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complete first draft of user guide.
author Robert McIntyre <rlm@mit.edu>
date Sat, 29 Mar 2014 20:17:58 -0400
parents 7e7f8d6d9ec5
children ebdedb039cbb
rev   line source
rlm@0 1 #+title: Capture Live Video Feeds from JMonkeyEngine
rlm@0 2 #+author: Robert McIntyre
rlm@0 3 #+email: rlm@mit.edu
rlm@0 4 #+description: Capture video from a JMonkeyEngine3 Application with Xuggle, and use gstreamer to compress the video to upload to YouTube.
rlm@306 5 #+keywords: JME3, video, Xuggle, JMonkeyEngine, YouTube, capture video, Java
rlm@4 6 #+SETUPFILE: ../../aurellem/org/setup.org
rlm@4 7 #+INCLUDE: ../../aurellem/org/level-0.org
rlm@0 8
rlm@0 9
rlm@0 10 * The Problem
rlm@0 11 So you've made your cool new JMonkeyEngine3 game and you want to
rlm@0 12 create a demo video to show off your hard work. Screen capturing is
rlm@0 13 the most straightforward way to do this, but it can slow down your
rlm@0 14 game and produce low-quality video as a result. A better way is to
rlm@280 15 record a video feed directly from the game while it is running.
rlm@0 16
rlm@0 17 In this post, I'll explain how you can alter your JMonkeyEngine3 game
rlm@0 18 to output video while it is running. The main trick is to alter the
rlm@0 19 pace of JMonkeyEngine3's in-game time: we allow the engine as much
rlm@0 20 time as it needs to compute complicated in-game events and to encode
rlm@0 21 video frames. As a result, the game appears to speed up and slow down
rlm@0 22 as the computational demands shift, but the end result is perfectly
rlm@0 23 smooth video output at a constant framerate.
rlm@0 24
rlm@0 25
ocsenave@275 26 * Video recording requires a steady framerate
ocsenave@275 27 ** The built-in =Timer= rushes to keep up.
ocsenave@275 28 #* Game-time vs. User-time vs. Video-time
rlm@0 29
rlm@280 30 Standard JME3 applications use a =Timer= object to manage time in the
rlm@280 31 simulated world. Because most JME3 applications (e.g. games) are
rlm@280 32 supposed to happen \ldquo{}live\rdquo{}, the built-in =Timer= requires
rlm@280 33 simulated time to match real time. This means that the application
rlm@280 34 must rush to finish all of its calculations on schedule: the more
rlm@280 35 complicated the calculations, the more the application is obligated to
rlm@280 36 rush. And if the workload becomes too much to handle on schedule,
rlm@280 37 =Timer= forces the application to cut corners: it demands fast,
rlm@280 38 approximate answers instead of careful, accurate ones. Although this
rlm@280 39 policy sometimes causes physically impossible glitches and choppy
rlm@280 40 framerates, it ensures that the user will never be kept waiting while
rlm@280 41 the computer stops to make a complicated calculation.
rlm@0 42
ocsenave@275 43 Now, the built-in =Timer= values speed over accuracy because real-time
rlm@280 44 applications require it. On the other hand, if your goal is to record
rlm@280 45 a glitch-free video, you need a =Timer= that will take its time to
rlm@280 46 ensure that all calculations are accurate, even if they take a long
rlm@280 47 time. In the next section, we will create a new kind of
rlm@280 48 =Timer=\mdash{}called =IsoTimer=\mdash{}which slows down to let the
rlm@280 49 computer finish all its calculations. The result is a perfectly steady
rlm@280 50 framerate and a flawless physical simulation.
rlm@0 51
ocsenave@275 52 # are supposed to happen \ldquo live \rdquo, this =Timer= requires the
rlm@280 53 # application to update in real-time. In order to keep up with the
rlm@280 54 # real world, JME applications cannot afford to take too much time on
rlm@280 55 # expensive computations. Whenever the workload becomes too much for
rlm@280 56 # the computer to handle on schedule, =Timer= forces the computer to
rlm@280 57 # cut corners, giving fast, approximate answers instead of careful,
rlm@280 58 # accurate ones. Although physical accuracy sometimes suffers as a
rlm@280 59 # result, this policy ensures that the user will never be kept waiting
rlm@280 60 # while the computer stops to make a complicated calculation.
rlm@0 61
ocsenave@275 62 #fast answers are more important than accurate ones.
ocsenave@275 63
ocsenave@275 64 # A standard JME3 application that extends =SimpleApplication= or
ocsenave@275 65 # =Application= tries as hard as it can to keep in sync with
rlm@280 66 # /user-time/. If a ball is rolling at 1 game-mile per game-hour in
rlm@280 67 # the game, and you wait for one user-hour as measured by the clock on
rlm@280 68 # your wall, then the ball should have traveled exactly one
rlm@280 69 # game-mile. In order to keep sync with the real world, the game
rlm@280 70 # throttles its physics engine and graphics display. If the
rlm@280 71 # computations involved in running the game are too intense, then the
rlm@280 72 # game will first skip frames, then sacrifice physics accuracy. If
rlm@306 73 # there are particularly demanding computations, then you may only get
rlm@280 74 # 1 fps, and the ball may tunnel through the floor or obstacles due to
rlm@280 75 # inaccurate physics simulation, but after the end of one user-hour,
rlm@280 76 # that ball will have traveled one game-mile.
