gstreamer/sys/kms/gstkmssink.c

/* GStreamer
 *
 * Copyright (C) 2016 Igalia
 *
 * Authors:
 *  Víctor Manuel Jáquez Leal <vjaquez@igalia.com>
 *  Javier Martin <javiermartin@by.com.es>
 *
 * 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-kmssink
 * @short_description: A KMS/DRM based video sink
 *
 * kmssink is a simple video sink that renders video frames directly
 * in a plane of a DRM device.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch-1.0 videotestsrc ! kmssink
 * ]|
 * </refsect2>
 */

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

#include <gst/video/video.h>

#include <drm.h>
#include <xf86drm.h>
#include <xf86drmMode.h>

#include <string.h>

#include "gstkmssink.h"
#include "gstkmsutils.h"
#include "gstkmsbufferpool.h"
#include "gstkmsallocator.h"

#define GST_PLUGIN_NAME "kmssink"
#define GST_PLUGIN_DESC "Video sink using the Linux kernel mode setting API"

GST_DEBUG_CATEGORY_STATIC (gst_kms_sink_debug);
#define GST_CAT_DEFAULT gst_kms_sink_debug

G_DEFINE_TYPE_WITH_CODE (GstKMSSink, gst_kms_sink, GST_TYPE_VIDEO_SINK,
    GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, GST_PLUGIN_NAME, 0,
        GST_PLUGIN_DESC));

enum
{
  PROP_DRIVER_NAME = 1,
  PROP_CONNECTOR_ID,
  PROP_N
};

static GParamSpec *g_properties[PROP_N] = { NULL, };

static int
kms_open (gchar ** driver)
{
  static const char *drivers[] = { "i915", "radeon", "nouveau", "vmwgfx",
    "exynos", "amdgpu", "imx-drm", "rockchip", "atmel-hlcdc"
  };
  int i, fd = -1;

  for (i = 0; i < G_N_ELEMENTS (drivers); i++) {
    fd = drmOpen (drivers[i], NULL);
    if (fd >= 0) {
      if (driver)
        *driver = g_strdup (drivers[i]);
      break;
    }
  }

  return fd;
}

static drmModePlane *
find_plane_for_crtc (int fd, drmModeRes * res, drmModePlaneRes * pres,
    int crtc_id)
{
  drmModePlane *plane;
  int i, pipe;

  plane = NULL;
  pipe = -1;
  for (i = 0; i < res->count_crtcs; i++) {
    if (crtc_id == res->crtcs[i]) {
      pipe = i;
      break;
    }
  }

  if (pipe == -1)
    return NULL;

  for (i = 0; i < pres->count_planes; i++) {
    plane = drmModeGetPlane (fd, pres->planes[i]);
    if (plane->possible_crtcs & (1 << pipe))
      return plane;
    drmModeFreePlane (plane);
  }

  return NULL;
}

static drmModeCrtc *
find_crtc_for_connector (int fd, drmModeRes * res, drmModeConnector * conn)
{
  int i;
  int crtc_id;
  drmModeEncoder *enc;
  drmModeCrtc *crtc;

  crtc_id = -1;
  for (i = 0; i < res->count_encoders; i++) {
    enc = drmModeGetEncoder (fd, res->encoders[i]);
    if (enc) {
      if (enc->encoder_id == conn->encoder_id) {
        crtc_id = enc->crtc_id;
        drmModeFreeEncoder (enc);
        break;
      }
      drmModeFreeEncoder (enc);
    }
  }

  if (crtc_id == -1)
    return NULL;

  for (i = 0; i < res->count_crtcs; i++) {
    crtc = drmModeGetCrtc (fd, res->crtcs[i]);
    if (crtc) {
      if (crtc_id == crtc->crtc_id)
        return crtc;
      drmModeFreeCrtc (crtc);
    }
  }

  return NULL;
}

static gboolean
connector_is_used (int fd, drmModeRes * res, drmModeConnector * conn)
{
  gboolean result;
  drmModeCrtc *crtc;

  result = FALSE;
  crtc = find_crtc_for_connector (fd, res, conn);
  if (crtc) {
    result = crtc->buffer_id != 0;
    drmModeFreeCrtc (crtc);
  }

