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Diffstat (limited to 'tests/examples/app/appsrc-stream2.c')
-rw-r--r-- | tests/examples/app/appsrc-stream2.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/tests/examples/app/appsrc-stream2.c b/tests/examples/app/appsrc-stream2.c new file mode 100644 index 00000000..866b0504 --- /dev/null +++ b/tests/examples/app/appsrc-stream2.c @@ -0,0 +1,219 @@ +/* GStreamer + * + * appsrc-stream2.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 pull mode. When the + * appsrc request data with the need-data signal, we retrieve a buffer of an + * arbitrary size and push it to appsrc. + * + * This example keeps the internal buffer queue of appsrc to a minimal size, + * only feeding data to appsrc when needed. + * + * This is a good example how one would deal with a live resource, such as a udp + * socket where one would feed the most recently acquired buffer to appsrc. + * + * Usually one would timestamp the buffers with the running_time of the + * pipeline or configure the appsrc to do timestamping by setting the + * do-timestamp property to TRUE. + * + * 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; + + GMappedFile *file; + guint8 *data; + gsize length; + guint64 offset; +}; + +App s_app; + +#define CHUNK_SIZE 4096 + +/* This method is called by the need-data signal callback, we feed data into the + * appsrc. + */ +static void +feed_data (GstElement * appsrc, guint size, App * app) +{ + GstBuffer *buffer; + guint len; + GstFlowReturn ret; + + buffer = gst_buffer_new (); + + if (app->offset >= app->length) { + /* we are EOS, send end-of-stream */ + g_signal_emit_by_name (app->appsrc, "end-of-stream", &ret); + return; + } + + /* 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); + gst_buffer_unref (buffer); + + app->offset += len; + + return; +} + +/* 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 a signals to push data into appsrc. */ +static void +found_source (GObject * object, GObject * orig, GParamSpec * pspec, App * app) +{ + /* get a handle to the appsrc */ + g_object_get (orig, 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 a buffer to appsrc when it needs more + * data */ + g_signal_connect (app->appsrc, "need-data", G_CALLBACK (feed_data), 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 */ + 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, "deep-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; +} |