gstreamer/gst/camerabin2/gstv4l2camerasrc.c

/*
 * GStreamer
 * Copyright (C) 2010 Texas Instruments, Inc
 *
 * 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:element-v4l2camerasrc
 *
 * A camera src element for camerabin.. currently uses v4l2 directly.
 * It could be worthwhile to make this subclassable, so that other
 * camera elements with a single src pad could re-use this..
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "gstv4l2camerasrc.h"
#include "camerabingeneral.h"
#include "gstcamerabin-enum.h"


#define CAMERABIN_DEFAULT_VF_CAPS "video/x-raw-yuv,format=(fourcc)I420"

/* Using "bilinear" as default zoom method */
#define CAMERABIN_DEFAULT_ZOOM_METHOD 1

GST_DEBUG_CATEGORY (v4l2_camera_src_debug);
#define GST_CAT_DEFAULT v4l2_camera_src_debug

GST_BOILERPLATE (GstV4l2CameraSrc, gst_v4l2_camera_src, GstBaseCameraSrc,
    GST_TYPE_BASE_CAMERA_SRC);

static void configure_format (GstV4l2CameraSrc * self, GstCaps * caps);
static void set_capsfilter_caps (GstV4l2CameraSrc * self, GstCaps * new_caps);

static void
gst_v4l2_camera_src_dispose (GObject * object)
{
  G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
gst_v4l2_camera_src_finalize (GstV4l2CameraSrc * self)
{
  G_OBJECT_CLASS (parent_class)->finalize ((GObject *) (self));
}

static void
gst_v4l2_camera_src_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (object);

  switch (prop_id) {
    case ARG_MODE:
      self->mode = g_value_get_enum (value);
      gst_base_camera_src_set_mode (GST_BASE_CAMERA_SRC (self), self->mode);
      break;
    case ARG_FILTER_CAPS:
      GST_OBJECT_LOCK (self);
      gst_caps_replace (&self->view_finder_caps,
          (GstCaps *) gst_value_get_caps (value));
      GST_OBJECT_UNLOCK (self);
      configure_format (self, self->view_finder_caps);
      break;
    case ARG_VIDEO_SOURCE_FILTER:
      if (GST_STATE (self) != GST_STATE_NULL) {
        GST_ELEMENT_ERROR (self, CORE, FAILED,
            ("camerasrc must be in NULL state when setting the video filter element"),
            (NULL));
      } else {
        if (self->app_video_filter)
          gst_object_unref (self->app_video_filter);
        self->app_video_filter = g_value_dup_object (value);
      }
      break;
    case ARG_VIDEO_SRC:
      if (GST_STATE (self) != GST_STATE_NULL) {
        GST_ELEMENT_ERROR (self, CORE, FAILED,
            ("camerasrc must be in NULL state when setting the video source element"),
            (NULL));
      } else {
        if (self->app_vid_src)
          gst_object_unref (self->app_vid_src);
        self->app_vid_src = g_value_get_object (value);
        gst_object_ref (self->app_vid_src);
      }
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
      break;
  }
}

static void
gst_v4l2_camera_src_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (object);

  switch (prop_id) {
    case ARG_MODE:
      g_value_set_enum (value, self->mode);
      break;
    case ARG_FILTER_CAPS:
      gst_value_set_caps (value, self->view_finder_caps);
      break;
    case ARG_VIDEO_SOURCE_FILTER:
      g_value_set_object (value, self->app_video_filter);
      break;
    case ARG_VIDEO_SRC:
      if (self->src_vid_src)
        g_value_set_object (value, self->src_vid_src);
      else
        g_value_set_object (value, self->app_vid_src);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (self, prop_id, pspec);
      break;
  }
}

/**
 * gst_v4l2_camera_src_imgsrc_probe:
 *
 * Buffer probe called before sending each buffer to image queue.
 */
static gboolean
gst_v4l2_camera_src_imgsrc_probe (GstPad * pad, GstBuffer * buffer,
    gpointer data)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (data);
  GST_DEBUG_OBJECT (self, "pass buffer: %d", self->mode == MODE_IMAGE);
  return self->mode == MODE_IMAGE;
}

/**
 * gst_v4l2_camera_src_vidsrc_probe:
 *
 * Buffer probe called before sending each buffer to image queue.
 */
static gboolean
gst_v4l2_camera_src_vidsrc_probe (GstPad * pad, GstBuffer * buffer,
    gpointer data)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (data);
  GST_DEBUG_OBJECT (self, "pass buffer: %d", self->mode == MODE_VIDEO);
  return self->mode == MODE_VIDEO;
}