  return result;
}

static drmModeConnector *
find_used_connector_by_type (int fd, drmModeRes * res, int type)
{
  int i;
  drmModeConnector *conn;

  conn = NULL;
  for (i = 0; i < res->count_connectors; i++) {
    conn = drmModeGetConnector (fd, res->connectors[i]);
    if (conn) {
      if ((conn->connector_type == type) && connector_is_used (fd, res, conn))
        return conn;
      drmModeFreeConnector (conn);
    }
  }

  return NULL;
}

static drmModeConnector *
find_first_used_connector (int fd, drmModeRes * res)
{
  int i;
  drmModeConnector *conn;

  conn = NULL;
  for (i = 0; i < res->count_connectors; i++) {
    conn = drmModeGetConnector (fd, res->connectors[i]);
    if (conn) {
      if (connector_is_used (fd, res, conn))
        return conn;
      drmModeFreeConnector (conn);
    }
  }

  return NULL;
}

static drmModeConnector *
find_main_monitor (int fd, drmModeRes * res)
{
  /* Find the LVDS and eDP connectors: those are the main screens. */
  static const int priority[] = { DRM_MODE_CONNECTOR_LVDS,
    DRM_MODE_CONNECTOR_eDP
  };
  int i;
  drmModeConnector *conn;

  conn = NULL;
  for (i = 0; !conn && i < G_N_ELEMENTS (priority); i++)
    conn = find_used_connector_by_type (fd, res, priority[i]);

  /* if we didn't find a connector, grab the first one in use */
  if (!conn)
    conn = find_first_used_connector (fd, res);

  return conn;
}

static void
log_drm_version (GstKMSSink * self)
{
#ifndef GST_DISABLE_GST_DEBUG
  drmVersion *v;

  v = drmGetVersion (self->fd);
  if (v) {
    GST_INFO_OBJECT (self, "DRM v%d.%d.%d [%s — %s — %s]", v->version_major,
        v->version_minor, v->version_patchlevel, GST_STR_NULL (v->name),
        GST_STR_NULL (v->desc), GST_STR_NULL (v->date));
    drmFreeVersion (v);
  } else {
    GST_WARNING_OBJECT (self, "could not get driver information: %s",
        GST_STR_NULL (self->devname));
  }
#endif
  return;
}

static gboolean
get_drm_caps (GstKMSSink * self)
{
  gint ret;
  guint64 has_dumb_buffer;

  has_dumb_buffer = 0;
  ret = drmGetCap (self->fd, DRM_CAP_DUMB_BUFFER, &has_dumb_buffer);
  if (ret)
    GST_WARNING_OBJECT (self, "could not get dumb buffer capability");
  if (has_dumb_buffer == 0) {
    GST_ERROR_OBJECT (self, "driver cannot handle dumb buffers");
    return FALSE;
  }

  return TRUE;
}

static gboolean
ensure_allowed_caps (GstKMSSink * self, drmModePlane * plane, drmModeRes * res)
{
  GstCaps *out_caps, *caps;
  int i;
  GstVideoFormat fmt;
  const gchar *format;

  if (self->allowed_caps)
    return TRUE;

  out_caps = gst_caps_new_empty ();
  if (!out_caps)
    return FALSE;

  for (i = 0; i < plane->count_formats; i++) {
    fmt = gst_video_format_from_drm (plane->formats[i]);
    if (fmt == GST_VIDEO_FORMAT_UNKNOWN) {
      GST_INFO_OBJECT (self, "ignoring format %" GST_FOURCC_FORMAT,
          GST_FOURCC_ARGS (plane->formats[i]));
      continue;
    }

    format = gst_video_format_to_string (fmt);
    caps = gst_caps_new_simple ("video/x-raw", "format", G_TYPE_STRING, format,
        "width", GST_TYPE_INT_RANGE, res->min_width, res->max_width,
        "height", GST_TYPE_INT_RANGE, res->min_height, res->max_height,
        "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);
    if (!caps)
      continue;

    out_caps = gst_caps_merge (out_caps, caps);
  }

  self->allowed_caps = gst_caps_simplify (out_caps);

