gstreamer/gst/camerabin/camerabinvideo.c

/*
 * GStreamer
 * Copyright (C) 2008 Nokia Corporation <multimedia@maemo.org>
 *
 * 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.
 */

/**
 * SECTION:camerabinvideo
 * @short_description: video recording module of #GstCameraBin
 *
 * <refsect2>
 * <para>
 *
 * The pipeline for this module is:
 *
 * <informalexample>
 * <programlisting>
 *-----------------------------------------------------------------------------
 * audiosrc -> audio_queue -> audioconvert -> volume -> audioenc
 *                                                       > videomux -> filesink
 *                       video_queue -> [timeoverlay] -> [csp] -> videoenc -> queue
 * -> [post proc] -> tee <
 *                       queue ->
 *-----------------------------------------------------------------------------
 * </programlisting>
 * </informalexample>
 *
 * The properties of elements are:
 *
 * queue - "leaky", 2 (Leaky on downstream (old buffers))
 *
 * </para>
 * </refsect2>
 */

/*
 * includes
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gst/gst.h>
#include "camerabindebug.h"
#include "camerabingeneral.h"

#include "camerabinvideo.h"

/*
 * defines and static global vars
 */

/* internal element names */

#define DEFAULT_AUD_ENC "vorbisenc"
#define DEFAULT_VID_ENC "theoraenc"
#define DEFAULT_MUX "oggmux"
#define DEFAULT_SINK "filesink"

#define DEFAULT_FLAGS 0

enum
{
  PROP_0,
  PROP_FILENAME
};

static void gst_camerabin_video_dispose (GstCameraBinVideo * sink);
static void gst_camerabin_video_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_camerabin_video_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static GstStateChangeReturn
gst_camerabin_video_change_state (GstElement * element,
    GstStateChange transition);

static
    gboolean camerabin_video_pad_tee_src0_have_buffer (GstPad * pad,
    GstBuffer * buffer, gpointer u_data);
static gboolean camerabin_video_pad_aud_src_have_buffer (GstPad * pad,
    GstBuffer * buffer, gpointer u_data);
static gboolean camerabin_video_sink_have_event (GstPad * pad, GstEvent * event,
    gpointer u_data);
static gboolean gst_camerabin_video_create_elements (GstCameraBinVideo * vid);
static void gst_camerabin_video_destroy_elements (GstCameraBinVideo * vid);

GST_BOILERPLATE (GstCameraBinVideo, gst_camerabin_video, GstBin, GST_TYPE_BIN);

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS_ANY);

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS_ANY);


/* GObject methods implementation */

static void
gst_camerabin_video_base_init (gpointer klass)
{
  GstElementClass *eklass = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (eklass,
      gst_static_pad_template_get (&sink_template));
  gst_element_class_add_pad_template (eklass,
      gst_static_pad_template_get (&src_template));
  gst_element_class_set_details_simple (eklass,
      "Video capture bin for camerabin", "Bin/Video",
      "Process and store video data",
      "Edgard Lima <edgard.lima@indt.org.br>, "
      "Nokia Corporation <multimedia@maemo.org>");
}

static void
gst_camerabin_video_class_init (GstCameraBinVideoClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *eklass = GST_ELEMENT_CLASS (klass);

  gobject_class = G_OBJECT_CLASS (klass);
  gobject_class->dispose =
      (GObjectFinalizeFunc) GST_DEBUG_FUNCPTR (gst_camerabin_video_dispose);
  eklass->change_state = GST_DEBUG_FUNCPTR (gst_camerabin_video_change_state);

  gobject_class->set_property =
      GST_DEBUG_FUNCPTR (gst_camerabin_video_set_property);
  gobject_class->get_property =
      GST_DEBUG_FUNCPTR (gst_camerabin_video_get_property);

