gst-basic-tutorial-1/basic-tutorial-3.c

166 lines
5.6 KiB
C

#include <gst/gst.h>
/* Structure to contain all our information, so we can pass it to callbacks*/
typedef struct _CustomData
{
GstElement *pipeline;
GstElement *source;
GstElement *convert;
GstElement *resample;
GstElement *audio_sink;
GstElement *video_sink;
} CustomData;
static void pad_added_handler(GstElement *src, GstPad *new_pad,CustomData *data);
int main(int argc, char *argv[])
{
CustomData data;
GstBus *bus;
GstMessage *message;
GstStateChangeReturn ret;
gboolean terminate = FALSE;
gst_init(&argc,&argv);
data.source = gst_element_factory_make("uridecodebin","source");
data.convert = gst_element_factory_make("audioconvert","convert");
data.resample = gst_element_factory_make("audioresample","resample");
data.audio_sink = gst_element_factory_make("autoaudiosink","audio_sink");
data.video_sink = gst_element_factory_make("autovideosink","video_sink");
data.pipeline = gst_pipeline_new("test-pipeline");
if(!data.pipeline|| !data.source || !data.convert || !data.resample || ! data.audio_sink || !data.video_sink)
{
g_printerr("Not all elements could be created.\n");
return -1;
}
gst_bin_add_many(GST_BIN(data.pipeline),data.source,data.convert,data.resample,data.audio_sink,data.video_sink,NULL);
if(!gst_element_link_many(data.convert,data.resample,data.audio_sink,NULL))
{
g_printerr("Elements could not be linked.\n");
gst_object_unref(data.pipeline);
return -1;
}
// g_object_set(data.source,"uri","https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm",NULL);
g_object_set(data.source,"uri","https://media.w3.org/2010/05/sintel/trailer.mp4",NULL);
g_signal_connect(data.source,"pad-added",G_CALLBACK(pad_added_handler),&data);
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;
}
bus = gst_element_get_bus(data.pipeline);
do {
message = gst_bus_timed_pop_filtered(bus,GST_CLOCK_TIME_NONE,GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
if(message != NULL)
{
GError *err;
gchar *debug_info;
switch(GST_MESSAGE_TYPE(message))
{
case GST_MESSAGE_ERROR:
gst_message_parse_error(message,&err,&debug_info);
g_printerr("Error recevied from element %s:%s\n",GST_OBJECT_NAME(message->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_printerr("End-Of-Stream reached.\n");
terminate = TRUE;
break;
case GST_MESSAGE_STATE_CHANGED:
if(GST_MESSAGE_SRC(message) == GST_OBJECT(data.pipeline))
{
GstState old_state, new_state, pending_state;
gst_message_parse_state_changed (message,&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:
g_printerr("Unexpected message received!\n");
break;
}
gst_message_unref(message);
}
} while (!terminate);
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 *audio_sink_pad = gst_element_get_static_pad(data->convert,"sink");
GstPad *video_sink_pad = gst_element_get_static_pad(data->video_sink,"sink");
GstPadLinkReturn ret;
GstCaps *new_pad_caps = NULL;
GstStructure *new_pad_struct = NULL;
const gchar *new_pad_type = NULL;
g_print("Received new pad '%s' from '%s':\n",GST_PAD_NAME(new_pad),GST_ELEMENT_NAME(src));
if(gst_pad_is_linked(audio_sink_pad))// && gst_pad_is_linked(video_sink_pad))
{
g_print("We are already linked. Ignoring.\n");
goto exit;
}
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);
if(g_str_has_prefix(new_pad_type,"audio/x-raw"))
{
ret = gst_pad_link(new_pad,audio_sink_pad);
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);
}
}
else if(g_str_has_prefix(new_pad_type,"video/x-raw"))
{
ret = gst_pad_link(new_pad,video_sink_pad);
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);
}
}
else
{
g_print("It has type '%s' which is not raw audio. Ignoring.\n",new_pad_type);
goto exit;
}
exit:
if(new_pad_caps != NULL)
{
gst_caps_unref(new_pad_caps);
}
gst_object_unref(audio_sink_pad);
}