/**
 * gst_v4l2_camera_src_construct_pipeline:
 * @bcamsrc: camerasrc object
 * @vfsrc: viewfinder src element (returned by reference)
 * @imgsrc: image src element (returned by reference)
 * @vidsrc: video src element (returned by reference)
 *
 * This function creates and links the elements of the camerasrc bin
 * videosrc ! cspconv ! capsfilter ! crop ! scale ! capsfilter ! tee ! ..
 *
 * Returns: TRUE, if elements were successfully created, FALSE otherwise
 */
static gboolean
gst_v4l2_camera_src_construct_pipeline (GstBaseCameraSrc * bcamsrc,
    GstPad ** vfsrc, GstPad ** imgsrc, GstPad ** vidsrc)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);
  GstBin *cbin = GST_BIN (bcamsrc);
  GstElement *tee;
  gboolean ret = FALSE;

  GST_DEBUG_OBJECT (self, "constructing pipeline");

  /* Add application set or default video src element */
  if (!(self->src_vid_src = gst_camerabin_setup_default_element (cbin,
              self->app_vid_src, "autovideosrc", DEFAULT_VIDEOSRC))) {
    self->src_vid_src = NULL;
    goto done;
  } else {
    if (!gst_camerabin_add_element (cbin, self->src_vid_src)) {
      goto done;
    }
  }

#if 0
  /* XXX srcbin needs to know of some flags, perhaps?? */
  if (camera->flags & GST_CAMERABIN_FLAG_SOURCE_COLOR_CONVERSION) {
#else
  if (1) {
#endif
    if (!gst_camerabin_create_and_add_element (cbin, "ffmpegcolorspace"))
      goto done;
  }

  if (!(self->src_filter =
          gst_camerabin_create_and_add_element (cbin, "capsfilter")))
    goto done;

#if 0
  /* XXX srcbin needs to know of some flags, perhaps?? */
  if (camera->flags & GST_CAMERABIN_FLAG_SOURCE_RESIZE) {
#else
  if (1) {
#endif
    if (!(self->src_zoom_crop =
            gst_camerabin_create_and_add_element (cbin, "videocrop")))
      goto done;
    if (!(self->src_zoom_scale =
            gst_camerabin_create_and_add_element (cbin, "videoscale")))
      goto done;
    if (!(self->src_zoom_filter =
            gst_camerabin_create_and_add_element (cbin, "capsfilter")))
      goto done;
  }

  if (self->app_video_filter) {
    if (!gst_camerabin_add_element (cbin, self->app_video_filter)) {
      goto done;
    }
  }

  if (!(tee = gst_camerabin_create_and_add_element (cbin, "tee")))
    goto done;

  self->tee_vf_srcpad = gst_element_get_request_pad (tee, "src%d");
  self->tee_image_srcpad = gst_element_get_request_pad (tee, "src%d");
  self->tee_video_srcpad = gst_element_get_request_pad (tee, "src%d");

  gst_pad_add_buffer_probe (self->tee_image_srcpad,
      G_CALLBACK (gst_v4l2_camera_src_imgsrc_probe), self);
  gst_pad_add_buffer_probe (self->tee_video_srcpad,
      G_CALLBACK (gst_v4l2_camera_src_vidsrc_probe), self);

  *vfsrc = self->tee_vf_srcpad;
  *imgsrc = self->tee_image_srcpad;
  *vidsrc = self->tee_video_srcpad;

#if 0
  /* XXX another idea... put common parts in GstBaseCameraSrc.. perhaps
   * derived class could use some flags, or something like this, to
   * indicate which pads in needs vscale and queue on.. (but I think it
   * doesn't hurt ot have on all..)
   */
  /* XXX perhaps we should keep queues and vscale's in camerabin itself,
   * because GstOmxCameraSrc would also probably need the queues.. and
   * maybe some OMX camera implementations would want the vscale's (and
   * at least the vscale's should become pass-through if OMX camera can
   * negotiate the requested sizes..
   */
  queue = gst_element_factory_make ("queue", "viewfinder-queue");
  if (!gst_camerabin_add_element (cbin, 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, NULL);
#endif

  ret = TRUE;
done:
  return ret;
}

/**
 * get_srcpad_current_format:
 * @element: element to get the format from
 *
 * Helper function to get the negotiated fourcc
 * format from @element src pad.
 *
 * Returns: negotiated format (fourcc), 0 if not found
 */
static guint32
get_srcpad_current_format (GstElement * element)
{
  GstPad *srcpad = NULL;
  GstCaps *srccaps = NULL;
  GstStructure *structure;
  guint32 format = 0;

  g_return_val_if_fail (element != NULL, 0);

  if ((srcpad = gst_element_get_static_pad (element, "src")) == NULL) {
    goto no_pad;
  }

  if ((srccaps = gst_pad_get_negotiated_caps (srcpad)) == NULL) {
    goto no_caps;
  }

