gstreamer/gst/gstparse.c

/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wtay@chello.be>
 *
 * :
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* #define DEBUG(format,args...) g_print (format, ##args) */
#define DEBUG(format,args...)
#define DEBUG_NOPREFIX(format,args...)
#define VERBOSE(format,args...)

#define GST_PARSE_LISTPAD(list)   ((GstPad*)(list->data))

#include <string.h>

#include "gst_private.h"
#include "gstparse.h"
#include "gstpipeline.h"
#include "gstthread.h"
#include "gstutils.h"

typedef struct _gst_parse_priv gst_parse_priv;
struct _gst_parse_priv
{
  guint bincount;
  guint threadcount;
  gint binlevel;
  gboolean verbose;
  gboolean debug;
};

typedef struct _gst_parse_delayed_pad gst_parse_delayed_pad;
struct _gst_parse_delayed_pad
{
  gchar *name;
  GstPad *peer;
};

typedef struct
{
  gchar *srcpadname;
  GstPad *target;
  GstElement *pipeline;
}
dyn_connect;

static void
dynamic_connect (GstElement * element, GstPad * newpad, gpointer data)
{
  dyn_connect *connect = (dyn_connect *) data;

  if (!strcmp (gst_pad_get_name (newpad), connect->srcpadname)) {
    gst_element_set_state (connect->pipeline, GST_STATE_PAUSED);
    if (!gst_pad_connect (newpad, connect->target))
      g_warning ("could not connect %s:%s to %s:%s", GST_DEBUG_PAD_NAME (newpad), 
                 GST_DEBUG_PAD_NAME (connect->target));
    gst_element_set_state (connect->pipeline, GST_STATE_PLAYING);
  }
}

static gint
gst_parse_launchv_recurse (const gchar **argv, GstBin * parent, gst_parse_priv * priv)
{
  gint i = -1, j = 0;
  const gchar *arg;
  GstElement *element = NULL, *previous = NULL, *prevelement = NULL;
  gchar closingchar = '\0';
  gint len;
  const gchar *cptr;
  gchar *ptr;
  gchar *sinkpadname = NULL, *srcpadname = NULL, *tempname;
  GstPad *temppad;
  GSList *sinkpads = NULL, *srcpads = NULL;
  gint numsrcpads = 0, numsinkpads = 0;
  GList *pads;
  gint elementcount = 0;
  gint retval = 0;
  gboolean backref = FALSE;

  if (!priv) {
    priv = g_new0 (gst_parse_priv, 1);
  }

  priv->binlevel++;

  if (GST_IS_PIPELINE (parent)) {
    closingchar = '\0';
    DEBUG ("in pipeline ");
  } else if (GST_IS_THREAD (parent)) {
    closingchar = '}';
    DEBUG ("in thread ");
  } else {
    closingchar = ')';
    DEBUG ("in bin ");
  }
  DEBUG_NOPREFIX ("%s\n", GST_ELEMENT_NAME (GST_ELEMENT (parent)));

  while ((arg = argv[++i])) {
    len = strlen (arg);
    element = NULL;
    DEBUG ("** ARGUMENT is '%s'\n", arg);

    if (len == 0) {
      DEBUG ("random arg, FIXME\n");

      continue;
    } else if (arg[0] == closingchar) {
      DEBUG ("exiting container %s\n", GST_ELEMENT_NAME (GST_ELEMENT (parent)));

      retval = i + 1;
      break;
    } else if ((cptr = strchr (arg, '!'))) {
      DEBUG ("attempting to connect pads together....\n");

      /* if it starts with the ! */
      if (arg[0] == '!') {
	srcpadname = NULL;
	/* if there's a sinkpad... */
	if (len > 1)
	  sinkpadname = g_strdup (&arg[1]);
	else
	  sinkpadname = NULL;
      } else {
	srcpadname = g_strndup (arg, (cptr - arg));
	/* if there's a sinkpad */
	if (len > (cptr - arg) + 1)
	  sinkpadname = g_strdup(&cptr[1]);
	else
	  sinkpadname = NULL;
      }

      if (srcpadname && (ptr = strchr (srcpadname, '.'))) {
	gchar *element_name = srcpadname;
	GstElement *new;

