[gst-devel] Problem using appsink on simple example
Andoni Morales
ylatuya at gmail.com
Thu Jul 9 00:51:22 CEST 2009
2009/7/9 Tiago Katcipis <katcipis at inf.ufsc.br>:
> Puting appsink on the place of filesink dont works too. My problem is that
> even filesink stops to work when i just add the appsink to the bin. It seens
If you need to have an element in the pipeline that it's not linked
b/c you may want to link it dinamically you need to lock it's state
usin GST_STATE_LOCK(appsink), this way state changes won't affect to
this element.
Andoni
> that only adding the appsink to the bin makes the pipe stop working.
>
> best regards,
> Katcipis
>
> On Wed, Jul 8, 2009 at 7:32 PM, thiagoss <thiagossantos at gmail.com> wrote:
>>
>>
>> On Wed, Jul 8, 2009 at 11:25 AM, Tiago Katcipis <katcipis at inf.ufsc.br>
>> wrote:
>>>
>>> Im going to use appsink on a project using gstreamer and started to build
>>> a basic example os]f how to use appsink using signals. My problem is that
>>> when i simply add the appsink to the pipeline, the pipe simply stops to
>>> work.
>>>
>>> On the following example im just trying to use the appsink instead the
>>> filesink to write the entire stream to a file. If i use the filesink and
>>> DONT add the appsink to the pipe, it works fine, if i just add the appsink
>>> to the pipe ....it stops working, im not even using the appsink yet, the
>>> filesink stops to write data, the result of the test will be an empty file,
>>> and no error msg is sent. I dont know what detail im missing on how to use
>>> appsink, hope someone can help me. By the way, gst_bin_add returns TRUE when
>>> i add the appsink.
>>>
>>> the source code of the example:
>>>
>>> #include <gst/gst.h>
>>> #include <glib.h>
>>> #include <gst/app/gstappsink.h>
>>> #include <stdio.h>
>>>
>>> static gboolean
>>> bus_call (GstBus *bus,
>>> GstMessage *msg,
>>> gpointer data)
>>> {
>>> GMainLoop *loop = (GMainLoop *) data;
>>>
>>> switch (GST_MESSAGE_TYPE (msg)) {
>>>
>>> case GST_MESSAGE_EOS:
>>> g_print ("End of stream\n");
>>> g_main_loop_quit (loop);
>>> break;
>>>
>>> case GST_MESSAGE_ERROR: {
>>> gchar *debug;
>>> GError *error;
>>>
>>> gst_message_parse_error (msg, &error, &debug);
>>> g_free (debug);
>>>
>>> g_printerr ("Error: %s\n", error->message);
>>> g_error_free (error);
>>>
>>> g_main_loop_quit (loop);
>>> break;
>>> }
>>> default:
>>> g_print("Msg type[%d], Msg type name[%s]\n", GST_MESSAGE_TYPE(msg),
>>> GST_MESSAGE_TYPE_NAME(msg));
>>> break;
>>> }
>>>
>>> return TRUE;
>>> }
>>>
>>>
>>> static void link_two_elements(GstElement* src_element, GstElement*
>>> sink_element)
>>> {
>>> if(!gst_element_link(src_element, sink_element))
>>> g_debug("Error linking %s to %s",
>>> gst_element_get_name(src_element), gst_element_get_name(sink_element));
>>>
>>> }
>>>
>>> static void link_two_pads(GstPad* src_pad, GstPad* sink_pad)
>>> {
>>> if(!src_pad){
>>> g_warning("Error: src_pad is NULL on link_two_pads");
>>> return;
>>> }
>>>
>>> if(!sink_pad){
>>> g_warning("Error: sink_pad is NULL on link_two_pads");
>>> return;
>>> }
>>>
>>> if(gst_pad_link(src_pad, sink_pad) != GST_PAD_LINK_OK)
>>> g_debug("Error linking pads %s to %s", gst_pad_get_name(src_pad),
>>> gst_pad_get_name(sink_pad));
>>>
>>> }
>>>
>>> static void on_new_buffer (GstElement* object,
>>> gpointer user_data)
>>> {
>>> FILE* file = (FILE*) user_data;
>>> GstAppSink* app_sink = (GstAppSink*) object;
>>> GstBuffer * buffer = gst_app_sink_pull_buffer(app_sink);
>>>
>>> if(fwrite (GST_BUFFER_DATA(buffer), 1 , GST_BUFFER_SIZE(buffer) , file)
>>> != GST_BUFFER_SIZE(buffer)){
>>> g_debug("Error writing data from appsink to file!!!");
>>> }else{
>>> g_debug("Data pulled from appsink and writed to file with
>>> success!!");
>>> }
>>>
>>> }
>>>
>>> // Pipe to test this src: gst-launch audiotestsrc ! audioconvert !