  GST_LOG ("negotiated caps %" GST_PTR_FORMAT, srccaps);

  structure = gst_caps_get_structure (srccaps, 0);
  if (gst_structure_has_field (structure, "format")) {
    gst_structure_get_fourcc (structure, "format", &format);
  }

  gst_caps_unref (srccaps);
no_caps:
  gst_object_unref (srcpad);
no_pad:
  GST_DEBUG ("current format for %" GST_PTR_FORMAT ": %" GST_FOURCC_FORMAT,
      element, GST_FOURCC_ARGS (format));
  return format;
}

/**
 * set_allowed_framerate:
 * @self: camerasrc object
 * @filter_caps: update allowed framerate to these caps
 *
 * Find allowed frame rate from video source that matches with
 * resolution in @filter_caps. Set found frame rate to @filter_caps.
 */
static void
set_allowed_framerate (GstV4l2CameraSrc * self, GstCaps * filter_caps)
{
  GstBaseCameraSrc *bcamsrc = GST_BASE_CAMERA_SRC (self);
  GstStructure *structure;
  GstCaps *allowed_caps = NULL, *intersect = NULL, *tmp_caps = NULL;
  const GValue *framerate = NULL;
  guint caps_size, i;
  guint32 format = 0;

  GST_INFO_OBJECT (self, "filter caps:%" GST_PTR_FORMAT, filter_caps);

  structure = gst_structure_copy (gst_caps_get_structure (filter_caps, 0));

  /* Set fourcc format according to current videosrc format */
  format = get_srcpad_current_format (self->src_vid_src);
  if (format) {
    GST_DEBUG_OBJECT (self,
        "using format %" GST_FOURCC_FORMAT " for matching",
        GST_FOURCC_ARGS (format));
    gst_structure_set (structure, "format", GST_TYPE_FOURCC, format, NULL);
  } else {
    GST_DEBUG_OBJECT (self, "not matching against fourcc format");
    gst_structure_remove_field (structure, "format");
  }

  tmp_caps = gst_caps_new_full (structure, NULL);

  /* Get supported caps from video src that matches with new filter caps */
  allowed_caps = gst_base_camera_src_get_allowed_input_caps (bcamsrc);
  intersect = gst_caps_intersect (allowed_caps, tmp_caps);
  GST_INFO_OBJECT (self, "intersect caps:%" GST_PTR_FORMAT, intersect);

  /* Find the best framerate from the caps */
  caps_size = gst_caps_get_size (intersect);
  for (i = 0; i < caps_size; i++) {
    structure = gst_caps_get_structure (intersect, i);
    framerate = gst_base_camera_src_find_better_framerate (bcamsrc,
        structure, framerate);
  }

  /* Set found frame rate to original caps */
  if (GST_VALUE_HOLDS_FRACTION (framerate)) {
    gst_caps_set_simple (filter_caps,
        "framerate", GST_TYPE_FRACTION,
        gst_value_get_fraction_numerator (framerate),
        gst_value_get_fraction_denominator (framerate), NULL);
  }

  /* Unref helper caps */
  if (allowed_caps) {
    gst_caps_unref (allowed_caps);
  }
  if (intersect) {
    gst_caps_unref (intersect);
  }
  if (tmp_caps) {
    gst_caps_unref (tmp_caps);
  }
}

/**
 * gst_v4l2_camera_src_setup_pipeline:
 * @bcamsrc: camerasrc object
 *
 * This function updates camerabin capsfilters according
 * to fps, resolution and zoom that have been configured
 * to camerabin.
 */
static gboolean
gst_v4l2_camera_src_setup_pipeline (GstBaseCameraSrc * bcamsrc)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);
  GstStructure *st;
  GstCaps *new_caps;
  gboolean detect_framerate = FALSE;

  /* clear video update status */
//XXX  self->video_capture_caps_update = FALSE;

  if (!self->view_finder_caps) {
    st = gst_structure_from_string (CAMERABIN_DEFAULT_VF_CAPS, NULL);
  } else {
    st = gst_structure_copy (gst_caps_get_structure (self->view_finder_caps,
            0));
  }

  if (bcamsrc->width > 0 && bcamsrc->height > 0) {
    gst_structure_set (st,
        "width", G_TYPE_INT, bcamsrc->width,
        "height", G_TYPE_INT, bcamsrc->height, NULL);
  }

