gstreamer/gst-libs/gst/gl/gstglupload.c

/*
 * GStreamer
 * Copyright (C) 2012-2014 Matthew Waters <ystree00@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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

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

#include <stdio.h>

#include "gl.h"
#include "gstglupload.h"

/**
 * SECTION:gstglupload
 * @short_description: an object that uploads to GL textures
 * @see_also: #GstGLDownload, #GstGLMemory
 *
 * #GstGLUpload is an object that uploads data from system memory into GL textures.
 *
 * A #GstGLUpload can be created with gst_gl_upload_new()
 */

#define USING_OPENGL(context) (gst_gl_context_get_gl_api (context) & GST_GL_API_OPENGL)
#define USING_OPENGL3(context) (gst_gl_context_get_gl_api (context) & GST_GL_API_OPENGL3)
#define USING_GLES(context) (gst_gl_context_get_gl_api (context) & GST_GL_API_GLES)
#define USING_GLES2(context) (gst_gl_context_get_gl_api (context) & GST_GL_API_GLES2)
#define USING_GLES3(context) (gst_gl_context_get_gl_api (context) & GST_GL_API_GLES3)

static void _do_upload (GstGLContext * context, GstGLUpload * upload);
static gboolean _do_upload_fill (GstGLContext * context, GstGLUpload * upload);
static gboolean _do_upload_make (GstGLContext * context, GstGLUpload * upload);
static void _init_upload (GstGLContext * context, GstGLUpload * upload);
static gboolean _init_upload_fbo (GstGLContext * context, GstGLUpload * upload);
static gboolean _gst_gl_upload_perform_with_data_unlocked (GstGLUpload * upload,
    GLuint texture_id, gpointer data[GST_VIDEO_MAX_PLANES]);
static void _do_upload_with_meta (GstGLContext * context, GstGLUpload * upload);

static gboolean _do_upload_draw (GstGLContext * context, GstGLUpload * upload);

/* *INDENT-OFF* */

#define YUV_TO_RGB_COEFFICIENTS \
      "uniform vec3 offset;\n" \
      "uniform vec3 rcoeff;\n" \
      "uniform vec3 gcoeff;\n" \
      "uniform vec3 bcoeff;\n"

/* FIXME: use the colormatrix support from videoconvert */

/* BT. 601 standard with the following ranges:
 * Y = [16..235] (of 255)
 * Cb/Cr = [16..240] (of 255)
 */
static const gfloat bt601_offset[] = {-0.0625, -0.5, -0.5};
static const gfloat bt601_rcoeff[] = {1.164, 0.000, 1.596};
static const gfloat bt601_gcoeff[] = {1.164,-0.391,-0.813};
static const gfloat bt601_bcoeff[] = {1.164, 2.018, 0.000};

/* BT. 709 standard with the following ranges:
 * Y = [16..235] (of 255)
 * Cb/Cr = [16..240] (of 255)
 */
static const gfloat bt709_offset[] = {-0.0625, -0.5, -0.5};
static const gfloat bt709_rcoeff[] = {1.164, 0.000, 1.787};
static const gfloat bt709_gcoeff[] = {1.164,-0.213,-0.531};
static const gfloat bt709_bcoeff[] = {1.164,-2.112, 0.000};

/** GRAY16 to RGB conversion 
 *  data transfered as GL_LUMINANCE_ALPHA then convert back to GRAY16 
 *  high byte weight as : 255*256/65535 
 *  ([0~1] denormalize to [0~255],shift to high byte,normalize to [0~1])
 *  low byte weight as : 255/65535 (similar)
 * */
#define COMPOSE_WEIGHT \
    "const vec2 compose_weight = vec2(0.996109, 0.003891);\n"

/* Channel reordering for XYZ <-> ZYX conversion */
static const char *frag_REORDER = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D tex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      "void main(void)\n"
      "{\n"
      " vec4 t = texture2D(tex, v_texcoord * tex_scale0);\n"
      " gl_FragColor = vec4(t.%c, t.%c, t.%c, 1.0);\n"
      "}"
};

/** GRAY16 to RGB conversion 
 *  data transfered as GL_LUMINANCE_ALPHA then convert back to GRAY16 
 *  high byte weight as : 255*256/65535 
 *  ([0~1] denormalize to [0~255],shift to high byte,normalize to [0~1])
 *  low byte weight as : 255/65535 (similar)
 * */
static const char *frag_COMPOSE = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D tex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      COMPOSE_WEIGHT
      "void main(void)\n"
      "{\n"
      " vec4 t = texture2D(tex, v_texcoord * tex_scale0);\n"
      " float value = dot(t.%c%c, compose_weight);"
      " gl_FragColor = vec4(value, value, value, 1.0);\n"
      "}"

};
static const char *frag_AYUV = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D tex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      YUV_TO_RGB_COEFFICIENTS
      "void main(void) {\n"
      "  float r,g,b;\n"
      "  vec3 yuv;\n"
      "  yuv  = texture2D(tex,v_texcoord * tex_scale0).gba;\n"
      "  yuv += offset;\n"
      "  r = dot(yuv, rcoeff);\n"
      "  g = dot(yuv, gcoeff);\n"
      "  b = dot(yuv, bcoeff);\n"
      "  gl_FragColor=vec4(r,g,b,1.0);\n"
      "}"
};

/** YUV to RGB conversion */
static const char *frag_PLANAR_YUV = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D Ytex,Utex,Vtex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      YUV_TO_RGB_COEFFICIENTS
      "void main(void) {\n"
      "  float r,g,b;\n"
      "  vec3 yuv;\n"
      "  yuv.x=texture2D(Ytex,v_texcoord * tex_scale0).r;\n"
      "  yuv.y=texture2D(Utex,v_texcoord * tex_scale1).r;\n"
      "  yuv.z=texture2D(Vtex,v_texcoord * tex_scale2).r;\n"
      "  yuv += offset;\n"
      "  r = dot(yuv, rcoeff);\n"
      "  g = dot(yuv, gcoeff);\n"
      "  b = dot(yuv, bcoeff);\n"
      "  gl_FragColor=vec4(r,g,b,1.0);\n"
      "}"
};

