Sur d’autres sites (6170)

• ANSI Code Coverage Followup

  9 mars 2012, par Multimedia Mike — Programming

  The people behind sixteencolors.net noticed my code coverage project concerning the ANSI video decoder and asked what they could do to help. I had already downloaded 350 / 4000 of their artpacks but didn’t want to download the remainder if I could avoid it. They offered to run my tool against their local collection of files.

  Aside : They have all of the artpacks archived at Github.

  The full corpus of nearly 4000 artpacks contains over 146,000 files. Versus my sampling of 350 artpacks and 13,000 files that covered all but 45 lines of the ansi.c source file, the full corpus has files to exercise… 6 more of those lines. Whee. This means that there are files which exercise the reverse and concealed attributes, all 3 “erase in line” modes, and one more error path (which probably wasn’t a valid file anyway).

  Missing features mostly cluster around different video modes, including : 320×200 (25 rows), 640×200 (25 rows), 640×350 (43 rows), and 640×480 (60 rows) ; on the plus side, nothing tripped the “unsupported screen mode” case. There are no files that switch modes during playback.

  I guess statistical sampling theory holds out here– a small set of randomly chosen files would do a fine job covering code. But this experiment is about finding the statistical outliers.

• Trying to use FFMPEG for android. Compiling but still not working

  15 avril 2014, par Austin Mueller

  So to start off... Im trying to use ffmpeg to compile an array of images into a video on Android.

  I have followed a variety of tutorials online and have gotten as far as being able to compile the lib for Android and still have to project run.
  The repo im now using can be found here : https://github.com/Batterii/android-ffmpeg-x264

  I made a couple tweaks to the setttings.sh just to correct ndk location. Besides that, I followed the instructions and it seemed to work flawlessly.

  After that, I converted the "Project" project into an Android stdio library module.
  

  I am not getting any compile errors, nor am I getting any runtime errors, or any other errors that I can detect... Nothing on logcat... But I am definitely not getting any video called out.mp4.
  In an onCreate of a particular activity, I am running this code :

  Videokit vk = new Videokit();
  
  vk.run(new String[]{"ffmpeg", "-r", "1/5", "-i", "%d.jpg", "-c:v", "libx264", "-r", "30", "-pix_fmt", "yuv420p", project.getProjectDirectory() + "/out.mp4"});

  This command is taken from the command line example found here :
  https://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images

  Thank you in advance for anyone taking the time to look through this post... I am pretty baffled at this point, as there are no errors I can find and no video...
  Thanks

  ======================================================================

  Update

  Turns out it is not actually compiling correctly... but i have found a few things.
  here is the make file from the Eclipse version of the project

  LOCAL_PATH := $(call my-dir)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE  := videokit
  
  # These need to be in the right order
  
  FFMPEG_LIBS := $(addprefix ffmpeg/, \
  
   libavdevice/libavdevice.a \
  
   libavformat/libavformat.a \
  
   libavfilter/libavfilter.a \
  
   libavcodec/libavcodec.a \
  
   libswscale/libswscale.a \
  
   libavutil/libavutil.a \
  
   libswresample/libswresample.a \
  
   libpostproc/libpostproc.a )
  
  # ffmpeg uses its own deprecated functions liberally, so turn off that annoying noise
  
  LOCAL_CFLAGS += -g -Iffmpeg -Ivideokit -Wno-deprecated-declarations 
  
  LOCAL_LDLIBS += -llog -lz $(FFMPEG_LIBS) x264/libx264.a
  
  LOCAL_SRC_FILES :=  ffmpeg/cmdutils.c ffmpeg/ffmpeg.c videokit/uk_co_halfninja_videokit_Videokit.c
  
  include $(BUILD_SHARED_LIBRARY)

  and here is the make file that gradle is auto-generating for me... thanks to Android Studio...

  LOCAL_PATH := $(call my-dir)
  
  include $(CLEAR_VARS)
  
  
  
  LOCAL_MODULE := videokit
  
  LOCAL_CFLAGS := -g -Isrc/main/jni/ffmpeg -Isrc/main/jni/videokit -Wno-deprecated-declarations
  
  LOCAL_LDLIBS := \
  
      -lffmpeg/libavformat/libavformat.a \
  
      -lffmpeg/libavcodec/libavcodec.a \
  
      -lffmpeg/libswresample/libswresample.a \
  
      -lffmpeg/libavfilter/libavfilter.a \
  
      -lffmpeg/libpostproc/libpostproc.a \
  
      -lffmpeg/libavdevice/libavdevice.a \
  
      -lx264/libx264.a \
  
      -lffmpeg/libavutil/libavutil.a \
  
      -llog \
  
      -lz \
  
      -lffmpeg/libswscale/libswscale.a \
  
  
  