  /**
   * GstCameraBinVideo:filename:
   *
   * This property can be used to specify the filename of the video.
   *
   **/
  g_object_class_install_property (gobject_class, PROP_FILENAME,
      g_param_spec_string ("filename", "Filename",
          "Filename of the video to save", NULL,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}

static void
gst_camerabin_video_init (GstCameraBinVideo * vid,
    GstCameraBinVideoClass * g_class)
{
  vid->filename = g_string_new ("");

  vid->app_post = NULL;
  vid->app_vid_enc = NULL;
  vid->app_aud_enc = NULL;
  vid->app_aud_src = NULL;
  vid->app_mux = NULL;

  vid->aud_src = NULL;
  vid->sink = NULL;
  vid->tee = NULL;
  vid->volume = NULL;
  vid->video_queue = NULL;

  vid->tee_video_srcpad = NULL;
  vid->tee_vf_srcpad = NULL;

  vid->pending_eos = NULL;

  vid->mute = ARG_DEFAULT_MUTE;
  vid->flags = DEFAULT_FLAGS;

  vid->aud_src_probe_id = 0;
  vid->vid_src_probe_id = 0;
  vid->vid_tee_probe_id = 0;
  vid->vid_sink_probe_id = 0;

  /* Create src and sink ghost pads */
  vid->sinkpad = gst_ghost_pad_new_no_target ("sink", GST_PAD_SINK);
  gst_element_add_pad (GST_ELEMENT (vid), vid->sinkpad);

  vid->srcpad = gst_ghost_pad_new_no_target ("src", GST_PAD_SRC);
  gst_element_add_pad (GST_ELEMENT (vid), vid->srcpad);

  /* Add probe for handling eos when stopping recording */
  vid->vid_sink_probe_id = gst_pad_add_event_probe (vid->sinkpad,
      G_CALLBACK (camerabin_video_sink_have_event), vid);
}

static void
gst_camerabin_video_dispose (GstCameraBinVideo * vid)
{
  GST_DEBUG_OBJECT (vid, "disposing");

  g_string_free (vid->filename, TRUE);
  vid->filename = NULL;

  if (vid->vid_sink_probe_id) {
    gst_pad_remove_event_probe (vid->sinkpad, vid->vid_sink_probe_id);
    vid->vid_sink_probe_id = 0;
  }

  /* Note: if videobin was never set to READY state the
     ownership of elements created by application were never
     taken by bin and therefore gst_object_sink is called for
     these elements (they may still be in floating state
     and not unreffed properly without sinking first)
     FIXME, something else is wrong when you have to sink here
   */
  if (vid->app_post) {
    //gst_object_sink (vid->app_post);
    gst_object_unref (vid->app_post);
    vid->app_post = NULL;
  }

  if (vid->app_vid_enc) {
    //gst_object_sink (vid->app_vid_enc);
    gst_object_unref (vid->app_vid_enc);
    vid->app_vid_enc = NULL;
  }

  if (vid->app_aud_enc) {
    //gst_object_sink (vid->app_aud_enc);
    gst_object_unref (vid->app_aud_enc);
    vid->app_aud_enc = NULL;
  }

  if (vid->app_aud_src) {
    //gst_object_sink (vid->app_aud_src);
    gst_object_unref (vid->app_aud_src);
    vid->app_aud_src = NULL;
  }

  if (vid->app_mux) {
    //gst_object_sink (vid->app_mux);
    gst_object_unref (vid->app_mux);
    vid->app_mux = NULL;
  }

  G_OBJECT_CLASS (parent_class)->dispose ((GObject *) vid);
}


static void
gst_camerabin_video_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstCameraBinVideo *bin = GST_CAMERABIN_VIDEO (object);

  switch (prop_id) {
    case PROP_FILENAME:
      g_string_assign (bin->filename, g_value_get_string (value));
      GST_INFO_OBJECT (bin, "received filename: '%s'", bin->filename->str);
      if (bin->sink) {
        g_object_set (G_OBJECT (bin->sink), "location", bin->filename->str,
            NULL);
      } else {
        GST_INFO_OBJECT (bin, "no sink, not setting name yet");
      }
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_camerabin_video_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstCameraBinVideo *bin = GST_CAMERABIN_VIDEO (object);

  switch (prop_id) {
    case PROP_FILENAME:
      g_value_set_string (value, bin->filename->str);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstStateChangeReturn
gst_camerabin_video_change_state (GstElement * element,
    GstStateChange transition)
{
  GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
  GstCameraBinVideo *vid = GST_CAMERABIN_VIDEO (element);