  if (bcamsrc->fps_n > 0 && bcamsrc->fps_d > 0) {
    if (bcamsrc->night_mode) {
      GST_INFO_OBJECT (self, "night mode, lowest allowed fps will be forced");
      bcamsrc->pre_night_fps_n = bcamsrc->fps_n;
      bcamsrc->pre_night_fps_d = bcamsrc->fps_d;
      detect_framerate = TRUE;
    } else {
      gst_structure_set (st,
          "framerate", GST_TYPE_FRACTION, bcamsrc->fps_n, bcamsrc->fps_d, NULL);
      new_caps = gst_caps_new_full (st, NULL);
    }
  } else {
    GST_DEBUG_OBJECT (self, "no framerate specified");
    detect_framerate = TRUE;
  }

  if (detect_framerate) {
    GST_DEBUG_OBJECT (self, "detecting allowed framerate");
    /* Remove old framerate if any */
    if (gst_structure_has_field (st, "framerate")) {
      gst_structure_remove_field (st, "framerate");
    }
    new_caps = gst_caps_new_full (st, NULL);

    /* Set allowed framerate for the resolution */
    set_allowed_framerate (self, new_caps);
  }

  /* Set default zoom method */
  if (self->src_zoom_scale) {
    g_object_set (self->src_zoom_scale, "method",
        CAMERABIN_DEFAULT_ZOOM_METHOD, NULL);
  }

  /* we create new caps in any way and they take ownership of the structure st */
  gst_caps_replace (&self->view_finder_caps, new_caps);
  gst_caps_unref (new_caps);

  /* Set caps for view finder mode */
  /* This also sets zoom */
  set_capsfilter_caps (self, self->view_finder_caps);

  return TRUE;
}

static gboolean
copy_missing_fields (GQuark field_id, const GValue * value, gpointer user_data)
{
  GstStructure *st = (GstStructure *) user_data;
  const GValue *val = gst_structure_id_get_value (st, field_id);

  if (G_UNLIKELY (val == NULL)) {
    gst_structure_id_set_value (st, field_id, value);
  }

  return TRUE;
}

/**
 * adapt_image_capture:
 * @self: camerasrc object
 * @in_caps: caps object that describes incoming image format
 *
 * Adjust capsfilters and crop according image capture caps if necessary.
 * The captured image format from video source might be different from
 * what application requested, so we can try to fix that in camerabin.
 *
 */
static void
adapt_image_capture (GstV4l2CameraSrc * self, GstCaps * in_caps)
{
  GstBaseCameraSrc *bcamsrc = GST_BASE_CAMERA_SRC (self);
  GstStructure *in_st, *new_st, *req_st;
  gint in_width = 0, in_height = 0, req_width = 0, req_height = 0, crop = 0;
  gdouble ratio_w, ratio_h;
  GstCaps *filter_caps = NULL;

  GST_LOG_OBJECT (self, "in caps: %" GST_PTR_FORMAT, in_caps);
  GST_LOG_OBJECT (self, "requested caps: %" GST_PTR_FORMAT,
      self->image_capture_caps);

  in_st = gst_caps_get_structure (in_caps, 0);
  gst_structure_get_int (in_st, "width", &in_width);
  gst_structure_get_int (in_st, "height", &in_height);

  req_st = gst_caps_get_structure (self->image_capture_caps, 0);
  gst_structure_get_int (req_st, "width", &req_width);
  gst_structure_get_int (req_st, "height", &req_height);

  GST_INFO_OBJECT (self, "we requested %dx%d, and got %dx%d", req_width,
      req_height, in_width, in_height);

  new_st = gst_structure_copy (req_st);
  /* If new fields have been added, we need to copy them */
  gst_structure_foreach (in_st, copy_missing_fields, new_st);

#if 0
  /* XXX srcbin needs to know of some flags, perhaps?? */
  if (!(camera->flags & GST_CAMERABIN_FLAG_SOURCE_RESIZE)) {
#else
  if (1) {
#endif
    GST_DEBUG_OBJECT (self,
        "source-resize flag disabled, unable to adapt resolution");
    gst_structure_set (new_st, "width", G_TYPE_INT, in_width, "height",
        G_TYPE_INT, in_height, NULL);
  }

  GST_LOG_OBJECT (self, "new image capture caps: %" GST_PTR_FORMAT, new_st);

  /* Crop if requested aspect ratio differs from incoming frame aspect ratio */
  if (self->src_zoom_crop) {

    ratio_w = (gdouble) in_width / req_width;
    ratio_h = (gdouble) in_height / req_height;

    if (ratio_w < ratio_h) {
      crop = in_height - (req_height * ratio_w);
      self->base_crop_top = crop / 2;
      self->base_crop_bottom = crop / 2;
    } else {
      crop = in_width - (req_width * ratio_h);
      self->base_crop_left = crop / 2;
      self->base_crop_right += crop / 2;
    }