ocsenave@275 77
rlm@280 78 # When we're recording video, we don't care if the game-time syncs
rlm@280 79 # with user-time, but instead whether the time in the recorded video
ocsenave@275 80 # (video-time) syncs with user-time. To continue the analogy, if we
rlm@280 81 # recorded the ball rolling at 1 game-mile per game-hour and watched
rlm@280 82 # the video later, we would want to see 30 fps video of the ball
rlm@280 83 # rolling at 1 video-mile per /user-hour/. It doesn't matter how much
rlm@280 84 # user-time it took to simulate that hour of game-time to make the
rlm@280 85 # high-quality recording.
ocsenave@275 86 ** COMMENT Two examples to clarify the point:
ocsenave@275 87 *** Recording from a Simple Simulation
ocsenave@275 88
ocsenave@275 89 **** Without a Special Timer
rlm@0 90 You have a simulation of a ball rolling on an infinite empty plane at
rlm@0 91 one game-mile per game-hour, and a really good computer. Normally,
rlm@0 92 JME3 will throttle the physics engine and graphics display to sync the
rlm@0 93 game-time with user-time. If it takes one-thousandth of a second
rlm@0 94 user-time to simulate one-sixtieth of a second game time and another
rlm@0 95 one-thousandth of a second to draw to the screen, then JME3 will just
rlm@0 96 sit around for the remainder of $\frac{1}{60} - \frac{2}{1000}$
rlm@0 97 user-seconds, then calculate the next frame in $\frac{2}{1000}$
rlm@0 98 user-seconds, then wait, and so on. For every second of user time that
rlm@0 99 passes, one second of game-time passes, and the game will run at 60
rlm@0 100 frames per user-second.
rlm@0 101
rlm@0 102
ocsenave@275 103 **** With a Special Timer
rlm@0 104 Then, you change the game's timer so that user-time will be synced to
rlm@0 105 video-time. Assume that encoding a single frame takes 0 seconds
rlm@0 106 user-time to complete.
rlm@0 107
rlm@0 108 Now, JME3 takes advantage of all available resources. It still takes
rlm@0 109 one-thousandth of a second to calculate a physics tick, and another
rlm@0 110 one-thousandth to render to the screen. Then it takes 0 seconds to
rlm@0 111 write the video frame to disk and encode the video. In only one second
rlm@0 112 of user time, JME3 will complete 500 physics-tick/render/encode-video
rlm@0 113 cycles, and $\frac{500}{60}=8\frac{1}{3}$ seconds of game-time will
rlm@0 114 have passed. Game-time appears to dilate $8\frac{1}{3}\times$ with
rlm@0 115 respect to user-time, and in only 7.2 minutes user-time, one hour of
rlm@0 116 video will have been recorded. The game itself will run at 500 fps.
rlm@0 117 When someone watches the video, they will see 60 frames per
rlm@0 118 user-second, and $\frac{1}{60}$ video-seconds will pass each frame. It
rlm@0 119 will take exactly one hour user-time (and one hour video-time) for the
rlm@0 120 ball in the video to travel one video-mile.
rlm@0 121
ocsenave@275 122 *** Recording from a Complex Simulation
rlm@0 123
rlm@0 124 *** Without a Special Timer
rlm@0 125 You have a simulation of a ball rolling on an infinite empty plane at
rlm@0 126 one game-mile per game-hour accompanied by multiple explosions
rlm@0 127 involving thousands of nodes, particle effects, and complicated shadow
rlm@0 128 shaders to create realistic shadows. You also have a slow
rlm@0 129 laptop. Normally, JME3 must sacrifice rendering and physics simulation
rlm@0 130 to try to keep up. If it takes $\frac{1}{120}$ of a user-second to
rlm@0 131 calculate $\frac{1}{60}$ game-seconds, and an additional
rlm@0 132 $\frac{1}{60}$ of a user-second to render to screen, then JME3 has
rlm@0 133 it's work cut out for it. In order to render to the screen, it will
rlm@0 134 first step the game forward by up to four physics ticks before
rlm@0 135 rendering to the screen. If it still isn't fast enough then it will
rlm@0 136 decrease the accuracy of the physics engine until game-time and user
rlm@306 137 time are synced or a certain threshold is reached, at which point the
rlm@0 138 game visibly slows down. In this case, JME3 continuously repeat a
rlm@0 139 cycle of two physics ticks, and one screen render. For every
rlm@0 140 user-second that passes, one game-second will pass, but the game will
rlm@0 141 run at 30 fps instead of 60 fps like before.
rlm@0 142
rlm@0 143 *** With a Special Timer
rlm@0 144 Then, you change the game's timer so that user-time will be synced to
rlm@0 145 video-time. Once again, assume video encoding takes $\frac{1}{60}$ of
rlm@0 146 a user-second.