        *ptr = '\0'; /* it was a '.' before */
        
	GST_DEBUG (0, "have pad for element %s\n", element_name);
	new = gst_bin_get_by_name_recurse_up (parent, element_name);
	if (!new) {
	  GST_DEBUG (0, "element %s does not exist! trying to continue\n", element_name);
	} else {
	  previous = new;
	  srcpadname = ptr + 1;
	  backref = TRUE;
	}
      }

      GST_DEBUG (0, "have srcpad %s, sinkpad %s\n", srcpadname, sinkpadname);

      g_slist_free (srcpads);
      srcpads = NULL;
      numsrcpads = 0;
      tempname = NULL;

      /* find src pads */
      if (srcpadname != NULL) {
	while (1) {
	  /* split name at commas */
	  if ((ptr = strchr (srcpadname, ','))) {
	    tempname = srcpadname;
	    srcpadname = &ptr[1];
            *ptr = '\0';
	  } else {
	    tempname = srcpadname;
	  }

	  /* look for pad with that name */
	  if ((temppad = gst_element_get_pad (previous, tempname))) {
	    srcpads = g_slist_append (srcpads, temppad);
	    numsrcpads++;
	  }

	  /* try to create a pad using that padtemplate name */
	  else if ((temppad = gst_element_request_pad_by_name (previous, tempname))) {
	    srcpads = g_slist_append (srcpads, temppad);
	    numsrcpads++;
	  }
	  if (!temppad) {
	    GST_DEBUG (0, "NO SUCH pad %s in element %s\n", tempname, GST_ELEMENT_NAME (previous));
	  } else {
	    GST_DEBUG (0, "have src pad %s:%s\n", GST_DEBUG_PAD_NAME (temppad));
	  }

	  /* if there is no more commas in srcpadname then we're done */
	  if (tempname == srcpadname)
	    break;
	  g_free (tempname);
	}
      } else {
	/* check through the list to find the first src pad */
	GST_DEBUG (0, "CHECKING element %s for pad named %s\n", GST_ELEMENT_NAME (previous),
		   srcpadname);
	pads = gst_element_get_pad_list (previous);
	while (pads) {
	  temppad = GST_PARSE_LISTPAD (pads);
	  GST_DEBUG (0, "have pad %s:%s\n", GST_DEBUG_PAD_NAME (temppad));
	  if (GST_IS_GHOST_PAD (temppad))
	    GST_DEBUG (0, "it's a ghost pad\n");
	  if (gst_pad_get_direction (temppad) == GST_PAD_SRC) {
	    srcpads = g_slist_append (srcpads, temppad);
	    numsrcpads++;
	    break;
	  }
	  pads = g_list_next (pads);
	}
	if (!srcpads)
	  GST_DEBUG (0, "error, can't find a src pad!!!\n");
	else
	  GST_DEBUG (0, "have src pad %s:%s\n", GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (srcpads)));
      }
    } else if (strchr (arg, '=')) {
      gchar *propname;
      gchar *propval;
      gchar *pos;
      
      DEBUG ("have a property\n");
      
      /* we have a property */
      propname = g_strdup (arg);
      pos = strchr (propname, '=');
      *pos = '\0';
      propval = pos + 1;
      
      /* use g_object_set in the future when gst_util_{set|get} go away */
      GST_DEBUG (0, "attempting to set property '%s' to '%s' on element '%s'\n",
		 propname, propval, GST_ELEMENT_NAME (previous));
      gst_util_set_object_arg (G_OBJECT (previous), propname, propval);
      g_free (propname);
    } else if (arg[0] == '[') {
      DEBUG ("have element name\n");
      
      if (arg[1] != '\0') {
        fprintf (stderr, "error, unexpected junk after [\n");
        return GST_PARSE_ERROR_SYNTAX;
      }
      
      if ((arg = argv[++i])) {
        if (!previous) {
          g_critical("parser error, please report");
          return GST_PARSE_ERROR_INTERNAL;
        }
        gst_element_set_name (previous, arg);
      } else {
        fprintf (stderr, "error, expected element name, found end of arguments\n");
        return GST_PARSE_ERROR_SYNTAX;
      }
      