  GST_DEBUG_OBJECT (self, "allowed caps = %" GST_PTR_FORMAT,
      self->allowed_caps);

  return TRUE;
}

static gboolean
gst_kms_sink_start (GstBaseSink * bsink)
{
  GstKMSSink *self;
  drmModeRes *res;
  drmModeConnector *conn;
  drmModeCrtc *crtc;
  drmModePlaneRes *pres;
  drmModePlane *plane;
  gboolean ret;

  self = GST_KMS_SINK (bsink);
  ret = FALSE;
  res = NULL;
  conn = NULL;
  crtc = NULL;
  pres = NULL;
  plane = NULL;

  if (self->devname)
    self->fd = drmOpen (self->devname, NULL);
  else
    self->fd = kms_open (&self->devname);
  if (self->fd < 0)
    goto open_failed;

  log_drm_version (self);
  if (!get_drm_caps (self))
    goto bail;

  res = drmModeGetResources (self->fd);
  if (!res)
    goto resources_failed;

  if (self->conn_id == -1)
    conn = find_main_monitor (self->fd, res);
  else
    conn = drmModeGetConnector (self->fd, self->conn_id);
  if (!conn)
    goto connector_failed;

  crtc = find_crtc_for_connector (self->fd, res, conn);
  if (!crtc)
    goto crtc_failed;

  pres = drmModeGetPlaneResources (self->fd);
  if (!pres)
    goto plane_resources_failed;

  plane = find_plane_for_crtc (self->fd, res, pres, crtc->crtc_id);
  if (!plane)
    goto plane_failed;

  /* let's get the available color formats in plane */
  if (!ensure_allowed_caps (self, plane, res))
    goto bail;

  self->conn_id = conn->connector_id;
  self->crtc_id = crtc->crtc_id;
  self->plane_id = plane->plane_id;

  GST_INFO_OBJECT (self, "connector id = %d / crtc id = %d / plane id = %d",
      self->conn_id, self->crtc_id, self->plane_id);

  self->hdisplay = crtc->mode.hdisplay;
  self->vdisplay = crtc->mode.vdisplay;

  self->mm_width = conn->mmWidth;
  self->mm_height = conn->mmHeight;

  GST_INFO_OBJECT (self, "display size: pixels = %dx%d / millimeters = %dx%d",
      self->hdisplay, self->vdisplay, self->mm_width, self->mm_height);

  ret = TRUE;

bail:
  if (plane)
    drmModeFreePlane (plane);
  if (pres)
    drmModeFreePlaneResources (pres);
  if (crtc)
    drmModeFreeCrtc (crtc);
  if (conn)
    drmModeFreeConnector (conn);
  if (res)
    drmModeFreeResources (res);

  if (!ret && self->fd >= 0) {
    drmClose (self->fd);
    self->fd = -1;
  }

  return ret;

  /* ERRORS */
open_failed:
  {
    GST_ERROR_OBJECT (self, "Could not open DRM module %s: %s",
        GST_STR_NULL (self->devname), strerror (errno));
    return FALSE;
  }

resources_failed:
  {
    GST_ERROR_OBJECT (self, "drmModeGetResources failed: %s (%d)",
        strerror (errno), errno);
    goto bail;
  }

connector_failed:
  {
    GST_ERROR_OBJECT (self, "Could not find a valid monitor connector");
    goto bail;
  }

crtc_failed:
  {
    GST_ERROR_OBJECT (self, "Could not find a crtc for connector");
    goto bail;
  }

plane_resources_failed:
  {
    GST_ERROR_OBJECT (self, "drmModeGetPlaneResources failed: %s (%d)",
        strerror (errno), errno);
    goto bail;
  }

plane_failed:
  {
    GST_ERROR_OBJECT (self, "Could not find a plane for crtc");
    goto bail;
  }
}

static gboolean
gst_kms_sink_stop (GstBaseSink * bsink)
{
  GstKMSSink *self;

  self = GST_KMS_SINK (bsink);

  gst_caps_replace (&self->allowed_caps, NULL);
  gst_object_replace ((GstObject **) & self->pool, NULL);
  gst_object_replace ((GstObject **) & self->allocator, NULL);

  if (self->fd >= 0) {
    drmClose (self->fd);
    self->fd = -1;
  }

  return TRUE;
}

static GstCaps *
gst_kms_sink_get_allowed_caps (GstKMSSink * self)
{
  if (!self->allowed_caps)
    return NULL;                /* base class will return the template caps */
  return gst_caps_ref (self->allowed_caps);
}

