diff options
Diffstat (limited to 'examples')
-rw-r--r-- | examples/app/.gitignore | 1 | ||||
-rw-r--r-- | examples/app/Makefile.am | 5 | ||||
-rw-r--r-- | examples/app/appsrc-stream.c | 248 | ||||
-rw-r--r-- | examples/app/appsrc_ex.c | 4 |
4 files changed, 256 insertions, 2 deletions
diff --git a/examples/app/.gitignore b/examples/app/.gitignore index f76db7ef..27d8cc2a 100644 --- a/examples/app/.gitignore +++ b/examples/app/.gitignore @@ -1 +1,2 @@ appsrc_ex +appsrc-stream diff --git a/examples/app/Makefile.am b/examples/app/Makefile.am index 0b950515..db1393dd 100644 --- a/examples/app/Makefile.am +++ b/examples/app/Makefile.am @@ -1,5 +1,5 @@ -noinst_PROGRAMS = appsrc_ex +noinst_PROGRAMS = appsrc_ex appsrc-stream appsrc_ex_SOURCES = appsrc_ex.c appsrc_ex_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS) @@ -7,3 +7,6 @@ appsrc_ex_LDFLAGS = \ $(GST_LIBS) \ $(top_builddir)/gst-libs/gst/app/libgstapp-@GST_MAJORMINOR@.la +appsrc_stream_SOURCES = appsrc-stream.c +appsrc_stream_CFLAGS = $(GST_CFLAGS) $(GCONF_CFLAGS) +appsrc_stream_LDFLAGS = $(GST_LIBS) diff --git a/examples/app/appsrc-stream.c b/examples/app/appsrc-stream.c new file mode 100644 index 00000000..781adc31 --- /dev/null +++ b/examples/app/appsrc-stream.c @@ -0,0 +1,248 @@ +/* GStreamer + * + * appsrc-stream.c: example for using appsrc in streaming mode. + * + * Copyright (C) 2008 Wim Taymans <wim.taymans@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gst/gst.h> + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +GST_DEBUG_CATEGORY (appsrc_playbin_debug); +#define GST_CAT_DEFAULT appsrc_playbin_debug + +/** + * an example application of using appsrc in streaming push mode. We simply push + * buffers into appsrc. The size of the buffers we push can be any size we + * choose. + * + * This example is very close to how one would deal with a streaming webserver + * that does not support range requests or does not report the total file size. + * + * Some optimisations are done so that we don't push too much data. We connect + * to the need-data and enough-data signals to start/stop sending buffers. + * + * Appsrc in streaming mode (the default) does not support seeking so we don't + * have to handle any seek callbacks. + * + * Some formats are able to estimate the duration of the media file based on the + * file length (mp3, mpeg,..), others report an unknown length (ogg,..). + */ +typedef struct _App App; + +struct _App +{ + GstElement *playbin; + GstElement *appsrc; + + GMainLoop *loop; + guint sourceid; + + GMappedFile *file; + guint8 *data; + gsize length; + guint64 offset; +}; + +App s_app; + +#define CHUNK_SIZE 4096 + +/* This method is called by the idle GSource in the mainloop. We feed CHUNK_SIZE + * bytes into appsrc. + * The ide handler is added to the mainloop when appsrc requests us to start + * sending data (need-data signal) and is removed when appsrc has enough data + * (enough-data signal). + */ +static gboolean +read_data (App * app) +{ + GstBuffer *buffer; + guint len; + GstFlowReturn ret; + + buffer = gst_buffer_new (); + + if (app->offset >= app->length) { + /* we are EOS, send end-of-stream and remove the source */ + g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret); + return FALSE; + } + + /* read the next chunk */ + len = CHUNK_SIZE; + if (app->offset + len > app->length) + len = app->length - app->offset; + + GST_BUFFER_DATA (buffer) = app->data + app->offset; + GST_BUFFER_SIZE (buffer) = len; + + GST_DEBUG ("feed buffer %p, offset %" G_GUINT64_FORMAT "-%u", buffer, + app->offset, len); + g_signal_emit_by_name (app->appsrc, "push-buffer", buffer, &ret); + if (ret != GST_FLOW_OK) { + /* some error, stop sending data */ + return FALSE; + } + + app->offset += len; + + return TRUE; +} + +/* This signal callback is called when appsrc needs data, we add an idle handler + * to the mainloop to start pushing data into the appsrc */ +static void +start_feed (GstElement * playbin, guint size, App * app) +{ + if (app->sourceid == 0) { + GST_DEBUG ("start feeding"); + app->sourceid = g_idle_add ((GSourceFunc) read_data, app); + } +} + +/* This callback is called when appsrc has enough data and we can stop sending. + * We remove the idle handler from the mainloop */ +static