/** NV12/NV21 to RGB conversion */
static const char *frag_NV12_NV21 = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D Ytex,UVtex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      YUV_TO_RGB_COEFFICIENTS
      "void main(void) {\n"
      "  float r,g,b;\n"
      "  vec3 yuv;\n"
      "  yuv.x=texture2D(Ytex, v_texcoord * tex_scale0).r;\n"
      "  yuv.yz=texture2D(UVtex, v_texcoord * tex_scale1).%c%c;\n"
      "  yuv += offset;\n"
      "  r = dot(yuv, rcoeff);\n"
      "  g = dot(yuv, gcoeff);\n"
      "  b = dot(yuv, bcoeff);\n"
      "  gl_FragColor=vec4(r,g,b,1.0);\n"
      "}"
};

/* Direct fragments copy with stride-scaling */
static const char *frag_COPY = {
      "#ifdef GL_ES\n"
      "precision mediump float;\n"
      "#endif\n"
      "varying vec2 v_texcoord;\n"
      "uniform sampler2D tex;\n"
      "uniform vec2 tex_scale0;\n"
      "uniform vec2 tex_scale1;\n"
      "uniform vec2 tex_scale2;\n"
      "void main(void)\n"
      "{\n"
      " vec4 t = texture2D(tex, v_texcoord * tex_scale0);\n"
      " gl_FragColor = vec4(t.rgb, 1.0);\n"
      "}"
};

/* YUY2:r,g,a
   UYVY:a,b,r */
static const gchar *frag_YUY2_UYVY =
    "#ifdef GL_ES\n"
    "precision mediump float;\n"
    "#endif\n"
    "varying vec2 v_texcoord;\n"
    "uniform sampler2D Ytex, UVtex;\n"
    "uniform vec2 tex_scale0;\n"
    "uniform vec2 tex_scale1;\n"
    "uniform vec2 tex_scale2;\n"
    YUV_TO_RGB_COEFFICIENTS
    "void main(void) {\n"
    "  vec3 yuv;\n"
    "  float fx, fy, y, u, v, r, g, b;\n"
    "  fx = v_texcoord.x;\n"
    "  fy = v_texcoord.y;\n"
    "  yuv.x = texture2D(Ytex,v_texcoord * tex_scale0).%c;\n"
    "  yuv.yz = texture2D(UVtex,v_texcoord * tex_scale1).%c%c;\n"
    "  yuv+=offset;\n"
    "  r = dot(yuv, rcoeff);\n"
    "  g = dot(yuv, gcoeff);\n"
    "  b = dot(yuv, bcoeff);\n"
    "  gl_FragColor = vec4(r, g, b, 1.0);\n"
    "}\n";

static const gchar *text_vertex_shader =
    "attribute vec4 a_position;   \n"
    "attribute vec2 a_texcoord;   \n"
    "varying vec2 v_texcoord;     \n"
    "void main()                  \n"
    "{                            \n"
    "   gl_Position = a_position; \n"
    "   v_texcoord = a_texcoord;  \n"
    "}                            \n";

/* *INDENT-ON* */

struct TexData
{
  guint internal_format, format, type, width, height;
  gfloat tex_scaling[2];
  const gchar *shader_name;
  guint unpack_length;
};

struct _GstGLUploadPrivate
{
  int n_textures;
  gboolean result;

  const gchar *YUY2_UYVY;
  const gchar *PLANAR_YUV;
  const gchar *AYUV;
  const gchar *NV12_NV21;
  const gchar *REORDER;
  const gchar *COPY;
  const gchar *COMPOSE;
  const gchar *vert_shader;

    gboolean (*draw) (GstGLContext * context, GstGLUpload * download);

  struct TexData texture_info[GST_VIDEO_MAX_PLANES];

  GstBuffer *buffer;
  GstVideoFrame frame;
  GstVideoGLTextureUploadMeta *meta;
  guint tex_id;
  gboolean mapped;
};

GST_DEBUG_CATEGORY_STATIC (gst_gl_upload_debug);
#define GST_CAT_DEFAULT gst_gl_upload_debug

#define DEBUG_INIT \
  GST_DEBUG_CATEGORY_INIT (gst_gl_upload_debug, "glupload", 0, "upload");

G_DEFINE_TYPE_WITH_CODE (GstGLUpload, gst_gl_upload, G_TYPE_OBJECT, DEBUG_INIT);
static void gst_gl_upload_finalize (GObject * object);

#define GST_GL_UPLOAD_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
    GST_TYPE_GL_UPLOAD, GstGLUploadPrivate))

static void
gst_gl_upload_class_init (GstGLUploadClass * klass)
{
  g_type_class_add_private (klass, sizeof (GstGLUploadPrivate));

  G_OBJECT_CLASS (klass)->finalize = gst_gl_upload_finalize;
}

static void
gst_gl_upload_init (GstGLUpload * upload)
{
  upload->priv = GST_GL_UPLOAD_GET_PRIVATE (upload);

  upload->context = NULL;

  g_mutex_init (&upload->lock);

  upload->fbo = 0;
  upload->depth_buffer = 0;
  upload->out_texture = 0;
  upload->shader = NULL;

  upload->shader_attr_position_loc = 0;
  upload->shader_attr_texture_loc = 0;
}

/**
 * gst_gl_upload_new:
 * @context: a #GstGLContext
 *
 * Returns: a new #GstGLUpload object
 */
GstGLUpload *
gst_gl_upload_new (GstGLContext * context)
{
  GstGLUpload *upload;
  GstGLUploadPrivate *priv;

  upload = g_object_new (GST_TYPE_GL_UPLOAD, NULL);

  upload->context = gst_object_ref (context);
  priv = upload->priv;

