gstreamer/examples/mixer/mixer.c
Thomas Vander Stichele 4ad674a2a2 mixer now works with variable inputs mixer creates custom volume envelopes allowing each song to play alone and end w...
Original commit message from CVS:
* mixer now works with variable inputs
* mixer creates custom volume envelopes allowing each song to play alone
and end with a mix of all of them, undistorted
2001-04-18 16:08:59 +00:00

360 lines
9.3 KiB
C

/*
* mixer.c - stereo audio mixer - thomas@apestaart.org
* example based on helloworld
* demonstrates the adder plugin and the volume envelope plugin
* work in progress but do try it out
*
* Latest change : 16/04/2001
* multiple input channels allowed
* volume envelope adapted
* Version : 0.3
*/
#include <stdlib.h>
#include <gst/gst.h>
#include "mixer.h"
#include <unistd.h>
//#define DEBUG
/* function prototypes */
input_channel_t* create_input_channel (int id, char* location);
void destroy_input_channel (input_channel_t *pipe);
void env_register_cp (GstElement *volenv, double cp_time, double cp_level);
gboolean playing;
/* eos will be called when the src element has an end of stream */
void eos(GstElement *element)
{
g_print("have eos, quitting ?\n");
// playing = FALSE;
}
static void
gst_play_have_type (GstElement *sink, GstElement *sink2, gpointer data)
{
GST_DEBUG (0,"GstPipeline: play have type %p\n", (gboolean *)data);
*(gboolean *)data = TRUE;
}
static GstCaps*
gst_play_typefind (GstBin *bin, GstElement *element)
{
gboolean found = FALSE;
GstElement *typefind;
GstCaps *caps = NULL;
GST_DEBUG (0,"GstPipeline: typefind for element \"%s\" %p\n",
GST_ELEMENT_NAME(element), &found);
typefind = gst_elementfactory_make ("typefind", "typefind");
g_return_val_if_fail (typefind != NULL, FALSE);
gtk_signal_connect (GTK_OBJECT (typefind), "have_type",
GTK_SIGNAL_FUNC (gst_play_have_type), &found);
gst_pad_connect (gst_element_get_pad (element, "src"),
gst_element_get_pad (typefind, "sink"));
gst_bin_add (bin, typefind);
gst_element_set_state (GST_ELEMENT (bin), GST_STATE_PLAYING);
// push a buffer... the have_type signal handler will set the found flag
gst_bin_iterate (bin);
gst_element_set_state (GST_ELEMENT (bin), GST_STATE_NULL);
caps = gst_pad_get_caps (gst_element_get_pad (element, "src"));
gst_pad_disconnect (gst_element_get_pad (element, "src"),
gst_element_get_pad (typefind, "sink"));
gst_bin_remove (bin, typefind);
gst_object_unref (GST_OBJECT (typefind));
return caps;
}
int main(int argc,char *argv[])
{
int i;
int num_channels;
char buffer[20];
GList *input_channels; /* structure holding all the input channels */
input_channel_t *channel_in;
GstElement *main_bin;
GstElement *adder;
GstElement *audiosink;
GstPad *pad; /* to request pads for the adder */
gst_init(&argc,&argv);
if (argc == 1) {
g_print("usage: %s <filename1> <filename2> <...>\n", argv[0]);
exit(-1);
}
num_channels = argc - 1;
/* set up output channel and main bin */
/* create adder */
adder = gst_elementfactory_make("adder", "adderel");
/* create an audio sink */
audiosink = gst_elementfactory_make("esdsink", "play_audio");
/* create main bin */
main_bin = gst_bin_new("bin");
/* connect adder and output to bin */
gst_bin_add(GST_BIN(main_bin), adder);
gst_bin_add(GST_BIN(main_bin), audiosink);
/* connect adder and audiosink */
gst_pad_connect(gst_element_get_pad(adder,"src"),
gst_element_get_pad(audiosink,"sink"));
/* create input channels, add to bin and connect */
input_channels = NULL;
for (i = 1; i < argc; ++i)
{
printf ("Opening channel %d from file %s...\n", i, argv[i]);
channel_in = create_input_channel (i, argv[i]);
input_channels = g_list_append (input_channels, channel_in);
gst_bin_add(GST_BIN(main_bin), channel_in->pipe);
/* request pads and connect to adder */
pad = gst_element_request_pad_by_name (adder, "sink%d");
g_print ("\tGot new adder sink pad %s\n", gst_pad_get_name (pad));
sprintf (buffer, "channel%d", i);
gst_pad_connect (gst_element_get_pad (channel_in->pipe, buffer), pad);
/* register a volume envelope */
printf ("\tregistering volume envelope...\n");
/*
* this is the volenv :
* each song gets a slot of 5 seconds, with a 5 second fadeout
* at the end of that, all audio streams play simultaneously
* at a level ensuring no distortion
* example for three songs :
* song1 : starts at full level, plays 5 seconds, faded out at 10 seconds,
* sleep until 25, fade to end level at 30
* song2 : starts silent, fades in at 5 seconds, full blast at 10 seconds,
* full level until 15, faded out at 20, sleep until 25, fade to end at 30
