GStreamer基础教程3：动态管道 里面的code不能正常运行。
参考：
GStreamer Windows 基辅3：全手动，声像作例，汝作大像也。导演：卡卡，你说老毛子东西啊？应该是 G 公创 Pad 极，1 曰 Video，二曰 Audio 需要改变成
#include <gst/gst.h>
/* Structure to contain all our information, so we can pass it to callbacks */
typedef struct _CustomData
{
GstElement* pipeline;
GstElement* source;
// audio
GstElement* audioConvert;
GstElement* audioResample;
GstElement* audioSink;
// video
GstElement* videoConvert;
GstElement* videoSink;
} CustomData;
/* Handler for the pad-added signal */
static void pad_added_handler (GstElement *src, GstPad *pad, CustomData *data);
int main(int argc, char *argv[]) {
CustomData data;
GstBus *bus;
GstMessage *msg;
GstStateChangeReturn ret;
gboolean terminate = FALSE;
/* Initialize GStreamer */
gst_init (&argc, &argv);
/* Create the elements */
data.source = gst_element_factory_make("uridecodebin", "source");
// audio
data.audioConvert = gst_element_factory_make("audioconvert", "convert");
data.audioResample = gst_element_factory_make("audioresample", "resample");
data.audioSink = gst_element_factory_make("autoaudiosink", "sink");
// video
data.videoConvert = gst_element_factory_make("videoconvert", "videoconvert");
data.videoSink = gst_element_factory_make("autovideosink", "video-sink");
data.pipeline = gst_pipeline_new("test-pipeline");
if (!data.pipeline || !data.source || !data.audioConvert || !data.audioResample
|| !data.audioSink || !data.videoConvert || !data.videoSink) {
g_printerr("Not all elements could be created.\n");
return -1;
}
/* Build the pipeline. Note that we are NOT linking the source at this
* point. We will do it later. */
gst_bin_add_many(GST_BIN(data.pipeline), data.source, data.audioConvert, data.audioResample, data.audioSink, NULL);
if (!gst_element_link_many(data.audioConvert, data.audioResample, data.audioSink, NULL)) {
g_printerr("Audio elements could not be linked.\n");
gst_object_unref(data.pipeline);
return -1;
}
gst_bin_add_many(GST_BIN(data.pipeline), data.source, data.videoConvert, data.videoSink, NULL);
if (!gst_element_link_many(data.videoConvert, data.videoSink, NULL)) {
g_printerr("Video elements could not be linked.\n");
gst_object_unref(data.pipeline);
return -1;
}
/* Set the URI to play */
g_object_set (data.source, "uri", "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm", NULL);
/* Connect to the pad-added signal */
g_signal_connect (data.source, "pad-added", G_CALLBACK (pad_added_handler), &data);
/* Start playing */
ret = gst_element_set_state (data.pipeline, GST_STATE_PLAYING);
if (ret == GST_STATE_CHANGE_FAILURE) {
g_printerr ("Unable to set the pipeline to the playing state.\n");
gst_object_unref (data.pipeline);
return -1;
}
/* Listen to the bus */
bus = gst_element_get_bus (data.pipeline);
do {
msg = gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE,
GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
/* Parse message */
if (msg != NULL) {
GError *err;
gchar *debug_info;
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_ERROR:
gst_message_parse_error (msg, &err, &debug_info);
g_printerr ("Error received from element %s: %s\n", GST_OBJECT_NAME (msg->src), err->message);
g_printerr ("Debugging information: %s\n", debug_info ? debug_info : "none");
g_clear_error (&err);
g_free (debug_info);
terminate = TRUE;
break;
case GST_MESSAGE_EOS:
g_print ("End-Of-Stream reached.\n");
terminate = TRUE;
break;
case GST_MESSAGE_STATE_CHANGED:
/* We are only interested in state-changed messages from the pipeline */
if (GST_MESSAGE_SRC (msg) == GST_OBJECT (data.pipeline)) {
GstState old_state, new_state, pending_state;
gst_message_parse_state_changed (msg, &old_state, &new_state, &pending_state);
g_print ("Pipeline state changed from %s to %s:\n",
gst_element_state_get_name (old_state), gst_element_state_get_name (new_state));
}
break;
default:
/* We should not reach here */
g_printerr ("Unexpected message received.\n");
break;
}
gst_message_unref (msg);
}
} while (!terminate);
/* Free resources */
gst_object_unref (bus);
gst_element_set_state (data.pipeline, GST_STATE_NULL);
gst_object_unref (data.pipeline);
return 0;
}
static void pad_added_handler(GstElement* src, GstPad* new_pad, CustomData* data) {
GstPad* audioPad = NULL;
GstPad* videoPad = NULL;
gboolean audioType = FALSE;
GstPadLinkReturn ret;
GstCaps* new_pad_caps = NULL;
GstStructure* new_pad_struct = NULL;
const gchar* new_pad_type = NULL;
g_print("\n ==========> Begin link\n");
g_print("\nReceived new pad '%s' from '%s':\n", GST_PAD_NAME(new_pad), GST_ELEMENT_NAME(src));
/* Check the new pad's type */
new_pad_caps = gst_pad_get_current_caps(new_pad);
new_pad_struct = gst_caps_get_structure(new_pad_caps, 0);
new_pad_type = gst_structure_get_name(new_pad_struct);
g_print("\n\n--------------> Testing audio/video type --------------> \n\n", new_pad_type);
if (g_str_has_prefix(new_pad_type, "audio/x-raw")) {
g_print("Found Raw Audio Type: '%s'\n", new_pad_type);
audioType = TRUE;
goto link;
}
else if (g_str_has_prefix(new_pad_type, "video/x-raw")) {
g_print("Found Raw Video Type: '%s'\n", new_pad_type);
audioType = FALSE;
goto link;
}
else {
g_print("It has type '%s' which is not raw audio/video type. Ignoring.\n", new_pad_type);
goto exit;
}
link:
/* Attempt the link */
if (audioType) {
audioPad = gst_element_get_static_pad(data->audioConvert, "sink");
if (gst_pad_is_linked(audioPad)) {
g_print("We are already linked. Ignoring.\n");
goto exit;
}
// link audio
ret = gst_pad_link(new_pad, audioPad);
}
else {
videoPad = gst_element_get_static_pad(data->videoConvert, "sink");
if (gst_pad_is_linked(videoPad)) {
g_print("We are already linked. Ignoring.\n");
goto exit;
}
// link video
ret = gst_pad_link(new_pad, videoPad);
}
if (GST_PAD_LINK_FAILED(ret)) {
g_print("Type is '%s' but link failed.\n", new_pad_type);
}
else {
g_print("Link succeeded (type '%s').\n", new_pad_type);
}
if (audioType) {
gst_object_unref(audioPad);
}
else {
gst_object_unref(videoPad);
}
exit:
/* Unreference the new pad's caps, if we got them */
if (new_pad_caps != NULL)
gst_caps_unref (new_pad_caps);
}