  priv->YUY2_UYVY = frag_YUY2_UYVY;
  priv->PLANAR_YUV = frag_PLANAR_YUV;
  priv->AYUV = frag_AYUV;
  priv->REORDER = frag_REORDER;
  priv->COMPOSE = frag_COMPOSE;
  priv->COPY = frag_COPY;
  priv->NV12_NV21 = frag_NV12_NV21;
  priv->vert_shader = text_vertex_shader;
  priv->draw = _do_upload_draw;

  return upload;
}

static void
gst_gl_upload_finalize (GObject * object)
{
  GstGLUpload *upload;
  guint i;

  upload = GST_GL_UPLOAD (object);

  for (i = 0; i < GST_VIDEO_MAX_PLANES; i++) {
    if (upload->in_texture[i]) {
      gst_gl_context_del_texture (upload->context, &upload->in_texture[i]);
      upload->in_texture[i] = 0;
    }
  }
  if (upload->out_texture) {
    gst_gl_context_del_texture (upload->context, &upload->out_texture);
    upload->out_texture = 0;
  }
  if (upload->priv->tex_id) {
    gst_gl_context_del_texture (upload->context, &upload->priv->tex_id);
    upload->priv->tex_id = 0;
  }
  if (upload->fbo || upload->depth_buffer) {
    gst_gl_context_del_fbo (upload->context, upload->fbo, upload->depth_buffer);
    upload->fbo = 0;
    upload->depth_buffer = 0;
  }
  if (upload->shader) {
    gst_object_unref (upload->shader);
    upload->shader = NULL;
  }

  if (upload->context) {
    gst_object_unref (upload->context);
    upload->context = NULL;
  }

  g_mutex_clear (&upload->lock);

  G_OBJECT_CLASS (gst_gl_upload_parent_class)->finalize (object);
}

static gboolean
_gst_gl_upload_init_format_unlocked (GstGLUpload * upload,
    GstVideoInfo * in_info, GstVideoInfo * out_info)
{
  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (GST_VIDEO_INFO_FORMAT (in_info) !=
      GST_VIDEO_FORMAT_UNKNOWN, FALSE);
  g_return_val_if_fail (GST_VIDEO_INFO_FORMAT (in_info) !=
      GST_VIDEO_FORMAT_ENCODED, FALSE);

  if (upload->initted) {
    return FALSE;
  } else {
    upload->initted = TRUE;
  }

  upload->in_info = *in_info;
  upload->out_info = *out_info;

  gst_gl_context_thread_add (upload->context,
      (GstGLContextThreadFunc) _init_upload, upload);

  return upload->priv->result;
}


/**
 * gst_gl_upload_init_format:
 * @upload: a #GstGLUpload
 * @in_info: input #GstVideoInfo
 * @out_info: output #GstVideoInfo
 *
 * Initializes @upload with the information required for upload.
 *
 * Returns: whether the initialization was successful
 */
gboolean
gst_gl_upload_init_format (GstGLUpload * upload, GstVideoInfo * in_info,
    GstVideoInfo * out_info)
{
  gboolean ret;

  g_mutex_lock (&upload->lock);

  ret = _gst_gl_upload_init_format_unlocked (upload, in_info, out_info);

  g_mutex_unlock (&upload->lock);

  return ret;
}

/**
 * gst_gl_upload_perform_with_buffer:
 * @upload: a #GstGLUpload
 * @buffer: a #GstBuffer
 * @tex_id: resulting texture
 *
 * Uploads @buffer to the texture given by @tex_id.  @tex_id is valid
 * until gst_gl_upload_release_buffer() is called.
 *
 * Returns: whether the upload was successful
 */
gboolean
gst_gl_upload_perform_with_buffer (GstGLUpload * upload, GstBuffer * buffer,
    guint * tex_id)
{
  GstMemory *mem;
  GstVideoGLTextureUploadMeta *gl_tex_upload_meta;

  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (buffer != NULL, FALSE);
  g_return_val_if_fail (tex_id != NULL, FALSE);
  g_return_val_if_fail (gst_buffer_n_memory (buffer) > 0, FALSE);

  /* GstGLMemory */
  mem = gst_buffer_peek_memory (buffer, 0);

  if (gst_is_gl_memory (mem)) {
    GST_LOG_OBJECT (upload, "Attempting upload with GstGLMemory");
    /* Assuming only one memory */
    if (!gst_video_frame_map (&upload->priv->frame, &upload->in_info, buffer,
            GST_MAP_READ | GST_MAP_GL)) {
      GST_ERROR_OBJECT (upload, "Failed to map memory");
      return FALSE;
    }

    *tex_id = *(guint *) upload->priv->frame.data[0];

    upload->priv->mapped = TRUE;
    return TRUE;
  }

  if (!upload->priv->tex_id)
    gst_gl_context_gen_texture (upload->context, &upload->priv->tex_id,
        GST_VIDEO_INFO_FORMAT (&upload->in_info),
        GST_VIDEO_INFO_WIDTH (&upload->in_info),
        GST_VIDEO_INFO_HEIGHT (&upload->in_info));

  /* GstVideoGLTextureUploadMeta */
  gl_tex_upload_meta = gst_buffer_get_video_gl_texture_upload_meta (buffer);
  if (gl_tex_upload_meta) {
    guint texture_ids[] = { 0, 0, 0, 0 };
    GST_LOG_OBJECT (upload, "Attempting upload with "
        "GstVideoGLTextureUploadMeta");
    texture_ids[0] = upload->priv->tex_id;

    if (!gst_gl_upload_perform_with_gl_texture_upload_meta (upload,
            gl_tex_upload_meta, texture_ids)) {
      GST_DEBUG_OBJECT (upload, "Upload with GstVideoGLTextureUploadMeta "
          "failed");
    } else {
      upload->priv->mapped = FALSE;
      *tex_id = upload->priv->tex_id;
      return TRUE;
    }
  }