rlm@0 147
rlm@0 148 Now, JME3 will spend $\frac{1}{120}$ of a user-second to step the
rlm@0 149 physics tick $\frac{1}{60}$ game-seconds, $\frac{1}{60}$ to draw to
rlm@0 150 the screen, and an additional $\frac{1}{60}$ to encode the video and
rlm@0 151 write the frame to disk. This is a total of $\frac{1}{24}$
rlm@0 152 user-seconds for each $\frac{1}{60}$ game-seconds. It will take
rlm@280 153 $(\frac{60}{24} = 2.5)$ user-hours to record one game-hour and
rlm@280 154 game-time will appear to flow two-fifths as fast as user time while
rlm@280 155 the game is running. However, just as in example one, when all is said
rlm@280 156 and done we will have an hour long video at 60 fps.
rlm@0 157
rlm@0 158
ocsenave@275 159 ** COMMENT proposed names for the new timer
rlm@0 160 # METRONOME
rlm@0 161 # IsoTimer
rlm@0 162 # EvenTimer
rlm@0 163 # PulseTimer
rlm@0 164 # FixedTimer
rlm@0 165 # RigidTimer
rlm@0 166 # FixedTempo
rlm@0 167 # RegularTimer
rlm@0 168 # MetronomeTimer
rlm@0 169 # ConstantTimer
rlm@0 170 # SteadyTimer
rlm@0 171
rlm@0 172
ocsenave@275 173 ** =IsoTimer= records time like a metronome
rlm@0 174
rlm@0 175 The easiest way to achieve this special timing is to create a new
rlm@0 176 timer that always reports the same framerate to JME3 every time it is
rlm@0 177 called.
rlm@0 178
rlm@0 179
rlm@42 180 =./src/com/aurellem/capture/IsoTimer.java=
rlm@42 181 #+include ../../jmeCapture/src/com/aurellem/capture/IsoTimer.java src java
rlm@0 182
rlm@0 183 If an Application uses this =IsoTimer= instead of the normal one, we
rlm@280 184 can be sure that every call to =simpleUpdate=, for example,
rlm@280 185 corresponds to exactly $(\frac{1}{fps})$ seconds of game-time.
rlm@0 186
ocsenave@275 187 * =VideoRecorder= manages video feeds in JMonkeyEngine.
ocsenave@275 188
ocsenave@275 189
ocsenave@275 190 ** =AbstractVideoRecorder= provides a general framework for managing videos.
rlm@0 191
rlm@0 192 Now that the issue of time is solved, we just need a function that
rlm@0 193 writes each frame to a video. We can put this function somewhere
ocsenave@275 194 where it will be called exactly once per frame.
rlm@0 195
rlm@42 196 The basic functions that a =VideoRecorder= should support are
ocsenave@275 197 recording, starting, stopping, and possibly a cleanup step
ocsenave@275 198 where it finalizes the recording (e.g. by writing headers for a video
rlm@42 199 file).
rlm@42 200
rlm@306 201 An appropriate interface describing this behavior could look like
rlm@42 202 this:
rlm@42 203
rlm@42 204 =./src/com/aurellem/capture/video/VideoRecorder.java=
rlm@42 205 #+include ../../jmeCapture/src/com/aurellem/capture/video/VideoRecorder.java src java
rlm@42 206
rlm@42 207
rlm@0 208 JME3 already provides exactly the class we need: the =SceneProcessor=
rlm@0 209 class can be attached to any viewport and the methods defined therein
rlm@0 210 will be called at the appropriate points in the rendering process.
rlm@0 211
rlm@42 212 However, it is also important to properly close the video stream and
rlm@42 213 write headers and such, and even though =SceneProcessor= has a
rlm@42 214 =.cleanup()= method, it is only called when the =SceneProcessor= is
rlm@42 215 removed from the =RenderManager=, not when the game is shutting down
rlm@42 216 when the user pressed ESC, for example. To obtain reliable shutdown
rlm@306 217 behavior, we also have to implement =AppState=, which provides a
rlm@42 218 =.cleanup()= method that /is/ called on shutdown.
rlm@42 219
rlm@42 220 Here is an AbstractVideoRecorder class that takes care of the details
rlm@42 221 of setup and teardown.
rlm@42 222
rlm@42 223 =./src/com/aurellem/capture/video/AbstractVideoRecorder.java=
rlm@42 224 #+include ../../jmeCapture/src/com/aurellem/capture/video/AbstractVideoRecorder.java src java
rlm@42 225
ocsenave@275 226
ocsenave@275 227 ** There are many options for handling video files in Java
ocsenave@275 228
rlm@0 229 If you want to generate video from Java, a great option is [[http://www.xuggle.com/][Xuggle]]. It
rlm@0 230 takes care of everything related to video encoding and decoding and
rlm@0 231 runs on Windows, Linux and Mac. Out of all the video frameworks for
ocsenave@275 232 Java, I personally like this one the best.
rlm@0 233
rlm@42 234 Here is a =VideoRecorder= that uses [[http://www.xuggle.com/][Xuggle]] to write each frame to a
rlm@0 235 video file.
rlm@0 236
rlm@42 237 =./src/com/aurellem/capture/video/XuggleVideoRecorder.java=
rlm@42 238 #+include ../../jmeCapture/src/com/aurellem/capture/video/XuggleVideoRecorder.java src java
rlm@0 239
rlm@0 240 With this, we are able to record video!
