AppSrc -> x264enc -> AppSink with unexpected return...

Jérémy Lauraire jeremy.lauraire at gmail.com
Fri Jul 29 07:12:57 PDT 2011


Hi,

I have built an app that is simply an encoder : I feed the appsrc of the
pipeline with my own buffer and get at the end the buffer encoded with h264
codec.

It seem to work fine until I get back the buffer encoded : it seems that
appsink return a GstBuffer with no data.... I get a segfault! :/ How is it
possible?

Here is part of the code : the run() and the pull_buffer() function....
pull_buffer() is called when the appsink emit the "new-buffer" signal which
is done... but the return of  *g_signal_emit_by_name (app->appsink,
"pull-buffer", gstBuffer, &ret); is unusable.*
**
I also provide the last log result of the GST_DEBUG at the end.

THANKS FOR YOUR HELP!

------------------------------------------------ Code starts
here ----------------------------------------------------

//brief To run the encoding

int GstEncoder::run()

{

App *app = &_app;

GstBus *bus;

gst_init (NULL, NULL);

/* create a mainloop to get messages and to handle the idle handler that
will

* feed data to appsrc.

*/

app->loop = g_main_loop_new (NULL, TRUE);

// Building a gst pipeline that take advantage out of vdpau

GstElement *pipeline, *appsrc, *encoder, *appsink;

pipeline = gst_pipeline_new ("pipeline");

appsrc = gst_element_factory_make ("appsrc", "app-src");

encoder = gst_element_factory_make ("x264enc","h264-enc"); //
ffenc_mpeg2video

appsink = gst_element_factory_make ("appsink", "app-sink");

if(!pipeline || !appsrc || !encoder || !appsink )

{

printf("Error while building elements... \n");

return 0;

}

// Caps for raw data

GstCaps *capsRaw;

capsRaw = gst_caps_new_simple ("video/x-raw-yuv", "format", GST_TYPE_FOURCC,
GST_MAKE_FOURCC ('I', '4', '2', '0'),

"width", G_TYPE_INT, 1280, "height", G_TYPE_INT, 720, "framerate",
GST_TYPE_FRACTION, 25, 1, NULL);

/* buil and link the pipeline */

gst_bin_add_many (GST_BIN (pipeline),

appsrc, encoder, appsink, NULL);

gst_element_link_filtered (appsrc, encoder, capsRaw);

gst_element_link (encoder, appsink);

/* define elements required in app stuct */

app->playbin = pipeline;

g_assert(app->playbin);

app->appsrc = appsrc;

g_assert(app->appsrc);

app->appsink = appsink;

g_assert(app->appsink);

g_object_set (G_OBJECT(app->appsink), "emit-signals", true, "sync", false,
NULL);

/* connect the appsrc to the signals "need data" and "enough data" */

g_signal_connect (app->appsrc, "need-data", G_CALLBACK
(VDPAUDecoder::start_feed), app);

g_signal_connect (app->appsrc, "enough-data", G_CALLBACK
(VDPAUDecoder::stop_feed), app);

g_signal_connect (app->appsink, "new-buffer", G_CALLBACK (pull_buffer),
app);

/* message handler gestion*/

bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin));

gst_bus_add_watch (bus, (GstBusFunc) VDPAUDecoder::bus_message, app);

gst_object_unref(bus);

/* go to playing and wait in a mainloop. */

g_print ("Playing... \n");

gst_element_set_state (app->playbin, GST_STATE_PLAYING);

/* this mainloop is stopped when we receive an error or EOS */

g_main_loop_run (app->loop);

GST_DEBUG ("stopping");

gst_element_set_state (app->playbin, GST_STATE_NULL);

gst_object_unref (bus);

g_main_loop_unref (app->loop);

return 0;

}

/**

* \brief To pull the encoded buffer from the appsink when "new-buffer"
message is emited

*/

gboolean GstEncoder::pull_buffer (App * app)

{

printf("new-buffer signal emitted!");

GstBuffer * gstBuffer;

GstFlowReturn ret;

Fifo * fifoOut = app->fifoOut;

g_signal_emit_by_name (app->appsink, "pull-buffer", gstBuffer, &ret);

if(ret == GST_FLOW_OK )