  GST_LOG_OBJECT (upload, "Attempting upload with raw data");
  /* GstVideoMeta map */
  if (!gst_video_frame_map (&upload->priv->frame, &upload->in_info, buffer,
          GST_MAP_READ)) {
    GST_ERROR_OBJECT (upload, "Failed to map memory");
    return FALSE;
  }

  if (!gst_gl_upload_perform_with_data (upload, upload->priv->tex_id,
          upload->priv->frame.data)) {
    return FALSE;
  }

  upload->priv->mapped = TRUE;
  *tex_id = upload->priv->tex_id;
  return TRUE;
}

void
gst_gl_upload_release_buffer (GstGLUpload * upload)
{
  g_return_if_fail (upload != NULL);

  if (upload->priv->mapped)
    gst_video_frame_unmap (&upload->priv->frame);
}

static gboolean
_upload_memory_unlocked (GstGLUpload * upload, GstGLMemory * gl_mem,
    guint tex_id)
{
  gpointer data[GST_VIDEO_MAX_PLANES];
  guint i;
  gboolean ret;

  for (i = 0; i < GST_VIDEO_INFO_N_PLANES (&upload->in_info); i++) {
    data[i] = (guint8 *) gl_mem->data +
        GST_VIDEO_INFO_PLANE_OFFSET (&upload->in_info, i);
  }

  ret = _gst_gl_upload_perform_with_data_unlocked (upload, tex_id, data);

  if (ret && tex_id == gl_mem->tex_id)
    GST_GL_MEMORY_FLAG_UNSET (gl_mem, GST_GL_MEMORY_FLAG_NEED_UPLOAD);

  return ret;
}

/**
 * gst_gl_upload_perform_with_memory:
 * @upload: a #GstGLUpload
 * @gl_mem: a #GstGLMemory
 *
 * Uploads the texture in @gl_mem
 *
 * Returns: whether the upload was successful
 */
gboolean
gst_gl_upload_perform_with_memory (GstGLUpload * upload, GstGLMemory * gl_mem)
{
  gboolean ret;

  g_return_val_if_fail (upload != NULL, FALSE);

  if (!GST_GL_MEMORY_FLAG_IS_SET (gl_mem, GST_GL_MEMORY_FLAG_UPLOAD_INITTED)) {
    gst_gl_upload_init_format (upload, &gl_mem->v_info, &gl_mem->v_info);
  }

  if (!GST_GL_MEMORY_FLAG_IS_SET (gl_mem, GST_GL_MEMORY_FLAG_NEED_UPLOAD))
    return FALSE;

  g_mutex_lock (&upload->lock);

  ret = _upload_memory_unlocked (upload, gl_mem, gl_mem->tex_id);

  g_mutex_unlock (&upload->lock);

  return ret;
}

/*
 * Uploads as a result of a call to gst_video_gl_texture_upload_meta_upload().
 * i.e. provider of GstVideoGLTextureUploadMeta
 */
static gboolean
_do_upload_for_meta (GstGLUpload * upload, GstVideoGLTextureUploadMeta * meta)
{
  GstVideoMeta *v_meta;
  GstVideoInfo in_info, out_info;
  GstVideoFrame frame;
  GstMemory *mem;
  gboolean ret;

  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (meta != NULL, FALSE);

  v_meta = gst_buffer_get_video_meta (upload->priv->buffer);

  if (!upload->initted) {
    GstVideoFormat v_format;
    guint width, height;

    if (v_meta == NULL)
      return FALSE;

    v_format = v_meta->format;
    width = v_meta->width;
    height = v_meta->height;

    gst_video_info_set_format (&in_info, v_format, width, height);
    gst_video_info_set_format (&out_info, GST_VIDEO_FORMAT_RGBA, width, height);

    if (!_gst_gl_upload_init_format_unlocked (upload, &in_info, &out_info))
      return FALSE;
  }

  /* GstGLMemory */
  mem = gst_buffer_peek_memory (upload->priv->buffer, 0);

  if (gst_is_gl_memory (mem)) {
    if (GST_GL_MEMORY_FLAG_IS_SET (mem, GST_GL_MEMORY_FLAG_NEED_UPLOAD)) {
      ret = _upload_memory_unlocked (upload, (GstGLMemory *) mem,
          upload->out_texture);
    } else {
      ret = gst_gl_memory_copy_into_texture ((GstGLMemory *) mem,
          upload->out_texture);
    }

    if (ret)
      return TRUE;
  }

  if (v_meta == NULL)
    return FALSE;

  gst_video_info_set_format (&in_info, v_meta->format, v_meta->width,
      v_meta->height);

  if (!gst_video_frame_map (&frame, &in_info, upload->priv->buffer,
          GST_MAP_READ)) {
    GST_ERROR ("failed to map video frame");
    return FALSE;
  }

  ret = _gst_gl_upload_perform_with_data_unlocked (upload, upload->out_texture,
      frame.data);

  gst_video_frame_unmap (&frame);

  if (ret)
    return TRUE;

  return ret;
}

/*
 * Uploads using gst_video_gl_texture_upload_meta_upload().
 * i.e. consumer of GstVideoGLTextureUploadMeta
 */
static void
_do_upload_with_meta (GstGLContext * context, GstGLUpload * upload)
{
  guint texture_ids[] = { upload->priv->tex_id, 0, 0, 0 };

  if (!gst_video_gl_texture_upload_meta_upload (upload->priv->meta,
          texture_ids))
    goto error;

  upload->priv->result = TRUE;
  return;

error:
  upload->priv->result = FALSE;
}

/**
 * gst_gl_upload_perform_with_gl_texture_upload_meta:
 * @upload: a #GstGLUpload
 * @meta: a #GstVideoGLTextureUploadMeta
 * @texture_id: resulting GL textures to place the data into.
 *
 * Uploads @meta into @texture_id.
 *
 * Returns: whether the upload was successful
 */
gboolean
gst_gl_upload_perform_with_gl_texture_upload_meta (GstGLUpload * upload,
    GstVideoGLTextureUploadMeta * meta, guint texture_id[4])
{
  gboolean ret;