  GST_DEBUG_OBJECT (element, "changing state: %s -> %s",
      gst_element_state_get_name (GST_STATE_TRANSITION_CURRENT (transition)),
      gst_element_state_get_name (GST_STATE_TRANSITION_NEXT (transition)));

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      if (!gst_camerabin_video_create_elements (vid)) {
        return GST_STATE_CHANGE_FAILURE;
      }
      /* Don't change sink to READY yet to allow changing the
         filename in READY state. */
      gst_element_set_locked_state (vid->sink, TRUE);
      break;
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      vid->calculate_adjust_ts_video = TRUE;
      vid->calculate_adjust_ts_aud = TRUE;
      g_object_set (G_OBJECT (vid->sink), "async", FALSE, NULL);
      gst_element_set_locked_state (vid->sink, FALSE);
      break;
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
      vid->calculate_adjust_ts_video = TRUE;
      vid->calculate_adjust_ts_aud = TRUE;
      break;

    case GST_STATE_CHANGE_PAUSED_TO_READY:
      /* Set sink to NULL in order to write the file _now_ */
      GST_INFO ("write video file: %s", vid->filename->str);
      gst_element_set_locked_state (vid->sink, TRUE);
      gst_element_set_state (vid->sink, GST_STATE_NULL);
      break;
    default:
      break;
  }

  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);

  switch (transition) {
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
      /* Write debug graph to file */
      GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (GST_ELEMENT_PARENT (vid)),
          GST_DEBUG_GRAPH_SHOW_MEDIA_TYPE |
          GST_DEBUG_GRAPH_SHOW_NON_DEFAULT_PARAMS, "videobin.playing");

      if (vid->pending_eos) {
        /* Video bin is still paused, so push eos directly to video queue */
        GST_DEBUG_OBJECT (vid, "pushing pending eos");
        gst_pad_push_event (vid->tee_video_srcpad, vid->pending_eos);
        vid->pending_eos = NULL;
      }
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      /* Reset counters related to timestamp rewriting */
      vid->adjust_ts_video = 0;
      vid->last_ts_video = 0;
      vid->adjust_ts_aud = 0;
      vid->last_ts_aud = 0;

      if (vid->pending_eos) {
        gst_event_unref (vid->pending_eos);
        vid->pending_eos = NULL;
      }
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      gst_camerabin_video_destroy_elements (vid);
      break;
    default:
      break;
  }

  GST_DEBUG_OBJECT (element, "changed state: %s -> %s = %s",
      gst_element_state_get_name (GST_STATE_TRANSITION_CURRENT (transition)),
      gst_element_state_get_name (GST_STATE_TRANSITION_NEXT (transition)),
      gst_element_state_change_return_get_name (ret));

  return ret;
}

/*
 * static helper functions implementation
 */

/*
 * camerabin_video_pad_tee_src0_have_buffer:
 * @pad: tee src pad leading to video encoding
 * @event: received buffer
 * @u_data: video bin object
 *
 * Buffer probe for rewriting video buffer timestamps.
 *
 * Returns: TRUE always
 */
static gboolean
camerabin_video_pad_tee_src0_have_buffer (GstPad * pad, GstBuffer * buffer,
    gpointer u_data)
{
  GstCameraBinVideo *vid = (GstCameraBinVideo *) u_data;