static GstCaps *
gst_kms_sink_get_caps (GstBaseSink * bsink, GstCaps * filter)
{
  GstKMSSink *self;
  GstCaps *caps, *out_caps;

  self = GST_KMS_SINK (bsink);

  caps = gst_kms_sink_get_allowed_caps (self);
  if (caps && filter) {
    out_caps = gst_caps_intersect_full (caps, filter, GST_CAPS_INTERSECT_FIRST);
    gst_caps_unref (caps);
  } else {
    out_caps = caps;
  }

  return out_caps;
}

static void
ensure_kms_allocator (GstKMSSink * self)
{
  if (self->allocator)
    return;
  self->allocator = gst_kms_allocator_new (self->fd);
}

static GstBufferPool *
gst_kms_sink_create_pool (GstKMSSink * self, GstCaps * caps, gsize size,
    gint min)
{
  GstBufferPool *pool;
  GstStructure *config;

  pool = gst_kms_buffer_pool_new ();
  if (!pool)
    goto pool_failed;

  config = gst_buffer_pool_get_config (pool);
  gst_buffer_pool_config_set_params (config, caps, size, min, 0);
  gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);

  ensure_kms_allocator (self);
  gst_buffer_pool_config_set_allocator (config, self->allocator, NULL);

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

  return pool;

  /* ERRORS */
pool_failed:
  {
    GST_ERROR_OBJECT (self, "failed to create buffer pool");
    return NULL;
  }
config_failed:
  {
    GST_ERROR_OBJECT (self, "failed to set config");
    gst_object_unref (pool);
    return NULL;
  }
}

static gboolean
gst_kms_sink_calculate_display_ratio (GstKMSSink * self, GstVideoInfo * vinfo)
{
  guint dar_n, dar_d;
  guint video_width, video_height;
  guint video_par_n, video_par_d;
  guint dpy_par_n, dpy_par_d;

  video_width = GST_VIDEO_INFO_WIDTH (vinfo);
  video_height = GST_VIDEO_INFO_HEIGHT (vinfo);
  video_par_n = GST_VIDEO_INFO_PAR_N (vinfo);
  video_par_d = GST_VIDEO_INFO_PAR_D (vinfo);

  gst_video_calculate_device_ratio (self->hdisplay, self->vdisplay,
      self->mm_width, self->mm_height, &dpy_par_n, &dpy_par_d);

  if (!gst_video_calculate_display_ratio (&dar_n, &dar_d, video_width,
          video_height, video_par_n, video_par_d, dpy_par_n, dpy_par_d))
    return FALSE;

  GST_DEBUG_OBJECT (self, "video calculated display ratio: %d/%d", dar_n,
      dar_d);

  /* now find a width x height that respects this display ratio.
   * prefer those that have one of w/h the same as the incoming video
   * using wd / hd = dar_n / dar_d */

  /* start with same height, because of interlaced video */
  /* check hd / dar_d is an integer scale factor, and scale wd with the PAR */
  if (video_height % dar_d == 0) {
    GST_DEBUG_OBJECT (self, "keeping video height");
    GST_VIDEO_SINK_WIDTH (self) = (guint)
        gst_util_uint64_scale_int (video_height, dar_n, dar_d);
    GST_VIDEO_SINK_HEIGHT (self) = video_height;
  } else if (video_width % dar_n == 0) {
    GST_DEBUG_OBJECT (self, "keeping video width");
    GST_VIDEO_SINK_WIDTH (self) = video_width;
    GST_VIDEO_SINK_HEIGHT (self) = (guint)
        gst_util_uint64_scale_int (video_width, dar_d, dar_n);
  } else {
    GST_DEBUG_OBJECT (self, "approximating while keeping video height");
    GST_VIDEO_SINK_WIDTH (self) = (guint)
        gst_util_uint64_scale_int (video_height, dar_n, dar_d);
    GST_VIDEO_SINK_HEIGHT (self) = video_height;
  }
  GST_DEBUG_OBJECT (self, "scaling to %dx%d", GST_VIDEO_SINK_WIDTH (self),
      GST_VIDEO_SINK_HEIGHT (self));

  return TRUE;
}

static gboolean
gst_kms_sink_set_caps (GstBaseSink * bsink, GstCaps * caps)
{
  GstKMSSink *self;
  GstVideoInfo vinfo;
  GstBufferPool *newpool, *oldpool;

  self = GST_KMS_SINK (bsink);

  if (!gst_video_info_from_caps (&vinfo, caps))
    goto invalid_format;

  if (!gst_kms_sink_calculate_display_ratio (self, &vinfo))
    goto no_disp_ratio;

  if (GST_VIDEO_SINK_WIDTH (self) <= 0 || GST_VIDEO_SINK_HEIGHT (self) <= 0)
    goto invalid_size;