    GST_INFO_OBJECT (self,
        "setting base crop: left:%d, right:%d, top:%d, bottom:%d",
        self->base_crop_left, self->base_crop_right, self->base_crop_top,
        self->base_crop_bottom);
    g_object_set (G_OBJECT (self->src_zoom_crop),
        "top", self->base_crop_top,
        "bottom", self->base_crop_bottom,
        "left", self->base_crop_left, "right", self->base_crop_right, NULL);
  }

  /* Update capsfilters */
  gst_caps_replace (&self->image_capture_caps,
      gst_caps_new_full (new_st, NULL));
  set_capsfilter_caps (self, self->image_capture_caps);

  /* Adjust the capsfilter before crop and videoscale elements if necessary */
  if (in_width == bcamsrc->width && in_height == bcamsrc->height) {
    GST_DEBUG_OBJECT (self, "no adaptation with resolution needed");
  } else {
    GST_DEBUG_OBJECT (self,
        "changing %" GST_PTR_FORMAT " from %dx%d to %dx%d", self->src_filter,
        bcamsrc->width, bcamsrc->height, in_width, in_height);
    /* Apply the width and height to filter caps */
    g_object_get (G_OBJECT (self->src_filter), "caps", &filter_caps, NULL);
    filter_caps = gst_caps_make_writable (filter_caps);
    gst_caps_set_simple (filter_caps, "width", G_TYPE_INT, in_width, "height",
        G_TYPE_INT, in_height, NULL);
    g_object_set (G_OBJECT (self->src_filter), "caps", filter_caps, NULL);
    gst_caps_unref (filter_caps);
  }
}

/**
 * img_capture_prepared:
 * @data: camerasrc object
 * @caps: caps describing the prepared image format
 *
 * Callback which is called after image capture has been prepared.
 */
static void
img_capture_prepared (gpointer data, GstCaps * caps)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (data);

  GST_INFO_OBJECT (self, "image capture prepared");

  /* It is possible we are about to get something else that we requested */
  if (!gst_caps_is_equal (self->image_capture_caps, caps)) {
    adapt_image_capture (self, caps);
  } else {
    set_capsfilter_caps (self, self->image_capture_caps);
  }
}

static void
set_image_capture_caps (GstV4l2CameraSrc * self, gint width, gint height)
{
  GstStructure *structure;
  GstCaps *new_caps = NULL;

  if (width && height && self->view_finder_caps) {
    /* Use view finder mode caps as a basis */
    structure = gst_caps_get_structure (self->view_finder_caps, 0);

    /* Set new resolution for image capture */
    new_caps = gst_caps_new_simple (gst_structure_get_name (structure),
        "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, NULL);

    /* Set allowed framerate for the resolution. */
    set_allowed_framerate (self, new_caps);
  }

  GST_INFO_OBJECT (self,
      "init filter caps for image capture %" GST_PTR_FORMAT, new_caps);
  gst_caps_replace (&self->image_capture_caps, new_caps);
  self->image_capture_caps_update = FALSE;
}

/**
 *
 */
static gboolean
start_image_capture (GstV4l2CameraSrc * self)
{
  GstBaseCameraSrc *bcamsrc = GST_BASE_CAMERA_SRC (self);
  GstPhotography *photography = gst_base_camera_src_get_photography (bcamsrc);
  gboolean wait_for_prepare = FALSE, ret = FALSE;

  if (photography) {
    wait_for_prepare = TRUE;

    if (!self->image_capture_caps || self->image_capture_caps_update) {
      if (bcamsrc->image_capture_width && bcamsrc->image_capture_height) {
        /* Resolution is set, but it isn't in use yet */
        set_image_capture_caps (self, bcamsrc->image_capture_width,
            bcamsrc->image_capture_height);
      } else {
        /* Capture resolution not set. Use viewfinder resolution */
        self->image_capture_caps = gst_caps_copy (self->view_finder_caps);
        self->image_capture_caps_update = FALSE;
      }
    }

    /* Start preparations for image capture */
    GST_DEBUG_OBJECT (self, "prepare image capture caps %" GST_PTR_FORMAT,
        self->image_capture_caps);

    ret = gst_photography_prepare_for_capture (photography,
        (GstPhotoCapturePrepared) img_capture_prepared,
        self->image_capture_caps, self);