  LOCAL_SRC_FILES := \
  
      Project/Module/src/main/jni/ffmpeg/cmdutils.c \
  
      Project/Module/src/main/jni/ffmpeg/ffmpeg.c \
  
      Project/Module/src/main/jni/videokit/com_t10_project_util_FfmpegHelper.c \
  
  
  
  LOCAL_C_INCLUDES += Project/Module/src/main/jni/ffmpeg/cmdutils.c
  
  LOCAL_C_INCLUDES += Project/Module/src/main/jni/ffmpeg/ffmpeg.c
  
  LOCAL_C_INCLUDES += Project/Module/src/main/jni/videokit/com_t10_project_util_FfmpegHelper.c
  
  LOCAL_C_INCLUDES += Project/Module/src/arm/jni
  
  LOCAL_C_INCLUDES += Project/Module/src/debug/jni
  
  LOCAL_C_INCLUDES += Project/Module/src/armDebug/jni
  
  
  
  include $(BUILD_SHARED_LIBRARY)

  And finally, here is my build.gradle

  apply plugin: 'android'
  
  
  
  android {
  
      compileSdkVersion 19
  
      buildToolsVersion '19.0.1'
  
  
  
      defaultConfig {
  
          minSdkVersion 14
  
          targetSdkVersion 19
  
          versionCode 1
  
          versionName "1.0"
  
  
  
          ndk {
  
              moduleName "videokit"
  
              stl "stlport_shared"
  
              ldLibs "log", "z",
  
                      "ffmpeg/libavdevice/libavdevice.a",
  
                      "ffmpeg/libavformat/libavformat.a",
  
                      "ffmpeg/libavfilter/libavfilter.a",
  
                      "ffmpeg/libavcodec/libavcodec.a",
  
                      "ffmpeg/libswscale/libswscale.a",
  
                      "ffmpeg/libavutil/libavutil.a",
  
                      "ffmpeg/libswresample/libswresample.a",
  
  
  
  
  
                "ffmpeg/libpostproc/libpostproc.a",
  
                  "x264/libx264.a"
  
              cFlags "-g -Isrc/main/jni/ffmpeg -Isrc/main/jni/videokit -Wno-deprecated-declarations"
  
  
  
          }
  
      }
  
  
  
      sourceSets.main {
  
          jniLibs.srcDir 'src/main/libs'
  
          jni.srcDirs = ['src/main/jni/ffmpeg/cmdutils.c',
  
                         'src/main/jni/ffmpeg/ffmpeg.c',
  
                         'src/main/jni/videokit/com_t10_project_util_FfmpegHelper.c']
  
      }
  
  
  
      productFlavors {
  
          x86 {
  
              versionCode Integer.parseInt("6" + defaultConfig.versionCode)
  
              ndk {
  
                  abiFilter "x86"
  
              }
  
          }
  
          mips {
  
              versionCode Integer.parseInt("4" + defaultConfig.versionCode)
  
              ndk {
  
                  abiFilter "mips"
  
              }
  
          }
  
          armv7 {
  
              versionCode Integer.parseInt("2" + defaultConfig.versionCode)
  
              ndk {
  
                  abiFilter "armeabi-v7a"
  
              }
  
          }
  
          arm {
  
              versionCode Integer.parseInt("1" + defaultConfig.versionCode)
  
              ndk {
  
                  abiFilter "armeabi"
  
              }
  
          }
  
          fat
  
      }
  
  
  
      buildTypes {
  
          release {
  
              runProguard false
  
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
  
          }
  
      }
  
  }
  
  
  
  dependencies {
  
      compile 'com.android.support:support-v4:19.0.0'
  
      compile fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
  
  }

  As you can see, my build.gradle generates something that is pretty close to the original... but not the same. When i try to run/compile it, gradle spits this out

  Executing tasks: [:Project:assembleArmDebug]
  
  
  
  :Project:compileArmDebugNdkcc1: warning: Project/Module/src/main/jni/ffmpeg/cmdutils.c: not a directory [enabled by default]
  
  cc1: warning: Project/Module/src/main/jni/ffmpeg/ffmpeg.c: not a directory [enabled by default]
  
  cc1: warning: Project/Module/src/main/jni/videokit/com_t10_project_util_FfmpegHelper.c: not a directory [enabled by default]
  
  In file included from Project/Module/src/main/jni/ffmpeg/cmdutils.c:32:0:
  
  Project/Module/src/main/jni/ffmpeg/libavformat/avformat.h:82:32: fatal error: libavcodec/avcodec.h: No such file or directory
  
  compilation terminated.
  
  make: *** [Project/Module/build/ndk/arm/debug/obj/local/armeabi/objs/videokit/Project/Module/src/main/jni/ffmpeg/cmdutils.o] Error 1
  
   FAILED
  
  
  
  FAILURE: Build failed with an exception.
  
