text: /* GStreamer
   * Copyright (C) 2010 Oblong Industries, Inc.
   * Copyright (C) 2010 Collabora Multimedia
   *
   * 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., 51 Franklin St, Fifth Floor,
   * Boston, MA 02110-1301, USA.
   */
  /**
   * SECTION:element-gstjp2kdecimator
   * @title: gstjp2kdecimator
   *
   * The jp2kdecimator element removes information from JPEG2000 images without reencoding.
   *
   * ## Example launch line
   * |[
   * gst-launch-1.0 -v videotestsrc num-buffers=1 ! jp2kenc ! \
   *   gstjp2kdecimator max-decomposition-levels=2 ! jp2kdec ! \
   *   videoconvert ! autovideosink
   * ]|
   * This pipelines encodes a test image to JPEG2000, only keeps 3 decomposition levels
   * decodes the decimated image again and shows it on the screen.
   *
   */
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include <gst/gst.h>
  
  #include "gstjp2kdecimator.h"
  
  #include "jp2kcodestream.h"
  
  #include <gst/base/gstbytereader.h>
  #include <gst/base/gstbytewriter.h>
  
  #include <string.h>
  
  static GstStaticPadTemplate sink_pad_template =
  GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
      GST_STATIC_CAPS ("image/x-jpc"));
  
  static GstStaticPadTemplate src_pad_template =
  GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
      GST_STATIC_CAPS ("image/x-jpc"));
  
  enum
  {
    PROP_0,
    PROP_MAX_LAYERS,
    PROP_MAX_DECOMPOSITION_LEVELS
  };
  
  #define DEFAULT_MAX_LAYERS (0)
  #define DEFAULT_MAX_DECOMPOSITION_LEVELS (-1)
  
  static void gst_jp2k_decimator_set_property (GObject * object,
      guint prop_id, const GValue * value, GParamSpec * pspec);
  static void gst_jp2k_decimator_get_property (GObject * object,
      guint prop_id, GValue * value, GParamSpec * pspec);
  
  static GstFlowReturn gst_jp2k_decimator_sink_chain (GstPad * pad,
      GstObject * parent, GstBuffer * inbuf);
  
  GST_DEBUG_CATEGORY (gst_jp2k_decimator_debug);
  #define GST_CAT_DEFAULT gst_jp2k_decimator_debug
  
  G_DEFINE_TYPE (GstJP2kDecimator, gst_jp2k_decimator, GST_TYPE_ELEMENT);
  
  static void
  gst_jp2k_decimator_class_init (GstJP2kDecimatorClass * klass)
  {
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
    GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
  
    gst_element_class_set_static_metadata (gstelement_class,
        "JPEG2000 decimator",
        "Filter/Image",
        "Removes information from JPEG2000 streams without recompression",
        "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
  
    gst_element_class_add_static_pad_template (gstelement_class,
        &sink_pad_template);
    gst_element_class_add_static_pad_template (gstelement_class,
        &src_pad_template);
  
    gobject_class->set_property = gst_jp2k_decimator_set_property;
    gobject_class->get_property = gst_jp2k_decimator_get_property;
  
    g_object_class_install_property (gobject_class, PROP_MAX_LAYERS,
        g_param_spec_int ("max-layers", "Maximum Number of Layers",
            "Maximum number of layers to keep (0 == all)", 0, 65535,
            DEFAULT_MAX_LAYERS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  
    g_object_class_install_property (gobject_class, PROP_MAX_DECOMPOSITION_LEVELS,
        g_param_spec_int ("max-decomposition-levels",
            "Maximum Number of Decomposition Levels",
            "Maximum number of decomposition levels to keep (-1 == all)", -1, 32,
            DEFAULT_MAX_DECOMPOSITION_LEVELS,
            G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  }
  
  static void
  gst_jp2k_decimator_init (GstJP2kDecimator * self)
  {
    self->max_layers = DEFAULT_MAX_LAYERS;
    self->max_decomposition_levels = DEFAULT_MAX_DECOMPOSITION_LEVELS;
  
    self->sinkpad = gst_pad_new_from_static_template (&sink_pad_template, "sink");
    GST_PAD_SET_PROXY_CAPS (self->sinkpad);
    GST_PAD_SET_PROXY_ALLOCATION (self->sinkpad);
  
    gst_pad_set_chain_function (self->sinkpad,
        GST_DEBUG_FUNCPTR (gst_jp2k_decimator_sink_chain));
    gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
  
    self->srcpad = gst_pad_new_from_static_template (&src_pad_template, "src");
    GST_PAD_SET_PROXY_CAPS (self->srcpad);
    gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
  }
  
  static void
  gst_jp2k_decimator_set_property (GObject * object,
      guint prop_id, const GValue * value, GParamSpec * pspec)
  {
    GstJP2kDecimator *self = GST_JP2K_DECIMATOR (object);
  
