/*
 * GStreamer
 * Copyright (C) 2007 David Schleef <ds@schleef.org>
 * Copyright (C) 2008 Julien Isorce <julien.isorce@gmail.com>
 *
 * 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-gldownload
 *
 * download opengl textures into video frames.
 *
 * <refsect2>
 * <title>Color space conversion</title>
 * <para>
 * When needed, the color space conversion is made in a fragment shader using 
 * one frame buffer object instance.
 * </para>
 * </refsect2>
 * <refsect2>
 * <title>Examples</title>
 * |[
 * gst-launch -v videotestsrc ! "video/x-raw-rgb" ! glupload ! gldownload ! \
 *   "video/x-raw-rgb" ! ximagesink
 * ]| A pipeline to test downloading.
 * No special opengl extension is used in this pipeline, that's why it should work
 * with OpenGL >= 1.1. That's the case if you are using the MESA3D driver v1.3.
  |[
 * gst-launch -v videotestsrc ! "video/x-raw-rgb, width=640, height=480" ! glupload ! gldownload ! \
 *   "video/x-raw-rgb, width=320, height=240" ! ximagesink
 * ]| A pipeline to test hardware scaling.
 * Frame buffer extension is required. Inded one FBO is used bettween glupload and gldownload,
 * because the texture needs to be resized.
 * |[
 * gst-launch -v gltestsrc ! gldownload ! xvimagesink
 * ]| A pipeline to test hardware colorspace conversion.
 * Your driver must support GLSL (OpenGL Shading Language needs OpenGL >= 2.1). 
 * Texture RGB32 is converted to one of the 4 following format YUY2, UYVY, I420, YV12 and AYUV,
 * through some fragment shaders and using one framebuffer (FBO extension OpenGL >= 1.4).
 * MESA >= 7.1 supports GLSL but it's made in software.
 * |[
 * gst-launch -v videotestsrc ! glupload ! gldownload ! "video/x-raw-yuv, format=(fourcc)YUY2" ! glimagesink
 * ]| A pipeline to test hardware colorspace conversion
 * FBO and GLSL are required. 
 * </refsect2>
 */

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

#include "gstgldownload.h"

#define GST_CAT_DEFAULT gst_gl_download_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

static const GstElementDetails element_details =
GST_ELEMENT_DETAILS ("OpenGL video maker",
    "Filter/Effect",
    "A from GL to video flow filter",
    "Julien Isorce <julien.isorce@gmail.com>");

#ifndef OPENGL_ES2
#define ADDITIONAL_CAPS \
        
#else
#define ADDITIONAL_CAPS
#endif

#ifndef OPENGL_ES2
static GstStaticPadTemplate gst_gl_download_src_pad_template =
    GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (
        GST_VIDEO_CAPS_RGB  ";"
        GST_VIDEO_CAPS_RGBx ";"
        GST_VIDEO_CAPS_RGBA ";"
        GST_VIDEO_CAPS_BGR  ";"
        GST_VIDEO_CAPS_BGRx ";"
        GST_VIDEO_CAPS_BGRA ";"
        GST_VIDEO_CAPS_xRGB ";"
        GST_VIDEO_CAPS_xBGR ";"
        GST_VIDEO_CAPS_ARGB ";"
        GST_VIDEO_CAPS_ABGR ";"
        GST_VIDEO_CAPS_YUV ("{ I420, YV12, YUY2, UYVY, AYUV }"))
    );
#else
static GstStaticPadTemplate gst_gl_download_src_pad_template =
    GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (
        GST_VIDEO_CAPS_RGB  ";"
        GST_VIDEO_CAPS_RGBx ";"
        GST_VIDEO_CAPS_RGBA ";"
        GST_VIDEO_CAPS_YUV ("{ YUY2, UYVY, AYUV }"))
    );
#endif

static GstStaticPadTemplate gst_gl_download_sink_pad_template =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_GL_VIDEO_CAPS)
    );

enum
{
  PROP_0
};

#define DEBUG_INIT(bla) \
    GST_DEBUG_CATEGORY_INIT (gst_gl_download_debug, "gldownload", 0, "gldownload element");