  /* create a new pool for the new configuration */
  newpool = gst_kms_sink_create_pool (self, caps, GST_VIDEO_INFO_SIZE (&vinfo),
      2);
  if (!newpool)
    goto no_pool;

  /* we don't activate the internal pool yet as it may not be needed */
  oldpool = self->pool;
  self->pool = newpool;

  if (oldpool) {
    gst_buffer_pool_set_active (oldpool, FALSE);
    gst_object_unref (oldpool);
  }

  self->vinfo = vinfo;

  GST_DEBUG_OBJECT (self, "negotiated caps = %" GST_PTR_FORMAT, caps);

  return TRUE;

  /* ERRORS */
invalid_format:
  {
    GST_ERROR_OBJECT (self, "caps invalid");
    return FALSE;
  }

invalid_size:
  {
    GST_ELEMENT_ERROR (self, CORE, NEGOTIATION, (NULL),
        ("Invalid image size."));
    return FALSE;
  }

no_disp_ratio:
  {
    GST_ELEMENT_ERROR (self, CORE, NEGOTIATION, (NULL),
        ("Error calculating the output display ratio of the video."));
    return FALSE;
  }
no_pool:
  {
    /* Already warned in create_pool */
    return FALSE;
  }
}

static gboolean
gst_kms_sink_propose_allocation (GstBaseSink * bsink, GstQuery * query)
{
  GstKMSSink *self;
  GstCaps *caps;
  gboolean need_pool;
  GstVideoInfo vinfo;
  GstBufferPool *pool;
  gsize size;

  self = GST_KMS_SINK (bsink);

  gst_query_parse_allocation (query, &caps, &need_pool);
  if (!caps)
    goto no_caps;
  if (!gst_video_info_from_caps (&vinfo, caps))
    goto invalid_caps;

  size = GST_VIDEO_INFO_SIZE (&vinfo);

  pool = NULL;
  if (need_pool) {
    pool = gst_kms_sink_create_pool (self, caps, size, 0);
    if (!pool)
      goto no_pool;
  }

  if (pool) {
    /* we need at least 2 buffer because we hold on to the last one */
    gst_query_add_allocation_pool (query, pool, size, 2, 0);
    gst_object_unref (pool);
  }

  gst_query_add_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL);
  gst_query_add_allocation_meta (query, GST_VIDEO_CROP_META_API_TYPE, NULL);

  return TRUE;

  /* ERRORS */
no_caps:
  {
    GST_DEBUG_OBJECT (bsink, "no caps specified");
    return FALSE;
  }
invalid_caps:
  {
    GST_DEBUG_OBJECT (bsink, "invalid caps specified");
    return FALSE;
  }
no_pool:
  {
    /* Already warned in create_pool */
    return FALSE;
  }
}

static void
gst_kms_sink_get_times (GstBaseSink * bsink, GstBuffer * buf,
    GstClockTime * start, GstClockTime * end)
{
  GstKMSSink *self;

  self = GST_KMS_SINK (bsink);

  if (GST_BUFFER_TIMESTAMP_IS_VALID (buf)) {
    *start = GST_BUFFER_TIMESTAMP (buf);
    if (GST_BUFFER_DURATION_IS_VALID (buf))
      *end = *start + GST_BUFFER_DURATION (buf);
    else {
      if (GST_VIDEO_INFO_FPS_N (&self->vinfo) > 0) {
        *end = *start +
            gst_util_uint64_scale_int (GST_SECOND,
            GST_VIDEO_INFO_FPS_D (&self->vinfo),
            GST_VIDEO_INFO_FPS_N (&self->vinfo));
      }
    }
  }
}