>>> alawenc ! rtppcmapay ! udpsink host=127.0.0.1 port=5000
>>> // Equivalent working pipe: gst-launch udpsrc port=5000
>>> caps=application/x-rtp ! gstrtpjitterbuffer ! rtppcmadepay ! alawdec !
>>> audioconvert ! lame ! appsink
>>> int
>>> main (int argc,
>>> char *argv[])
>>> {
>>> GMainLoop *loop;
>>>
>>> GstElement *pipeline, *source, *rtp_jitter, *rtp_alaw_depay,
>>> *alaw_decoder, *audio_convert, *lame, *filesink, *appsink;
>>> GstBus* bus;
>>> GstCaps* udp_caps;
>>> FILE* appsink_file;
>>> int udp_port;
>>>
>>> if(argc < 2){
>>> g_warning("Usage: %s [port_to_be_listened]", argv[0]);
>>> return -1;
>>> }
>>>
>>> udp_port = atoi(argv[1]);
>>>
>>> /* Initialisation */
>>> gst_init (&argc, &argv);
>>>
>>> udp_caps = gst_caps_from_string("application/x-rtp");
>>> if(!udp_caps){
>>> g_warning("Error alocating the udp caps");
>>> return -1;
>>> }
>>>
>>> loop = g_main_loop_new (NULL, FALSE);
>>>
>>> /* Create gstreamer elements */
>>> pipeline = gst_pipeline_new("rtp-mp3-stream-decoder");
>>> source = gst_element_factory_make("udpsrc", "udp-rtp-source");
>>> rtp_jitter = gst_element_factory_make("gstrtpjitterbuffer",
>>> "rtp-jitter-buffer");
>>> rtp_alaw_depay = gst_element_factory_make("rtppcmadepay",
>>> "rtp_alaw_depay");
>>> alaw_decoder = gst_element_factory_make("alawdec","alaw-decoder");
>>> audio_convert =
>>> gst_element_factory_make("audioconvert","audio-convert");
>>> lame = gst_element_factory_make("lame","mp3-encoder");
>>> filesink = gst_element_factory_make("filesink",
>>> "file-mp3-output");
>>> appsink = gst_element_factory_make("appsink", "sink-buffer");
>>>
>>>
>>> if (!pipeline || !source || !rtp_jitter || !appsink ||
>>> !rtp_alaw_depay || !alaw_decoder || !audio_convert || !lame ||
>>> !filesink) {
>>> g_printerr ("Elements could not be created. Exiting.\n");
>>> return -1;
>>> }
>>>
>>> appsink_file = fopen("received_audio_appsink.mp3", "w");
>>> if(!appsink_file){
>>> g_printerr ("Appsink file could not be created. Exiting.\n");
>>> return -1;
>>> }
>>>
>>> /* Set up the pipeline */
>>>
>>> /* we set the properties to the source element to receive only rtp
>>> packets*/
>>> g_object_set(G_OBJECT (source), "port", udp_port, NULL);
>>> g_object_set(G_OBJECT (source), "caps", udp_caps, NULL);
>>> /* we set the location of the mp3 generated file */
>>> g_object_set(G_OBJECT (filesink), "location",
>>> "received_audio_filesink.mp3", NULL);
>>>
>>> /*
>>> Make appsink emit the "new-preroll" and "new-buffer" signals. This
>>> option is by default disabled because
>>> signal emission is expensive and unneeded when the application
>>> prefers to operate in pull mode.