  
  
  * What went wrong:
  
  Execution failed for task ':Project:compileArmDebugNdk'.
  
  > com.android.ide.common.internal.LoggedErrorException: Failed to run command:
  
      android-ndk-r9d/ndk-build NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=Project/Module/build/ndk/arm/debug/Android.mk APP_PLATFORM=android-19 NDK_OUT=Project/Module/build/ndk/arm/debug/obj NDK_LIBS_OUT=Project/Module/build/ndk/arm/debug/lib APP_STL=stlport_shared APP_ABI=armeabi
  
    Error Code:
  
      2
  
    Output:
  
      cc1: warning: Project/Module/src/main/jni/ffmpeg/cmdutils.c: not a directory [enabled by default]
  
      cc1: warning: Project/Module/src/main/jni/ffmpeg/ffmpeg.c: not a directory [enabled by default]
  
      cc1: warning: Project/Module/src/main/jni/videokit/com_t10_project_util_FfmpegHelper.c: not a directory [enabled by default]
  
      In file included from Project/Module/src/main/jni/ffmpeg/cmdutils.c:32:0:
  
      Project/Module/src/main/jni/ffmpeg/libavformat/avformat.h:82:32: fatal error: libavcodec/avcodec.h: No such file or directory
  
      compilation terminated.
  
      make: *** [Project/Module/build/ndk/arm/debug/obj/local/armeabi/objs/videokit/Project/Module/src/main/jni/ffmpeg/cmdutils.o] Error 1
  
  
  
  
  
  * Try:
  
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  
  
  BUILD FAILED
  
  
  
  Total time: 8.184 secs

  I've been messing around with it for a couple hours now and pretty much every time, i get gradle yelling at me about the fact that it can't find some file. I'm beginning to think that maybe it is because my LOCAL_LDLIBS aren't in the same order as the original...? Im not entirely sure... Does anyone else have any ideas...?

• Finding Optimal Code Coverage

  7 mars 2012, par Multimedia Mike — Programming

  A few months ago, I published a procedure for analyzing code coverage of the test suites exercised in FFmpeg and Libav. I used it to add some more tests and I have it on good authority that it has helped other developers fill in some gaps as well (beginning with students helping out with the projects as part of the Google Code-In program). Now I’m wondering about ways to do better.

  Current Process
  When adding a test that depends on a sample (like a demuxer or decoder test), it’s ideal to add a sample that’s A) small, and B) exercises as much of the codebase as possible. When I was studying code coverage statistics for the WC4-Xan video decoder, I noticed that the sample didn’t exercise one of the 2 possible frame types. So I scouted samples until I found one that covered both types, trimmed the sample down, and updated the coverage suite.

  I started wondering about a method for finding the optimal test sample for a given piece of code, one that exercises every code path in a module. Okay, so that’s foolhardy in the vast majority of cases (although I was able to add one test spec that pushed a module’s code coverage from 0% all the way to 100% — but the module in question only had 2 exercisable lines). Still, given a large enough corpus of samples, how can I find the smallest set of samples that exercise the complete codebase ?

  This almost sounds like an NP-complete problem. But why should that stop me from trying to find a solution ?

  Science Project
  Here’s the pitch :

  • Instrument FFmpeg with code coverage support
  • Download lots of media to exercise a particular module
  • Run FFmpeg against each sample and log code coverage statistics
  • Distill the resulting data in some meaningful way in order to obtain more optimal code coverage

  That first step sounds harsh– downloading lots and lots of media. Fortunately, there is at least one multimedia format in the projects that tends to be extremely small : ANSI. These are files that are designed to display elaborate scrolling graphics using text mode. Further, the FATE sample currently deployed for this test (TRE_IOM5.ANS) only exercises a little less than 50% of the code in libavcodec/ansi.c. I believe this makes the ANSI video decoder a good candidate for this experiment.

