path: root/gst-libs/gst/video/gstvideofilter.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 * Copyright (C) <2003> David Schleef <ds@schleef.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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

 /**
 * SECTION:gstvideofilter
 * @short_description: Base class for video filters
 * 
 * <refsect2>
 * <para>
 * Provides useful functions and a base class for video filters.
 * </para>
 * <para>
 * The videofilter will by default enable QoS on the parent GstBaseTransform
 * to implement frame dropping.
 * </para>
 * </refsect2>
 */

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

#include "gstvideofilter.h"

#include <gst/video/video.h>
#include <gst/video/gstvideometa.h>
#include <gst/video/gstvideopool.h>

GST_DEBUG_CATEGORY_STATIC (gst_video_filter_debug);
#define GST_CAT_DEFAULT gst_video_filter_debug

#define gst_video_filter_parent_class parent_class
G_DEFINE_ABSTRACT_TYPE (GstVideoFilter, gst_video_filter,
    GST_TYPE_BASE_TRANSFORM);

/* Answer the allocation query downstream. */
static gboolean
gst_video_filter_propose_allocation (GstBaseTransform * trans,
    GstQuery * decide_query, GstQuery * query)
{
  GstVideoFilter *filter = GST_VIDEO_FILTER_CAST (trans);
  GstVideoInfo info;
  GstBufferPool *pool;
  GstCaps *caps;
  guint size;

  if (!GST_BASE_TRANSFORM_CLASS (parent_class)->propose_allocation (trans,
          decide_query, query))
    return FALSE;

  /* passthrough, we're done */
  if (decide_query == NULL)
    return TRUE;

  gst_query_parse_allocation (query, &caps, NULL);

  if (caps == NULL)
    return FALSE;

  if (!gst_video_info_from_caps (&info, caps))
    return FALSE;

  size = GST_VIDEO_INFO_SIZE (&info);

  if (gst_query_get_n_allocation_pools (query) == 0) {
    GstStructure *structure;
    GstAllocator *allocator = NULL;
    GstAllocationParams params = { 0, 15, 0, 0, };

    if (gst_query_get_n_allocation_params (query) > 0)
      gst_query_parse_nth_allocation_param (query, 0, &allocator, &params);
    else
      gst_query_add_allocation_param (query, allocator, &params);

    pool = gst_video_buffer_pool_new ();

    structure = gst_buffer_pool_get_config (pool);
    gst_buffer_pool_config_set_params (structure, caps, size, 0, 0);
    gst_buffer_pool_config_set_allocator (structure, allocator, &params);

    if (allocator)
      gst_object_unref (allocator);

    if (!gst_buffer_pool_set_config (pool, structure))
      goto config_failed;

    gst_query_add_allocation_pool (query, pool, size, 0, 0);
    gst_object_unref (pool);
    gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL);
  }

  return TRUE;

  /* ERRORS */
config_failed:
  {
    GST_ERROR_OBJECT (filter, "failed to set config");
    gst_object_unref (pool);
    return FALSE;
  }
}

/* configure the allocation query that was answered downstream, we can configure
 * some properties on it. Only called when not in passthrough mode. */
static gboolean
gst_video_filter_decide_allocation (GstBaseTransform * trans, GstQuery * query)
{
  GstBufferPool *pool = NULL;
  GstStructure *config;
  guint min, max, size;
  gboolean update_pool;
  GstCaps *outcaps = NULL;

  if (gst_query_get_n_allocation_pools (query) > 0) {
    gst_query_parse_nth_allocation_pool (query, 0, &pool, &size, &min, &max);

    update_pool = TRUE;
  } else {
    GstVideoInfo vinfo;

    gst_query_parse_allocation (query, &outcaps, NULL);
    gst_video_info_init (&vinfo);
    gst_video_info_from_caps (&vinfo, outcaps);
    size = vinfo.size;
    min = max = 0;
    update_pool = FALSE;
  }

  if (!pool)
    pool = gst_video_buffer_pool_new ();

  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);
  if (outcaps)
    gst_buffer_pool_config_set_params (config, outcaps, size, 0, 0);
  gst_buffer_pool_set_config (pool, config);

  if (update_pool)
    gst_query_set_nth_allocation_pool (query, 0, pool, size, min, max);
  else
    gst_query_add_allocation_pool (query, pool, size, min, max);

  gst_object_unref (pool);

  return GST_BASE_TRANSFORM_CLASS (parent_class)->decide_allocation (trans,
      query);
}