      if ((arg = argv[++i])) {
        if (strcmp (arg, "]") != 0) {
          fprintf (stderr, "error, expected ], found '%s'\n", arg);
          return GST_PARSE_ERROR_SYNTAX;
        }
      } else {
        fprintf (stderr, "error, expected ], found end of arguments\n");
        return GST_PARSE_ERROR_SYNTAX;
      }
    } else {
      /* we have an element, a bin, or a thread. we treat these together because
       * once we rech them we have to resolve any dangling connections from
       * previous array arguments. */
      
      if (strchr ("({", arg[0])) {
        DEBUG ("have bin or thread\n");
        
        if (arg[0] == '(') {
          /* create a bin and add it to the current parent */
          priv->bincount++;
          element = gst_elementfactory_make ("bin", NULL);
          if (!element) {
            fprintf (stderr, "Couldn't create a bin!\n");
            return GST_PARSE_ERROR_CREATING_ELEMENT;
          }
          GST_DEBUG (0, "CREATED bin %s\n", GST_ELEMENT_NAME (element));
        } else if (arg[0] == '{') {
          /* create a thread and add it to the current parent */
          priv->threadcount++;
          element = gst_elementfactory_make ("thread", NULL);
          if (!element) {
            fprintf (stderr, "Couldn't create a thread!\n");
            return GST_PARSE_ERROR_CREATING_ELEMENT;
          }
          GST_DEBUG (0, "CREATED thread %s\n", GST_ELEMENT_NAME (element));
        } else {
          fprintf (stderr, "Illegal argument: %s\n", arg);
          return GST_PARSE_ERROR_CREATING_ELEMENT;
        }
        
        gst_bin_add (GST_BIN (parent), element);
        
        j = gst_parse_launchv_recurse (argv + i + 1, GST_BIN (element), priv);
        /* check for parse error */
        if (j < 0)
          return j;
        
        /* we will get autoincremented at the while */
        i += j;
        
      } else {
        /* we have an element */
        DEBUG ("attempting to create element '%s'\n", arg);
        
        element = gst_elementfactory_make (arg, NULL);
        if (!element) {
#ifndef GST_DISABLE_REGISTRY
          fprintf (stderr,
                   "Couldn't create a '%s', no such element or need to run gst-register?\n", arg);
#else
          fprintf (stderr, "Couldn't create a '%s', no such element or need to load plugin?\n",
                   arg);
#endif
          return GST_PARSE_ERROR_NOSUCH_ELEMENT;
        }
        
        GST_DEBUG (0, "CREATED element %s\n", GST_ELEMENT_NAME (element));
        gst_bin_add (GST_BIN (parent), element);
      }
      
      elementcount++;
      
      g_slist_free (sinkpads);
      sinkpads = NULL;
      numsinkpads = 0;
      tempname = NULL;
      
      /* find sink pads */
      if (sinkpadname != NULL) {
        while (1) {
          /* split name at commas */
          if ((ptr = strchr (sinkpadname, ','))) {
            tempname = g_strndup (sinkpadname, (ptr - sinkpadname));
            sinkpadname = &ptr[1];
          } else {
            tempname = sinkpadname;
          }
          
          /* look for pad with that name */
          if ((temppad = gst_element_get_pad (element, tempname))) {
            sinkpads = g_slist_append (sinkpads, temppad);
            numsinkpads++;
          }
          
          /* try to create a pad using that padtemplate name */
          else if ((temppad = gst_element_request_pad_by_name (element, tempname))) {
            sinkpads = g_slist_append (sinkpads, temppad);
            numsinkpads++;
          }
          if (!temppad) {
            GST_DEBUG (0, "NO SUCH pad %s in element %s\n", tempname, GST_ELEMENT_NAME (element));
          } else {
            GST_DEBUG (0, "have sink pad %s:%s\n", GST_DEBUG_PAD_NAME (temppad));
          }
          