  GST_LOG ("buffer in with size %d ts %" GST_TIME_FORMAT,
      GST_BUFFER_SIZE (buffer), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));

  if (G_UNLIKELY (vid->calculate_adjust_ts_video)) {
    GstEvent *event;
    GstObject *tee;
    GstPad *sinkpad;

    vid->adjust_ts_video = GST_BUFFER_TIMESTAMP (buffer) - vid->last_ts_video;
    vid->calculate_adjust_ts_video = FALSE;
    event = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_TIME,
        0, GST_CLOCK_TIME_NONE, vid->last_ts_video);
    /* Send the newsegment to both view finder and video bin */
    tee = gst_pad_get_parent (pad);
    sinkpad = gst_element_get_static_pad (GST_ELEMENT (tee), "sink");
    gst_pad_send_event (sinkpad, event);
    gst_object_unref (tee);
    gst_object_unref (sinkpad);
    GST_LOG_OBJECT (vid, "vid ts adjustment: %" GST_TIME_FORMAT,
        GST_TIME_ARGS (vid->adjust_ts_video));
    GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
  }
  GST_BUFFER_TIMESTAMP (buffer) -= vid->adjust_ts_video;
  vid->last_ts_video = GST_BUFFER_TIMESTAMP (buffer);
  if (GST_BUFFER_DURATION_IS_VALID (buffer))
    vid->last_ts_video += GST_BUFFER_DURATION (buffer);

  GST_LOG ("buffer out with size %d ts %" GST_TIME_FORMAT,
      GST_BUFFER_SIZE (buffer), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));
  return TRUE;
}

/*
 * camerabin_video_pad_aud_src_have_buffer:
 * @pad: audio source src pad
 * @event: received buffer
 * @u_data: video bin object
 *
 * Buffer probe for rewriting audio buffer timestamps.
 *
 * Returns: TRUE always
 */
static gboolean
camerabin_video_pad_aud_src_have_buffer (GstPad * pad, GstBuffer * buffer,
    gpointer u_data)
{
  GstCameraBinVideo *vid = (GstCameraBinVideo *) u_data;

  GST_LOG ("buffer in with size %d duration %" G_GINT64_FORMAT " ts %"
      GST_TIME_FORMAT, GST_BUFFER_SIZE (buffer), GST_BUFFER_DURATION (buffer),
      GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));

  if (vid->calculate_adjust_ts_aud) {
    GstEvent *event;
    GstPad *peerpad = NULL;

    vid->adjust_ts_aud = GST_BUFFER_TIMESTAMP (buffer) - vid->last_ts_aud;
    vid->calculate_adjust_ts_aud = FALSE;
    event = gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_TIME,
        0, GST_CLOCK_TIME_NONE, vid->last_ts_aud);
    peerpad = gst_pad_get_peer (pad);
    if (peerpad) {
      gst_pad_send_event (peerpad, event);
      gst_object_unref (peerpad);
    }
    GST_LOG_OBJECT (vid, "aud ts adjustment: %" GST_TIME_FORMAT,
        GST_TIME_ARGS (vid->adjust_ts_aud));
    GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT);
  }
  GST_BUFFER_TIMESTAMP (buffer) -= vid->adjust_ts_aud;
  vid->last_ts_aud = GST_BUFFER_TIMESTAMP (buffer);
  if (GST_BUFFER_DURATION_IS_VALID (buffer))
    vid->last_ts_aud += GST_BUFFER_DURATION (buffer);

  GST_LOG ("buffer out with size %d ts %" GST_TIME_FORMAT,
      GST_BUFFER_SIZE (buffer), GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));
  return TRUE;
}

/*
 * camerabin_video_sink_have_event:
 * @pad: video bin sink pad
 * @event: received event
 * @u_data: video bin object
 *
 * Event probe for video bin eos handling.
 * Copies the eos event to audio branch of video bin.
 *
 * Returns: FALSE to drop the event, TRUE otherwise
 */
static gboolean
camerabin_video_sink_have_event (GstPad * pad, GstEvent * event,
    gpointer u_data)
{
  GstCameraBinVideo *vid = (GstCameraBinVideo *) u_data;
  gboolean ret = TRUE;