static GstBuffer *
gst_kms_sink_get_input_buffer (GstKMSSink * self, GstBuffer * inbuf)
{
  GstMemory *mem;
  GstBuffer *buf;
  GstFlowReturn ret;
  GstVideoFrame inframe, outframe;
  gboolean success;

  mem = gst_buffer_peek_memory (inbuf, 0);
  if (!mem)
    return NULL;

  if (gst_is_kms_memory (mem))
    return gst_buffer_ref (inbuf);

  if (!gst_buffer_pool_set_active (self->pool, TRUE))
    goto activate_pool_failed;

  buf = NULL;
  ret = gst_buffer_pool_acquire_buffer (self->pool, &buf, NULL);
  if (ret != GST_FLOW_OK)
    goto create_buffer_failed;

  if (!gst_video_frame_map (&inframe, &self->vinfo, inbuf, GST_MAP_READ))
    goto error_map_src_buffer;

  if (!gst_video_frame_map (&outframe, &self->vinfo, buf, GST_MAP_WRITE))
    goto error_map_dst_buffer;

  success = gst_video_frame_copy (&outframe, &inframe);
  gst_video_frame_unmap (&outframe);
  gst_video_frame_unmap (&inframe);
  if (!success)
    goto error_copy_buffer;

  return buf;

bail:
  {
    if (buf)
      gst_buffer_unref (buf);
    return NULL;
  }

  /* ERRORS */
activate_pool_failed:
  {
    GST_ELEMENT_ERROR (self, STREAM, FAILED, ("failed to activate buffer pool"),
        ("failed to activate buffer pool"));
    goto bail;
  }
create_buffer_failed:
  {
    GST_ELEMENT_ERROR (self, STREAM, FAILED, ("allocation failed"),
        ("failed to create buffer"));
    goto bail;
  }
error_copy_buffer:
  {
    GST_WARNING_OBJECT (self, "failed to upload buffer");
    goto bail;
  }
error_map_dst_buffer:
  {
    gst_video_frame_unmap (&inframe);
    /* fall-through */
  }
error_map_src_buffer:
  {
    GST_WARNING_OBJECT (self, "failed to map buffer");
    goto bail;
  }
}

static GstFlowReturn
gst_kms_sink_show_frame (GstVideoSink * vsink, GstBuffer * buf)
{
  gint ret;
  GstBuffer *buffer;
  guint32 fb_id;
  GstKMSSink *self;
  GstVideoCropMeta *crop;
  GstVideoRectangle src = { 0, };
  GstVideoRectangle dst = { 0, };
  GstVideoRectangle result;

  self = GST_KMS_SINK (vsink);

  buffer = gst_kms_sink_get_input_buffer (self, buf);
  if (!buffer)
    return GST_FLOW_ERROR;
  fb_id = gst_kms_memory_get_fb_id (gst_buffer_peek_memory (buffer, 0));
  if (fb_id == 0)
    goto buffer_invalid;

  GST_DEBUG_OBJECT (self, "displaying fb %d", fb_id);

  {
    if ((crop = gst_buffer_get_video_crop_meta (buffer))) {
      src.x = crop->x;
      src.y = crop->y;
      src.w = crop->width;
      src.h = crop->height;
    } else {
      src.w = GST_VIDEO_SINK_WIDTH (self);
      src.h = GST_VIDEO_SINK_HEIGHT (self);
    }
  }

  dst.w = self->hdisplay;
  dst.h = self->vdisplay;

  gst_video_sink_center_rect (src, dst, &result, FALSE);

  /* if the frame size is bigger than the display size, the source
   * must be the display size */
  src.w = MIN (src.w, self->hdisplay);
  src.h = MIN (src.h, self->vdisplay);

  ret = drmModeSetPlane (self->fd, self->plane_id, self->crtc_id, fb_id, 0,
      result.x, result.y, result.w, result.h,
      /* source/cropping coordinates are given in Q16 */
      src.x << 16, src.y << 16, src.w << 16, src.h << 16);

  gst_buffer_unref (buffer);

  if (ret)
    goto set_plane_failed;

  return GST_FLOW_OK;

