   426 

   427 Thats a terribly large size!

   428 Let's compress it:

   429 

   430 ** COMMENT Compressing the HelloPhysics Video

   431 First, we'll scale the video, then, we'll decrease it's bitrate. The

   432 end result will be perfect for upload to YouTube.

   433 

   434 #+begin_src sh :results silent

   435 cd youtube

   436 

   437 gst-launch-0.10 \

   438  filesrc location=./helloPhysics.flv ! decodebin ! \

   439  videoscale ! ffmpegcolorspace ! \

   440  `: # the original size is 1280 by 960` \

   441  video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \

   442  videoscale ! \

   443  `: # here we scale the video down` \

   444  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   445  `: # and here we limit the bitrate` \

   446  theoraenc bitrate=1024 quality=30 ! \

   447  oggmux ! progressreport update-freq=1 ! \

   448  filesink location=./helloPhysics.ogg 

   449 #+end_src

   450 

   451 #+begin_src sh :results verbatim

   452 du -h youtube/helloPhysics.ogg

   453 #+end_src

   454 

   455 #+results:

   456 : 13M	youtube/helloPhysics.ogg

   457 

   458 [[http://www.youtube.com/watch?v=WIJt9aRGusc][helloPhysics.ogg]]

   459 

   460 #+begin_html

   461 <iframe width="425" height="349" 

   462 	src="http://www.youtube.com/embed/WIJt9aRGusc?hl=en&fs=1" 

   463 	frameborder="0" allowfullscreen>

   464 </iframe>

   465 #+end_html

   466 

   467 

   468 ** COMMENT failed attempts

   469 Let's try the [[http://diracvideo.org/][Dirac]] video encoder.

   470 

   471 #+begin_src sh :results verbatim

   472 cd youtube

   473 START=$(date +%s) 

   474 gst-launch-0.10 \

   475  filesrc location=./helloPhysics.flv ! decodebin ! \

   476  videoscale ! ffmpegcolorspace ! \

   477  video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \

   478  schroenc ! filesink location=./helloPhysics.drc > /dev/null

   479 echo `expr $(( $(date +%s) - $START))`

   480 #+end_src

   481 

   482 

   483 #+results:

   484 : 142

   485 

   486 That took 142 seconds. Let's see how it does compression-wise:

   487 

   488 #+begin_src sh :results verbatim

   489 du -h ./youtube/helloPhysics.drc

   490 #+end_src

   491 

   492 #+results:

   493 : 22M	./physics-videos/helloPhysics.drc

   494 

   495 

   496 #+begin_src sh :results verbatim

   497 cd youtube

   498 START=$(date +%s) 

   499 gst-launch-0.10 \

   500  filesrc location=./helloPhysics.flv ! decodebin ! \

   501  videoscale ! ffmpegcolorspace ! \

   502  video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \

   503  theoraenc ! oggmux ! filesink location=./helloPhysics.ogg \

   504  > /dev/null

   505 echo `expr $(( $(date +%s) - $START))`

   506 #+end_src

   507 

   508 #+results:

   509 : 123

   510 

   511 #+begin_src sh :results verbatim

   512 du -h youtube/helloPhysics.ogg

   513 #+end_src

   514 

   515 #+results:

   516 : 59M	physics-videos/helloPhysics.ogg

   517 

   518 

   519 =*.drc= files can not be uploaded to YouTube, so I'll go for the

   520 avi file.

   521 

   522 

   523 ** COMMENT text for videos

   524 Video output from JMonkeyEngine3 (www.jmonkeyengine.org/) using Xuggle

   525 (www.xuggle.com/).  Everything is explained at

   526 http://aurellem.org/cortex/capture-video.html.

   527 

   528 

   529 Video output from JMonkeyEngine3 (www.jmonkeyengine.org/) HelloPhysics

   530 demo application using Xuggle (www.xuggle.com/).  Everything is

   531 explained at http://aurellem.org/cortex/capture-video.html.  Here,

   532 four points of view are simultaneously recorded and then glued

   533 together later.

   534 

   535  JME3 Xuggle Aurellem video capture

   536  

   537  

   538 * Sample Videos

   539 I encoded most of the original JME3 Hello demos for your viewing

   540 pleasure, all using the =Capture= and =IsoTimer= classes.

   541 

   542 ** HelloTerrain

   543 [[http://youtu.be/5_4wyDFwrVQ][HelloTerrain.avi]]

   544 

   545 #+begin_html

   546 <iframe width="425" height="349" 

   547 	src="http://www.youtube.com/embed/5_4wyDFwrVQ" 

   548 	frameborder="0" allowfullscreen>

   549 </iframe>

   550 #+end_html

   551 

   552 ** HelloAssets

   553 [[http://www.youtube.com/watch?v=oGg-Q6k1BM4][HelloAssets.avi]]

   554 

   555 #+begin_html

   556 <iframe width="425" height="349" 

   557 	src="http://www.youtube.com/embed/oGg-Q6k1BM4?hl=en&fs=1" 

   558 	frameborder="0" allowfullscreen>

   559 </iframe>

   560 #+end_html

   561 

   562 ** HelloEffects

   563 [[http://www.youtube.com/watch?v=TuxlLMe53hA][HelloEffects]]

   564 

   565 #+begin_html

   566 <iframe width="425" height="349" 

   567 	src="http://www.youtube.com/embed/TuxlLMe53hA?hl=en&fs=1" 

   568 	frameborder="0" allowfullscreen>

   569 </iframe>

   570 #+end_html

   571 

   572 ** HelloCollision

   573 [[http://www.youtube.com/watch?v=GPlvJkiZfFw][HelloCollision.avi]]

   574 

   575 #+begin_html

   576 <iframe width="425" height="349" 