  GST_DEBUG_OBJECT (vid, "got videobin sink event: %s",
      GST_EVENT_TYPE_NAME (event));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_EOS:
      if (vid->aud_src) {
        GST_DEBUG_OBJECT (vid, "copying %s to audio branch",
            GST_EVENT_TYPE_NAME (event));
        gst_element_send_event (vid->aud_src, gst_event_copy (event));
      }

      /* If we're paused, we can't pass eos to video now to avoid blocking.
         Instead send eos when changing to playing next time. */
      if (GST_STATE (GST_ELEMENT (vid)) == GST_STATE_PAUSED) {
        GST_DEBUG_OBJECT (vid, "paused, delay eos sending");
        vid->pending_eos = gst_event_ref (event);
        ret = FALSE;            /* Drop the event */
      }
      break;
    default:
      break;
  }
  return ret;
}

/*
 * gst_camerabin_video_create_elements:
 * @vid: a pointer to #GstCameraBinVideo
 *
 * This function creates the needed #GstElements and resources to record videos.
 * Use gst_camerabin_video_destroy_elements() to free these resources.
 *
 * Returns: %TRUE if succeeded or FALSE if failed
 */
static gboolean
gst_camerabin_video_create_elements (GstCameraBinVideo * vid)
{
  GstPad *pad = NULL, *vid_sinkpad = NULL, *vid_srcpad = NULL;
  GstBin *vidbin = GST_BIN (vid);
  GstElement *queue = NULL;

  vid->adjust_ts_video = 0;
  vid->last_ts_video = 0;
  vid->calculate_adjust_ts_video = FALSE;

  vid->adjust_ts_aud = 0;
  vid->last_ts_aud = 0;
  vid->calculate_adjust_ts_aud = FALSE;

  /* Add video post processing element if any */
  if (vid->app_post) {
    if (!gst_camerabin_add_element (vidbin, vid->app_post)) {
      goto error;
    }
    vid_sinkpad = gst_element_get_static_pad (vid->app_post, "sink");
  }

  /* Add tee element */
  if (!(vid->tee =
          gst_camerabin_create_and_add_element (vidbin, "tee", "video-tee"))) {
    goto error;
  }

  /* Set up sink ghost pad for video bin */
  if (!vid_sinkpad) {
    vid_sinkpad = gst_element_get_static_pad (vid->tee, "sink");
  }
  gst_ghost_pad_set_target (GST_GHOST_PAD (vid->sinkpad), vid_sinkpad);
  gst_object_unref (vid_sinkpad);

  /* Add queue element for video */
  vid->tee_video_srcpad = gst_element_get_request_pad (vid->tee, "src%d");

  vid->video_queue = gst_element_factory_make ("queue", "video-queue");
  if (!gst_camerabin_add_element (vidbin, vid->video_queue)) {
    goto error;
  }
  g_object_set (vid->video_queue, "silent", TRUE, NULL);

  /* Add probe for rewriting video timestamps */
  vid->vid_tee_probe_id = gst_pad_add_buffer_probe (vid->tee_video_srcpad,
      G_CALLBACK (camerabin_video_pad_tee_src0_have_buffer), vid);

  if (vid->flags & GST_CAMERABIN_FLAG_VIDEO_COLOR_CONVERSION) {
    /* Add colorspace converter */
    if (gst_camerabin_create_and_add_element (vidbin,
            "ffmpegcolorspace", "video-ffmpegcolorspace") == NULL) {
      goto error;
    }
  }

  /* Add user set or default video encoder element */
  if (vid->app_vid_enc) {
    vid->vid_enc = vid->app_vid_enc;
    if (!gst_camerabin_add_element (vidbin, vid->vid_enc)) {
      goto error;
    }
  } else if (!(vid->vid_enc =
          gst_camerabin_create_and_add_element (vidbin, DEFAULT_VID_ENC,
              "video-encoder"))) {
    goto error;
  }