          /* if there is no more commas in sinkpadname then we're done */
          if (tempname == sinkpadname)
            break;
          g_free (tempname);
        }
      } else {
        /* check through the list to find the first sink pad */
        pads = gst_element_get_pad_list (element);
        while (pads) {
          temppad = GST_PAD (pads->data);
          pads = g_list_next (pads);
          if (gst_pad_get_direction (temppad) == GST_PAD_SINK) {
	    sinkpads = g_slist_append (sinkpads, temppad);
	    numsinkpads++;
	    break;
          }
        }
      }
      
      if (!sinkpads)
        GST_DEBUG (0, "can't find a sink pad for element\n");
      else
        GST_DEBUG (0, "have sink pad %s:%s\n", GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (sinkpads)));
      
      if (!srcpads && sinkpads && previous && srcpadname) {
        dyn_connect *connect = g_malloc (sizeof (dyn_connect));
        
        connect->srcpadname = srcpadname;
        connect->target = GST_PARSE_LISTPAD (sinkpads);
        connect->pipeline = GST_ELEMENT (parent);
        
        GST_DEBUG (0, "SETTING UP dynamic connection %s:%s and %s:%s\n",
                   gst_element_get_name (previous),
                   srcpadname, GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (sinkpads)));
        
        g_signal_connect (G_OBJECT (previous), "new_pad", G_CALLBACK (dynamic_connect), connect);
      } else {
        for (j = 0; (j < numsrcpads) && (j < numsinkpads); j++) {
          GST_DEBUG (0, "CONNECTING %s:%s and %s:%s\n",
                     GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (g_slist_nth (srcpads, j))),
                     GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (g_slist_nth (sinkpads, j))));
          if (!gst_pad_connect (GST_PARSE_LISTPAD (g_slist_nth (srcpads, j)),
                                GST_PARSE_LISTPAD (g_slist_nth (sinkpads, j)))) {
            g_warning ("could not connect %s:%s to %s:%s",
                       GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (g_slist_nth (srcpads, j))), 
                       GST_DEBUG_PAD_NAME (GST_PARSE_LISTPAD (g_slist_nth (sinkpads, j))));
            return GST_PARSE_ERROR_CONNECT;
          }
        }
      }
      
      g_slist_free (srcpads);
      srcpads = NULL;
      
      g_slist_free (sinkpads);
      sinkpads = NULL;
      
      /* if we're the first element, ghost all the sinkpads */
      if (elementcount == 1 && !backref) {
        DEBUG ("first element, ghosting all of %s's sink pads to parent %s\n",
               GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (GST_ELEMENT (parent)));
        pads = gst_element_get_pad_list (element);
        while (pads) {
          temppad = GST_PAD (pads->data);
          pads = g_list_next (pads);
          if (!temppad)
            DEBUG ("much oddness, pad doesn't seem to exist\n");
          else if (gst_pad_get_direction (temppad) == GST_PAD_SINK) {
            gst_element_add_ghost_pad (GST_ELEMENT (parent), temppad,
                                       g_strdup_printf ("%s-ghost", GST_PAD_NAME (temppad)));
            GST_DEBUG (0, "GHOSTED %s:%s to %s as %s-ghost\n",
                       GST_DEBUG_PAD_NAME (temppad), GST_ELEMENT_NAME (GST_ELEMENT (parent)),
                       GST_PAD_NAME (temppad));
          }
        }
      }
      
      previous = element;
      if (!GST_IS_BIN (element))
        prevelement = element;
    }
  }
  
  /* ghost all the src pads of the bin */
  if (prevelement != NULL) {
    DEBUG ("last element, ghosting all of %s's src pads to parent %s\n",
	   GST_ELEMENT_NAME (prevelement), GST_ELEMENT_NAME (GST_ELEMENT (parent)));
    pads = gst_element_get_pad_list (prevelement);
    while (pads) {
      temppad = GST_PAD (pads->data);
      pads = g_list_next (pads);
      if (!temppad)
	DEBUG ("much oddness, pad doesn't seem to exist\n");
      else if (gst_pad_get_direction (temppad) == GST_PAD_SRC) {
	gst_element_add_ghost_pad (GST_ELEMENT (parent), temppad,
				   g_strdup_printf ("%s-ghost", GST_PAD_NAME (temppad)));
	GST_DEBUG (0, "GHOSTED %s:%s to %s as %s-ghost\n",
		   GST_DEBUG_PAD_NAME (temppad), GST_ELEMENT_NAME (parent), GST_PAD_NAME (temppad));
      }
    }
  }
  
  priv->binlevel--;
  
  if (retval)
    return retval;
  