   577 	src="http://www.youtube.com/embed/GPlvJkiZfFw?hl=en&fs=1" 

   578 	frameborder="0" allowfullscreen>

   579 </iframe>

   580 #+end_html

   581 

   582 ** HelloAnimation

   583 [[http://www.youtube.com/watch?v=SDCfOSPYUkg][HelloAnimation.avi]]

   584 

   585 #+begin_html

   586 <iframe width="425" height="349" 

   587 	src="http://www.youtube.com/embed/SDCfOSPYUkg?hl=en&fs=1" 

   588 	frameborder="0" allowfullscreen>

   589 </iframe>

   590 #+end_html

   591 

   592 ** HelloNode

   593 [[http://www.youtube.com/watch?v=pL-0fR0-ilQ][HelloNode.avi]]

   594 

   595 #+begin_html

   596 <iframe width="425" height="349" 

   597 	src="http://www.youtube.com/embed/pL-0fR0-ilQ?hl=en&fs=1" 

   598 	frameborder="0" allowfullscreen>

   599 </iframe>

   600 #+end_html

   601 

   602 ** HelloLoop

   603 [[http://www.youtube.com/watch?v=mosZzzcdE5w][HelloLoop.avi]]

   604 

   605 #+begin_html

   606 <iframe width="425" height="349" 

   607 	src="http://www.youtube.com/embed/mosZzzcdE5w?hl=en&fs=1" 

   608 	frameborder="0" allowfullscreen>

   609 </iframe>

   610 #+end_html

   611 

   612 

   613 *** COMMENT x-form the other stupid 

   614 progressreport update-freq=1 

   615 

   616 gst-launch-0.10 \

   617  filesrc location=./helloPhy ! decodebin ! \

   618  videoscale ! ffmpegcolorspace ! \

   619  video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \

   620  x264enc ! avimux ! filesink location=helloPhysics.avi \

   621 

   622 

   623 gst-launch-0.10 \

   624  filesrc location=./HelloAnimationStatic.flv ! decodebin ! \

   625  videoscale ! ffmpegcolorspace ! \

   626  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   627  videobox border-alpha=0 left=-640 ! \

   628  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   629  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   630   x264enc ! avimux ! progressreport update-freq=1 ! \

   631   filesink location=../youtube/HelloAnimation.avi \

   632  \

   633  filesrc location=./HelloAnimationMotion.flv ! decodebin ! \

   634  videoscale ! ffmpegcolorspace ! \

   635  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   636  videobox right=-640 ! mix.

   637 

   638 gst-launch-0.10 \

   639  filesrc location=./HelloCollisionMotion.flv ! decodebin ! \

   640  videoscale ! ffmpegcolorspace ! \

   641  video/x-raw-yuv, width=800, height=600, framerate=25/1 ! \

   642  x264enc bitrate=1024 ! avimux ! \

   643  filesink location=../youtube/HelloCollision.avi 

   644 

   645 gst-launch-0.10 \

   646  filesrc location=./HelloEffectsStatic.flv ! decodebin ! \

   647  videoscale ! ffmpegcolorspace ! \

   648  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   649  videobox border-alpha=0 left=-640 ! \

   650  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   651  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   652   x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \

   653   filesink location=../youtube/HelloEffects.avi \

   654  \

   655  filesrc location=./HelloEffectsMotion.flv ! decodebin ! \

   656  videoscale ! ffmpegcolorspace ! \

   657  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   658  videobox right=-640 ! mix.

   659 

   660 gst-launch-0.10 \

   661  filesrc location=./HelloTerrainMotion.flv ! decodebin ! \

   662  videoscale ! ffmpegcolorspace ! \

   663  video/x-raw-yuv, width=800, height=600, framerate=25/1 ! \

   664  x264enc bitrate=1024 ! avimux ! \

   665  filesink location=../youtube/HelloTerrain.avi 

   666 

   667 

   668 gst-launch-0.10 \

   669  filesrc location=./HelloAssetsStatic.flv ! decodebin ! \

   670  videoscale ! ffmpegcolorspace ! \

   671  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   672  videobox border-alpha=0 left=-640 ! \

   673  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   674  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   675   x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \

   676   filesink location=../youtube/HelloAssets.avi \

   677  \

   678  filesrc location=./HelloAssetsMotion.flv ! decodebin ! \

   679  videoscale ! ffmpegcolorspace ! \

   680  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   681  videobox right=-640 ! mix.

   682 

   683 

   684 gst-launch-0.10 \

   685  filesrc location=./HelloNodeStatic.flv ! decodebin ! \

   686  videoscale ! ffmpegcolorspace ! \

   687  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   688  videobox border-alpha=0 left=-640 ! \

   689  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   690  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   691   x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \

   692   filesink location=../youtube/HelloNode.avi \

   693  \

   694  filesrc location=./HelloNodeMotion.flv ! decodebin ! \

   695  videoscale ! ffmpegcolorspace ! \

   696  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   697  videobox right=-640 ! mix.

   698 

   699 gst-launch-0.10 \

   700  filesrc location=./HelloLoopStatic.flv ! decodebin ! \

   701  videoscale ! ffmpegcolorspace ! \

   702  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   703  videobox border-alpha=0 left=-640 ! \

   704  videomixer name=mix ! ffmpegcolorspace ! videorate ! \

   705  video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \

   706   x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \

   707   filesink location=../youtube/HelloLoop.avi \

   708  \

   709  filesrc location=./HelloLoopMotion.flv ! decodebin ! \

   710  videoscale ! ffmpegcolorspace ! \

   711  video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \

   712  videobox right=-640 ! mix.

   713 

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author	Robert McIntyre <rlm@mit.edu>
date	Fri, 11 Nov 2011 00:52:47 -0700
parents	ecafe87ffddc
children	da4de661c5d9