  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (meta != NULL, FALSE);

  if (meta->texture_orientation !=
      GST_VIDEO_GL_TEXTURE_ORIENTATION_X_NORMAL_Y_NORMAL)
    GST_FIXME_OBJECT (upload, "only x-normal,y-normal textures supported, "
        "the images will not appear the right way up");
  if (meta->texture_type[0] != GST_VIDEO_GL_TEXTURE_TYPE_RGBA) {
    GST_FIXME_OBJECT (upload, "only single rgba texture supported");
    return FALSE;
  }

  g_mutex_lock (&upload->lock);

  upload->priv->meta = meta;
  upload->priv->tex_id = texture_id[0];

  GST_LOG ("Uploading with GLTextureUploadMeta with textures %i,%i,%i,%i",
      texture_id[0], texture_id[1], texture_id[2], texture_id[3]);

  gst_gl_context_thread_add (upload->context,
      (GstGLContextThreadFunc) _do_upload_with_meta, upload);

  ret = upload->priv->result;

  g_mutex_unlock (&upload->lock);

  return ret;
}

static gboolean
_gst_gl_upload_perform_for_gl_texture_upload_meta (GstVideoGLTextureUploadMeta *
    meta, guint texture_id[4])
{
  GstGLUpload *upload;
  gboolean ret;

  g_return_val_if_fail (meta != NULL, FALSE);
  g_return_val_if_fail (texture_id != NULL, FALSE);

  upload = meta->user_data;

  g_mutex_lock (&upload->lock);

  upload->out_texture = texture_id[0];

  GST_LOG ("Uploading for meta with textures %i,%i,%i,%i", texture_id[0],
      texture_id[1], texture_id[2], texture_id[3]);

  ret = _do_upload_for_meta (upload, meta);

  g_mutex_unlock (&upload->lock);

  return ret;
}

/**
 * gst_gl_upload_add_video_gl_texture_upload_meta:
 * @upload: a #GstGLUpload
 * @buffer: a #GstBuffer
 *
 * Adds a #GstVideoGLTextureUploadMeta on @buffer using @upload
 *
 * Returns: whether it was successful
 */
gboolean
gst_gl_upload_add_video_gl_texture_upload_meta (GstGLUpload * upload,
    GstBuffer * buffer)
{
  GstVideoGLTextureType texture_types[] =
      { GST_VIDEO_GL_TEXTURE_TYPE_RGBA, 0, 0, 0 };

  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (buffer != NULL, FALSE);
  g_return_val_if_fail (gst_buffer_n_memory (buffer) == 1, FALSE);

  upload->priv->buffer = buffer;

  gst_buffer_add_video_gl_texture_upload_meta (buffer,
      GST_VIDEO_GL_TEXTURE_ORIENTATION_X_NORMAL_Y_NORMAL, 1, texture_types,
      _gst_gl_upload_perform_for_gl_texture_upload_meta,
      gst_object_ref (upload), gst_object_ref, gst_object_unref);

  return TRUE;
}

/**
 * gst_gl_upload_perform_with_data:
 * @upload: a #GstGLUpload
 * @texture_id: the texture id to download
 * @data: where the downloaded data should go
 *
 * Uploads @data into @texture_id. data size and format is specified by
 * the #GstVideoInfo<!--  -->s passed to gst_gl_upload_init_format() 
 *
 * Returns: whether the upload was successful
 */
gboolean
gst_gl_upload_perform_with_data (GstGLUpload * upload, GLuint texture_id,
    gpointer data[GST_VIDEO_MAX_PLANES])
{
  gboolean ret;

  g_return_val_if_fail (upload != NULL, FALSE);

  g_mutex_lock (&upload->lock);

  ret = _gst_gl_upload_perform_with_data_unlocked (upload, texture_id, data);

  g_mutex_unlock (&upload->lock);

  return ret;
}

static gboolean
_gst_gl_upload_perform_with_data_unlocked (GstGLUpload * upload,
    GLuint texture_id, gpointer data[GST_VIDEO_MAX_PLANES])
{
  guint i;

  g_return_val_if_fail (upload != NULL, FALSE);
  g_return_val_if_fail (texture_id > 0, FALSE);

  upload->out_texture = texture_id;
  for (i = 0; i < GST_VIDEO_INFO_N_PLANES (&upload->in_info); i++) {
    upload->data[i] = data[i];
  }

  GST_LOG ("Uploading data into texture %u", texture_id);

  gst_gl_context_thread_add (upload->context,
      (GstGLContextThreadFunc) _do_upload, upload);

  return TRUE;
}

static gboolean
_create_shader (GstGLContext * context, const gchar * vertex_src,
    const gchar * fragment_src, GstGLShader ** out_shader)
{
  GstGLShader *shader;
  GError *error = NULL;

  g_return_val_if_fail (vertex_src != NULL || fragment_src != NULL, FALSE);

  shader = gst_gl_shader_new (context);

  if (vertex_src)
    gst_gl_shader_set_vertex_source (shader, vertex_src);
  if (fragment_src)
    gst_gl_shader_set_fragment_source (shader, fragment_src);

  if (!gst_gl_shader_compile (shader, &error)) {
    gst_gl_context_set_error (context, "%s", error->message);
    g_error_free (error);
    gst_gl_context_clear_shader (context);
    gst_object_unref (shader);
    return FALSE;
  }

  *out_shader = shader;
  return TRUE;
}

/* Called in the gl thread */
void
_init_upload (GstGLContext * context, GstGLUpload * upload)
{
  GstGLFuncs *gl;
  GstVideoFormat v_format;
  gchar *frag_prog = NULL;
  gboolean free_frag_prog, res;

  gl = context->gl_vtable;

  v_format = GST_VIDEO_INFO_FORMAT (&upload->in_info);