  DEBUG (closingchar != '\0' ? "returning IN THE WRONG PLACE\n" : "ending pipeline\n");
  
  return i + 1;
}


/**
 * gst_parse_launchv:
 * @argv: null-terminated array of arguments
 *
 * Create a new pipeline based on command line syntax.
 *
 * Returns: a new pipeline on success, NULL on failure
 */
GstPipeline *
gst_parse_launchv (const gchar **argv)
{
  GstPipeline *pipeline;
  gint ret;

  /* defer error detection to the _recurse function */

  pipeline = (GstPipeline*) gst_pipeline_new ("launch");

  ret = gst_parse_launchv_recurse (argv, GST_BIN (pipeline), NULL);

  if (ret <= 0) {
    // print an error
    gst_object_unref (GST_OBJECT (pipeline));
    return NULL;
  } else {
    return pipeline;
  }
}

/**
 * gst_parse_launch:
 * @pipeline_description: the command line describing the pipeline
 *
 * Create a new pipeline based on command line syntax.
 *
 * Returns: a new GstPipeline (cast to a Bin) on success, NULL on failure
 */
GstPipeline *
gst_parse_launch (const gchar * pipeline_description)
{
  gchar **argvn;
  gint newargc;
  gint i;
  const gchar *cp, *start, *end;
  gchar *temp;
  GSList *string_list = NULL, *slist;
  GstPipeline *pipeline;

  end = pipeline_description + strlen (pipeline_description);
  newargc = 0;

  temp = "";

  /* Extract the arguments to a gslist in reverse order */
  for (cp = pipeline_description; cp < end;) {
    i = strcspn (cp, "([{}]) \"\\");

    if (i > 0) {
      temp = g_strconcat (temp, g_strndup (cp, i), NULL);

      /* see if we have an escape char */
      if (cp[i] != '\\') {
	/* normal argument - copy and add to the list */
	string_list = g_slist_prepend (string_list, temp);
	newargc++;
	temp = "";
      } else {
	temp = g_strconcat (temp, g_strndup (&cp[++i], 1), NULL);
      }
      cp += i;
    }

    /* skip spaces */
    while (cp < end && *cp == ' ') {
      cp++;
    }

    /* handle quoted arguments */
    if (*cp == '"') {
      start = ++cp;

      /* find matching quote */
      while (cp < end && *cp != '"')
	cp++;

      /* make sure we got it */
      if (cp == end) {
	g_warning ("gst_parse_launch: Unbalanced quote in command line");
	/* FIXME: The list leaks here */
	return 0;
      }

      /* copy the string sans quotes */
      string_list = g_slist_prepend (string_list, g_strndup (start, cp - start));
      newargc++;
      cp += 2;			/* skip the quote aswell */
    }

    /* brackets exist in a separate argument slot */
    if (*cp && strchr ("([{}])", *cp)) {
      string_list = g_slist_prepend (string_list, g_strndup (cp, 1));
      newargc++;
      cp++;
    }
  }

  /* now allocate the new argv array, with room for NULL termination */
  argvn = g_new0 (char *, newargc + 1);

  GST_DEBUG (0, "got %d args\n", newargc);

  /* reverse the list and put the strings in the new array */
  i = newargc;

  for (slist = string_list; slist; slist = slist->next)
    argvn[--i] = slist->data;

  g_slist_free (string_list);

  /* print them out */
  while (argvn[i]) {
    GST_DEBUG (0, "arg %d is: %s\n", i, argvn[i++]);
  }

  /* do it! */
  pipeline = gst_parse_launchv ((const char**) argvn);

  GST_DEBUG(0, "Finished - freeing temporary argument array");
  g_strfreev(argvn);

  return pipeline;
}