rlm@0 241
rlm@280 242 However, it can be hard to properly install Xuggle. If you would
rlm@280 243 rather not use Xuggle, here is an alternate class that uses [[http://www.randelshofer.ch/blog/2008/08/writing-avi-videos-in-pure-java/][Werner
rlm@280 244 Randelshofer's]] excellent pure Java AVI file writer.
rlm@42 245
rlm@42 246 =./src/com/aurellem/capture/video/AVIVideoRecorder.java=
rlm@42 247 #+include ../../jmeCapture/src/com/aurellem/capture/video/AVIVideoRecorder.java src java
rlm@42 248
rlm@42 249 This =AVIVideoRecorder= is more limited than the
rlm@42 250 =XuggleVideoRecorder=, but requires less external dependencies.
rlm@42 251
rlm@42 252 Finally, for those of you who prefer to create the final video from a
rlm@42 253 sequence of images, there is the =FileVideoRecorder=, which records
rlm@42 254 each frame to a folder as a sequentially numbered image file. Note
rlm@42 255 that you have to remember the FPS at which you recorded the video, as
rlm@42 256 this information is lost when saving each frame to a file.
rlm@42 257
rlm@42 258 =./src/com/aurellem/capture/video/FileVideoRecorder.java=
rlm@42 259 #+include ../../jmeCapture/src/com/aurellem/capture/video/FileVideoRecorder.java src java
rlm@42 260
rlm@42 261
rlm@42 262
ocsenave@275 263
ocsenave@275 264 * How to record videos yourself
ocsenave@275 265
ocsenave@275 266 ** Include this code.
ocsenave@275 267
rlm@280 268 No matter how complicated your application is, it's easy to add
rlm@280 269 support for video output with just a few lines of code.
ocsenave@275 270 # You can also record from multiple ViewPorts as the above example shows.
ocsenave@275 271
rlm@280 272 And although you can use =VideoRecorder= to record advanced
rlm@280 273 split-screen videos with multiple views, in the simplest case, you
rlm@280 274 want to capture a single view\mdash{} exactly what's on screen. In
rlm@280 275 this case, the following simple =captureVideo= method will do the job:
rlm@42 276
rlm@42 277 #+begin_src java
rlm@42 278 public static void captureVideo(final Application app,
rlm@42 279 final File file) throws IOException{
rlm@42 280 final AbstractVideoRecorder videoRecorder;
rlm@42 281 if (file.getCanonicalPath().endsWith(".avi")){
rlm@42 282 videoRecorder = new AVIVideoRecorder(file);}
rlm@42 283 else if (file.isDirectory()){
rlm@42 284 videoRecorder = new FileVideoRecorder(file);}
rlm@42 285 else { videoRecorder = new XuggleVideoRecorder(file);}
rlm@42 286
rlm@42 287 Callable<Object> thunk = new Callable<Object>(){
rlm@42 288 public Object call(){
rlm@42 289 ViewPort viewPort =
rlm@42 290 app.getRenderManager()
rlm@42 291 .createPostView("aurellem record", app.getCamera());
rlm@42 292 viewPort.setClearFlags(false, false, false);
rlm@42 293 // get GUI node stuff
rlm@42 294 for (Spatial s : app.getGuiViewPort().getScenes()){
rlm@42 295 viewPort.attachScene(s);
rlm@42 296 }
rlm@42 297 app.getStateManager().attach(videoRecorder);
rlm@42 298 viewPort.addProcessor(videoRecorder);
rlm@42 299 return null;
rlm@42 300 }
rlm@42 301 };
rlm@42 302 app.enqueue(thunk);
rlm@42 303 }
rlm@42 304 #+end_src
rlm@42 305
rlm@280 306 This method selects the appropriate =VideoRecorder= class for the file
rlm@280 307 type you specify, and instructs your application to record video to
rlm@280 308 the file.
ocsenave@275 309
ocsenave@275 310 Now that you have a =captureVideo= method, you use it like this:
ocsenave@275 311
ocsenave@275 312 - Establish an =Isotimer= and set its framerate :: For example, if
ocsenave@275 313 you want to record video with a framerate of 30 fps, include
rlm@306 314 the following line of code somewhere in the initialization of
ocsenave@275 315 your application:
ocsenave@275 316 #+begin_src java :exports code
ocsenave@275 317 this.setTimer(new IsoTimer(30));
ocsenave@275 318 #+end_src
ocsenave@275 319
ocsenave@275 320 - Choose the output file :: If you want to record from the game's
ocsenave@275 321 main =ViewPort= to a file called =/home/r/record.flv=, then
rlm@280 322 include the following line of code somewhere before you call
rlm@280 323 =app.start()=;
ocsenave@275 324
ocsenave@275 325 #+begin_src java :exports code
ocsenave@275 326 Capture.captureVideo(app, new File("/home/r/record.flv"));
ocsenave@275 327 #+end_src
ocsenave@275 328
ocsenave@275 329
ocsenave@275 330 ** Simple example
ocsenave@275 331
rlm@42 332
rlm@42 333 This example will record video from the ocean scene from the
ocsenave@275 334 JMonkeyEngine test suite.
rlm@42 335 #+begin_src java
rlm@42 336 File video = File.createTempFile("JME-water-video", ".avi");
rlm@42 337 captureVideo(app, video);
rlm@42 338 app.start();
rlm@42 339 System.out.println(video.getCanonicalPath());
rlm@42 340 #+end_src
rlm@42 341
rlm@42 342
rlm@42 343 I've added support for this under a class called
rlm@42 344 =com.aurellem.capture.Capture=. You can get it [[http://hg.bortreb.com/jmeCapture/][here]].
