[gst-devel] Converting pipeline to C
Stefan Kost
ensonic at hora-obscura.de
Wed Oct 28 09:54:47 CET 2009
hi,
This is wrong
gst_element_link_many (source, demuxer, decoder, sink, NULL);
do
gst_element_link(source, demuxer);
gst_element_link(decoder, sink);
you will link demuxer to decoder in the on_pad_added() callback.
Stefan
>
> On Wed, Oct 28, 2009 at 12:12 AM, Gabriel Duarte <confusosk8 at gmail.com
> <mailto:confusosk8 at gmail.com>> wrote:
>
> sorry, I sent the wrong code, this is the right:
>
> #include <gst/gst.h>
> #include <glib.h>
>
>
> static gboolean
> cb_print_position (GstElement *pipeline)
> {
> GstFormat fmt = GST_FORMAT_TIME;
> gint64 pos, len;
>
> if (gst_element_query_position (pipeline, &fmt, &pos)
> && gst_element_query_duration (pipeline, &fmt, &len)) {
> g_print ("Time: %" GST_TIME_FORMAT " / %" GST_TIME_FORMAT "\r",
> GST_TIME_ARGS (pos), GST_TIME_ARGS (len));
> }
>
> /* call me again */
> return TRUE;
> }
>
>
>
> 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, *demuxer, *decoder, *sink;
> GstBus *bus;
>
> /* 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;
> }*/
>
> /*gst-launch-0.10 dv1394src num-buffers=8192 ! dvdemux ! dvdec !
> xvimagesink sync=false*/
> /* Create gstreamer elements */
> pipeline = gst_pipeline_new ("DV_FIREWIRE");
> source = gst_element_factory_make ("dv1394src",
> "dv1394src");
> demuxer = gst_element_factory_make ("dvdemux", "dvdemux");
> decoder = gst_element_factory_make ("dvdec", "dvdec");
> sink = gst_element_factory_make ("ximagesink", "ximagesink");
>
> if (!pipeline || !source || !demuxer || !decoder || !sink) {
> g_printerr ("One element could not be created. Exiting.\n");
> return -1;
> }
>
> /* Set up the pipeline */
>
> /* we set the input filename to the source element */
> /*g_object_set (G_OBJECT (sink), "sync", FALSE, NULL);*/
>
> /* 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 */
> /* file-source | ogg-demuxer | vorbis-decoder | converter |
> alsa-output */
> gst_bin_add_many (GST_BIN (pipeline), source, demuxer, decoder,
> sink, NULL);
>
> /* we link the elements together */
> /* file-source -> ogg-demuxer ~> vorbis-decoder -> converter ->
> alsa-output */
> /* gst_element_link (source, demuxer);*/
> gst_element_link_many (source, demuxer, decoder, sink, NULL);
> g_signal_connect (demuxer, "pad-added", G_CALLBACK
> (on_pad_added), decoder);
>
> /* note that the demuxer will be linked to the decoder dynamically.
> The reason is that Ogg may contain various streams (for example
> audio and video). The source pad(s) will be created at run time,
> by the demuxer when it detects the amount and nature of streams.
> Therefore we connect a callback function which will be executed
> when the "pad-added" is emitted.*/
>
>
> /* Set the pipeline to "playing" state*/
> g_print ("Now playing: %s\n", argv[1]);
> gst_element_set_state (pipeline, GST_STATE_PLAYING);
>
>
> /* Iterate */
> g_print ("Running...\n");
> g_timeout_add (200, (GSourceFunc) cb_print_position, pipeline);
> g_main_loop_run (loop);
>
>
> /* Out of the main loop, clean up nicely */
> 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));
> printf("THE END\n");
> return 0;
> }
>
>
> On Tue, Oct 27, 2009 at 8:24 PM, Gabriel Duarte
> <confusosk8 at gmail.com <mailto:confusosk8 at gmail.com>> wrote:
>
> hello all, I'm trying to convert this pipeline to C, but I'm
> having problems....
