gstreamer-0.10 に基づいて音楽プレーヤーを構築しています。を正常に再生できますが、パイプラインの状態を変更すると問題が発生します。以下のパイプラインを初期化して開始するコードを投稿しました。
void start_gstreamer()
{
gst_init(0,NULL);//call to initialise gstreamer
time_val=0;//set to default value
volume = 1.0;//set volume to default value
player = gst_element_factory_make ("playbin2", "player");//get pipeline
equalizer = gst_element_factory_make ("equalizer-10bands", "equalizer");//get the 10band equalizer
convert = gst_element_factory_make ("audioconvert", "convert");
sink = gst_element_factory_make ("autoaudiosink", "audio_sink");//get the audio-sink
if (!equalizer || !convert || !sink)//check is all elements were created
{
g_printerr ("Not all elements could be created.\n");
//return -1;
}
//int i=0;
/* Create the sink bin, add the elements and link them */
bin = gst_bin_new ("audio_sink_bin");//get new bin
gst_bin_add_many (GST_BIN (bin), equalizer, convert, sink, NULL);//add elements to bin
if(!(gst_element_link_many (equalizer, convert, sink, NULL)))//link all elements
g_print("Could not link all elements\n");
pad = gst_element_get_static_pad (equalizer, "sink");//set equalizer to sink
ghost_pad = gst_ghost_pad_new ("sink", pad);//get a ghost pad to sink
gst_pad_set_active (ghost_pad, TRUE);
gst_element_add_pad (bin, ghost_pad);//add ghost pad to the bin
gst_object_unref (pad);//unreference pad
gst_element_set_state (player, GST_STATE_READY);//set pipeline to ready state
//gst_element_set_state (player, GST_STATE_PAUSED);
/* Configure the equalizer */
g_object_set (G_OBJECT (equalizer), "band0",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band1",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band2",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band3",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band4",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band5",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band6",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band7",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band8",(gdouble) 0.0, NULL);
g_object_set (G_OBJECT (equalizer), "band9",(gdouble) 0.0, NULL);
/* Set playbin2's audio sink to be our sink bin */
g_object_set (GST_OBJECT (player), "audio-sink", bin, NULL);
}
上記のコードは、gstreamer パイプラインを初期化します。playbin2 を使用しています。
void start_playbin (char *gargv1)
{
time_t rawtime;
struct tm * timeinfo;
static gboolean i=TRUE;
gchar* uri;//to hold the path temporarily
gchar* dname;//to hold the directory name
time ( &rawtime );
timeinfo = localtime ( &rawtime );
printf ( "START:%s\n", asctime (timeinfo) );
uri = (gchar *)g_malloc( sizeof("file://") + strlen(gargv1) + 1);//get complete path
strcpy(uri,"file://");
strcat(uri,gargv1);//add path with the file path
dname = g_uri_escape_string(uri,G_URI_RESERVED_CHARS_ALLOWED_IN_PATH,TRUE);
g_free(uri);
uri = dname;
g_object_set(player,"uri",uri,NULL);//set file path for playback in the pipeline
g_print("\n\nPlaying %s\n", gargv1);
g_free(uri);//free path
/* start playback */
gst_element_set_state (GST_ELEMENT (player), GST_STATE_READY);//set pipeline to ready state
if(i==TRUE)
{
unsigned int count=0;
while(gst_element_set_state (GST_ELEMENT (player), GST_STATE_PLAYING)!=GST_STATE_CHANGE_SUCCESS);
//g_print("here:%d\n",count++);
i=FALSE;
}
else
play_playbin();//start playback
bus = gst_pipeline_get_bus(GST_PIPELINE(player));//get bus reference
gst_bus_add_watch(bus,(GstBusFunc)cb_message,player);//add bus to be monitored by process events
g_object_unref(bus);//unreference bus
time ( &rawtime );
timeinfo = localtime ( &rawtime );
printf ( "AFTER START:%s\n", asctime (timeinfo) );
}
パイプラインが初めて状態を変更しないという理由だけで、if(i == TRUE) 条件を使用する必要がありました。
void stop_playbin()
{
if(gst_element_set_state (GST_ELEMENT (player), GST_STATE_NULL)!=GST_STATE_CHANGE_SUCCESS)
g_print("Playbin could not be stopped\n");
//g_assert(gst_element_set_state (GST_ELEMENT (player),GST_STATE_NULL)==GST_STATE_CHANGE_SUCCESS);
}
void pause_playbin()
{
if(gst_element_set_state (GST_ELEMENT (player), GST_STATE_PAUSED)!=GST_STATE_CHANGE_SUCCESS)
g_print("Playbin could not be paused\n");
//g_assert(gst_element_set_state (GST_ELEMENT (player), GST_STATE_PAUSED)==GST_STATE_CHANGE_SUCCESS);
}
void play_playbin()
{
if(gst_element_set_state (GST_ELEMENT (player), GST_STATE_PLAYING)!=GST_STATE_CHANGE_SUCCESS)
g_print("Playbin could not be played\n");
//g_assert(gst_element_set_state (GST_ELEMENT (player),GST_STATE_PLAYING)==GST_STATE_CHANGE_SUCCESS);
}
上記の関数は、それぞれ再生、一時停止、および停止機能を実行します。問題は、ファイルのパスを関数に送信するとstart_playbin()、パイプラインのみを準備完了に設定した後にファイルのパスを変更できないことです。1) 準備完了 2) 一時停止または再生 (状態を設定できません) 3) 曲を停止してから再生 (状態を成功に設定) します。
私を助けてください。パイプラインを準備完了のみに設定してもエラーは発生しませんが、プログラムはハングします。何が問題なのですか？パイプラインをセットアップしてファイルのパスを設定するために従うべき特定の順序はありますか?