rlm@42 345
rlm@42 346
ocsenave@275 347 ** Hello Video! example
rlm@0 348
rlm@0 349 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
rlm@0 350 augmented it with video output as follows:
rlm@0 351
rlm@42 352 =./src/com/aurellem/capture/examples/HelloVideo.java=
rlm@42 353 #+include ../../src/com/aurellem/capture/examples/HelloVideo.java src java
rlm@0 354
rlm@0 355 The videos are created in the =hello-video= directory
rlm@0 356
rlm@42 357 #+begin_src sh :results verbatim :exports both
rlm@0 358 du -h hello-video/*
rlm@0 359 #+end_src
rlm@0 360
rlm@0 361 #+results:
rlm@0 362 : 932K hello-video/hello-video-moving.flv
rlm@0 363 : 640K hello-video/hello-video-static.flv
rlm@0 364
rlm@306 365 And can be immediately uploaded to YouTube
rlm@0 366
rlm@0 367 - [[http://www.youtube.com/watch?v=C8gxVAySaPg][hello-video-moving.flv]]
rlm@0 368 #+BEGIN_HTML
rlm@0 369 <iframe width="425" height="349"
rlm@0 370 src="http://www.youtube.com/embed/C8gxVAySaPg"
rlm@0 371 frameborder="0" allowfullscreen>
rlm@0 372 </iframe>
rlm@0 373 #+END_HTML
rlm@0 374 - [[http://www.youtube.com/watch?v=pHcFOtIS07Q][hello-video-static.flv]]
rlm@0 375 #+BEGIN_HTML
rlm@0 376 <iframe width="425" height="349"
rlm@0 377 src="http://www.youtube.com/embed/pHcFOtIS07Q"
rlm@0 378 frameborder="0" allowfullscreen>
rlm@0 379 </iframe>
rlm@0 380
rlm@0 381 #+END_HTML
rlm@0 382
rlm@0 383
ocsenave@275 384 * COMMENT More Examples
rlm@42 385 ** COMMENT Hello Physics
rlm@280 386
rlm@280 387 =HelloVideo= is boring. Let's add some video capturing to
rlm@280 388 =HelloPhysics= and create something fun!
rlm@0 389
rlm@0 390 This example is a modified version of =HelloPhysics= that creates four
rlm@0 391 simultaneous views of the same scene of cannonballs careening into a
rlm@0 392 brick wall.
rlm@0 393
rlm@0 394 =./jme3/src/test/jme3test/helloworld/HelloPhysicsWithVideo.java=
rlm@0 395 #+include ./jme3/src/test/jme3test/helloworld/HelloPhysicsWithVideo.java src java
rlm@0 396
rlm@0 397 Running the program outputs four videos into the =./physics-videos=
rlm@0 398 directory.
rlm@0 399
rlm@0 400 #+begin_src sh :exports both :results verbatim
rlm@0 401 ls ./physics-videos | grep -
rlm@0 402 #+end_src
rlm@0 403
rlm@0 404 #+results:
rlm@0 405 : lower-left.flv
rlm@0 406 : lower-right.flv
rlm@0 407 : upper-left.flv
rlm@0 408 : upper-right.flv
rlm@0 409
rlm@0 410 The videos are fused together with the following =gstreamer= commands:
rlm@0 411
rlm@0 412 #+begin_src sh :results silent
rlm@0 413 cd physics-videos
rlm@0 414
rlm@0 415 gst-launch-0.10 \
rlm@0 416 filesrc location=./upper-right.flv ! decodebin ! \
rlm@0 417 videoscale ! ffmpegcolorspace ! \
rlm@0 418 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 419 videobox border-alpha=0 left=-640 ! \
rlm@0 420 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 421 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 422 jpegenc ! avimux ! filesink location=upper.flv \
rlm@0 423 \
rlm@0 424 filesrc location=./upper-left.flv ! decodebin ! \
rlm@0 425 videoscale ! ffmpegcolorspace ! \
rlm@0 426 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 427 videobox right=-640 ! mix.
rlm@0 428 #+end_src
rlm@0 429
rlm@0 430 #+begin_src sh :results silent
rlm@0 431 cd physics-videos
rlm@0 432
rlm@0 433 gst-launch-0.10 \
rlm@0 434 filesrc location=./lower-left.flv ! decodebin ! \
rlm@0 435 videoscale ! ffmpegcolorspace ! \
rlm@0 436 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 437 videobox border-alpha=0 left=-640 ! \
rlm@0 438 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 439 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 440 jpegenc ! avimux ! filesink location=lower.flv \
rlm@0 441 \
rlm@0 442 filesrc location=./lower-right.flv ! decodebin ! \
rlm@0 443 videoscale ! ffmpegcolorspace ! \
rlm@0 444 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 445 videobox right=-640 ! mix.
