Here is a gst-plugins-bad-0.10.17 build trace:

  CC    osxvideosrc.o
In file included from osxvideosrc.c:48:
osxvideosrc.h:54: error: expected specifier-qualifier-list before ‘SeqGrabComponent’
osxvideosrc.c: In function ‘device_list’:
osxvideosrc.c:361: error: ‘SeqGrabComponent’ undeclared (first use in this function)
osxvideosrc.c:361: error: (Each undeclared identifier is reported only once
osxvideosrc.c:361: error: for each function it appears in.)
osxvideosrc.c:361: error: expected ‘;’ before ‘component’
osxvideosrc.c:362: error: ‘SGChannel’ undeclared (first use in this function)
osxvideosrc.c:362: error: expected ‘;’ before ‘channel’
osxvideosrc.c:363: error: ‘SGDeviceList’ undeclared (first use in this function)
osxvideosrc.c:363: error: expected ‘;’ before ‘deviceList’
osxvideosrc.c:364: error: ‘SGDeviceName’ undeclared (first use in this function)
osxvideosrc.c:364: error: ‘deviceEntry’ undeclared (first use in this function)
osxvideosrc.c:365: error: ‘SGDeviceInputList’ undeclared (first use in this function)
osxvideosrc.c:365: error: expected ‘;’ before ‘inputList’
osxvideosrc.c:366: error: ‘SGDeviceInputName’ undeclared (first use in this function)
osxvideosrc.c:366: error: ‘inputEntry’ undeclared (first use in this function)
osxvideosrc.c:367: warning: ISO C90 forbids mixed declarations and code
osxvideosrc.c:377: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:380: error: ‘channel’ undeclared (first use in this function)
osxvideosrc.c:380: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:383: error: ‘component’ undeclared (first use in this function)
osxvideosrc.c:383: error: ‘SeqGrabComponentType’ undeclared (first use in this function)
osxvideosrc.c:391: warning: implicit declaration of function ‘SGInitialize’
osxvideosrc.c:397: warning: implicit declaration of function ‘SGSetDataRef’
osxvideosrc.c:397: error: ‘seqGrabDontMakeMovie’ undeclared (first use in this function)
osxvideosrc.c:403: warning: implicit declaration of function ‘SGNewChannel’
osxvideosrc.c:411: warning: implicit declaration of function ‘SGGetChannelDeviceList’
osxvideosrc.c:411: error: ‘sgDeviceListIncludeInputs’ undeclared (first use in this function)
osxvideosrc.c:411: error: ‘deviceList’ undeclared (first use in this function)
osxvideosrc.c:420: error: ‘sgDeviceNameFlagDeviceUnavailable’ undeclared (first use in this function)
osxvideosrc.c:423: warning: implicit declaration of function ‘p2cstrcpy’
osxvideosrc.c:424: error: ‘inputList’ undeclared (first use in this function)
osxvideosrc.c:479: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c: In function ‘device_select’:
osxvideosrc.c:587: warning: implicit declaration of function ‘c2pstrcpy’
osxvideosrc.c:590: warning: implicit declaration of function ‘SGSetChannelDevice’
osxvideosrc.c:590: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:596: warning: implicit declaration of function ‘SGSetChannelDeviceInput’
osxvideosrc.c:596: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c: In function ‘gst_osx_video_src_class_init’:
osxvideosrc.c:699: warning: implicit declaration of function ‘EnterMovies’
osxvideosrc.c: In function ‘gst_osx_video_src_dispose’:
osxvideosrc.c:733: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:734: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:735: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
In file included from osxvideoplugin.c:31:
osxvideosrc.h:54: error: expected specifier-qualifier-list before ‘SeqGrabComponent’
osxvideosrc.c: In function ‘gst_osx_video_src_get_caps’:
osxvideosrc.c:810: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:818: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c:819: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c: In function ‘gst_osx_video_src_set_caps’:
osxvideosrc.c:841: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:852: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c:854: warning: implicit declaration of function ‘QTNewGWorld’
osxvideosrc.c:854: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:854: error: ‘k422YpCbCr8PixelFormat’ undeclared (first use in this function)
osxvideosrc.c:854: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c:861: warning: implicit declaration of function ‘LockPixels’
osxvideosrc.c:861: warning: implicit declaration of function ‘GetPortPixMap’
osxvideosrc.c:861: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:866: warning: implicit declaration of function ‘SGSetGWorld’
osxvideosrc.c:866: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:866: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:872: warning: implicit declaration of function ‘SGSetChannelBounds’
osxvideosrc.c:872: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:872: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c:887: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:888: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:889: warning: implicit declaration of function ‘DisposeGWorld’