  /* ERRORS */
buffer_invalid:
  {
    GST_ERROR_OBJECT (self, "invalid buffer: it doesn't have a fb id");
    return GST_FLOW_ERROR;
  }
set_plane_failed:
  {
    GST_DEBUG_OBJECT (self, "result = { %d, %d, %d, %d} / "
        "src = { %d, %d, %d %d } / dst = { %d, %d, %d %d }", result.x, result.y,
        result.w, result.h, src.x, src.y, src.w, src.h, dst.x, dst.y, dst.w,
        dst.h);
    GST_ELEMENT_ERROR (self, RESOURCE, FAILED,
        (NULL), ("drmModeSetPlane failed: %s (%d)", strerror (-ret), ret));
    return GST_FLOW_ERROR;
  }
}

static void
gst_kms_sink_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstKMSSink *sink;

  sink = GST_KMS_SINK (object);

  switch (prop_id) {
    case PROP_DRIVER_NAME:
      sink->devname = g_value_dup_string (value);
      break;
    case PROP_CONNECTOR_ID:
      sink->conn_id = g_value_get_int (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_kms_sink_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstKMSSink *sink;

  sink = GST_KMS_SINK (object);

  switch (prop_id) {
    case PROP_DRIVER_NAME:
      g_value_take_string (value, sink->devname);
      break;
    case PROP_CONNECTOR_ID:
      g_value_set_int (value, sink->conn_id);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_kms_sink_finalize (GObject * object)
{
  GstKMSSink *sink;

  sink = GST_KMS_SINK (object);
  g_clear_pointer (&sink->devname, g_free);
}

static void
gst_kms_sink_init (GstKMSSink * sink)
{
  sink->fd = -1;
  sink->conn_id = -1;
  gst_video_info_init (&sink->vinfo);
}

static void
gst_kms_sink_class_init (GstKMSSinkClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *element_class;
  GstBaseSinkClass *basesink_class;
  GstVideoSinkClass *videosink_class;
  GstCaps *caps;

  gobject_class = G_OBJECT_CLASS (klass);
  element_class = GST_ELEMENT_CLASS (klass);
  basesink_class = GST_BASE_SINK_CLASS (klass);
  videosink_class = GST_VIDEO_SINK_CLASS (klass);

  gst_element_class_set_static_metadata (element_class, "KMS video sink",
      "Sink/Video", GST_PLUGIN_DESC, "Víctor Jáquez <vjaquez@igalia.com>");

  caps = gst_kms_sink_caps_template_fill ();
  gst_element_class_add_pad_template (element_class,
      gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, caps));
  gst_caps_unref (caps);

  basesink_class->start = GST_DEBUG_FUNCPTR (gst_kms_sink_start);
  basesink_class->stop = GST_DEBUG_FUNCPTR (gst_kms_sink_stop);
  basesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_kms_sink_set_caps);
  basesink_class->get_caps = GST_DEBUG_FUNCPTR (gst_kms_sink_get_caps);
  basesink_class->propose_allocation = gst_kms_sink_propose_allocation;
  basesink_class->get_times = gst_kms_sink_get_times;

  videosink_class->show_frame = gst_kms_sink_show_frame;

  gobject_class->finalize = gst_kms_sink_finalize;
  gobject_class->set_property = gst_kms_sink_set_property;
  gobject_class->get_property = gst_kms_sink_get_property;

  /**
   * kmssink:driver-name:
   *
   * If you have a system with multiple GPUs, you can choose which GPU
   * to use setting the DRM device driver name. Otherwise, the first
   * one from an internal list is used.
   */
  g_properties[PROP_DRIVER_NAME] = g_param_spec_string ("driver-name",
      "device name", "DRM device driver name", NULL,
      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT);

  /**
   * kmssink:connector-id:
   *
   * A GPU has several output connectors, for example: LVDS, VGA,
   * HDMI, etc. By default the first LVDS is tried, then the first
   * eDP, and at the end, the first connected one.
   */
  g_properties[PROP_CONNECTOR_ID] = g_param_spec_int ("connector-id",
      "Connector ID", "DRM connector id", -1, G_MAXINT32, -1,
      G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS | G_PARAM_CONSTRUCT);

  g_object_class_install_properties (gobject_class, PROP_N, g_properties);
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_element_register (plugin, GST_PLUGIN_NAME, GST_RANK_SECONDARY,
          GST_TYPE_KMS_SINK))
    return FALSE;

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, kms,
    GST_PLUGIN_DESC, plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME,
    GST_PACKAGE_ORIGIN)