  } else {
    ret = TRUE;
  }

  return ret;
}

static gboolean
gst_v4l2_camera_src_set_mode (GstBaseCameraSrc * bcamsrc, GstCameraBinMode mode)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);
  GstPhotography *photography = gst_base_camera_src_get_photography (bcamsrc);

  if (photography) {
    if (g_object_class_find_property (G_OBJECT_GET_CLASS (photography),
            "capture-mode")) {
      g_object_set (G_OBJECT (photography), "capture-mode", mode, NULL);
    }
  }

  self->mode = mode;

  switch (mode) {
    case MODE_PREVIEW:
      return TRUE;              // XXX
    case MODE_IMAGE:
      return start_image_capture (GST_V4L2_CAMERA_SRC (bcamsrc));
    case MODE_VIDEO:
      return TRUE;              // XXX
  }

  g_assert_not_reached ();

  return FALSE;
}

static gboolean
set_videosrc_zoom (GstV4l2CameraSrc * self, gint zoom)
{
  gboolean ret = FALSE;

  if (g_object_class_find_property (G_OBJECT_GET_CLASS (self->src_vid_src),
          "zoom")) {
    g_object_set (G_OBJECT (self->src_vid_src), "zoom",
        (gfloat) zoom / 100, NULL);
    ret = TRUE;
  }
  return ret;
}

static gboolean
set_element_zoom (GstV4l2CameraSrc * self, gint zoom)
{
  gboolean ret = FALSE;
  GstBaseCameraSrc *bcamsrc = GST_BASE_CAMERA_SRC (self);
  gint w2_crop = 0, h2_crop = 0;
  GstPad *pad_zoom_sink = NULL;
  gint left = self->base_crop_left;
  gint right = self->base_crop_right;
  gint top = self->base_crop_top;
  gint bottom = self->base_crop_bottom;

  if (self->src_zoom_crop) {
    /* Update capsfilters to apply the zoom */
    GST_INFO_OBJECT (self, "zoom: %d, orig size: %dx%d", zoom,
        bcamsrc->width, bcamsrc->height);

    if (zoom != ZOOM_1X) {
      w2_crop = (bcamsrc->width - (bcamsrc->width * ZOOM_1X / zoom)) / 2;
      h2_crop = (bcamsrc->height - (bcamsrc->height * ZOOM_1X / zoom)) / 2;

      left += w2_crop;
      right += w2_crop;
      top += h2_crop;
      bottom += h2_crop;

      /* force number of pixels cropped from left to be even, to avoid slow code
       * path on videoscale */
      left &= 0xFFFE;
    }

    pad_zoom_sink = gst_element_get_static_pad (self->src_zoom_crop, "sink");

    GST_INFO_OBJECT (self,
        "sw cropping: left:%d, right:%d, top:%d, bottom:%d", left, right, top,
        bottom);

    GST_PAD_STREAM_LOCK (pad_zoom_sink);
    g_object_set (self->src_zoom_crop, "left", left, "right", right, "top",
        top, "bottom", bottom, NULL);
    GST_PAD_STREAM_UNLOCK (pad_zoom_sink);
    gst_object_unref (pad_zoom_sink);
    ret = TRUE;
  }
  return ret;
}

static void
gst_v4l2_camera_src_set_zoom (GstBaseCameraSrc * bcamsrc, gint zoom)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);

  GST_INFO_OBJECT (self, "setting zoom %d", zoom);

  if (set_videosrc_zoom (self, zoom)) {
    set_element_zoom (self, ZOOM_1X);
    GST_INFO_OBJECT (self, "zoom set using videosrc");
  } else if (set_element_zoom (self, zoom)) {
    GST_INFO_OBJECT (self, "zoom set using gst elements");
  } else {
    GST_INFO_OBJECT (self, "setting zoom failed");
  }
}

static GstCaps *
gst_v4l2_camera_src_get_allowed_input_caps (GstBaseCameraSrc * bcamsrc)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);
  GstCaps *caps = NULL;
  GstPad *pad = NULL, *peer_pad = NULL;
  GstState state;
  GstElement *videosrc;

  videosrc = self->src_vid_src ? self->src_vid_src : self->app_vid_src;

  if (!videosrc) {
    GST_WARNING_OBJECT (self, "no videosrc, can't get allowed caps");
    goto failed;
  }

  if (self->allowed_caps) {
    GST_DEBUG_OBJECT (self, "returning cached caps");
    goto done;
  }

  pad = gst_element_get_static_pad (videosrc, "src");

  if (!pad) {
    GST_WARNING_OBJECT (self, "no srcpad in videosrc");
    goto failed;
  }

  state = GST_STATE (videosrc);

  /* Make this function work also in NULL state */
  if (state == GST_STATE_NULL) {
    GST_DEBUG_OBJECT (self, "setting videosrc to ready temporarily");
    peer_pad = gst_pad_get_peer (pad);
    if (peer_pad) {
      gst_pad_unlink (pad, peer_pad);
    }
    /* Set videosrc to READY to open video device */
    gst_element_set_locked_state (videosrc, TRUE);
    gst_element_set_state (videosrc, GST_STATE_READY);
  }

  self->allowed_caps = gst_pad_get_caps (pad);