osxvideosrc.c:889: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:890: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c: In function ‘gst_osx_video_src_start’:
osxvideosrc.c:930: error: ‘GstOSXVideoSrc’ has no member named ‘seq_num’
osxvideosrc.c:932: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:932: error: ‘SeqGrabComponentType’ undeclared (first use in this function)
osxvideosrc.c:933: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:940: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:946: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:946: error: ‘seqGrabDontMakeMovie’ undeclared (first use in this function)
osxvideosrc.c:952: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:952: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:965: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:967: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:968: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:971: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c: In function ‘gst_osx_video_src_stop’:
osxvideosrc.c:987: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:989: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:992: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:994: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:995: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:997: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:998: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:999: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c: In function ‘gst_osx_video_src_change_state’:
osxvideosrc.c:1073: warning: implicit declaration of function ‘SGStartRecord’
osxvideosrc.c:1073: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1076: warning: implicit declaration of function ‘SGRelease’
osxvideosrc.c:1076: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1084: warning: implicit declaration of function ‘SGGetChannelSampleDescription’
osxvideosrc.c:1084: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:1087: warning: implicit declaration of function ‘SGStop’
osxvideosrc.c:1087: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1088: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1099: warning: implicit declaration of function ‘RectMatrix’
osxvideosrc.c:1099: error: ‘GstOSXVideoSrc’ has no member named ‘rect’
osxvideosrc.c:1101: warning: implicit declaration of function ‘DecompressSequenceBegin’
osxvideosrc.c:1101: error: ‘GstOSXVideoSrc’ has no member named ‘dec_seq’
osxvideosrc.c:1101: error: ‘GstOSXVideoSrc’ has no member named ‘world’
osxvideosrc.c:1102: error: ‘codecNormalQuality’ undeclared (first use in this function)
osxvideosrc.c:1103: error: ‘bestSpeedCodec’ undeclared (first use in this function)
osxvideosrc.c:1105: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1106: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1126: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1128: warning: implicit declaration of function ‘CDSequenceEnd’
osxvideosrc.c:1128: error: ‘GstOSXVideoSrc’ has no member named ‘dec_seq’
osxvideosrc.c:1131: error: ‘GstOSXVideoSrc’ has no member named ‘dec_seq’
osxvideosrc.c:1133: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c: In function ‘gst_osx_video_src_create’:
osxvideosrc.c:1168: warning: implicit declaration of function ‘SGIdle’
osxvideosrc.c:1168: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1175: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:1186: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:1189: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c:1190: error: ‘GstOSXVideoSrc’ has no member named ‘buffer’
osxvideosrc.c: At top level:
osxvideosrc.c:1200: error: expected ‘)’ before ‘c’
osxvideosrc.c: In function ‘prepare_capture’:
osxvideosrc.c:1269: warning: implicit declaration of function ‘SGSetChannelUsage’
osxvideosrc.c:1269: error: ‘GstOSXVideoSrc’ has no member named ‘video_chan’
osxvideosrc.c:1269: error: ‘seqGrabRecord’ undeclared (first use in this function)
osxvideosrc.c:1275: warning: implicit declaration of function ‘SGSetDataProc’
osxvideosrc.c:1275: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
osxvideosrc.c:1275: warning: implicit declaration of function ‘NewSGDataUPP’
osxvideosrc.c:1275: error: ‘data_proc’ undeclared (first use in this function)
osxvideosrc.c:1281: warning: implicit declaration of function ‘SGPrepare’
osxvideosrc.c:1281: error: ‘GstOSXVideoSrc’ has no member named ‘seq_grab’
make[3]: *** [libgstosxvideosrc_la-osxvideoplugin.lo] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: *** [libgstosxvideosrc_la-osxvideosrc.lo] Error 1
make[2]: *** [all-recursive] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2
sh-3.2#

Also, the following command line plays audio but no video (is osxvideosink broken in Snow Leopard?):

sh-3.2# gst-launch-0.10 --gst-debug-spew filesrc location="/Users/silentm/trailer_videos/big_buck_bunny_1080p_stereo.ogg" ! oggdemux name=d d. ! queue ! theoradec ! ffmpegcolorspace ! osxvideosink d. ! queue ! vorbisdec ! audioconvert ! audioresample ! osxaudiosink