rlm@0 446 #+end_src
rlm@0 447
rlm@0 448 #+begin_src sh :results silent
rlm@0 449 cd physics-videos
rlm@0 450
rlm@0 451 gst-launch-0.10 \
rlm@0 452 filesrc location=./upper.flv ! decodebin ! \
rlm@0 453 videoscale ! ffmpegcolorspace ! \
rlm@0 454 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 455 videobox border-alpha=0 bottom=-480 ! \
rlm@0 456 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 457 video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \
rlm@0 458 jpegenc ! avimux ! filesink location=../youtube/helloPhysics.flv \
rlm@0 459 \
rlm@0 460 filesrc location=./lower.flv ! decodebin ! \
rlm@0 461 videoscale ! ffmpegcolorspace ! \
rlm@0 462 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 463 videobox top=-480 ! mix.
rlm@0 464 #+end_src
rlm@0 465
rlm@0 466 #+begin_src sh :results verbatim
rlm@0 467 du -h youtube/helloPhysics.flv
rlm@0 468 #+end_src
rlm@0 469
rlm@0 470 #+results:
rlm@0 471 : 180M physics-videos/helloPhysics.flv
rlm@0 472
rlm@0 473
rlm@306 474 That's a terribly large size!
rlm@0 475 Let's compress it:
rlm@0 476
rlm@42 477 ** COMMENT Compressing the HelloPhysics Video
rlm@306 478 First, we'll scale the video, then, we'll decrease it's bit-rate. The
rlm@0 479 end result will be perfect for upload to YouTube.
rlm@0 480
rlm@0 481 #+begin_src sh :results silent
rlm@0 482 cd youtube
rlm@0 483
rlm@0 484 gst-launch-0.10 \
rlm@0 485 filesrc location=./helloPhysics.flv ! decodebin ! \
rlm@0 486 videoscale ! ffmpegcolorspace ! \
rlm@0 487 `: # the original size is 1280 by 960` \
rlm@0 488 video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \
rlm@0 489 videoscale ! \
rlm@0 490 `: # here we scale the video down` \
rlm@0 491 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 492 `: # and here we limit the bitrate` \
rlm@0 493 theoraenc bitrate=1024 quality=30 ! \
rlm@0 494 oggmux ! progressreport update-freq=1 ! \
rlm@0 495 filesink location=./helloPhysics.ogg
rlm@0 496 #+end_src
rlm@0 497
rlm@0 498 #+begin_src sh :results verbatim
rlm@0 499 du -h youtube/helloPhysics.ogg
rlm@0 500 #+end_src
rlm@0 501
rlm@0 502 #+results:
rlm@0 503 : 13M youtube/helloPhysics.ogg
rlm@0 504
rlm@0 505 [[http://www.youtube.com/watch?v=WIJt9aRGusc][helloPhysics.ogg]]
rlm@0 506
rlm@0 507 #+begin_html
rlm@0 508 <iframe width="425" height="349"
rlm@0 509 src="http://www.youtube.com/embed/WIJt9aRGusc?hl=en&fs=1"
rlm@0 510 frameborder="0" allowfullscreen>
rlm@0 511 </iframe>
rlm@0 512 #+end_html
rlm@0 513
rlm@0 514
rlm@0 515 ** COMMENT failed attempts
rlm@0 516 Let's try the [[http://diracvideo.org/][Dirac]] video encoder.
rlm@0 517
rlm@0 518 #+begin_src sh :results verbatim
rlm@0 519 cd youtube
rlm@0 520 START=$(date +%s)
rlm@0 521 gst-launch-0.10 \
rlm@0 522 filesrc location=./helloPhysics.flv ! decodebin ! \
rlm@0 523 videoscale ! ffmpegcolorspace ! \
rlm@0 524 video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \
rlm@0 525 schroenc ! filesink location=./helloPhysics.drc > /dev/null
rlm@0 526 echo `expr $(( $(date +%s) - $START))`
rlm@0 527 #+end_src
rlm@0 528
rlm@0 529
rlm@0 530 #+results:
rlm@0 531 : 142
rlm@0 532
rlm@0 533 That took 142 seconds. Let's see how it does compression-wise:
rlm@0 534
rlm@0 535 #+begin_src sh :results verbatim
rlm@0 536 du -h ./youtube/helloPhysics.drc
rlm@0 537 #+end_src
rlm@0 538
rlm@0 539 #+results:
rlm@0 540 : 22M ./physics-videos/helloPhysics.drc
rlm@0 541
rlm@0 542
rlm@0 543 #+begin_src sh :results verbatim
rlm@0 544 cd youtube
rlm@0 545 START=$(date +%s)
rlm@0 546 gst-launch-0.10 \
rlm@0 547 filesrc location=./helloPhysics.flv ! decodebin ! \
rlm@0 548 videoscale ! ffmpegcolorspace ! \
rlm@0 549 video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \
rlm@0 550 theoraenc ! oggmux ! filesink location=./helloPhysics.ogg \
rlm@0 551 > /dev/null
rlm@0 552 echo `expr $(( $(date +%s) - $START))`
rlm@0 553 #+end_src
rlm@0 554
rlm@0 555 #+results:
rlm@0 556 : 123
rlm@0 557
rlm@0 558 #+begin_src sh :results verbatim
rlm@0 559 du -h youtube/helloPhysics.ogg
rlm@0 560 #+end_src
rlm@0 561
rlm@0 562 #+results:
rlm@0 563 : 59M physics-videos/helloPhysics.ogg
rlm@0 564
rlm@0 565
rlm@0 566 =*.drc= files can not be uploaded to YouTube, so I'll go for the
rlm@0 567 avi file.
