gstextractor.c

/*
 * compile: gcc -O0 -g $(pkg-config --cflags --libs glib-2.0 gobject-2.0 gstreamer-1.0) -o gstextractor gstextractor.c
 * pipeline: gnlcomposition. ( gnlsource. ( bin. ( filesrc ! decodebin ) ), gnlsource. ( bin. ( filesrc ! decodebin ) ) ... ) ! \
 *                           audioconvert ! faac ! qtmux ! filesink
 *           gnlcomposition. ( gnlsource. ( bin. ( filesrc ! decodebin ) ), gnlsource. ( bin. ( filesrc ! decodebin ) ) ... ) ! \
 *                           videoconvert ! x264enc ! qtmux0.
 */

#include <stdio.h>
#include <stdlib.h>
#include <glib-unix.h>
#include <gst/gst.h>

typedef struct {
  GstElement *linkelement;
  GstElement *bin;
} GstExtractorCallbackArgs;

typedef struct {
  GstElement *audiocomp;
  GstElement *audioconvert;
  GstElement *audioenc;
  GstElement *mux;
  GstElement *out;
  GstElement *videocomp;
  GstElement *videoconvert;
  GstElement *videoenc;
} GstExtractorElements;

typedef struct {
  GstExtractorElements *elements;
  GstElement *pipeline;
  GMainLoop *mainloop;
  GstBus *msgbus;
} GstExtractor;

static guint64 gstextractor_timestamp_to_nanoseconds(gchar *timestamp) {
  gchar **timev = g_strsplit(timestamp, ":", -1);
  gint timec = g_strv_length(timev);
  gdouble time = 0;

  time = time + ((timec - 1) >= 0 && timev[timec - 1] ? g_strtod(timev[timec - 1], NULL) : 0);
  time = time + ((timec - 2) >= 0 && timev[timec - 2] ? g_strtod(timev[timec - 2], NULL) * 60 : 0);
  time = time + ((timec - 3) >= 0 && timev[timec - 3] ? g_strtod(timev[timec - 3], NULL) * 60 * 60 : 0);

  g_strfreev(timev);
  return (guint64) (time * GST_SECOND);
}

static gstextractor_no_more_pads_cb(GstElement *element, gpointer data) {
  GstElement *linkelement = (GstElement *) data;
  if(!gst_element_link(element, linkelement)) {
    g_printerr("element->linkelement not linked\n");
  }
}

static gstextractor_pad_added_cb(GstElement *element, GstPad *pad, gpointer data) {
  GstExtractorCallbackArgs *args = (GstExtractorCallbackArgs *) data;
  if(gst_caps_is_always_compatible(gst_pad_query_caps(pad, NULL),
				   gst_pad_query_caps(gst_element_get_static_pad(args->linkelement,
										 "sink"),
						      NULL))) {
    GstPad *gpad = gst_ghost_pad_new(NULL, pad);
    gst_pad_set_active(gpad, TRUE);
    gst_element_add_pad(args->bin, gpad);
  }
}

static GstElement* gstextractor_gen_comp(GstExtractor *this, GstElement *linkelement, gchar *filesinfo) {
  GstElement *comp = gst_element_factory_make("gnlcomposition", NULL);
  gchar **filesv = g_strsplit(filesinfo, ",", -1);
  gint filesc = g_strv_length(filesv);
  gint i = 0;
  guint64 offset = 0;
  gboolean ret = TRUE;

  for(; i < filesc; i++) {
    gchar **detailsv = g_strsplit(filesv[i], "|", -1);
    GstElement *in = gst_element_factory_make("filesrc", NULL);
    GstElement *decode = gst_element_factory_make("decodebin", NULL);
    char *binname = g_strdup_printf("bin%d", i);
    GstElement *bin = gst_bin_new(binname);
    GstElement *source = gst_element_factory_make("gnlsource", NULL);
    GstExtractorCallbackArgs *args = g_new(GstExtractorCallbackArgs, 1);
    guint64 start = offset;
    guint64 inpoint = gstextractor_timestamp_to_nanoseconds(detailsv[1]);
    guint64 duration = gstextractor_timestamp_to_nanoseconds(detailsv[2]) - inpoint;

    gst_bin_add(GST_BIN(comp), source);
    gst_bin_add(GST_BIN(source), bin);
    gst_bin_add_many(GST_BIN(bin), in, decode, NULL);

    gst_element_link(in, decode);
    args->linkelement = linkelement;
    args->bin = bin;
    g_signal_connect(decode,
		     "pad-added",
		     G_CALLBACK(gstextractor_pad_added_cb),
		     args);