  Procedure
  First, find a site that hosts a lot ANSI files. Hi, sixteencolors.net. This site has lots (on the order of 4000) artpacks, which are ZIP archives that contain multiple ANSI files (and sometimes some other files). I scraped a list of all the artpack names.

  In an effort to be responsible, I randomized the list of artpacks and downloaded periodically and with limited bandwidth ('wget --limit-rate=20k').

  Run ‘gcov’ on ansi.c in order to gather the full set of line numbers to be covered.

  For each artpack, unpack the contents, run the instrumented FFmpeg on each file inside, run ‘gcov’ on ansi.c, and log statistics including the file’s size, the file’s location (artpack.zip:filename), and a comma-separated list of line numbers touched.

  Definition of ‘Optimal’
  The foregoing procedure worked and yielded useful, raw data. Now I have to figure out how to analyze it.

  I think it’s most desirable to have the smallest files (in terms of bytes) that exercise the most lines of code. To that end, I sorted the results by filesize, ascending. A Python script initializes a set of all exercisable line numbers in ansi.c, then iterates through each each file’s stats line, adding the file to the list of candidate samples if its set of exercised lines can remove any line numbers from the overall set of lines. Ideally, that set of lines should devolve to an empty set.

  I think a second possible approach is to find the single sample that exercises the most code and then proceed with the previously described method.

  Initial Results
  So far, I have analyzed 13324 samples from 357 different artpacks provided by sixteencolors.net.

  Using the first method, I can find a set of samples that covers nearly 80% of ansi.c :

  <br />
0 bytes: bad-0494.zip:5<br />
1 bytes: grip1293.zip:-ANSI---.---<br />
1 bytes: pur-0794.zip:.<br />
2 bytes: awe9706.zip:-ANSI───.───<br />
61 bytes: echo0197.zip:-(ART)-<br />
62 bytes: hx03.zip:HX005.DAT<br />
76 bytes: imp-0494.zip:IMPVIEW.CFG<br />
82 bytes: ice0010b.zip:_cont'd_.___<br />
101 bytes: bdp-0696.zip:BDP2.WAD<br />
112 bytes: plain12.zip:--------.---<br />
181 bytes: ins1295v.zip:-°VGA°-.  н<br />
219 bytes: purg-22.zip:NEM-SHIT.ASC<br />
289 bytes: srg1196.zip:HOWTOREQ.JNK<br />
315 bytes: karma-04.zip:FASHION.COM<br />
318 bytes: buzina9.zip:ox-rmzzy.ans<br />
411 bytes: solo1195.zip:FU-BLAH1.RIP<br />
621 bytes: ciapak14.zip:NA-APOC1.ASC<br />
951 bytes: lght9404.zip:AM-TDHO1.LIT<br />
1214 bytes: atb-1297.zip:TX-ROKL.ASC<br />
2332 bytes: imp-0494.zip:STATUS.ANS<br />
3218 bytes: acepak03.zip:TR-STAT5.ANS<br />
6068 bytes: lgc-0193.zip:LGC-0193.MEM<br />
16778 bytes: purg-20.zip:EZ-HIR~1.JPG<br />
20582 bytes: utd0495.zip:LT-CROW3.ANS<br />
26237 bytes: quad0597.zip:MR-QPWP.GIF<br />
29208 bytes: mx-pack17.zip:mx-mobile-source-logo.jpg<br />
----<br />
109440 bytes total<br />

  A few notes about that list : Some of those filenames are comprised primarily of control characters. 133t, and all that. The first file is 0 bytes. I wondered if I should discard 0-length files but decided to keep those in, especially if they exercise lines that wouldn’t normally be activated. Also, there are a few JPEG and GIF files in the set. I should point out that I forced the tty demuxer using -f tty and there isn’t much in the way of signatures for this format. So, again, whatever exercises more lines is better.

  Using this same corpus, I tried approach 2– which single sample exercises the most lines of the decoder ? Answer : blde9502.zip:REQUEST.EXE. Huh. I checked it out and ‘file’ ID’s it as a MS-DOS executable. So, that approach wasn’t fruitful, at least not for this corpus since I’m forcing everything through this narrow code path.

  Think About The Future
  Where can I take this next ? The cloud ! I have people inside the search engine industry who have furnished me with extensive lists of specific types of multimedia files from around the internet. I also see that Amazon Web Services Elastic Compute Cloud (AWS EC2) instances don’t charge for incoming bandwidth.

  I think you can see where I’m going with this.

  See Also :

  • Running this experiment on 4000 artpacks / 146,000 files