{

VBuffer * vBuffer = new VBuffer((char *)GST_BUFFER_DATA(gstBuffer),
GST_BUFFER_SIZE(gstBuffer));

vBuffer->setWidth(1280);

vBuffer->setHeight(720);

//vBuffer->setPixelFormat(720);

vBuffer->setVideoCodec(CODEC_ID_H264);

vBuffer->setDecimation(1);

vBuffer->setBasicFramerate(25);

vBuffer->setDecimation(1);

fifoOut->push(vBuffer);

printf(" OK\n");

}

else

{

    printf("...failed! \n");

    return false;

}

    return true;

}



----------------------------------------- Log errors starts here
----------------------------------------------------

0:00:02.542250985 8708 0x27e7990 INFO GST_STATES
gstbin.c:2910:bin_handle_async_done:<pipeline> committing state from READY
to PAUSED, old pending PLAYING

0:00:02.542285393 8708 0x27e7990 INFO GST_STATES
gstbin.c:2939:bin_handle_async_done:<pipeline> continue state change,
pending PLAYING

0:00:02.542355532 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstbin.c:2732:gst_bin_continue_func:<pipeline> continue state change PAUSED
to PLAYING, final PLAYING

0:00:02.542629619 8708 0x7f71dc3d5cb0 INFO GST_EVENT
gstevent.c:1135:gst_event_new_latency: creating latency event
0:00:00.000000000

0:00:02.542667143 8708 0x7f71dc3d5cb0 WARN bin
gstbin.c:2380:gst_bin_do_latency_func:<pipeline> did not really configure
latency of 0:00:00.000000000

0:00:02.542712971 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2408:gst_element_continue_state:<app-sink> completed state
change to PLAYING

0:00:02.542733986 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2421:gst_element_continue_state:<app-sink> posting
state-changed PAUSED to PLAYING

0:00:02.542751235 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstbin.c:2497:gst_bin_change_state_func:<pipeline> child 'app-sink' changed
state to 4(PLAYING) successfully

0:00:02.542763205 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2408:gst_element_continue_state:<h264-enc> completed state
change to PLAYING

0:00:02.542771494 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2421:gst_element_continue_state:<h264-enc> posting
state-changed PAUSED to PLAYING

0:00:02.542782454 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstbin.c:2497:gst_bin_change_state_func:<pipeline> child 'h264-enc' changed
state to 4(PLAYING) successfully

(<unknown>:8708): GLib-GObject-WARNING **: invalid (NULL) pointer instance

0:00:02.542793490 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2408:gst_element_continue_state:<capsfilter0> completed state
change to PLAYING

(<unknown>:8708): GLib-GObject-CRITICAL **: g_signal_emit_by_name: assertion
`G_TYPE_CHECK_INSTANCE (instance)' failed

0:00:02.542803216 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2421:gst_element_continue_state:<capsfilter0> posting
state-changed PAUSED to PLAYING

new-buffer signal emitted! OK

0:00:02.542821007 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstbin.c:2497:gst_bin_change_state_func:<pipeline> child 'capsfilter0'
changed state to 4(PLAYING) successfully

0:00:02.542833817 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2408:gst_element_continue_state:<app-src> completed state
change to PLAYING

0:00:02.542850587 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2421:gst_element_continue_state:<app-src> posting state-changed
PAUSED to PLAYING

0:00:02.542861178 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstbin.c:2497:gst_bin_change_state_func:<pipeline> child 'app-src' changed
state to 4(PLAYING) successfully

Start feed...

0:00:02.542873530 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2408:gst_element_continue_state:<pipeline> completed state
change to PLAYING

0:00:02.542887630 8708 0x7f71dc3d5cb0 INFO GST_STATES
gstelement.c:2421:gst_element_continue_state:<pipeline> posting
state-changed PAUSED to PLAYING

Read data...

FifoIn is empty...

Push in fifoIn...

fifoOut is empty... skipping output treatment!

Read data...

fifoIn is read...

Read data...

FifoIn is empty...

(<unknown>:8708): GLib-GObject-WARNING **: invalid (NULL) pointer instance

(<unknown>:8708): GLib-GObject-CRITICAL **: g_signal_emit_by_name: assertion
`G_TYPE_CHECK_INSTANCE (instance)' failed

Erreur de segmentation
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