    g_object_set(in, "location", detailsv[0], NULL);
    g_object_set(source, "start", start, NULL);
    g_object_set(source, "inpoint", inpoint, NULL);
    g_object_set(source, "duration", duration, NULL);
    g_object_set(source, "priority", 1, NULL);
    offset += duration;

    g_strfreev(detailsv);
    g_free(binname);
  }

  g_signal_connect(comp,
		   "no-more-pads",
		   G_CALLBACK(gstextractor_no_more_pads_cb),
		   linkelement);
  g_signal_emit_by_name(comp, "commit", TRUE, &ret);

  g_strfreev(filesv);
  return comp;
}

static gstextractor_elements_init(GstExtractor *this, gchar *filesinfo, gchar *outfile) {
  this->elements = g_new(GstExtractorElements, 1);
  this->elements->audioconvert = gst_element_factory_make("audioconvert", NULL);
  this->elements->audioenc = gst_element_factory_make("faac", NULL);
  this->elements->mux = gst_element_factory_make("qtmux", NULL);
  this->elements->out = gst_element_factory_make("filesink", NULL);
  this->elements->videoconvert = gst_element_factory_make("videoconvert", NULL);
  this->elements->videoenc = gst_element_factory_make("x264enc", NULL);

  this->elements->audiocomp = gstextractor_gen_comp(this, this->elements->audioconvert, filesinfo);
  this->elements->videocomp = gstextractor_gen_comp(this, this->elements->videoconvert, filesinfo);

  gst_bin_add_many(GST_BIN(this->pipeline),
		   this->elements->audiocomp,
		   this->elements->audioconvert,
		   this->elements->audioenc,
		   this->elements->mux,
		   this->elements->out,
		   this->elements->videocomp,
		   this->elements->videoconvert,
		   this->elements->videoenc,
		   NULL);

  gst_element_link_many(this->elements->audioconvert,
			this->elements->audioenc,
			this->elements->mux,
			this->elements->out,
			NULL);

  gst_element_link_many(this->elements->videoconvert,
			this->elements->videoenc,
			this->elements->mux,
			NULL);

  g_object_set(this->elements->out, "location", outfile, NULL);
}

static void gstextractor_run(GstExtractor *this) {
  gst_element_set_state(this->pipeline, GST_STATE_PLAYING);
  g_main_loop_run(this->mainloop);
}

static void gstextractor_stop(GstExtractor *this) {
  gst_element_set_state(this->pipeline, GST_STATE_NULL);
  g_main_loop_quit(this->mainloop);
}

static gboolean gstextractor_msgbus_cb(GstBus *bus, GstMessage *message, gpointer *data) {
  GstExtractor *this = (GstExtractor *) data;
  switch(GST_MESSAGE_TYPE(message)) {
  case(GST_MESSAGE_EOS): gstextractor_stop(this);
    break;
  case(GST_MESSAGE_STATE_CHANGED): {
    GstState old;
    GstState new;
    gst_message_parse_state_changed(message, &old, &new, NULL);
    g_printerr("%d: state changed from %s to %s on %s\n",
	       GST_MESSAGE_SEQNUM(message),
	       gst_element_state_get_name(old),
	       gst_element_state_get_name(new),
	       GST_MESSAGE_SRC_NAME(message));
  }
    break;
  default: g_printerr("%d: received %s from %s..\n",
		      GST_MESSAGE_SEQNUM(message),
		      GST_MESSAGE_TYPE_NAME(message),
		      GST_MESSAGE_SRC_NAME(message));
  }
  return TRUE;
}

static void gstextractor_init(GstExtractor *this, gchar *filesinfo, gchar *outfile) {
  if(! gst_is_initialized()) gst_init(NULL, NULL);
  this->mainloop = g_main_loop_new(NULL, FALSE);
  this->pipeline = gst_pipeline_new("pipeline0");
  gstextractor_elements_init(this, filesinfo, outfile);
  this->msgbus = gst_element_get_bus(GST_ELEMENT(this->pipeline));
  gst_bus_add_watch_full(this->msgbus,
			 G_PRIORITY_DEFAULT,
			 (GstBusFunc) gstextractor_msgbus_cb,
			 this,
			 NULL);
}

int main(int argc, char *argv[]) {
  if(argc < 3) {
    g_printerr("[usage] %s \"file|start([hh:mm:]ss)|stop([hh:mm:]ss)[,...]\" outfile\n", argv[0]);
    exit(EXIT_FAILURE);
  }
  GstExtractor gstextractor;
  gstextractor_init(&gstextractor, argv[1], argv[2]);
  gstextractor_run(&gstextractor);
  return 0;
}