sbGStreamerMediacoreUtils.h

Go to the documentation of this file.

/*
//
// BEGIN SONGBIRD GPL
//
// This file is part of the Songbird web player.
//
// Copyright(c) 2005-2008 POTI, Inc.
// http://songbirdnest.com
//
// This file may be licensed under the terms of of the
// GNU General Public License Version 2 (the "GPL").
//
// Software distributed under the License is distributed
// on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either
// express or implied. See the GPL for the specific language
// governing rights and limitations.
//
// You should have received a copy of the GPL along with this
// program. If not, go to http://www.gnu.org/licenses/gpl.html
// or write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// END SONGBIRD GPL
//
*/

#ifndef _SB_GSTREAMERMEDIACOREUTILS_H_
#define _SB_GSTREAMERMEDIACOREUTILS_H_

#include <nsCOMPtr.h>
#include <nsCOMArray.h>
#include <nsStringGlue.h>
#include <nsIDOMEventListener.h>
#include <nsIDOMWindow.h>
#include <nsITimer.h>
#include <nsComponentManagerUtils.h>
#include <nsIStringBundle.h>
#include <nsIVariant.h>
#include <nsIPropertyBag.h>
#include <nsIProperty.h>
#include <nsIWritablePropertyBag2.h>

#include <sbIPropertyArray.h>
#include <sbMediacoreError.h>
#include <sbMemoryUtils.h>

#include <gst/gst.h>

SB_AUTO_CLASS(sbGstCaps, GstCaps*, !!mValue, gst_caps_unref(mValue), mValue = NULL);

/* Custom GStreamer tag names. Must match those used in the various gstreamer
   muxers/taggers we have.
 */
#define SB_GST_TAG_GRACENOTE_TAGID         "gracenote-tagid"
#define SB_GST_TAG_GRACENOTE_EXTENDED_DATA "gracenote-extdata"

/*
  Simple enum of possible primary pipeline operations. This is used
  by sbGStreamerPipeline and derived classes as well as 
  GetMediacoreErrorFromGstError. It helps determine which error message
  should be constructed based on the primary operation being performed.

  This type is defined in the GStreamer namespace to avoid clashing with
  other types.
 */
namespace GStreamer {

typedef enum {
  OP_UNKNOWN = 0, /* unknown: default behavior */
  OP_INSPECTING,  /* inspecting (eg. scanning for metadata) */
  OP_PLAYING,     /* playing: playing back a file for the user */
  OP_STREAMING,   /* streaming: acting as server during streaming */
  OP_TRANSCODING  /* transcoding: transcoding a media file to another format */
} pipelineOp_t;

} /*namespace GStreamer*/


/* Apply all the properties from 'props' to element.
   If any property cannot be set (the type is incompatible, or the element
   does not have such a property), this will return an error.

   Type compatibility: numerical types MUST match exactly (e.g. if the
   GObject property contains an unsigned 32 bit int, then the property in
   the property bag must also be an unsigned 32 bit int.

   Strings MAY be either nsString or nsCString.

   Enum values (for the GObject properties) MUST be 32 bit unsigned integers
   in the nsIVariant; they'll be converted as appropriate.

   Current limitations: only 32 bit or 64 bit (signed or unsigned) integers,
   floats, doubles, booleans, strings (AString and ACString), and enums
   are supported.
 */
nsresult ApplyPropertyBagToElement(GstElement *element, nsIPropertyBag *props);

GstTagList *ConvertPropertyArrayToTagList(sbIPropertyArray *properties);

nsresult ConvertTagListToPropertyArray(GstTagList *taglist, 
        sbIPropertyArray **aPropertyArray);

class sbGStreamerMessageHandler : public nsISupports {
public:
  virtual ~sbGStreamerMessageHandler() {};
  virtual void HandleMessage(GstMessage *message) = 0;
  virtual PRBool HandleSynchronousMessage(GstMessage *message) = 0;
};
GstBusSyncReply SyncToAsyncDispatcher(GstBus* bus, GstMessage* message,
                                      gpointer data);

/* Get a mediacore error from the gstreamer error. The error string may include
   a reference to a filename or URI; if so the string aResource will be used

   \param aResource  the URI string points to the file that has error.
                     Will be unescaped in the processing.
   \param aPipelineOp Optional pipeline primary operation to pick the error 
                      message that is most representative. Pass 
                      GStreamer::OP_UNKNOWN for the default behavior.
 */
nsresult GetMediacoreErrorFromGstError(GError *gerror, nsString aResource, 
                                       GStreamer::pipelineOp_t aPipelineOp,
                                       sbIMediacoreError **_retval);

const char *
FindMatchingElementName(const char *srcCapsString, const char *typeName);

const char *
FindMatchingElementName(GstCaps *srcCaps, const char *typeName);

/* Register any the custom tags we need to use */
void
RegisterCustomTags();

/* Get the mime type string to use for a given GStreamer caps type */
nsresult
GetMimeTypeForCaps (GstCaps *aCaps, nsACString &aMimeType);

enum sbGstCapsMapType {
  SB_GST_CAPS_MAP_NONE,
  SB_GST_CAPS_MAP_CONTAINER,
  SB_GST_CAPS_MAP_AUDIO,
  SB_GST_CAPS_MAP_VIDEO
};

/* Get a GstCaps object (possibly incomplete) for a given mime type string */
GstCaps *
GetCapsForMimeType (const nsACString &aMimeType, enum sbGstCapsMapType);

/* Copy fields from aStructure to aPropertyBag.  If aFieldList is supplied,
   it shall have aFieldCount field names and any fields so named shall be
   copied to a property of the same name.  Missing fields will be skipped
   without error.  If aFieldList is not present, all fields in aStructure
   shall be copied. */
nsresult
SetPropertiesFromGstStructure(nsIWritablePropertyBag2 * aPropertyBag,
                              const GstStructure * aStructure,
                              const gchar * const aFieldList[] = NULL,
                              PRUint32 aFieldCount = 0);

/* Copy aValue to aPropertyBag using aFieldName. */
nsresult
SetPropertyFromGValue(nsIWritablePropertyBag2 * aPropertyBag,
                      const nsAString & aProperty,
                      const GValue * aValue);

/* Return the real pad, skipping ghosts. The return object is add ref'd */
GstPad *
GetRealPad (GstPad *pad);

#endif // _SB_GSTREAMERMEDIACOREUTILS_H_