在Mac上使用VLCJ出现错误

Question

我正在使用VLCJ库来开发一款简单的媒体播放器应用程序，可以在Mac和PC上运行。在PC上，所有媒体文件都可以流畅地运行。 但是在Mac上运行该应用程序（在配置Mac .dylib文件后），我已经成功打开了应用程序，并且当我点击进度条时，帧可以正确显示，但是当我想实际播放文件时，会出现以下错误：

    /Users/ronenshani/Desktop/Cinenote/CineNotes/resources/icons/control_start_blue.png/Users/ronenshani/Desktop/Cinenote/CineNotes/resources/icons/control_rewind_blue.png/Users/ronenshani/Desktop/Cinenote/CineNotes/resources/icons/control_fastforward_blue.png/Users/ronenshani/Desktop/Cinenote/CineNotes/resources/icons/control_end_blue.pngSep 12 13:48:59 Ronens-MacBook-Pro.local java[59043] <Error>: CGContextGetCTM: invalid context 0x0
Sep 12 13:48:59 Ronens-MacBook-Pro.local java[59043] <Error>: CGContextSetBaseCTM: invalid context 0x0
Sep 12 13:48:59 Ronens-MacBook-Pro.local java[59043] <Error>: CGContextGetCTM: invalid context 0x0
Sep 12 13:48:59 Ronens-MacBook-Pro.local java[59043] <Error>: CGContextSetBaseCTM: invalid context 0x0
mediaChanged
opening
playing 
paused
Fontconfig error: Cannot load default config file
Fontconfig error: Cannot load default config file
Fontconfig error: Cannot load default config file
[0x7faeb4413f50] main vout display error: option macosx-video-autoresize does not exist
2012-09-12 13:49:18.133 java[59043:407] -[CocoaAppWindow isFullscreen]: unrecognized selector sent to instance 0x7faeaa4aba90
2012-09-12 13:49:18.134 java[59043:407] -[CocoaAppWindow isFullscreen]: unrecognized selector sent to instance 0x7faeaa4aba90
2012-09-12 13:49:18.166 java[59043:407] (
 0   CoreFoundation                      0x00007fff8dcf6f56 __exceptionPreprocess + 198
 1   libobjc.A.dylib                     0x00007fff8db84d5e objc_exception_throw + 43
 2   CoreFoundation                      0x00007fff8dd831be -[NSObject doesNotRecognizeSelector:] + 190
 3   CoreFoundation                      0x00007fff8dce3e23 ___forwarding___ + 371
 4   CoreFoundation                      0x00007fff8dce3c38 _CF_forwarding_prep_0 + 232
 5   libvout_macosx_plugin.dylib         0x0000000123affc21 -[VLCOpenGLVideoView setWindowFrameWithValue:] + 49
 6   CoreFoundation                      0x00007fff8dce670d -[NSObject performSelector:withObject:] + 61
 7   Foundation                          0x00007fff8eba6d70 __NSThreadPerformPerform + 214
 8   CoreFoundation                      0x00007fff8dc654f1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
 9   CoreFoundation                      0x00007fff8dc64d5d __CFRunLoopDoSources0 + 253
 10  CoreFoundation                      0x00007fff8dc8bb49 __CFRunLoopRun + 905
 11  CoreFoundation                      0x00007fff8dc8b486 CFRunLoopRunSpecific + 230
 12  HIToolbox                           0x00007fff868174d3 RunCurrentEventLoopInMode + 277
 13  HIToolbox                           0x00007fff8681e781 ReceiveNextEventCommon + 355
 14  HIToolbox                           0x00007fff8681e60e BlockUntilNextEventMatchingListInMode + 62
 15  AppKit                              0x00007fff83befe31 _DPSNextEvent + 659
 16  AppKit                              0x00007fff83bef735 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 135
 17  libawt.jnilib                       0x0000000118bdcfe3 -[NSApplicationAWT nextEventMatchingMask:untilDate:inMode:dequeue:] + 124
 18  AppKit                              0x00007fff83bec071 -[NSApplication run] + 470
 19  libawt.jnilib                       0x0000000118bdb694 +[AWTStarter startAWT:] + 1495
 20  libawt.jnilib                       0x0000000118bdb00e -[CPerformer perform] + 93
 21  CoreFoundation                      0x00007fff8dce670d -[NSObject performSelector:withObject:] + 61
 22  Foundation                          0x00007fff8eba6d70 __NSThreadPerformPerform + 214
 23  CoreFoundation                      0x00007fff8dc654f1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
 24  CoreFoundation                      0x00007fff8dc64d5d __CFRunLoopDoSources0 + 253
 25  CoreFoundation                      0x00007fff8dc8bb49 __CFRunLoopRun + 905
 26  CoreFoundation                      0x00007fff8dc8b486 CFRunLoopRunSpecific + 230
 27  java                                0x000000010fa3a843 java + 18499
 28  java                                0x000000010fa3a29a java + 17050
 29  java                                0x000000010fa37a98 java + 6808
)
playingAssertion failed: (p->pause_date != VLC_TS_INVALID), function aout_PacketPause, file ../../extras/package/macosx/../../../src/audio_output/output.c, line 431.

我认为这是错误的核心，尽管我不确定：

[0x7faeb4413f50] main vout display error: option macosx-video-autoresize does not exist
2012-09-12 13:49:18.133 java[59043:407] -[CocoaAppWindow isFullscreen]: unrecognized selector sent to instance 0x7faeaa4aba90
2012-09-12 13:49:18.134 java[59043:407] -[CocoaAppWindow isFullscreen]: unrecognized selector sent to instance 0x7faeaa4aba90

该应用程序使用VLCJ包装器访问libvlc库。如果有人对此有一些见解，请告诉我。我已经困扰了几天了，但仍然没有设法弄清楚。谢谢，Tamash。

编辑：在查看代码后，我发现来自VLCJ的以下代码会导致错误：

static inline char * __config_GetLabel( vlc_object_t *p_this, const char *psz_name )
{
    module_config_t *p_config;

    **p_config = config_FindConfig( p_this, psz_name );**

    /* sanity checks */
    if( !p_config )
    {
        msg_Err( p_this, "option %s does not exist", psz_name );
        return NULL;
    }

    if ( p_config->psz_longtext )
        return p_config->psz_longtext;
    else if( p_config->psz_text )
        return p_config->psz_text;
    else
        msg_Warn( p_this, "option %s does not include any help", psz_name );

    return NULL;
}

这个函数无法加载一些配置文件（这是有道理的，因为在上面的错误消息中指出了一些错误：“Fontconfig error: Cannot load default config file”）。在Mac上我应该在哪里找到这些配置文件并加载它们？

- Tamas Ionut

---

VLCJ库始终是JNA包装器（使用Java语言）到VLC动态库（libVLC）。我相信你最后一次编辑后的代码不是来自VLCJ；它来自于libVLC本身（使用C/C++语言）。不同的VLCJ版本需要不同的libVLC版本。您能告诉我您现在在Windows和OSX下使用的VLCJ和libVLC的版本吗？请同时说明JNA版本。http://code.google.com/p/vlcj/wiki/WhichVersion - ee.

Answer 1

在这个bug的所有问题解决后，我们发现libvlc库在Mac上查找“/Library/Preferences/org.videolan.vlc”文件夹下的“vlcrc”文件。此外，在打开视频文件后，我还启动并暂停了由VLCJ库提供的嵌入式媒体播放器组件。

mediaPlayer.start();
mediaPlayer.pause();

因为我想让电影在启动时暂停，但第一帧仍然显示。注释掉第二行后，它就可以正常工作了。

- Tamas Ionut