  /* Restore state and re-link if necessary */
  if (state == GST_STATE_NULL) {
    GST_DEBUG_OBJECT (self, "restoring videosrc state %d", state);
    /* Reset videosrc to NULL state, some drivers seem to need this */
    gst_element_set_state (videosrc, GST_STATE_NULL);
    if (peer_pad) {
      gst_pad_link (pad, peer_pad);
      gst_object_unref (peer_pad);
    }
    gst_element_set_locked_state (videosrc, FALSE);
  }

  gst_object_unref (pad);

done:
  if (self->allowed_caps) {
    caps = gst_caps_copy (self->allowed_caps);
  }
  GST_DEBUG_OBJECT (self, "allowed caps:%" GST_PTR_FORMAT, caps);
failed:
  return caps;
}

/**
 * configure_format:
 * @self: camerasrc object
 * @caps: caps describing new format
 *
 * Configure internal video format for camerabin.
 */
static void
configure_format (GstV4l2CameraSrc * self, GstCaps * caps)
{
  GstBaseCameraSrc *bcamsrc = GST_BASE_CAMERA_SRC (self);
  GstStructure *st;

  st = gst_caps_get_structure (caps, 0);

  gst_structure_get_int (st, "width", &bcamsrc->width);
  gst_structure_get_int (st, "height", &bcamsrc->height);

  if (gst_structure_has_field_typed (st, "framerate", GST_TYPE_FRACTION)) {
    gst_structure_get_fraction (st, "framerate", &bcamsrc->fps_n,
        &bcamsrc->fps_d);
  }
}


/**
 * update_aspect_filter:
 * @self: camerasrc object
 * @new_caps: new caps of next buffers arriving to view finder sink element
 *
 * Updates aspect ratio capsfilter to maintain aspect ratio, if we need to
 * scale frames for showing them in view finder.
 */
static void
update_aspect_filter (GstV4l2CameraSrc * self, GstCaps * new_caps)
{
  // XXX why not instead add a preserve-aspect-ratio property to videoscale?
#if 0
  if (camera->flags & GST_CAMERABIN_FLAG_VIEWFINDER_SCALE) {
    GstCaps *sink_caps, *ar_caps;
    GstStructure *st;
    gint in_w = 0, in_h = 0, sink_w = 0, sink_h = 0, target_w = 0, target_h = 0;
    gdouble ratio_w, ratio_h;
    GstPad *sink_pad;
    const GValue *range;

    sink_pad = gst_element_get_static_pad (camera->view_sink, "sink");

    if (sink_pad) {
      sink_caps = gst_pad_get_caps (sink_pad);
      gst_object_unref (sink_pad);
      if (sink_caps) {
        if (!gst_caps_is_any (sink_caps)) {
          GST_DEBUG_OBJECT (camera, "sink element caps %" GST_PTR_FORMAT,
              sink_caps);
          /* Get maximum resolution that view finder sink accepts */
          st = gst_caps_get_structure (sink_caps, 0);
          if (gst_structure_has_field_typed (st, "width", GST_TYPE_INT_RANGE)) {
            range = gst_structure_get_value (st, "width");
            sink_w = gst_value_get_int_range_max (range);
          }
          if (gst_structure_has_field_typed (st, "height", GST_TYPE_INT_RANGE)) {
            range = gst_structure_get_value (st, "height");
            sink_h = gst_value_get_int_range_max (range);
          }
          GST_DEBUG_OBJECT (camera, "sink element accepts max %dx%d", sink_w,
              sink_h);

          /* Get incoming frames' resolution */
          if (sink_h && sink_w) {
            st = gst_caps_get_structure (new_caps, 0);
            gst_structure_get_int (st, "width", &in_w);
            gst_structure_get_int (st, "height", &in_h);
            GST_DEBUG_OBJECT (camera, "new caps with %dx%d", in_w, in_h);
          }
        }
        gst_caps_unref (sink_caps);
      }
    }

    /* If we get bigger frames than view finder sink accepts, then we scale.
       If we scale we need to adjust aspect ratio capsfilter caps in order
       to maintain aspect ratio while scaling. */
    if (in_w && in_h && (in_w > sink_w || in_h > sink_h)) {
      ratio_w = (gdouble) sink_w / in_w;
      ratio_h = (gdouble) sink_h / in_h;

      if (ratio_w < ratio_h) {
        target_w = sink_w;
        target_h = (gint) (ratio_w * in_h);
      } else {
        target_w = (gint) (ratio_h * in_w);
        target_h = sink_h;
      }

      GST_DEBUG_OBJECT (camera, "setting %dx%d filter to maintain aspect ratio",
          target_w, target_h);
      ar_caps = gst_caps_copy (new_caps);
      gst_caps_set_simple (ar_caps, "width", G_TYPE_INT, target_w, "height",
          G_TYPE_INT, target_h, NULL);
    } else {
      GST_DEBUG_OBJECT (camera, "no scaling");
      ar_caps = new_caps;
    }