rlm@0 568
rlm@0 569
rlm@0 570 ** COMMENT text for videos
rlm@0 571 Video output from JMonkeyEngine3 (www.jmonkeyengine.org/) using Xuggle
rlm@0 572 (www.xuggle.com/). Everything is explained at
rlm@0 573 http://aurellem.org/cortex/capture-video.html.
rlm@0 574
rlm@0 575
rlm@0 576 Video output from JMonkeyEngine3 (www.jmonkeyengine.org/) HelloPhysics
rlm@0 577 demo application using Xuggle (www.xuggle.com/). Everything is
rlm@0 578 explained at http://aurellem.org/cortex/capture-video.html. Here,
rlm@0 579 four points of view are simultaneously recorded and then glued
rlm@0 580 together later.
rlm@0 581
rlm@280 582 JME3 Xuggle Aurellem video capture
rlm@0 583
rlm@0 584
ocsenave@275 585 * Showcase of recorded videos
rlm@0 586 I encoded most of the original JME3 Hello demos for your viewing
rlm@42 587 pleasure, all using the =Capture= and =IsoTimer= classes.
rlm@0 588
rlm@0 589 ** HelloTerrain
rlm@0 590 [[http://youtu.be/5_4wyDFwrVQ][HelloTerrain.avi]]
rlm@0 591
rlm@0 592 #+begin_html
rlm@0 593 <iframe width="425" height="349"
rlm@0 594 src="http://www.youtube.com/embed/5_4wyDFwrVQ"
rlm@0 595 frameborder="0" allowfullscreen>
rlm@0 596 </iframe>
rlm@0 597 #+end_html
rlm@0 598
rlm@0 599 ** HelloAssets
rlm@0 600 [[http://www.youtube.com/watch?v=oGg-Q6k1BM4][HelloAssets.avi]]
rlm@0 601
rlm@0 602 #+begin_html
rlm@0 603 <iframe width="425" height="349"
rlm@0 604 src="http://www.youtube.com/embed/oGg-Q6k1BM4?hl=en&fs=1"
rlm@0 605 frameborder="0" allowfullscreen>
rlm@0 606 </iframe>
rlm@0 607 #+end_html
rlm@0 608
rlm@0 609 ** HelloEffects
rlm@0 610 [[http://www.youtube.com/watch?v=TuxlLMe53hA][HelloEffects]]
rlm@0 611
rlm@0 612 #+begin_html
rlm@0 613 <iframe width="425" height="349"
rlm@0 614 src="http://www.youtube.com/embed/TuxlLMe53hA?hl=en&fs=1"
rlm@0 615 frameborder="0" allowfullscreen>
rlm@0 616 </iframe>
rlm@0 617 #+end_html
rlm@0 618
rlm@0 619 ** HelloCollision
rlm@0 620 [[http://www.youtube.com/watch?v=GPlvJkiZfFw][HelloCollision.avi]]
rlm@0 621
rlm@0 622 #+begin_html
rlm@0 623 <iframe width="425" height="349"
rlm@0 624 src="http://www.youtube.com/embed/GPlvJkiZfFw?hl=en&fs=1"
rlm@0 625 frameborder="0" allowfullscreen>
rlm@0 626 </iframe>
rlm@0 627 #+end_html
rlm@0 628
rlm@0 629 ** HelloAnimation
rlm@0 630 [[http://www.youtube.com/watch?v=SDCfOSPYUkg][HelloAnimation.avi]]
rlm@0 631
rlm@0 632 #+begin_html
rlm@0 633 <iframe width="425" height="349"
rlm@0 634 src="http://www.youtube.com/embed/SDCfOSPYUkg?hl=en&fs=1"
rlm@0 635 frameborder="0" allowfullscreen>
rlm@0 636 </iframe>
rlm@0 637 #+end_html
rlm@0 638
rlm@0 639 ** HelloNode
rlm@0 640 [[http://www.youtube.com/watch?v=pL-0fR0-ilQ][HelloNode.avi]]
rlm@0 641
rlm@0 642 #+begin_html
rlm@0 643 <iframe width="425" height="349"
rlm@0 644 src="http://www.youtube.com/embed/pL-0fR0-ilQ?hl=en&fs=1"
rlm@0 645 frameborder="0" allowfullscreen>
rlm@0 646 </iframe>
rlm@0 647 #+end_html
rlm@0 648
rlm@0 649 ** HelloLoop
rlm@0 650 [[http://www.youtube.com/watch?v=mosZzzcdE5w][HelloLoop.avi]]
rlm@0 651
rlm@0 652 #+begin_html
rlm@0 653 <iframe width="425" height="349"
rlm@0 654 src="http://www.youtube.com/embed/mosZzzcdE5w?hl=en&fs=1"
rlm@0 655 frameborder="0" allowfullscreen>
rlm@0 656 </iframe>
rlm@0 657 #+end_html
rlm@0 658
rlm@0 659
rlm@0 660 *** COMMENT x-form the other stupid
rlm@0 661 progressreport update-freq=1
rlm@0 662
rlm@0 663 gst-launch-0.10 \
rlm@0 664 filesrc location=./helloPhy ! decodebin ! \
rlm@0 665 videoscale ! ffmpegcolorspace ! \
rlm@0 666 video/x-raw-yuv, width=1280, height=960, framerate=25/1 ! \
rlm@0 667 x264enc ! avimux ! filesink location=helloPhysics.avi \
rlm@0 668
rlm@0 669
rlm@0 670 gst-launch-0.10 \
rlm@0 671 filesrc location=./HelloAnimationStatic.flv ! decodebin ! \
rlm@0 672 videoscale ! ffmpegcolorspace ! \
rlm@0 673 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 674 videobox border-alpha=0 left=-640 ! \
rlm@0 675 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 676 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 677 x264enc ! avimux ! progressreport update-freq=1 ! \
rlm@0 678 filesink location=../youtube/HelloAnimation.avi \
rlm@0 679 \
rlm@0 680 filesrc location=./HelloAnimationMotion.flv ! decodebin ! \
rlm@0 681 videoscale ! ffmpegcolorspace ! \
rlm@0 682 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 683 videobox right=-640 ! mix.
