2 * mixer.c - stereo audio mixer - thomas@apestaart.org
3 * example based on helloworld
4 * demonstrates the adder plugin and the volume envelope plugin
5 * work in progress but do try it out
7 * Latest change : 28/04/2001
8 * trying to adapt to incsched
9 * delayed start for channels > 1
10 * now works by quickhacking the
12 * GST_ELEMENT_COTHREAD_STOPPING
24 //#define AUTOPLUG /* define if you want autoplugging of input channels */
25 /* function prototypes */
27 input_channel_t* create_input_channel (int id, char* location);
28 void destroy_input_channel (input_channel_t *pipe);
29 void env_register_cp (GstElement *volenv, double cp_time, double cp_level);
35 /* eos will be called when the src element has an end of stream */
36 void eos(GstElement *element)
38 g_print("have eos, quitting ?\n");
44 gst_play_typefind (GstBin *bin, GstElement *element)
50 GST_DEBUG (0,"GstPipeline: typefind for element \"%s\"\n",
51 GST_ELEMENT_NAME(element));
53 pipeline = gst_pipeline_new ("autoplug_pipeline");
55 typefind = gst_elementfactory_make ("typefind", "typefind");
56 g_return_val_if_fail (typefind != NULL, FALSE);
58 gst_pad_connect (gst_element_get_pad (element, "src"),
59 gst_element_get_pad (typefind, "sink"));
60 gst_bin_add (bin, typefind);
61 gst_bin_add (GST_BIN (pipeline), GST_ELEMENT (bin));
63 gst_element_set_state (pipeline, GST_STATE_PLAYING);
65 // push a buffer... the have_type signal handler will set the found flag
66 gst_bin_iterate (GST_BIN (pipeline));
68 gst_element_set_state (pipeline, GST_STATE_NULL);
70 caps = gst_pad_get_caps (gst_element_get_pad (element, "src"));
72 gst_pad_disconnect (gst_element_get_pad (element, "src"),
73 gst_element_get_pad (typefind, "sink"));
74 gst_bin_remove (bin, typefind);
75 gst_bin_remove (GST_BIN (pipeline), GST_ELEMENT (bin));
76 gst_object_unref (GST_OBJECT (typefind));
77 gst_object_unref (GST_OBJECT (pipeline));
82 int main(int argc,char *argv[])
90 GList *input_channels; /* structure holding all the input channels */
92 input_channel_t *channel_in;
96 GstElement *audiosink;
98 GstPad *pad; /* to request pads for the adder */
100 gst_init(&argc,&argv);
103 g_print("usage: %s <filename1> <filename2> <...>\n", argv[0]);
106 num_channels = argc - 1;
108 /* set up output channel and main bin */
111 adder = gst_elementfactory_make ("adder", "adderel");
113 /* create an audio sink */
114 audiosink = gst_elementfactory_make ("esdsink", "play_audio");
116 /* create main bin */
117 main_bin = gst_pipeline_new("bin");
119 /* connect adder and output to bin */
120 GST_INFO (0, "main: adding adder to bin");
121 gst_bin_add (GST_BIN(main_bin), adder);
122 GST_INFO (0, "main: adding audiosink to bin");
123 gst_bin_add (GST_BIN(main_bin), audiosink);
125 /* connect adder and audiosink */
127 gst_pad_connect(gst_element_get_pad(adder,"src"),
128 gst_element_get_pad(audiosink,"sink"));
131 input_channels = NULL;
133 for (i = 1; i < argc; ++i)
135 printf ("Opening channel %d from file %s...\n", i, argv[i]);
136 channel_in = create_input_channel (i, argv[i]);
137 input_channels = g_list_append (input_channels, channel_in);
139 if (i > 1) gst_element_set_state (main_bin, GST_STATE_PAUSED);
140 gst_bin_add (GST_BIN(main_bin), channel_in->pipe);
142 /* request pads and connect to adder */
143 GST_INFO (0, "requesting pad\n");
144 pad = gst_element_request_pad_by_name (adder, "sink%d");
145 printf ("\tGot new adder sink pad %s\n", gst_pad_get_name (pad));
146 sprintf (buffer, "channel%d", i);
147 gst_pad_connect (gst_element_get_pad (channel_in->pipe, buffer), pad);
149 /* register a volume envelope */
150 printf ("\tregistering volume envelope...\n");
153 * this is the volenv :
154 * each song gets a slot of 5 seconds, with a 5 second fadeout
155 * at the end of that, all audio streams play simultaneously
156 * at a level ensuring no distortion
157 * example for three songs :
158 * song1 : starts at full level, plays 5 seconds, faded out at 10 seconds,
159 * sleep until 25, fade to end level at 30
160 * song2 : starts silent, fades in at 5 seconds, full blast at 10 seconds,
161 * full level until 15, faded out at 20, sleep until 25, fade to end at 30
162 * song3 : starts muted, fades in from 15, full at 20, until 25, fade to end level
167 /* first song gets special treatment for end style */
168 env_register_cp (channel_in->volenv, 0.0, 1.0);
172 env_register_cp (channel_in->volenv, 0.0 , 0.0000001); /* start muted */
173 env_register_cp (channel_in->volenv, i * 10.0 - 15.0, 0.0000001); /* start fade in */
174 env_register_cp (channel_in->volenv, i * 10.0 - 10.0, 1.0);
176 env_register_cp (channel_in->volenv, i * 10.0 - 5.0, 1.0); /* end of full level */
178 if (i != num_channels)
180 env_register_cp (channel_in->volenv, i * 10.0 , 0.0000001); /* fade to black */