>
>
> gst-launch-0.10 dv1394src num-buffers=8192 ! dvdemux ! dvdec !
> xvimagesink sync=false
>
>
> I've wrote this code:
>
>
> #include <string.h> /* for memset () */
> #include <gst/gst.h>
>
> static void
> cb_handoff (GstElement *fakesrc,
> GstBuffer *buffer,
> GstPad *pad,
> gpointer user_data)
> {
> static gboolean white = FALSE;
>
> /* this makes the image black/white */
> memset (GST_BUFFER_DATA (buffer), white ? 0xff : 0x0,
> GST_BUFFER_SIZE (buffer));
> white = !white;
> }
>
> gint
> main (gint argc,
> gchar *argv[])
> {
> GstElement *pipeline, *fakesrc, *flt, *conv, *videosink;
> GMainLoop *loop;
>
> /* init GStreamer */
> gst_init (&argc, &argv);
> loop = g_main_loop_new (NULL, FALSE);
>
> /* setup pipeline */
> pipeline = gst_pipeline_new ("pipeline");
> fakesrc = gst_element_factory_make ("fakesrc", "source");
> flt = gst_element_factory_make ("capsfilter", "flt");
> conv = gst_element_factory_make ("ffmpegcolorspace", "conv");
> videosink = gst_element_factory_make ("xvimagesink", "videosink");
>
> /* setup */
> g_object_set (G_OBJECT (flt), "caps",
> gst_caps_new_simple ("video/x-raw-rgb",
> "width", G_TYPE_INT, 384,
> "height", G_TYPE_INT, 288,
> "framerate", GST_TYPE_FRACTION, 1, 1,
> "bpp", G_TYPE_INT, 16,
> "depth", G_TYPE_INT, 16,
> "endianness", G_TYPE_INT, G_BYTE_ORDER,
> NULL), NULL);
> gst_bin_add_many (GST_BIN (pipeline), fakesrc, flt, conv, videosink, NULL);
> gst_element_link_many (fakesrc, flt, conv, videosink, NULL);
>
> /* setup fake source */
> g_object_set (G_OBJECT (fakesrc),
> "signal-handoffs", TRUE,
> "sizemax", 384 * 288 * 2,
> "sizetype", 2, NULL);
> g_signal_connect (fakesrc, "handoff", G_CALLBACK (cb_handoff), NULL);
>
> /* play */
> gst_element_set_state (pipeline, GST_STATE_PLAYING);
> g_main_loop_run (loop);
>
> /* clean up */
> gst_element_set_state (pipeline, GST_STATE_NULL);
> gst_object_unref (GST_OBJECT (pipeline));
>
> return 0;
> }
>
>
>
>
>
> Any ideas???
>
> Best regards :D
>
>
>
>
>
>
> --
> Gabriel Duarte
> Linux User #471185
> Rio de Janeiro - RJ
> http://kinuxlinux.org/gabriel_duarte
>
> Phones:
> (55) (21) 9463-7760 /*Mobile*/
> (55) (21) 2464-9302 /*Home*/
> (55) (21) 2529-5080 /*Work*/
>
>
> -----BEGIN GEEK CODE BLOCK-----
> Version: 3.12
> GCS d- s: a--- C++ UL+++ P L++++ E- W+ N++ o++ K++ w---
> O- M- V- PS++ PE++ Y PGP- t++ 5-- X+++ R tv++ b++ DI+ D++
> G++ e+ h* r+ y++++
> ------END GEEK CODE BLOCK------
>
>
>
>
> --
> Gabriel Duarte
> Linux User #471185
> Rio de Janeiro - RJ
> http://kinuxlinux.org/gabriel_duarte
>
> Phones:
> (55) (21) 9463-7760 /*Mobile*/
> (55) (21) 2464-9302 /*Home*/
> (55) (21) 2529-5080 /*Work*/
>
>
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