我按照本教程使用 gst-omx 编译了 gstreamer：http://www.onepitwopi.com/raspberry-pi/gstreamer-1-2-on-the-raspberry-pi/ http://www.onepitwopi.com/raspberry-pi/gstreamer-1-2-on-the-raspberry-pi/
一切都很顺利，最后当我运行 gst-inspect-1.0 | grep omx 我得到：
omx: omxmpeg2videodec: OpenMAX MPEG2 Video Decoder
omx: omxmpeg4videodec: OpenMAX MPEG4 Video Decoder
omx: omxh263dec: OpenMAX H.263 Video Decoder
omx: omxh264dec: OpenMAX H.264 Video Decoder
omx: omxtheoradec: OpenMAX Theora Video Decoder
omx: omxvp8dec: OpenMAX VP8 Video Decoder
omx: omxmjpegdec: OpenMAX MJPEG Video Decoder
omx: omxvc1dec: OpenMAX WMV Video Decoder
omx: omxh264enc: OpenMAX H.264 Video Encoder
omx: omxanalogaudiosink: OpenMAX Analog Audio Sink
omx: omxhdmiaudiosink: OpenMAX HDMI Audio Sink
一切看起来都很好，但是当我尝试将 gst-launch-1.0 与 omx 解码器一起使用时，我什么也没得到。
该管道运行良好（但非常慢，所以我在中间关闭了它）：
pi@raspberrypi ~ $ gst-launch-1.0 filesrc location=./h264_720p_hp_5.1_6mbps_ac3_planet.mp4 ! qtdemux ! h264parse ! avdec_h264 ! eglglessink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Got context from element 'eglglessink0': gst.egl.EGLDisplay=context, display=(Gst EGLDisplay)NULL;
Redistribute latency...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
WARNING: from element /GstPipeline:pipeline0/GstEglGlesSink:eglglessink0: A lot of buffers are being dropped.
Additional debug info:
gstbasesink.c(2791): gst_base_sink_is_too_late (): /GstPipeline:pipeline0/GstEglGlesSink:eglglessink0:
There may be a timestamping problem, or this computer is too slow.
^Chandling interrupt.
Interrupt: Stopping pipeline ...
Execution ended after 0:00:07.915424268
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...
然后我尝试使用 omx 执行相同的管道，我得到：
pi@raspberrypi ~ $ gst-launch-1.0 -v filesrc location=h264_720p_hp_5.1_6mbps_ac3_planet.mp4 ! qtdemux ! h264parse ! omxh264dec ! eglglessink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Got context from element 'eglglessink0': gst.egl.EGLDisplay=context, display=(GstEGLDisplay)NULL;
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:sink: caps = video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)5.1, profile=(string)high, codec_data=(buffer)01640033ffe1001867640033ac34e2805005ba10001974f004c4b408f18318a801008468eebce5531cc305d2628d13080214868783a1c0d04e12142c0ac0da02fe10042ad35e9e850b748c778a1410088b172105449ca3050e204448b20a4d8a081827090809848541dc4290a43164215a201900cae8340f81e86f03300b6017002ac05981d61a07802a8400a902087404700bc010506e036404b811805902e07203e0087ff85b, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:src: caps = video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, level=(string)5.1, profile=(string)high, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1, parsed=(boolean)true
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:sink: caps = video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, level=(string)5.1, profile=(string)high, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1, parsed=(boolean)true
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt709, framerate=(fraction)24000/1001
/GstPipeline:pipeline0/GstEglGlesSink:eglglessink0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt709, framerate=(fraction)24000/1001
ERROR: from element /GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0: Could not configure supporting library.
Additional debug info:
gstomxvideodec.c(1505): gst_omx_video_dec_loop (): /GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0:
Unable to reconfigure output port
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
/GstPipeline:pipeline0/GstEglGlesSink:eglglessink0.GstPad:sink: caps = NULL
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:src: caps = NULL
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:sink: caps = NULL
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:src: caps = NULL
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:sink: caps = NULL
/GstPipeline:pipeline0/GstQTDemux:qtdemux0.GstPad:video_0: caps = NULL
/GstPipeline:pipeline0/GstQTDemux:qtdemux0.GstPad:audio_0: caps = NULL
Freeing pipeline ...
我认为这是这个错误最重要的部分：
ERROR: from element /GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0: Could not configure supporting library.
但找不到任何对此错误的引用...
尝试检查 gst-omx 但它没有任何检查例程。
谁能解释一下这个问题？
多谢！
=D
UPDATE:
奇怪的是，如果我在没有 hdmi 电缆的情况下启动 rpi 并通过 ssh 执行我的管道，它就可以工作（但我没有看到任何图像，因为 hdmi 电缆已关闭）
pi@raspberrypi ~ $ gst-launch-1.0 -v filesrc location=h264_720p_hp_5.1_6mbps_ac3_planet.mp4 ! qtdemux ! h264parse ! omxh264dec ! eglglessink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Got context from element 'eglglessink0': gst.egl.EGLDisplay=context, display=(GstEGLDisplay)NULL;
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:sink: caps = video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)5.1, profile=(string)high, codec_data=(buffer)01640033ffe1001867640033ac34e2805005ba10001974f004c4b408f18318a801008468eebce5531cc305d2628d13080214868783a1c0d04e12142c0ac0da02fe10042ad35e9e850b748c778a1410088b172105449ca3050e204448b20a4d8a081827090809848541dc4290a43164215a201900cae8340f81e86f03300b6017002ac05981d61a07802a8400a902087404700bc010506e036404b811805902e07203e0087ff85b, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1
/GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:src: caps = video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, level=(string)5.1, profile=(string)high, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1, parsed=(boolean)true
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:sink: caps = video/x-h264, stream-format=(string)byte-stream, alignment=(string)au, level=(string)5.1, profile=(string)high, width=(int)1280, height=(int)720, framerate=(fraction)24000/1001, pixel-aspect-ratio=(fraction)1/1, parsed=(boolean)true
/GstPipeline:pipeline0/GstOMXH264Dec-omxh264dec:omxh264dec-omxh264dec0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt709, framerate=(fraction)24000/1001
/GstPipeline:pipeline0/GstEglGlesSink:eglglessink0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt709, framerate=(fraction)24000/1001
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Got EOS from element "pipeline0".
Execution ended after 0:01:52.821428472
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...
这是否意味着问题出在egglessink 上？