void +stop_feed (GstElement * playbin, App * app) +{ + if (app->sourceid != 0) { + GST_DEBUG ("stop feeding"); + g_source_remove (app->sourceid); + app->sourceid = 0; + } +} + +/* this callback is called when playbin2 has constructed a source object to read + * from. Since we provided the appsrc:// uri to playbin2, this will be the + * appsrc that we must handle. We set up some signals to start and stop pushing + * data into appsrc */ +static void +found_source (GObject * playbin, GParamSpec * pspec, App * app) +{ + /* get a handle to the appsrc */ + g_object_get (playbin, pspec->name, &app->appsrc, NULL); + + GST_DEBUG ("got appsrc %p", app->appsrc); + + /* we can set the length in appsrc. This allows some elements to estimate the + * total duration of the stream. It's a good idea to set the property when you + * can but it's not required. */ + g_object_set (app->appsrc, "size", app->length, NULL); + + /* configure the appsrc, we will push data into the appsrc from the + * mainloop. */ + g_signal_connect (app->appsrc, "need-data", G_CALLBACK (start_feed), app); + g_signal_connect (app->appsrc, "enough-data", G_CALLBACK (stop_feed), app); +} + +static gboolean +bus_message (GstBus * bus, GstMessage * message, App * app) +{ + GST_DEBUG ("got message %s", + gst_message_type_get_name (GST_MESSAGE_TYPE (message))); + + switch (GST_MESSAGE_TYPE (message)) { + case GST_MESSAGE_ERROR: + g_error ("received error"); + g_main_loop_quit (app->loop); + break; + case GST_MESSAGE_EOS: + g_main_loop_quit (app->loop); + break; + default: + break; + } + return TRUE; +} + +int +main (int argc, char *argv[]) +{ + App *app = &s_app; + GError *error = NULL; + GstBus *bus; + + gst_init (&argc, &argv); + + GST_DEBUG_CATEGORY_INIT (appsrc_playbin_debug, "appsrc-playbin", 0, + "appsrc playbin example"); + + if (argc < 2) { + g_print ("usage: %s <filename>\n", argv[0]); + return -1; + } + + /* try to open the file as an mmapped file */ + app->file = g_mapped_file_new (argv[1], FALSE, &error); + if (error) { + g_print ("failed to open file: %s\n", error->message); + g_error_free (error); + return -2; + } + /* get some vitals, this will be used to read data from the mmapped file and + * feed it to appsrc. */ + app->length = g_mapped_file_get_length (app->file); + app->data = (guint8 *) g_mapped_file_get_contents (app->file); + app->offset = 0; + + /* create a mainloop to get messages and to handle the idle handler that will + * feed data to appsrc. */ + app->loop = g_main_loop_new (NULL, TRUE); + + app->playbin = gst_element_factory_make ("playbin2", NULL); + g_assert (app->playbin); + + bus = gst_pipeline_get_bus (GST_PIPELINE (app->playbin)); + + /* add watch for messages */ + gst_bus_add_watch (bus, (GstBusFunc) bus_message, app); + + /* set to read from appsrc */ + g_object_set (app->playbin, "uri", "appsrc://", NULL); + + /* get notification when the source is created so that we get a handle to it + * and can configure it */ + g_signal_connect (app->playbin, "notify::source", (GCallback) found_source, + app); + + /* go to playing and wait in a mainloop. */ + gst_element_set_state (app->playbin, GST_STATE_PLAYING); + + /* this mainloop is stopped when we receive an error or EOS */ + g_main_loop_run (app->loop); + + GST_DEBUG ("stopping"); + + gst_element_set_state (app->playbin, GST_STATE_NULL); + + /* free the file */ + g_mapped_file_free (app->file); + + gst_object_unref (bus); + g_main_loop_unref (app->loop); + + return 0; +} diff --git a/examples/app/appsrc_ex.c b/examples/app/appsrc_ex.c index c6f8b29e..bc629fb0 100644 --- a/examples/app/appsrc_ex.c +++ b/examples/app/appsrc_ex.c @@ -62,8 +62,8 @@ main (int argc, char *argv[]) data = malloc (100); memset (data, i, 100); - printf ("%d: creating buffer for pointer %p\n", i, data); buf = gst_app_buffer_new (data, 100, dont_eat_my_chicken_wings, data); + printf ("%d: creating buffer for pointer %p, %p\n", i, data, buf); gst_app_src_push_buffer (GST_APP_SRC (app->src), buf); } @@ -73,8 +73,10 @@ main (int argc, char *argv[]) GstBuffer *buf; buf = gst_app_sink_pull_buffer (GST_APP_SINK (app->sink)); + printf ("retrieved buffer %p\n", buf); gst_buffer_unref (buf); } + gst_element_set_state (app->pipe, GST_STATE_NULL); return 0; } |