  GST_INFO ("Initializing texture upload for format:%s",
      gst_video_format_to_string (v_format));

  if (!gl->CreateProgramObject && !gl->CreateProgram) {
    gst_gl_context_set_error (context,
        "Cannot upload YUV formats without OpenGL shaders");
    goto error;
  }

  if (!_init_upload_fbo (context, upload)) {
    goto error;
  }

  switch (v_format) {
    case GST_VIDEO_FORMAT_AYUV:
      frag_prog = (gchar *) upload->priv->AYUV;
      free_frag_prog = FALSE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_Y444:
    case GST_VIDEO_FORMAT_I420:
    case GST_VIDEO_FORMAT_YV12:
    case GST_VIDEO_FORMAT_Y42B:
    case GST_VIDEO_FORMAT_Y41B:
      frag_prog = (gchar *) upload->priv->PLANAR_YUV;
      free_frag_prog = FALSE;
      upload->priv->n_textures = 3;
      break;
    case GST_VIDEO_FORMAT_NV12:
      frag_prog = g_strdup_printf (upload->priv->NV12_NV21, 'r', 'a');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 2;
      break;
    case GST_VIDEO_FORMAT_NV21:
      frag_prog = g_strdup_printf (upload->priv->NV12_NV21, 'a', 'r');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 2;
      break;
    case GST_VIDEO_FORMAT_BGR:
    case GST_VIDEO_FORMAT_BGRx:
    case GST_VIDEO_FORMAT_BGRA:
      frag_prog = g_strdup_printf (upload->priv->REORDER, 'b', 'g', 'r');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_xRGB:
    case GST_VIDEO_FORMAT_ARGB:
      frag_prog = g_strdup_printf (upload->priv->REORDER, 'g', 'b', 'a');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_xBGR:
    case GST_VIDEO_FORMAT_ABGR:
      frag_prog = g_strdup_printf (upload->priv->REORDER, 'a', 'b', 'g');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_GRAY16_BE:
      frag_prog = g_strdup_printf (upload->priv->COMPOSE, 'r', 'a');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_GRAY16_LE:
      frag_prog = g_strdup_printf (upload->priv->COMPOSE, 'a', 'r');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_GRAY8:
    case GST_VIDEO_FORMAT_RGB:
    case GST_VIDEO_FORMAT_RGBx:
    case GST_VIDEO_FORMAT_RGBA:
    case GST_VIDEO_FORMAT_RGB16:
      frag_prog = (gchar *) upload->priv->COPY;
      free_frag_prog = FALSE;
      upload->priv->n_textures = 1;
      break;
    case GST_VIDEO_FORMAT_YUY2:
      frag_prog = g_strdup_printf (upload->priv->YUY2_UYVY, 'r', 'g', 'a');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 2;
      break;
    case GST_VIDEO_FORMAT_UYVY:
      frag_prog = g_strdup_printf (upload->priv->YUY2_UYVY, 'a', 'r', 'b');
      free_frag_prog = TRUE;
      upload->priv->n_textures = 2;
      break;
    default:
      g_assert_not_reached ();
      break;
  }

  res =
      _create_shader (context, upload->priv->vert_shader, frag_prog,
      &upload->shader);
  if (free_frag_prog)
    g_free (frag_prog);
  frag_prog = NULL;
  if (!res)
    goto error;

  upload->shader_attr_position_loc =
      gst_gl_shader_get_attribute_location (upload->shader, "a_position");
  upload->shader_attr_texture_loc =
      gst_gl_shader_get_attribute_location (upload->shader, "a_texcoord");

  if (!_do_upload_make (context, upload))
    goto error;

  upload->priv->result = TRUE;
  return;

error:
  upload->priv->result = FALSE;
}


/* called by _init_upload (in the gl thread) */
gboolean
_init_upload_fbo (GstGLContext * context, GstGLUpload * upload)
{
  GstGLFuncs *gl;
  guint out_width, out_height;
  GLuint fake_texture = 0;      /* a FBO must hava texture to init */

  gl = context->gl_vtable;

  out_width = GST_VIDEO_INFO_WIDTH (&upload->out_info);
  out_height = GST_VIDEO_INFO_HEIGHT (&upload->out_info);

  if (!gl->GenFramebuffers) {
    /* turn off the pipeline because Frame buffer object is a not present */
    gst_gl_context_set_error (context,
        "Context, EXT_framebuffer_object supported: no");
    return FALSE;
  }

  GST_INFO ("Context, EXT_framebuffer_object supported: yes");

  /* setup FBO */
  gl->GenFramebuffers (1, &upload->fbo);
  gl->BindFramebuffer (GL_FRAMEBUFFER, upload->fbo);

  /* setup the render buffer for depth */
  gl->GenRenderbuffers (1, &upload->depth_buffer);
  gl->BindRenderbuffer (GL_RENDERBUFFER, upload->depth_buffer);
  if (USING_OPENGL (context)) {
    gl->RenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_COMPONENT,
        out_width, out_height);
    gl->RenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH24_STENCIL8,
        out_width, out_height);
  }
  if (USING_GLES2 (context)) {
    gl->RenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
        out_width, out_height);
  }

  /* a fake texture is attached to the upload FBO (cannot init without it) */
  gl->GenTextures (1, &fake_texture);
  gl->BindTexture (GL_TEXTURE_2D, fake_texture);
  gl->TexImage2D (GL_TEXTURE_2D, 0, GL_RGBA8, out_width, out_height,
      0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
  gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

  /* attach the texture to the FBO to renderer to */
  gl->FramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
      GL_TEXTURE_2D, fake_texture, 0);