181 env_register_cp (channel_in->volenv, num_channels * 10.0 - 5.0, 0.0000001); /* start fade in */
183 env_register_cp (channel_in->volenv, num_channels * 10.0 , 1.0 / num_channels); /* to end level */
185 xmlSaveFile("mixer.xml", gst_xml_write(GST_ELEMENT(main_bin)));
188 gst_element_set_state(main_bin, GST_STATE_PLAYING);
190 // write out the schedule
191 gst_schedule_show(GST_ELEMENT_SCHED(main_bin));
195 //printf ("main: start iterating from 0");
196 while (playing && j < 100)
198 // printf ("main: iterating %d\n", j);
199 gst_bin_iterate(GST_BIN(main_bin));
200 //fprintf(stderr,"after iterate()\n");
204 printf ("main: all the channels are open\n");
207 gst_bin_iterate(GST_BIN(main_bin));
208 //fprintf(stderr,"after iterate()\n");
211 gst_element_set_state(main_bin, GST_STATE_NULL);
213 while (input_channels)
215 destroy_input_channel (input_channels->data);
216 input_channels = g_list_next (input_channels);
218 g_list_free (input_channels);
220 gst_object_destroy(GST_OBJECT(audiosink));
222 gst_object_destroy(GST_OBJECT(main_bin));
228 create_input_channel (int id, char* location)
230 /* create an input channel, reading from location
231 * return a pointer to the channel
232 * return NULL if failed
235 input_channel_t *channel;
237 char buffer[20]; /* hold the names */
239 GstAutoplug *autoplug;
241 GstElement *new_element;
244 GST_DEBUG (0, "c_i_p : creating channel with id %d for file %s\n",
247 /* allocate channel */
249 channel = (input_channel_t *) malloc (sizeof (input_channel_t));
252 printf ("create_input_channel : could not allocate memory for channel !\n");
258 GST_DEBUG (0, "c_i_p : creating pipeline\n");
260 sprintf (buffer, "pipeline%d", id);
261 channel->pipe = gst_bin_new (buffer);
262 g_assert(channel->pipe != NULL);
264 /* create elements */
266 GST_DEBUG(0, "c_i_p : creating disksrc\n");
268 sprintf (buffer, "disksrc%d", id);
269 channel->disksrc = gst_elementfactory_make ("disksrc", buffer);
270 g_assert(channel->disksrc != NULL);
272 GST_DEBUG(0, "c_i_p : setting location\n");
273 gtk_object_set(GTK_OBJECT(channel->disksrc),"location", location, NULL);
275 /* add disksrc to the bin before autoplug */
276 gst_bin_add(GST_BIN(channel->pipe), channel->disksrc);
278 /* connect signal to eos of disksrc */
279 gtk_signal_connect(GTK_OBJECT(channel->disksrc),"eos",
280 GTK_SIGNAL_FUNC(eos),NULL);
284 printf ("DEBUG : c_i_p : creating volume envelope\n");
287 sprintf (buffer, "volenv%d", id);
288 channel->volenv = gst_elementfactory_make ("volenv", buffer);
289 g_assert(channel->volenv != NULL);
291 /* autoplug the pipe */
294 printf ("DEBUG : c_i_p : getting srccaps\n");
298 srccaps = gst_play_typefind (GST_BIN (channel->pipe), channel->disksrc);
302 GstElement *pipeline;
304 pipeline = gst_pipeline_new ("autoplug_pipeline");
306 gst_bin_add (GST_BIN (pipeline), channel->pipe);
307 gst_element_set_state (pipeline, GST_STATE_PLAYING);
308 gst_element_set_state (pipeline, GST_STATE_NULL);
309 gst_bin_remove (GST_BIN (pipeline), channel->pipe);
316 g_print ("could not autoplug, unknown media type...\n");
321 printf ("DEBUG : c_i_p : creating autoplug\n");
324 autoplug = gst_autoplugfactory_make ("static");
325 g_assert (autoplug != NULL);
328 printf ("DEBUG : c_i_p : autoplugging\n");
331 new_element = gst_autoplug_to_caps (autoplug, srccaps,
332 gst_caps_new ("audio", "audio/raw", NULL), NULL);
335 g_print ("could not autoplug, no suitable codecs found...\n");
341 new_element = gst_bin_new ("autoplug_bin");
343 /* static plug, use mad plugin and assume mp3 input */
344 decoder = gst_elementfactory_make ("mad", "mpg123");
346 gst_bin_add (GST_BIN (new_element), decoder);
348 gst_element_add_ghost_pad (new_element,
349 gst_element_get_pad (decoder, "sink"), "sink");
350 gst_element_add_ghost_pad (new_element,
351 gst_element_get_pad (decoder, "src"), "src_00");
354 xmlSaveFile ("mixer.gst", gst_xml_write (new_element));
356 gst_bin_add (GST_BIN(channel->pipe), channel->volenv);
357 gst_bin_add (GST_BIN (channel->pipe), new_element);
359 gst_element_connect (channel->disksrc, "src", new_element, "sink");
360 gst_element_connect (new_element, "src_00", channel->volenv, "sink");
362 /* add a ghost pad */
363 sprintf (buffer, "channel%d", id);
364 gst_element_add_ghost_pad (channel->pipe,
365 gst_element_get_pad (channel->volenv, "src"), buffer);
369 printf ("DEBUG : c_i_p : end function\n");
376 destroy_input_channel (input_channel_t *channel)
379 * destroy an input channel
383 printf ("DEBUG : d_i_p : start\n");
386 /* destroy elements */
388 gst_object_destroy (GST_OBJECT (channel->pipe));
393 void env_register_cp (GstElement *volenv, double cp_time, double cp_level)
397 sprintf (buffer, "%f:%f", cp_time, cp_level);
398 gtk_object_set(GTK_OBJECT(volenv), "controlpoint", buffer, NULL);