Cool! It works right now. However, I had another issue. I just try to let appsrc keep reading data from a array and then write data into file. My pipleline is like appsrc->queue->filesink. However, I cannot get right data in the file, actually there is no data in the file but a bunch of symbols. I attached my codes here. Anyone met this problem before or know why? #include <gst/gst.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <gst/app/gstappsrc.h> #include <gst/app/gstappbuffer.h> #include <gst/app/gstappsink.h> static const guint8 mp3[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,0x07, 0x08, 0x09, 0x10, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; typedef struct _App App; struct _App { GstElement *pipe; GstElement *src; GstElement *q; GstElement *id; GstElement *q1; GstElement *sink; }; App s_app; static void finalize (void *priv); int main (int argc, char *argv[]) { FILE *fp; size_t bytes_read; App *app = &s_app; int i; int mp3size; gst_init (&argc, &argv); app->pipe = gst_pipeline_new (NULL); g_assert (app->pipe); app->src = gst_element_factory_make ("appsrc", NULL); g_assert (app->src); gst_bin_add (GST_BIN (app->pipe), app->src); app->q = gst_element_factory_make ("queue", NULL); g_assert (app->q); gst_bin_add (GST_BIN (app->pipe), app->q); /* app->id = gst_element_factory_make ("identity", NULL); g_assert (app->id); gst_bin_add (GST_BIN (app->pipe), app->id); app->q1 = gst_element_factory_make ("queue", NULL); g_assert (app->q1); gst_bin_add (GST_BIN (app->pipe), app->q1); */ app->sink = gst_element_factory_make ("filesink", NULL); g_object_set (G_OBJECT (app->sink), "location", "mp3.data", NULL); g_assert (app->sink); gst_bin_add (GST_BIN (app->pipe), app->sink); gst_element_link (app->src, app->q); //gst_element_link (app->q, app->id); // gst_element_link (app->id, app->q1); gst_element_link (app->q, app->sink); printf("Setting PIPELINE to PLAY.......\n"); gst_element_set_state (app->pipe, GST_STATE_PLAYING); mp3size=sizeof(mp3); for (i = 0; i < mp3size-1; i++) { GstBuffer *buf; guint8 *data=malloc(1); *data=mp3[i]; buf = gst_app_buffer_new (data, 1, finalize, data); gst_app_src_push_buffer (GST_APP_SRC (app->src), buf); printf("framenum %d\n", (i+1)); printf("framenum data %d\n",*GST_BUFFER_DATA(buf)); } gst_app_src_end_of_stream (GST_APP_SRC (app->src)); gst_element_set_state (app->pipe, GST_STATE_NULL); //g_object_unref (buf); //free(data); return 0; } static void finalize (void *priv) { //printf ("\nfreeing buffer for pointer %p\n", priv); //free (priv); } //================= <div class="gmail_quote">On Fri, Dec 9, 2011 at 5:47 AM, Mailing List SVR [via GStreamer-devel] <<a href="/user/SendEmail.jtp?type=node&node=4176938&i=0" target="_top" rel="nofollow" link="external">[hidden email]</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="im"> Il 08/12/2011 21:11, Jun Zhang ha scritto: </div><blockquote style="border-left: 2px solid rgb(204, 204, 204); padding: 0pt 1em;" type="cite">Hello,<div class="im"> I am trying to use appsrc to get data from my C application and met following problems. 1.undefined reference to `gst_app_buffer_new' 2. undefined reference to `gst_app_src_push_buffer' 3.undefined reference to gst_app_src_end_of_stream After searching for a solution, I saw someone suggest add -lgstapp-0.10 into the make file: Following is the commands in the make file. export PKG_CONFIG_PATH=/root/targetfs/opt/gstreame/lib/pkgconfig:$PKG_CONFIG_PATH /root/CodeSourcery/Sourcery_G++_Lite//bin/arm-none-linux-gnueabi-gcc -lgstapp-0.10 `pkg-config --cflags --libs gstreamer-0.10`-o syn test_syn.c And then I have following compile errors. However, i did check and found that the missing libgstbase-0.10.so.0 is in the same place with <a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>. Any suggestions? </div></blockquote> <div class="im"> try lo link to gstreamer-app-0.10 too, Nicola </div><blockquote style="border-left: 2px solid rgb(204, 204, 204); padding: 0pt 1em;" type="cite"> <div class="im"> /root/CodeSourcery/Sourcery_G++_Lite/bin/../lib/gcc/arm-none-linux-gnueabi/4.3.3/../../../../arm-none-linux-gnueabi/bin/ld: warning: libgstbase-0.10.so.0, needed by /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>, not found (try using -rpath or -rpath-link) /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_sink_wait_preroll' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_src_set_live' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_src_get_type' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_src_query_latency' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_src_set_format' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_src_is_live' /root/targetfs///opt/gstreamer/lib/<a href="http://libgstapp-0.10.so" rel="nofollow" link="external" target="_blank">libgstapp-0.10.so</a>: undefined reference to `gst_base_sink_get_type' Thanks, Jun <fieldset></fieldset> </div><pre>_______________________________________________ gstreamer-devel mailing list <a href="http://user/SendEmail.jtp?type=node&node=4176080&i=0" rel="nofollow" link="external" target="_blank">[hidden email]</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" rel="nofollow" link="external" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </pre> </blockquote> _______________________________________________ gstreamer-devel mailing list <a href="http://user/SendEmail.jtp?type=node&node=4176080&i=1" rel="nofollow" link="external" target="_blank">[hidden email]</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" rel="nofollow" link="external" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> <hr color="#cccccc" noshade size="1"> <div style="color: rgb(68, 68, 68); font: 12px tahoma,geneva,helvetica,arial,sans-serif;"> <div style="font-weight: bold;">If you reply to this email, your message will be added to the discussion below:</div> <a href="http://gstreamer-devel.966125.n4.nabble.com/appsrc-undefined-reference-to-gst-app-buffer-new-tp4174142p4176080.html" target="_blank" rel="nofollow" link="external">http://gstreamer-devel.966125.n4.nabble.com/appsrc-undefined-reference-to-gst-app-buffer-new-tp4174142p4176080.html</a> </div> <div style="color: rgb(102, 102, 102); font: 11px/1.5em tahoma,geneva,helvetica,arial,sans-serif; margin-top: 0.4em;"> To unsubscribe from appsrc undefined reference to 'gst_app_buffer_new', <a href="" target="_blank" rel="nofollow" link="external">click here</a>. <a href="http://gstreamer-devel.966125.n4.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.InstantMailNamespace&breadcrumbs=instant+emails%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml" rel="nofollow" style="font: 9px serif;" target="_blank" link="external">NAML</a> </div></blockquote></div> <hr align="left" width="300" /> View this message in context: <a href="http://gstreamer-devel.966125.n4.nabble.com/appsrc-undefined-reference-to-gst-app-buffer-new-tp4174142p4176938.html">Re: appsrc undefined reference to 'gst_app_buffer_new'</a> Sent from the <a href="http://gstreamer-devel.966125.n4.nabble.com/">GStreamer-devel mailing list archive</a> at Nabble.com.