>>> */
>>> gst_app_sink_set_emit_signals ((GstAppSink*) appsink, TRUE);
>>>
>>> /* we add a message handler */
>>> bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
>>> gst_bus_add_watch (bus, bus_call, loop);
>>> gst_object_unref (bus);
>>>
>>> /* we add all elements into the pipeline */
>>> gst_bin_add_many (GST_BIN (pipeline),
>>> source, rtp_jitter, rtp_alaw_depay, alaw_decoder,
>>> audio_convert, lame, filesink, NULL);
>>>
>>> /* When i just addn the appsink this the example stops to work and the
>>> file will be empty (and im not using the appsink, just the filesink)
>>> if(gst_bin_add(GST_BIN (pipeline), appsink)){
>>> g_debug("Adcionou appsink com sucesso");
>>> }else{
>>> g_debug("Erro ao Adcionar appsink");
>>> }*/
>>>
>>> /* we link all the elements together */
>>> link_two_elements(source, rtp_jitter);
>>> link_two_elements(rtp_jitter, rtp_alaw_depay);
>>> link_two_elements(rtp_alaw_depay, alaw_decoder);
>>> link_two_elements(alaw_decoder, audio_convert);
>>> link_two_elements(audio_convert, lame);
>>> link_two_elements(lame, filesink);
>>
>> Appsink (in this case of yours) is meant to *replace* filesink. You don't
>> seem to link appsink to anything and also you link filesink to lame. So,
>> remove filesink from your pipeline, and use appsink in its place.
>>
>>>
>>> /* Conecting to the new-buffer signal emited by the appsink */
>>> g_signal_connect (appsink, "new-buffer", G_CALLBACK (on_new_buffer),
>>> appsink_file);
>>>
>>> /* Set the pipeline to "playing" state*/
>>> g_print ("Now listening on port: %d\n", udp_port);
>>> gst_element_set_state (pipeline, GST_STATE_PLAYING);
>>>
>>> /* Iterate */
>>> g_print ("Running...\n");
>>> g_main_loop_run (loop);
>>>
>>> /* Out of the main loop, clean up nicely */
>>> g_print ("Returned, stopping listening\n");
>>> gst_element_set_state (pipeline, GST_STATE_NULL);
>>>
>>> g_print ("Deleting pipeline\n");
>>> gst_object_unref (GST_OBJECT (pipeline));
>>> fclose(appsink_file);
>>>
>>> return 0;
>>> }
>>>
>>>
>>>
>>> best regards,
>>> Katcipis
>>> --
>>> "it might be a profitable thing to learn Java, but it has no intellectual
>>> value whatsoever" Alexander Stepanov
>>>
>>>
>>> ------------------------------------------------------------------------------
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>>> gstreamer-devel at lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
>>>
>>
>>
>>
>> --
>> Thiago Sousa Santos
>>
>> Embedded Systems and Pervasive Computing Lab (Embedded)
>> Center of Electrical Engineering and Informatics (CEEI)
>> Federal University of Campina Grande (UFCG)
>>
>>
>> ------------------------------------------------------------------------------
>> Enter the BlackBerry Developer Challenge
>> This is your chance to win up to $100,000 in prizes! For a limited time,
>> vendors submitting new applications to BlackBerry App World(TM) will have
>> the opportunity to enter the BlackBerry Developer Challenge. See full
>> prize
>> details at: http://p.sf.net/sfu/Challenge
>> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
>>
>
>
>
> --
> "it might be a profitable thing to learn Java, but it has no intellectual
> value whatsoever" Alexander Stepanov
>
> ------------------------------------------------------------------------------
> Enter the BlackBerry Developer Challenge
> This is your chance to win up to $100,000 in prizes! For a limited time,
> vendors submitting new applications to BlackBerry App World(TM) will have
> the opportunity to enter the BlackBerry Developer Challenge. See full prize
> details at: http://p.sf.net/sfu/Challenge
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
>
>
--
Andoni Morales Alastruey
LongoMatch:The Digital Coach
http://www.longomatch.ylatuya.es
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