/* our output size only depends on the caps, not on the input caps */
static gboolean
gst_video_filter_transform_size (GstBaseTransform * btrans,
    GstPadDirection direction, GstCaps * caps, gsize size,
    GstCaps * othercaps, gsize * othersize)
{
  gboolean ret = TRUE;
  GstVideoInfo info;

  g_assert (size);

  ret = gst_video_info_from_caps (&info, othercaps);
  if (ret)
    *othersize = info.size;

  return ret;
}

static gboolean
gst_video_filter_get_unit_size (GstBaseTransform * btrans, GstCaps * caps,
    gsize * size)
{
  GstVideoInfo info;

  if (!gst_video_info_from_caps (&info, caps)) {
    GST_WARNING_OBJECT (btrans, "Failed to parse caps %" GST_PTR_FORMAT, caps);
    return FALSE;
  }

  *size = info.size;

  GST_DEBUG_OBJECT (btrans, "Returning size %" G_GSIZE_FORMAT " bytes"
      "for caps %" GST_PTR_FORMAT, *size, caps);

  return TRUE;
}

static gboolean
gst_video_filter_set_caps (GstBaseTransform * trans, GstCaps * incaps,
    GstCaps * outcaps)
{
  GstVideoFilter *filter = GST_VIDEO_FILTER_CAST (trans);
  GstVideoFilterClass *fclass;
  GstVideoInfo in_info, out_info;
  gboolean res;

  /* input caps */
  if (!gst_video_info_from_caps (&in_info, incaps))
    goto invalid_caps;

  /* output caps */
  if (!gst_video_info_from_caps (&out_info, outcaps))
    goto invalid_caps;

  fclass = GST_VIDEO_FILTER_GET_CLASS (filter);
  if (fclass->set_info)
    res = fclass->set_info (filter, incaps, &in_info, outcaps, &out_info);
  else
    res = TRUE;

  if (res) {
    filter->in_info = in_info;
    filter->out_info = out_info;
    if (fclass->transform_frame == NULL)
      gst_base_transform_set_in_place (trans, TRUE);
    if (fclass->transform_frame_ip == NULL)
      GST_BASE_TRANSFORM_CLASS (fclass)->transform_ip_on_passthrough = FALSE;
  }
  filter->negotiated = res;

  return res;

  /* ERRORS */
invalid_caps:
  {
    GST_ERROR_OBJECT (filter, "invalid caps");
    filter->negotiated = FALSE;
    return FALSE;
  }
}

static GstFlowReturn
gst_video_filter_transform (GstBaseTransform * trans, GstBuffer * inbuf,
    GstBuffer * outbuf)
{
  GstFlowReturn res;
  GstVideoFilter *filter = GST_VIDEO_FILTER_CAST (trans);
  GstVideoFilterClass *fclass;

  if (G_UNLIKELY (!filter->negotiated))
    goto unknown_format;

  fclass = GST_VIDEO_FILTER_GET_CLASS (filter);
  if (fclass->transform_frame) {
    GstVideoFrame in_frame, out_frame;

    if (!gst_video_frame_map (&in_frame, &filter->in_info, inbuf, GST_MAP_READ))
      goto invalid_buffer;

    if (!gst_video_frame_map (&out_frame, &filter->out_info, outbuf,
            GST_MAP_WRITE))
      goto invalid_buffer;

    /* GstVideoFrame has another reference, so the buffer looks unwriteable,
     * meaning that we can't attach any metas or anything to it. Other
     * map() functions like gst_buffer_map() don't get another reference
     * of the buffer and expect the buffer reference to be kept until
     * the buffer is unmapped again. */
    gst_buffer_unref (inbuf);
    gst_buffer_unref (outbuf);
    res = fclass->transform_frame (filter, &in_frame, &out_frame);
    gst_buffer_ref (inbuf);
    gst_buffer_ref (outbuf);

    gst_video_frame_unmap (&out_frame);
    gst_video_frame_unmap (&in_frame);
  } else {
    GST_DEBUG_OBJECT (trans, "no transform_frame vmethod");
    res = GST_FLOW_OK;
  }

  return res;