  /* attach the depth render buffer to the FBO */
  gl->FramebufferRenderbuffer (GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
      GL_RENDERBUFFER, upload->depth_buffer);

  if (USING_OPENGL (context)) {
    gl->FramebufferRenderbuffer (GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
        GL_RENDERBUFFER, upload->depth_buffer);
  }

  if (!gst_gl_context_check_framebuffer_status (context)) {
    gst_gl_context_set_error (context, "GL framebuffer status incomplete");
    return FALSE;
  }

  /* unbind the FBO */
  gl->BindFramebuffer (GL_FRAMEBUFFER, 0);

  gl->DeleteTextures (1, &fake_texture);

  return TRUE;
}

/* Called by the idle function in the gl thread */
void
_do_upload (GstGLContext * context, GstGLUpload * upload)
{
  guint in_width, in_height, out_width, out_height;

  out_width = GST_VIDEO_INFO_WIDTH (&upload->out_info);
  out_height = GST_VIDEO_INFO_HEIGHT (&upload->out_info);
  in_width = GST_VIDEO_INFO_WIDTH (&upload->in_info);
  in_height = GST_VIDEO_INFO_HEIGHT (&upload->in_info);

  GST_TRACE ("uploading to texture:%u dimensions:%ux%u, "
      "from textures:%u,%u,%u dimensions:%ux%u", upload->out_texture,
      out_width, out_height, upload->in_texture[0], upload->in_texture[1],
      upload->in_texture[2], in_width, in_height);

  if (!_do_upload_fill (context, upload))
    goto error;

  if (!upload->priv->draw (context, upload))
    goto error;

  upload->priv->result = TRUE;
  return;

error:
  {
    upload->priv->result = FALSE;
    return;
  }
}

static inline guint
_gl_format_n_components (GLenum format)
{
  switch (format) {
    case GL_RGBA:
      return 4;
    case GL_RGB:
      return 3;
    case GL_LUMINANCE_ALPHA:
      return 2;
    case GL_LUMINANCE:
      return 1;
    default:
      return 1;
  }
}

/* called by gst_gl_context_thread_do_upload (in the gl thread) */
gboolean
_do_upload_make (GstGLContext * context, GstGLUpload * upload)
{
  GstGLFuncs *gl;
  GstVideoFormat v_format;
  guint in_height;
  struct TexData *tex = upload->priv->texture_info;
  guint i;

  gl = context->gl_vtable;

  in_height = GST_VIDEO_INFO_HEIGHT (&upload->in_info);
  v_format = GST_VIDEO_INFO_FORMAT (&upload->in_info);

  switch (v_format) {
    case GST_VIDEO_FORMAT_RGBx:
    case GST_VIDEO_FORMAT_BGRx:
    case GST_VIDEO_FORMAT_xRGB:
    case GST_VIDEO_FORMAT_xBGR:
    case GST_VIDEO_FORMAT_RGBA:
    case GST_VIDEO_FORMAT_BGRA:
    case GST_VIDEO_FORMAT_ARGB:
    case GST_VIDEO_FORMAT_ABGR:
    case GST_VIDEO_FORMAT_AYUV:
      tex[0].internal_format = GL_RGBA;
      tex[0].format = GL_RGBA;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "tex";
      break;
    case GST_VIDEO_FORMAT_RGB:
    case GST_VIDEO_FORMAT_BGR:
      tex[0].internal_format = GL_RGB;
      tex[0].format = GL_RGB;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "tex";
      break;
    case GST_VIDEO_FORMAT_GRAY8:
      tex[0].internal_format = GL_LUMINANCE;
      tex[0].format = GL_LUMINANCE;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "tex";
      break;
    case GST_VIDEO_FORMAT_GRAY16_BE:
    case GST_VIDEO_FORMAT_GRAY16_LE:
      tex[0].internal_format = GL_LUMINANCE_ALPHA;
      tex[0].format = GL_LUMINANCE_ALPHA;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "tex";
      break;
    case GST_VIDEO_FORMAT_YUY2:
    case GST_VIDEO_FORMAT_UYVY:
      tex[0].internal_format = GL_LUMINANCE_ALPHA;
      tex[0].format = GL_LUMINANCE_ALPHA;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "Ytex";
      tex[1].internal_format = GL_RGBA8;
      tex[1].format = GL_RGBA;
      tex[1].type = GL_UNSIGNED_BYTE;
      tex[1].height = in_height;
      tex[1].shader_name = "UVtex";
      break;
    case GST_VIDEO_FORMAT_NV12:
    case GST_VIDEO_FORMAT_NV21:
      tex[0].internal_format = GL_LUMINANCE;
      tex[0].format = GL_LUMINANCE;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "Ytex";
      tex[1].internal_format = GL_LUMINANCE_ALPHA;
      tex[1].format = GL_LUMINANCE_ALPHA;
      tex[1].type = GL_UNSIGNED_BYTE;
      tex[1].height = GST_ROUND_UP_2 (in_height) / 2;
      tex[1].shader_name = "UVtex";
      break;
    case GST_VIDEO_FORMAT_Y444:
    case GST_VIDEO_FORMAT_Y42B:
    case GST_VIDEO_FORMAT_Y41B:
      tex[0].internal_format = GL_LUMINANCE;
      tex[0].format = GL_LUMINANCE;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "Ytex";
      tex[1].internal_format = GL_LUMINANCE;
      tex[1].format = GL_LUMINANCE;
      tex[1].type = GL_UNSIGNED_BYTE;
      tex[1].height = in_height;
      tex[1].shader_name = "Utex";
      tex[2].internal_format = GL_LUMINANCE;
      tex[2].format = GL_LUMINANCE;
      tex[2].type = GL_UNSIGNED_BYTE;
      tex[2].height = in_height;
      tex[2].shader_name = "Vtex";
      break;
    case GST_VIDEO_FORMAT_I420:
    case GST_VIDEO_FORMAT_YV12:
      tex[0].internal_format = GL_LUMINANCE;
      tex[0].format = GL_LUMINANCE;
      tex[0].type = GL_UNSIGNED_BYTE;
      tex[0].height = in_height;
      tex[0].shader_name = "Ytex";
      tex[1].internal_format = GL_LUMINANCE;
      tex[1].format = GL_LUMINANCE;
      tex[1].type = GL_UNSIGNED_BYTE;
      tex[1].height = GST_ROUND_UP_2 (in_height) / 2;
      tex[1].shader_name = "Utex";
      tex[2].internal_format = GL_LUMINANCE;
      tex[2].format = GL_LUMINANCE;
      tex[2].type = GL_UNSIGNED_BYTE;
      tex[2].height = GST_ROUND_UP_2 (in_height) / 2;
      tex[2].shader_name = "Vtex";
      break;
    default:
      gst_gl_context_set_error (context, "Unsupported upload video format %d",
          v_format);
      g_assert_not_reached ();
      break;
  }

