GStreamer(Gst) - play wav file

環境: apq8009
gst-launch-1.0

gst-launch-1.0 filesrc location=a.wav ! wavparse ! audioconvert ! autoaudiosink

copy if from gst_HelloWorld and modify it

#include <gst/gst.h>
#include <glib.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:
            break;
    }

    return TRUE;
}


static void on_pad_added (GstElement *element,
                          GstPad     *pad,
                          gpointer    data)
{
    GstPad *sinkpad;
    GstElement *decoder = (GstElement *) data;

    /* We can now link this pad with the vorbis-decoder sink pad */
    g_print ("Dynamic pad created, linking demuxer/decoder\n");

    sinkpad = gst_element_get_static_pad (decoder, "sink");

    gst_pad_link (pad, sinkpad);

    gst_object_unref (sinkpad);
}


int main (int argc, char *argv[])
{
    GMainLoop *loop;

    GstElement *pipeline, *source, *decoder, *conv, *sink;
    GstBus *bus;
    guint bus_watch_id;

    /* Initialisation */
    gst_init (&argc, &argv);

    loop = g_main_loop_new (NULL, FALSE);


    /* Check input arguments */
    if (argc != 2)
    {
        g_printerr ("Usage: %s <Ogg/Vorbis filename>\n", argv[0]);
        return -1;
    }

    /* Create gstreamer elements */
    pipeline = gst_pipeline_new ("audio-player");
    source   = gst_element_factory_make ("filesrc",       "file-source");
    decoder  = gst_element_factory_make ("wavparse", "wav-decoder");
    conv     = gst_element_factory_make ("audioconvert",  "converter");
    sink     = gst_element_factory_make ("autoaudiosink", "audio-output");

    if (!pipeline || !source || !decoder || !conv || !sink)
    {
        g_printerr ("One element could not be created. Exiting.\n");
        return -1;
    }

    g_object_set (G_OBJECT (source), "location", argv[1], NULL);

    bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
    bus_watch_id = gst_bus_add_watch (bus, bus_call, loop);
    gst_object_unref (bus);

    gst_bin_add_many (GST_BIN (pipeline),
                      source, decoder, conv, sink, NULL);

    gst_element_link_many (source, decoder, conv, sink, NULL);
    g_signal_connect (source, "pad-added", G_CALLBACK (on_pad_added), decoder);


    g_print ("Now playing: %s\n", argv[1]);
    gst_element_set_state (pipeline, GST_STATE_PLAYING);


    g_print ("Running...\n");
    g_main_loop_run (loop);


    g_print ("Returned, stopping playback\n");
    gst_element_set_state (pipeline, GST_STATE_NULL);

    g_print ("Deleting pipeline\n");
    gst_object_unref (GST_OBJECT (pipeline));
    g_source_remove (bus_watch_id);
    g_main_loop_unref (loop);

    return 0;
}

Compile:
gcc -Wall helloworld.c -o helloworld $(pkg-config --cflags --libs gstreamer-1.0)


Makefile

CC=gcc
CFLAGS = -MMD
CFLAGS += `pkg-config --cflags --libs gstreamer-1.0`
CFLAGS += -lrt -lpthread

SRCS=$(shell ls *.c)
OBJS = $(patsubst %.c, %.o, $(SRCS))

#Output
OUT_DIR = build
OUT_OBJS = $(addprefix $(OUT_DIR)/, $(OBJS))
DEPS = $(patsubst %.o, %.d, $(OUT_OBJS))

TARGET = y_gst_server

$(OUT_DIR)/$(TARGET): $(OUT_OBJS)
        $(CC) -o $@ $^ $(CFLAGS)

$(OUT_DIR)/%.o:%.c
        mkdir -p $(OUT_DIR)
        $(CC) -c $< -o $@ $(CFLAGS)

clean:
        -rm -rf $(OUT_DIR) $(TARGET) $(OBJS)

ref:
1. gst_HelloWorld(basic-tutorial-1.c)
2. gst_Seeking_example(basic-tutorial-4.c)
3. gst_plugin