xcode.c

   1 /*
   2  * gstfs - gstreamer glue routines for transcoding
   3  */
   4
   5 #include <gst/gst.h>
   6 #include <glib.h>
   7 #include <unistd.h>
   8 #include <sys/wait.h>
   9 #include <pthread.h>
  10
  11 struct pipe_params
  12 {
  13     int fd;
  14     void (*add_data_cb)(char *, size_t, void *);
  15     void *user_data;
  16 };
  17
  18 void *send_pipe(void *data)
  19 {
  20     struct pipe_params *param = (struct pipe_params *) data;
  21     char buf[PIPE_BUF];
  22     size_t sizeread;
  23
  24     while ((sizeread = read(param->fd, buf, sizeof(buf))) > 0)
  25     {
  26         param->add_data_cb(buf, sizeread, param->user_data);
  27     }
  28     return NULL;
  29 }
  30
  31 /*
  32  *  Transcodes a file into a buffer, blocking until done.
  33  */
  34 int transcode(char *filename, void (*add_data_cb)(char *, size_t, void *),
  35     void *user_data)
  36 {
  37     GstElement *pipeline, *source, *dest;
  38     GError *error = NULL;
  39     GstBus *bus;
  40     char *pipeline_str = "filesrc name=\"_source\" ! oggdemux ! "
  41         "vorbisdec ! audioconvert ! lame bitrate=160 ! "
  42         "fdsink name=\"_dest\" sync=false";
  43
  44     int pipefds[2];
  45
  46     struct pipe_params thread_params;
  47     pthread_t thread;
  48     void *thread_status;
  49
  50     pipeline = gst_parse_launch(pipeline_str, &error);
  51     if (error)
  52     {
  53         fprintf(stderr, "Error parsing pipeline: %s\n", error->message);
  54         return -1;
  55     }
  56
  57     source = gst_bin_get_by_name(GST_BIN(pipeline), "_source");
  58     dest = gst_bin_get_by_name(GST_BIN(pipeline), "_dest");
  59
  60     if (!pipeline || !source || !dest)
  61     {
  62         fprintf(stderr, "Could not initialize pipeline\n");
  63         return -2;
  64     }
  65
  66     if (pipe(pipefds))
  67     {
  68         perror("gstfs");
  69         return -1;
  70     }
  71
  72     thread_params.fd = pipefds[0];
  73     thread_params.add_data_cb = add_data_cb;
  74     thread_params.user_data = user_data;
  75
  76     pthread_create(&thread, NULL, send_pipe, (void *) &thread_params);
  77
  78     g_object_set(G_OBJECT(source), "location", filename, NULL);
  79     g_object_set(G_OBJECT(dest), "fd", pipefds[1], NULL);
  80
  81     bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
  82     gst_bus_add_signal_watch(bus);
  83     gst_element_set_state(pipeline, GST_STATE_PLAYING);
  84     GstMessage *message = gst_bus_poll(bus, GST_MESSAGE_EOS |
  85             GST_MESSAGE_ERROR, -1);
  86     gst_message_unref(message);
  87
  88     // close read-side so pipe will terminate
  89     close(pipefds[1]);
  90     pthread_join(thread, thread_status);
  91
  92     return 0;
  93 }