rlm@0 684
rlm@0 685 gst-launch-0.10 \
rlm@0 686 filesrc location=./HelloCollisionMotion.flv ! decodebin ! \
rlm@0 687 videoscale ! ffmpegcolorspace ! \
rlm@0 688 video/x-raw-yuv, width=800, height=600, framerate=25/1 ! \
rlm@0 689 x264enc bitrate=1024 ! avimux ! \
rlm@0 690 filesink location=../youtube/HelloCollision.avi
rlm@0 691
rlm@0 692 gst-launch-0.10 \
rlm@0 693 filesrc location=./HelloEffectsStatic.flv ! decodebin ! \
rlm@0 694 videoscale ! ffmpegcolorspace ! \
rlm@0 695 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 696 videobox border-alpha=0 left=-640 ! \
rlm@0 697 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 698 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 699 x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \
rlm@0 700 filesink location=../youtube/HelloEffects.avi \
rlm@0 701 \
rlm@0 702 filesrc location=./HelloEffectsMotion.flv ! decodebin ! \
rlm@0 703 videoscale ! ffmpegcolorspace ! \
rlm@0 704 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 705 videobox right=-640 ! mix.
rlm@0 706
rlm@0 707 gst-launch-0.10 \
rlm@0 708 filesrc location=./HelloTerrainMotion.flv ! decodebin ! \
rlm@0 709 videoscale ! ffmpegcolorspace ! \
rlm@0 710 video/x-raw-yuv, width=800, height=600, framerate=25/1 ! \
rlm@0 711 x264enc bitrate=1024 ! avimux ! \
rlm@0 712 filesink location=../youtube/HelloTerrain.avi
rlm@0 713
rlm@0 714
rlm@0 715 gst-launch-0.10 \
rlm@0 716 filesrc location=./HelloAssetsStatic.flv ! decodebin ! \
rlm@0 717 videoscale ! ffmpegcolorspace ! \
rlm@0 718 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 719 videobox border-alpha=0 left=-640 ! \
rlm@0 720 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 721 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 722 x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \
rlm@0 723 filesink location=../youtube/HelloAssets.avi \
rlm@0 724 \
rlm@0 725 filesrc location=./HelloAssetsMotion.flv ! decodebin ! \
rlm@0 726 videoscale ! ffmpegcolorspace ! \
rlm@0 727 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 728 videobox right=-640 ! mix.
rlm@0 729
rlm@0 730
rlm@0 731 gst-launch-0.10 \
rlm@0 732 filesrc location=./HelloNodeStatic.flv ! decodebin ! \
rlm@0 733 videoscale ! ffmpegcolorspace ! \
rlm@0 734 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 735 videobox border-alpha=0 left=-640 ! \
rlm@0 736 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 737 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 738 x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \
rlm@0 739 filesink location=../youtube/HelloNode.avi \
rlm@0 740 \
rlm@0 741 filesrc location=./HelloNodeMotion.flv ! decodebin ! \
rlm@0 742 videoscale ! ffmpegcolorspace ! \
rlm@0 743 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 744 videobox right=-640 ! mix.
rlm@0 745
rlm@0 746 gst-launch-0.10 \
rlm@0 747 filesrc location=./HelloLoopStatic.flv ! decodebin ! \
rlm@0 748 videoscale ! ffmpegcolorspace ! \
rlm@0 749 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 750 videobox border-alpha=0 left=-640 ! \
rlm@0 751 videomixer name=mix ! ffmpegcolorspace ! videorate ! \
rlm@0 752 video/x-raw-yuv, width=1280, height=480, framerate=25/1 ! \
rlm@0 753 x264enc bitrate=1024 ! avimux ! progressreport update-freq=1 ! \
rlm@0 754 filesink location=../youtube/HelloLoop.avi \
rlm@0 755 \
rlm@0 756 filesrc location=./HelloLoopMotion.flv ! decodebin ! \
rlm@0 757 videoscale ! ffmpegcolorspace ! \
rlm@0 758 video/x-raw-yuv, width=640, height=480, framerate=25/1 ! \
rlm@0 759 videobox right=-640 ! mix.