    GST_DEBUG_OBJECT (camera, "aspect ratio filter caps %" GST_PTR_FORMAT,
        ar_caps);
    g_object_set (G_OBJECT (camera->aspect_filter), "caps", ar_caps, NULL);
    if (ar_caps != new_caps)
      gst_caps_unref (ar_caps);
  }
#endif
}


/**
 * set_capsfilter_caps:
 * @self: camerasrc object
 * @new_caps: pointer to caps object to set
 *
 * Set given caps to camerabin capsfilters.
 */
static void
set_capsfilter_caps (GstV4l2CameraSrc * self, GstCaps * new_caps)
{
  GST_INFO_OBJECT (self, "new_caps:%" GST_PTR_FORMAT, new_caps);

  configure_format (self, new_caps);

  /* Update zoom */
  gst_base_camera_src_setup_zoom (GST_BASE_CAMERA_SRC (self));

  /* Update capsfilters */
  g_object_set (G_OBJECT (self->src_filter), "caps", new_caps, NULL);
  if (self->src_zoom_filter)
    g_object_set (G_OBJECT (self->src_zoom_filter), "caps", new_caps, NULL);
  update_aspect_filter (self, new_caps);
  GST_INFO_OBJECT (self, "udpated");
}

static void
gst_v4l2_camera_src_finish_image_capture (GstBaseCameraSrc * bcamsrc)
{
  GstV4l2CameraSrc *self = GST_V4L2_CAMERA_SRC (bcamsrc);

  if (self->image_capture_caps) {
    /* If we used specific caps for image capture we need to
       restore the caps and zoom/crop for view finder mode */
    if (self->src_zoom_crop) {
      GST_DEBUG_OBJECT (self, "resetting crop in camerabin");
      g_object_set (self->src_zoom_crop, "left", 0, "right", 0,
          "top", 0, "bottom", 0, NULL);
    }
    self->base_crop_left = 0;
    self->base_crop_right = 0;
    self->base_crop_top = 0;
    self->base_crop_bottom = 0;
    set_capsfilter_caps (self, self->view_finder_caps);
  }
}

static void
gst_v4l2_camera_src_base_init (gpointer g_class)
{
  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);

  GST_DEBUG_CATEGORY_INIT (v4l2_camera_src_debug, "v4l2camerasrc", 0,
      "V4l2 camera src");

  gst_element_class_set_details_simple (gstelement_class,
      "V4l2 camera src element for camerabin", "Source/Video",
      "V4l2 camera src element for camerabin", "Rob Clark <rob@ti.com>");
}

static void
gst_v4l2_camera_src_class_init (GstV4l2CameraSrcClass * klass)
{
  GObjectClass *gobject_class;
  GstBaseCameraSrcClass *gstbasecamerasrc_class;

  gobject_class = G_OBJECT_CLASS (klass);
  gstbasecamerasrc_class = GST_BASE_CAMERA_SRC_CLASS (klass);

  gobject_class->dispose = gst_v4l2_camera_src_dispose;
  gobject_class->finalize = (GObjectFinalizeFunc) gst_v4l2_camera_src_finalize;
  gobject_class->set_property = gst_v4l2_camera_src_set_property;
  gobject_class->get_property = gst_v4l2_camera_src_get_property;

  // g_object_class_install_property ....
  g_object_class_install_property (gobject_class, ARG_MODE,
      g_param_spec_enum ("mode", "Mode",
          "The capture mode (still image capture, video recording or "
          "viewfinder)",
          GST_TYPE_CAMERABIN_MODE, MODE_PREVIEW,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  gstbasecamerasrc_class->construct_pipeline =
      gst_v4l2_camera_src_construct_pipeline;
  gstbasecamerasrc_class->setup_pipeline = gst_v4l2_camera_src_setup_pipeline;
  gstbasecamerasrc_class->set_zoom = gst_v4l2_camera_src_set_zoom;
  gstbasecamerasrc_class->set_mode = gst_v4l2_camera_src_set_mode;
  gstbasecamerasrc_class->get_allowed_input_caps =
      gst_v4l2_camera_src_get_allowed_input_caps;
  gstbasecamerasrc_class->finish_image_capture =
      gst_v4l2_camera_src_finish_image_capture;
}

static void
gst_v4l2_camera_src_init (GstV4l2CameraSrc * self,
    GstV4l2CameraSrcClass * klass)
{
  self->mode = MODE_PREVIEW;
}

gboolean
gst_v4l2_camera_src_plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "v4l2camerasrc", GST_RANK_NONE,
      gst_v4l2_camera_src_get_type ());
}