  /* Add application set or default muxer element */
  if (vid->app_mux) {
    vid->muxer = vid->app_mux;
    if (!gst_camerabin_add_element (vidbin, vid->muxer)) {
      goto error;
    }
  } else if (!(vid->muxer =
          gst_camerabin_create_and_add_element (vidbin, DEFAULT_MUX,
              "video-muxer"))) {
    goto error;
  }

  /* Add sink element for storing the video */
  if (!(vid->sink =
          gst_camerabin_create_and_add_element (vidbin, DEFAULT_SINK,
              "video-sink"))) {
    goto error;
  }
  g_object_set (G_OBJECT (vid->sink), "location", vid->filename->str, "buffer-mode", 2, /* non buffered io */
      NULL);

  if (!(vid->flags & GST_CAMERABIN_FLAG_DISABLE_AUDIO)) {
    /* Add application set or default audio source element */
    if (!(vid->aud_src = gst_camerabin_setup_default_element (vidbin,
                vid->app_aud_src, "autoaudiosrc", DEFAULT_AUDIOSRC))) {
      vid->aud_src = NULL;
      goto error;
    } else {
      if (!gst_camerabin_add_element (vidbin, vid->aud_src))
        goto error;
    }

    /* Add queue element for audio */
    queue = gst_element_factory_make ("queue", "audio-queue");
    if (!gst_camerabin_add_element (vidbin, queue)) {
      goto error;
    }
    g_object_set (queue, "silent", TRUE, NULL);

    /* Add optional audio conversion and volume elements and
       raise no errors if adding them fails */
    if (vid->flags & GST_CAMERABIN_FLAG_AUDIO_CONVERSION) {
      if (!gst_camerabin_try_add_element (vidbin,
              gst_element_factory_make ("audioconvert", NULL))) {
        GST_WARNING_OBJECT (vid, "unable to add audio conversion element");
        /* gst_camerabin_try_add_element() destroyed the element */
      }
    }

    vid->volume = gst_element_factory_make ("volume", NULL);
    if (!gst_camerabin_try_add_element (vidbin, vid->volume)) {
      GST_WARNING_OBJECT (vid, "unable to add volume element");
      /* gst_camerabin_try_add_element() destroyed the element */
      vid->volume = NULL;
    } else {
      g_object_set (vid->volume, "mute", vid->mute, NULL);
    }

    /* Add application set or default audio encoder element */
    if (vid->app_aud_enc) {
      vid->aud_enc = vid->app_aud_enc;
      if (!gst_camerabin_add_element (vidbin, vid->aud_enc)) {
        goto error;
      }
    } else if (!(vid->aud_enc =
            gst_camerabin_create_and_add_element (vidbin, DEFAULT_AUD_ENC,
                "audio-encoder"))) {
      goto error;
    }

    /* Link audio part to the muxer */
    if (!gst_element_link_pads_full (vid->aud_enc, NULL, vid->muxer, NULL,
            GST_PAD_LINK_CHECK_CAPS)) {
      GST_ELEMENT_ERROR (vid, CORE, NEGOTIATION, (NULL),
          ("linking audio encoder and muxer failed"));
      goto error;
    }
  }
  /* Add queue leading out of the video bin and to view finder */
  vid->tee_vf_srcpad = gst_element_get_request_pad (vid->tee, "src%d");
  queue = gst_element_factory_make ("queue", "viewfinder-queue");
  if (!gst_camerabin_add_element (vidbin, queue)) {
    goto error;
  }
  /* Set queue leaky, we don't want to block video encoder feed, but
     prefer leaking view finder buffers instead. */
  g_object_set (G_OBJECT (queue), "leaky", 2, "max-size-buffers", 1, "silent",
      TRUE, NULL);