  /* ERRORS */
unknown_format:
  {
    GST_ELEMENT_ERROR (filter, CORE, NOT_IMPLEMENTED, (NULL),
        ("unknown format"));
    return GST_FLOW_NOT_NEGOTIATED;
  }
invalid_buffer:
  {
    GST_ELEMENT_WARNING (filter, CORE, NOT_IMPLEMENTED, (NULL),
        ("invalid video buffer received"));
    return GST_FLOW_OK;
  }
}

static GstFlowReturn
gst_video_filter_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
{
  GstFlowReturn res;
  GstVideoFilter *filter = GST_VIDEO_FILTER_CAST (trans);
  GstVideoFilterClass *fclass;

  if (G_UNLIKELY (!filter->negotiated))
    goto unknown_format;

  fclass = GST_VIDEO_FILTER_GET_CLASS (filter);
  if (fclass->transform_frame_ip) {
    GstVideoFrame frame;
    GstMapFlags flags;

    flags = GST_MAP_READ;

    if (!gst_base_transform_is_passthrough (trans))
      flags |= GST_MAP_WRITE;

    if (!gst_video_frame_map (&frame, &filter->in_info, buf, flags))
      goto invalid_buffer;

    /* GstVideoFrame has another reference, so the buffer looks unwriteable,
     * meaning that we can't attach any metas or anything to it. Other
     * map() functions like gst_buffer_map() don't get another reference
     * of the buffer and expect the buffer reference to be kept until
     * the buffer is unmapped again. */
    gst_buffer_unref (buf);
    res = fclass->transform_frame_ip (filter, &frame);
    gst_buffer_ref (buf);

    gst_video_frame_unmap (&frame);
  } else {
    GST_DEBUG_OBJECT (trans, "no transform_frame_ip vmethod");
    res = GST_FLOW_OK;
  }

  return res;

  /* ERRORS */
unknown_format:
  {
    GST_ELEMENT_ERROR (filter, CORE, NOT_IMPLEMENTED, (NULL),
        ("unknown format"));
    return GST_FLOW_NOT_NEGOTIATED;
  }
invalid_buffer:
  {
    GST_ELEMENT_WARNING (filter, CORE, NOT_IMPLEMENTED, (NULL),
        ("invalid video buffer received"));
    return GST_FLOW_OK;
  }
}

static gboolean
gst_video_filter_transform_meta (GstBaseTransform * trans, GstBuffer * inbuf,
    GstMeta * meta, GstBuffer * outbuf)
{
  const GstMetaInfo *info = meta->info;
  const gchar *const *tags;

  tags = gst_meta_api_type_get_tags (info->api);

  if (tags && g_strv_length ((gchar **) tags) == 1
      && gst_meta_api_type_has_tag (info->api,
          g_quark_from_string (GST_META_TAG_VIDEO_STR)))
    return TRUE;

  return GST_BASE_TRANSFORM_CLASS (parent_class)->transform_meta (trans, inbuf,
      meta, outbuf);
}

static void
gst_video_filter_class_init (GstVideoFilterClass * g_class)
{
  GstBaseTransformClass *trans_class;
  GstVideoFilterClass *klass;

  klass = (GstVideoFilterClass *) g_class;
  trans_class = (GstBaseTransformClass *) klass;

  trans_class->set_caps = GST_DEBUG_FUNCPTR (gst_video_filter_set_caps);
  trans_class->propose_allocation =
      GST_DEBUG_FUNCPTR (gst_video_filter_propose_allocation);
  trans_class->decide_allocation =
      GST_DEBUG_FUNCPTR (gst_video_filter_decide_allocation);
  trans_class->transform_size =
      GST_DEBUG_FUNCPTR (gst_video_filter_transform_size);
  trans_class->get_unit_size =
      GST_DEBUG_FUNCPTR (gst_video_filter_get_unit_size);
  trans_class->transform = GST_DEBUG_FUNCPTR (gst_video_filter_transform);
  trans_class->transform_ip = GST_DEBUG_FUNCPTR (gst_video_filter_transform_ip);
  trans_class->transform_meta =
      GST_DEBUG_FUNCPTR (gst_video_filter_transform_meta);

  GST_DEBUG_CATEGORY_INIT (gst_video_filter_debug, "videofilter", 0,
      "videofilter");
}

static void
gst_video_filter_init (GstVideoFilter * instance)
{
  GstVideoFilter *videofilter = GST_VIDEO_FILTER (instance);

  GST_DEBUG_OBJECT (videofilter, "gst_video_filter_init");

  videofilter->negotiated = FALSE;
  /* enable QoS */
  gst_base_transform_set_qos_enabled (GST_BASE_TRANSFORM (videofilter), TRUE);
}