* song3 : starts muted, fades in from 15, full at 20, until 25, fade to end level
*/
if (i == 1)
{
/* first song gets special treatment for end style */
env_register_cp (channel_in->volenv, 0.0, 1.0);
}
else
{
env_register_cp (channel_in->volenv, 0.0 , 0.0000001); /* start muted */
env_register_cp (channel_in->volenv, i * 10.0 - 15.0, 0.0000001); /* start fade in */
env_register_cp (channel_in->volenv, i * 10.0 - 10.0, 1.0);
}
env_register_cp (channel_in->volenv, i * 10.0 - 5.0, 1.0); /* end of full level */
if (i != num_channels)
{
env_register_cp (channel_in->volenv, i * 10.0 , 0.0000001); /* fade to black */
env_register_cp (channel_in->volenv, num_channels * 10.0 - 5.0, 0.0000001); /* start fade in */
}
env_register_cp (channel_in->volenv, num_channels * 10.0 , 1.0 / num_channels); /* to end level */
}
/* sleep a few seconds doesn't seem to help anyway */
printf ("Sleeping a few seconds ...\n");
sleep (2);
printf ("Waking up ...\n");
/* start playing */
gst_element_set_state(main_bin, GST_STATE_PLAYING);
playing = TRUE;
while (playing) {
gst_bin_iterate(GST_BIN(main_bin));
}
/* stop the bin */
gst_element_set_state(main_bin, GST_STATE_NULL);
while (input_channels)
{
destroy_input_channel (input_channels->data);
input_channels = g_list_next (input_channels);
}
g_list_free (input_channels);
gst_object_destroy(GST_OBJECT(audiosink));
gst_object_destroy(GST_OBJECT(main_bin));
exit(0);
}
input_channel_t*
create_input_channel (int id, char* location)
{
/* create an input channel, reading from location
* return a pointer to the channel
* return NULL if failed
*/
input_channel_t *channel;
char buffer[20]; /* hold the names */
GstAutoplug *autoplug;
GstCaps *srccaps;
GstElement *new_element;
#ifdef DEBUG
printf ("DEBUG : c_i_p : creating channel with id %d for file %s\n",
id, location);
#endif
/* allocate channel */
channel = (input_channel_t *) malloc (sizeof (input_channel_t));
if (channel == NULL)
{
printf ("create_input_channel : could not allocate memory for channel !\n");
return NULL;
}
/* create channel */
#ifdef DEBUG
printf ("DEBUG : c_i_p : creating pipeline\n");
#endif
channel->pipe = gst_bin_new ("pipeline");
g_assert(channel->pipe != NULL);
/* create elements */
#ifdef DEBUG
printf ("DEBUG : c_i_p : creating disksrc\n");
#endif
sprintf (buffer, "disksrc%d", id);
channel->disksrc = gst_elementfactory_make ("disksrc", buffer);
g_assert(channel->disksrc != NULL);
gtk_object_set(GTK_OBJECT(channel->disksrc),"location", location, NULL);
/* add disksrc to the bin before autoplug */
gst_bin_add(GST_BIN(channel->pipe), channel->disksrc);
/* connect signal to eos of disksrc */
gtk_signal_connect(GTK_OBJECT(channel->disksrc),"eos",
GTK_SIGNAL_FUNC(eos),NULL);
#ifdef DEBUG
printf ("DEBUG : c_i_p : creating volume envelope\n");
#endif
sprintf (buffer, "volenv%d", id);
channel->volenv = gst_elementfactory_make ("volenv", buffer);
g_assert(channel->volenv != NULL);
/* autoplug the pipe */
#ifdef DEBUG
printf ("DEBUG : c_i_p : getting srccaps\n");
#endif
srccaps = gst_play_typefind (GST_BIN (channel->pipe), channel->disksrc);
if (!srccaps) {
g_print ("could not autoplug, unknown media type...\n");
exit (-1);
}
#ifdef DEBUG
printf ("DEBUG : c_i_p : creating autoplug\n");
#endif
autoplug = gst_autoplugfactory_make ("static");
g_assert (autoplug != NULL);
#ifdef DEBUG
printf ("DEBUG : c_i_p : autoplugging\n");
#endif
new_element = gst_autoplug_to_caps (autoplug, srccaps,
gst_caps_new ("audio", "audio/raw", NULL), NULL);
if (!new_element) {
g_print ("could not autoplug, no suitable codecs found...\n");
exit (-1);
}
gst_bin_add (GST_BIN(channel->pipe), channel->volenv);
gst_bin_add (GST_BIN (channel->pipe), new_element);
gst_element_connect (channel->disksrc, "src", new_element, "sink");
gst_element_connect (new_element, "src_00", channel->volenv, "sink");
/* add a ghost pad */
sprintf (buffer, "channel%d", id);
gst_element_add_ghost_pad (channel->pipe,
gst_element_get_pad (channel->volenv, "src"), buffer);
#ifdef DEBUG
printf ("DEBUG : c_i_p : end function\n");
#endif
return channel;
}
void
destroy_input_channel (input_channel_t *channel)
{
/*
* destroy an input channel
*/
#ifdef DEBUG
printf ("DEBUG : d_i_p : start\n");
#endif
/* destroy elements */
gst_object_destroy (GST_OBJECT (channel->pipe));
free (channel);
}
void env_register_cp (GstElement *volenv, double cp_time, double cp_level)
{
char buffer[30];
sprintf (buffer, "%f:%f", cp_time, cp_level);
gtk_object_set(GTK_OBJECT(volenv), "controlpoint", buffer, NULL);
}