  /* Set up src ghost pad for video bin */
  vid_srcpad = gst_element_get_static_pad (queue, "src");
  gst_ghost_pad_set_target (GST_GHOST_PAD (vid->srcpad), vid_srcpad);
  /* Never let video bin eos events reach view finder */
  vid->vid_src_probe_id = gst_pad_add_event_probe (vid_srcpad,
      G_CALLBACK (gst_camerabin_drop_eos_probe), vid);
  gst_object_unref (vid_srcpad);

  if (!(vid->flags & GST_CAMERABIN_FLAG_DISABLE_AUDIO)) {
    pad = gst_element_get_static_pad (vid->aud_src, "src");
    vid->aud_src_probe_id = gst_pad_add_buffer_probe (pad,
        G_CALLBACK (camerabin_video_pad_aud_src_have_buffer), vid);
    gst_object_unref (pad);
  }
  GST_DEBUG ("created video elements");

  return TRUE;

error:

  gst_camerabin_video_destroy_elements (vid);

  return FALSE;

}

/*
 * gst_camerabin_video_destroy_elements:
 * @vid: a pointer to #GstCameraBinVideo
 *
 * This function destroys all the elements created by
 * gst_camerabin_video_create_elements().
 *
 */
static void
gst_camerabin_video_destroy_elements (GstCameraBinVideo * vid)
{
  GST_DEBUG ("destroying video elements");

  /* Remove buffer probe from audio src pad */
  if (vid->aud_src_probe_id) {
    GstPad *pad = gst_element_get_static_pad (vid->aud_src, "src");
    if (pad) {
      gst_pad_remove_buffer_probe (pad, vid->aud_src_probe_id);
      gst_object_unref (pad);
    }
    vid->aud_src_probe_id = 0;
  }

  /* Remove EOS event probe from videobin srcpad (queue's srcpad) */
  if (vid->vid_src_probe_id) {
    GstPad *pad = gst_ghost_pad_get_target (GST_GHOST_PAD (vid->srcpad));
    if (pad) {
      gst_pad_remove_event_probe (pad, vid->vid_src_probe_id);
      gst_object_unref (pad);
    }
    vid->vid_src_probe_id = 0;
  }

  /* Remove buffer probe from video tee srcpad */
  if (vid->vid_tee_probe_id) {
    gst_pad_remove_buffer_probe (vid->tee_video_srcpad, vid->vid_tee_probe_id);
    vid->vid_tee_probe_id = 0;
  }

  /* Release tee request pads */
  if (vid->tee_video_srcpad) {
    gst_element_release_request_pad (vid->tee, vid->tee_video_srcpad);
    gst_object_unref (vid->tee_video_srcpad);
    vid->tee_video_srcpad = NULL;
  }
  if (vid->tee_vf_srcpad) {
    gst_element_release_request_pad (vid->tee, vid->tee_vf_srcpad);
    gst_object_unref (vid->tee_vf_srcpad);
    vid->tee_vf_srcpad = NULL;
  }

  gst_ghost_pad_set_target (GST_GHOST_PAD (vid->sinkpad), NULL);
  gst_ghost_pad_set_target (GST_GHOST_PAD (vid->srcpad), NULL);

  gst_camerabin_remove_elements_from_bin (GST_BIN (vid));

  vid->aud_src = NULL;
  vid->sink = NULL;
  vid->tee = NULL;
  vid->volume = NULL;
  vid->video_queue = NULL;
  vid->vid_enc = NULL;
  vid->aud_enc = NULL;
  vid->muxer = NULL;

  if (vid->pending_eos) {
    gst_event_unref (vid->pending_eos);
    vid->pending_eos = NULL;
  }
}

/*
 * Set & get mute and video capture elements
 */

void
gst_camerabin_video_set_mute (GstCameraBinVideo * vid, gboolean mute)
{
  g_return_if_fail (vid != NULL);