GST_BOILERPLATE_FULL (GstGLDownload, gst_gl_download, GstBaseTransform,
    GST_TYPE_BASE_TRANSFORM, DEBUG_INIT);

static void gst_gl_download_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_gl_download_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static gboolean gst_gl_download_src_query (GstPad *pad, GstQuery * query);

static void gst_gl_download_reset (GstGLDownload * download);
static gboolean gst_gl_download_set_caps (GstBaseTransform * bt,
    GstCaps * incaps, GstCaps * outcaps);
static GstCaps *gst_gl_download_transform_caps (GstBaseTransform * bt,
    GstPadDirection direction, GstCaps * caps);
static gboolean gst_gl_download_start (GstBaseTransform * bt);
static gboolean gst_gl_download_stop (GstBaseTransform * bt);
static GstFlowReturn gst_gl_download_transform (GstBaseTransform * trans,
    GstBuffer * inbuf, GstBuffer * outbuf);
static gboolean gst_gl_download_get_unit_size (GstBaseTransform * trans,
    GstCaps * caps, guint * size);


static void
gst_gl_download_base_init (gpointer klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_set_details (element_class, &element_details);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_gl_download_src_pad_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_gl_download_sink_pad_template));
}


static void
gst_gl_download_class_init (GstGLDownloadClass * klass)
{
  GObjectClass *gobject_class;

  gobject_class = (GObjectClass *) klass;
  gobject_class->set_property = gst_gl_download_set_property;
  gobject_class->get_property = gst_gl_download_get_property;

  GST_BASE_TRANSFORM_CLASS (klass)->transform_caps =
      gst_gl_download_transform_caps;
  GST_BASE_TRANSFORM_CLASS (klass)->transform = gst_gl_download_transform;
  GST_BASE_TRANSFORM_CLASS (klass)->start = gst_gl_download_start;
  GST_BASE_TRANSFORM_CLASS (klass)->stop = gst_gl_download_stop;
  GST_BASE_TRANSFORM_CLASS (klass)->set_caps = gst_gl_download_set_caps;
  GST_BASE_TRANSFORM_CLASS (klass)->get_unit_size =
      gst_gl_download_get_unit_size;
}


static void
gst_gl_download_init (GstGLDownload * download, GstGLDownloadClass * klass)
{
  GstBaseTransform *base_trans = GST_BASE_TRANSFORM (download);
  
  gst_pad_set_query_function (base_trans->srcpad,
      GST_DEBUG_FUNCPTR (gst_gl_download_src_query));
  
  gst_gl_download_reset (download);
}


static void
gst_gl_download_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  //GstGLDownload *download = GST_GL_DOWNLOAD (object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


static void
gst_gl_download_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  //GstGLDownload *download = GST_GL_DOWNLOAD (object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gboolean
gst_gl_download_src_query (GstPad * pad, GstQuery * query)
{
  GstGLDownload *download = GST_GL_DOWNLOAD (gst_pad_get_parent (pad));
  gboolean res = FALSE;

  switch (GST_QUERY_TYPE (query)) {
    case GST_QUERY_CUSTOM:
    {
      GstStructure *structure = gst_query_get_structure (query);
      gst_structure_set (structure, "gstgldisplay", G_TYPE_POINTER, download->display, NULL);
      res = gst_pad_query_default (pad, query);
      break;
    }
    default:
      res = gst_pad_query_default (pad, query);
      break;
  }

  return res;
}

static void
gst_gl_download_reset (GstGLDownload * download)
{
  if (download->display) {
    g_object_unref (download->display);
    download->display = NULL;
  }
}


static gboolean
gst_gl_download_start (GstBaseTransform * bt)
{
  GstGLDownload* download = GST_GL_DOWNLOAD (bt);

  download->display = gst_gl_display_new ();
  gst_gl_display_create_context (download->display, 0);

  return TRUE;
}

static gboolean
gst_gl_download_stop (GstBaseTransform * bt)
{
  GstGLDownload *download = GST_GL_DOWNLOAD (bt);

  gst_gl_download_reset (download);

  return TRUE;
}

static GstCaps *
gst_gl_download_transform_caps (GstBaseTransform * bt,
    GstPadDirection direction, GstCaps * caps)
{
  GstGLDownload *download;
  GstStructure *structure;
  GstCaps *newcaps, *newothercaps;
  GstStructure *newstruct;
  const GValue *width_value;
  const GValue *height_value;
  const GValue *framerate_value;
  const GValue *par_value;

  download = GST_GL_DOWNLOAD (bt);