    switch (prop_id) {
      case PROP_MAX_LAYERS:
        self->max_layers = g_value_get_int (value);
        break;
      case PROP_MAX_DECOMPOSITION_LEVELS:
        self->max_decomposition_levels = g_value_get_int (value);
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
        break;
    }
  }
  
  static void
  gst_jp2k_decimator_get_property (GObject * object,
      guint prop_id, GValue * value, GParamSpec * pspec)
  {
    GstJP2kDecimator *self = GST_JP2K_DECIMATOR (object);
  
    switch (prop_id) {
      case PROP_MAX_LAYERS:
        g_value_set_int (value, self->max_layers);
        break;
      case PROP_MAX_DECOMPOSITION_LEVELS:
        g_value_set_int (value, self->max_decomposition_levels);
        break;
      default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
        break;
    }
  }
  
  static GstFlowReturn
  gst_jp2k_decimator_decimate_jpc (GstJP2kDecimator * self, GstBuffer * inbuf,
      GstBuffer ** outbuf_)
  {
    GstBuffer *outbuf = NULL;
    GstFlowReturn ret = GST_FLOW_OK;
    GstMapInfo info;
    GstByteReader reader;
    GstByteWriter writer;
    MainHeader main_header;
  
  
    if (!gst_buffer_map (inbuf, &info, GST_MAP_READ)) {
      GST_ELEMENT_ERROR (self, STREAM, WRONG_TYPE, ("Unable to map memory"),
          (NULL));
      gst_buffer_unref (inbuf);
      return GST_FLOW_ERROR;
    }
  
    gst_byte_reader_init (&reader, info.data, info.size);
    gst_byte_writer_init_with_size (&writer, gst_buffer_get_size (inbuf), FALSE);
  
    /* main header */
    memset (&main_header, 0, sizeof (MainHeader));
    ret = parse_main_header (self, &reader, &main_header);
    if (ret != GST_FLOW_OK)
      goto done;
  
    ret = decimate_main_header (self, &main_header);
    if (ret != GST_FLOW_OK)
      goto done;
  
    ret = write_main_header (self, &writer, &main_header);
    if (ret != GST_FLOW_OK)
      goto done;
  
    outbuf = gst_byte_writer_reset_and_get_buffer (&writer);
    gst_buffer_copy_into (outbuf, inbuf, GST_BUFFER_COPY_METADATA, 0, -1);
  
    GST_DEBUG_OBJECT (self,
        "Decimated buffer from %" G_GSIZE_FORMAT " bytes to %" G_GSIZE_FORMAT
        " bytes (%.2lf%%)",
        gst_buffer_get_size (inbuf), gst_buffer_get_size (outbuf),
        (100 * gst_buffer_get_size (outbuf)) /
        ((gdouble) gst_buffer_get_size (inbuf)));
  
  done:
    gst_buffer_unmap (inbuf, &info);
  
    *outbuf_ = outbuf;
    reset_main_header (self, &main_header);
    gst_buffer_unref (inbuf);
  
    return ret;
  }
  
  static GstFlowReturn
  gst_jp2k_decimator_sink_chain (GstPad * pad, GstObject * parent,
      GstBuffer * inbuf)
  {
    GstJP2kDecimator *self = GST_JP2K_DECIMATOR (parent);
    GstFlowReturn ret;
    GstBuffer *outbuf = NULL;
  
    GST_LOG_OBJECT (pad,
        "Handling inbuf with timestamp %" GST_TIME_FORMAT " and duration %"
        GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_PTS (inbuf)),
        GST_TIME_ARGS (GST_BUFFER_DURATION (inbuf)));
  
    if (self->max_layers == 0 && self->max_decomposition_levels == -1) {
      outbuf = inbuf;
      inbuf = NULL;
      ret = GST_FLOW_OK;
    } else {
      ret = gst_jp2k_decimator_decimate_jpc (self, inbuf, &outbuf);
    }
  
    if (G_UNLIKELY (ret != GST_FLOW_OK))
      return ret;
  
    ret = gst_pad_push (self->srcpad, outbuf);
  
    return ret;
  }
  
  static gboolean
  plugin_init (GstPlugin * plugin)
  {
    GST_DEBUG_CATEGORY_INIT (gst_jp2k_decimator_debug, "jp2kdecimator", 0,
        "JPEG2000 decimator");
  
    gst_element_register (plugin, "jp2kdecimator", GST_RANK_NONE,
        GST_TYPE_JP2K_DECIMATOR);
  
    return TRUE;
  }
  
  GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
      GST_VERSION_MINOR,
      jp2kdecimator,
      "JPEG2000 decimator", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
      GST_PACKAGE_ORIGIN)
  