  GST_DEBUG_OBJECT (vid, "setting mute %s", mute ? "on" : "off");
  vid->mute = mute;
  if (vid->volume) {
    g_object_set (vid->volume, "mute", mute, NULL);
  }
}

void
gst_camerabin_video_set_post (GstCameraBinVideo * vid, GstElement * post)
{
  GstElement **app_post;
  GST_DEBUG_OBJECT (vid, "setting video post processing: %" GST_PTR_FORMAT,
      post);
  GST_OBJECT_LOCK (vid);
  app_post = &vid->app_post;
  gst_object_replace ((GstObject **) app_post, GST_OBJECT (post));
  GST_OBJECT_UNLOCK (vid);
}

void
gst_camerabin_video_set_video_enc (GstCameraBinVideo * vid,
    GstElement * video_enc)
{
  GstElement **app_vid_enc;
  GST_DEBUG_OBJECT (vid, "setting video encoder: %" GST_PTR_FORMAT, video_enc);
  GST_OBJECT_LOCK (vid);
  app_vid_enc = &vid->app_vid_enc;
  gst_object_replace ((GstObject **) app_vid_enc, GST_OBJECT (video_enc));
  GST_OBJECT_UNLOCK (vid);
}

void
gst_camerabin_video_set_audio_enc (GstCameraBinVideo * vid,
    GstElement * audio_enc)
{
  GstElement **app_aud_enc;
  GST_DEBUG_OBJECT (vid, "setting audio encoder: %" GST_PTR_FORMAT, audio_enc);
  GST_OBJECT_LOCK (vid);
  app_aud_enc = &vid->app_aud_enc;
  gst_object_replace ((GstObject **) app_aud_enc, GST_OBJECT (audio_enc));
  GST_OBJECT_UNLOCK (vid);
}

void
gst_camerabin_video_set_muxer (GstCameraBinVideo * vid, GstElement * muxer)
{
  GstElement **app_mux;
  GST_DEBUG_OBJECT (vid, "setting muxer: %" GST_PTR_FORMAT, muxer);
  GST_OBJECT_LOCK (vid);
  app_mux = &vid->app_mux;
  gst_object_replace ((GstObject **) app_mux, GST_OBJECT (muxer));
  GST_OBJECT_UNLOCK (vid);
}

void
gst_camerabin_video_set_audio_src (GstCameraBinVideo * vid,
    GstElement * audio_src)
{
  GstElement **app_aud_src;
  GST_DEBUG_OBJECT (vid, "setting audio source: %" GST_PTR_FORMAT, audio_src);
  GST_OBJECT_LOCK (vid);
  app_aud_src = &vid->app_aud_src;
  gst_object_replace ((GstObject **) app_aud_src, GST_OBJECT (audio_src));
  GST_OBJECT_UNLOCK (vid);
}

void
gst_camerabin_video_set_flags (GstCameraBinVideo * vid, GstCameraBinFlags flags)
{
  GST_DEBUG_OBJECT (vid, "setting video flags: %d", flags);
  GST_OBJECT_LOCK (vid);
  vid->flags = flags;
  GST_OBJECT_UNLOCK (vid);
}


gboolean
gst_camerabin_video_get_mute (GstCameraBinVideo * vid)
{
  g_return_val_if_fail (vid != NULL, FALSE);

  if (vid->volume) {
    g_object_get (vid->volume, "mute", &vid->mute, NULL);
  }

  return vid->mute;
}

GstElement *
gst_camerabin_video_get_post (GstCameraBinVideo * vid)
{
  return vid->app_post;
}

GstElement *
gst_camerabin_video_get_video_enc (GstCameraBinVideo * vid)
{
  return vid->vid_enc ? vid->vid_enc : vid->app_vid_enc;
}

GstElement *
gst_camerabin_video_get_audio_enc (GstCameraBinVideo * vid)
{
  return vid->aud_enc ? vid->aud_enc : vid->app_aud_enc;
}

GstElement *
gst_camerabin_video_get_muxer (GstCameraBinVideo * vid)
{
  return vid->muxer ? vid->muxer : vid->app_mux;
}

GstElement *
gst_camerabin_video_get_audio_src (GstCameraBinVideo * vid)
{
  return vid->aud_src ? vid->aud_src : vid->app_aud_src;
}