  GST_DEBUG ("transform caps %" GST_PTR_FORMAT, caps);

  structure = gst_caps_get_structure (caps, 0);

  width_value = gst_structure_get_value (structure, "width");
  height_value = gst_structure_get_value (structure, "height");
  framerate_value = gst_structure_get_value (structure, "framerate");
  par_value = gst_structure_get_value (structure, "pixel-aspect-ratio");

  if (direction == GST_PAD_SINK) {
    newothercaps = gst_caps_new_simple ("video/x-raw-rgb", NULL);
    newstruct = gst_caps_get_structure (newothercaps, 0);
    gst_structure_set_value (newstruct, "width", width_value);
    gst_structure_set_value (newstruct, "height", height_value);
    gst_structure_set_value (newstruct, "framerate", framerate_value);
    if (par_value)
      gst_structure_set_value (newstruct, "pixel-aspect-ratio", par_value);
    else
      gst_structure_set (newstruct, "pixel-aspect-ratio", GST_TYPE_FRACTION,
          1, 1, NULL);
    newcaps = gst_caps_new_simple ("video/x-raw-yuv", NULL);
    gst_caps_append (newcaps, newothercaps);
  } else
    newcaps = gst_caps_new_simple ("video/x-raw-gl", NULL);

  newstruct = gst_caps_get_structure (newcaps, 0);
  gst_structure_set_value (newstruct, "width", width_value);
  gst_structure_set_value (newstruct, "height", height_value);
  gst_structure_set_value (newstruct, "framerate", framerate_value);
  if (par_value)
    gst_structure_set_value (newstruct, "pixel-aspect-ratio", par_value);
  else
    gst_structure_set (newstruct, "pixel-aspect-ratio", GST_TYPE_FRACTION,
        1, 1, NULL);

  GST_DEBUG ("new caps %" GST_PTR_FORMAT, newcaps);

  return newcaps;
}

static gboolean
gst_gl_download_set_caps (GstBaseTransform * bt, GstCaps * incaps,
    GstCaps * outcaps)
{
  GstGLDownload *download;
  gboolean ret;

  download = GST_GL_DOWNLOAD (bt);

  GST_DEBUG ("called with %" GST_PTR_FORMAT, incaps);

  ret = gst_video_format_parse_caps (outcaps, &download->video_format,
      &download->width, &download->height);

  if (!ret) {
    GST_ERROR ("bad caps");
    return FALSE;
  }

  if (!download->display) {
    GST_ERROR ("display is null");
    return FALSE;
  }

  //blocking call, init color space conversion if needed
  gst_gl_display_init_download (download->display, download->video_format,
      download->width, download->height);

  return ret;
}

static gboolean
gst_gl_download_get_unit_size (GstBaseTransform * trans, GstCaps * caps,
    guint * size)
{
  gboolean ret;
  GstStructure *structure;
  gint width;
  gint height;

  structure = gst_caps_get_structure (caps, 0);
  if (gst_structure_has_name (structure, "video/x-raw-gl")) {
    ret = gst_gl_buffer_parse_caps (caps, &width, &height);
    if (ret)
      *size = gst_gl_buffer_get_size (width, height);
  } else {
    GstVideoFormat video_format;
    ret = gst_video_format_parse_caps (caps, &video_format, &width, &height);
    if (ret)
      *size = gst_video_format_get_size (video_format, width, height);
  }

  return ret;
}

static GstFlowReturn
gst_gl_download_transform (GstBaseTransform * trans, GstBuffer * inbuf,
    GstBuffer * outbuf)
{
  GstGLDownload *download = GST_GL_DOWNLOAD (trans);
  GstGLBuffer *gl_inbuf = GST_GL_BUFFER (inbuf);

  GST_DEBUG ("making video %p size %d",
      GST_BUFFER_DATA (outbuf), GST_BUFFER_SIZE (outbuf));

  //blocking call
  if (gst_gl_display_do_download (download->display, gl_inbuf->texture,
          gl_inbuf->width, gl_inbuf->height, GST_BUFFER_DATA (outbuf)))
    return GST_FLOW_OK;
  else
    return GST_FLOW_UNEXPECTED;

}