  for (i = 0; i < upload->priv->n_textures; i++) {
    guint plane_stride, plane_width;

    if (GST_VIDEO_INFO_IS_YUV (&upload->in_info))
      /* For now component width and plane width are the same and the
       * plane-component mapping matches
       */
      plane_width = GST_VIDEO_INFO_COMP_WIDTH (&upload->in_info, i);
    else                        /* RGB, GRAY */
      plane_width = GST_VIDEO_INFO_WIDTH (&upload->in_info);
    plane_stride = GST_VIDEO_INFO_PLANE_STRIDE (&upload->in_info, i);

    /* YUV interleaved packed formats require special attention as we upload
     * multiple textures from the same plane.
     */
    if (v_format == GST_VIDEO_FORMAT_YUY2 || v_format == GST_VIDEO_FORMAT_UYVY) {
      if (i == 1)
        plane_stride = GST_VIDEO_INFO_COMP_STRIDE (&upload->in_info, 1);
    }

    tex[i].width = plane_width;
    tex[i].tex_scaling[0] = 1.0f;
    tex[i].tex_scaling[1] = 1.0f;

#if GST_GL_HAVE_OPENGL || GST_GL_HAVE_GLES3
    if (USING_OPENGL (context) || USING_GLES3 (context)) {
      guint n_gl_comps = _gl_format_n_components (tex[i].format);

      tex[i].unpack_length = plane_stride / n_gl_comps;
    }
#endif
#if GST_GL_HAVE_GLES2
    if (USING_GLES2 (context)) {
      guint pstride, n_planes;
      guint j = 8;

      pstride = GST_VIDEO_INFO_COMP_PSTRIDE (&upload->in_info, i);
      n_planes = GST_VIDEO_INFO_N_PLANES (&upload->in_info);

      while (j >= pstride) {
        /* GST_ROUND_UP_j(plane_width * pstride) */
        guint round_up_j = ((plane_width * pstride) + j - 1) & ~(j - 1);

        if (round_up_j == plane_stride) {
          GST_LOG ("Found alignment of %u for plane %u based on width (with "
              "plane width:%u, plane stride:%u and pixel stride:%u. "
              "RU%u(%u*%u) = %u)", j, i, plane_width, plane_stride, pstride,
              j, plane_width, pstride, round_up_j);

          tex[i].unpack_length = j;
          break;
        }
        j >>= 1;
      }

      if (j < pstride) {
        /* Failed to find a suitable alignment, try based on plane_stride and
         * scale in the shader.  Useful for alignments that are greater than 8.
         */
        j = 8;

        while (j >= n_planes) {
          /* GST_ROUND_UP_j(plane_stride) */
          guint round_up_j = ((plane_stride) + j - 1) & ~(j - 1);

          if (round_up_j == plane_stride) {
            GST_LOG ("Found alignment of %u for plane %u based on stride "
                "(with plane stride:%u and pixel stride:%u. RU%u(%u) = %u)",
                j, i, plane_stride, pstride, j, plane_stride, round_up_j);

            tex[i].unpack_length = j;
            tex[i].tex_scaling[0] =
                (gfloat) (plane_width * pstride) / (gfloat) plane_stride;
            break;
          }
          j >>= 1;
        }

        if (j < n_planes) {
          GST_ERROR
              ("Failed to find matching alignment for plane %u, Image may "
              "look corrupted. plane width:%u, plane stride:%u and pixel "
              "stride:%u", i, plane_width, plane_stride, pstride);
        }
      }
    }
#endif

    gl->GenTextures (1, &upload->in_texture[i]);
    gl->BindTexture (GL_TEXTURE_2D, upload->in_texture[i]);

    gl->TexImage2D (GL_TEXTURE_2D, 0, tex[i].internal_format,
        tex[i].width, tex[i].height, 0, tex[i].format, tex[i].type, NULL);
  }

  return TRUE;
}


/* called by gst_gl_context_thread_do_upload (in the gl thread) */
gboolean
_do_upload_fill (GstGLContext * context, GstGLUpload * upload)
{
  guint i;
  GstVideoFormat v_format;
  struct TexData *tex = upload->priv->texture_info;
  const GstGLFuncs *gl = context->gl_vtable;

  v_format = GST_VIDEO_INFO_FORMAT (&upload->in_info);

  for (i = 0; i < upload->priv->n_textures; i++) {
    guint data_i = i;

    /* upload from the same plane */
    if (v_format == GST_VIDEO_FORMAT_YUY2 || v_format == GST_VIDEO_FORMAT_UYVY)
      data_i = 0;

    /* YV12 is the same as I420 except that planes 1+2 are swapped */
    if (v_format == GST_VIDEO_FORMAT_YV12) {
      if (i == 1)
        data_i = 2;
      else if (i == 2)
        data_i = 1;
    }
#if GST_GL_HAVE_OPENGL || GST_GL_HAVE_GLES3
    if (USING_OPENGL (context) || USING_GLES3 (context)) {
      gl->PixelStorei (GL_UNPACK_ROW_LENGTH, tex[i].unpack_length);
    }
#endif
#if GST_GL_HAVE_GLES2
    if (USING_GLES2 (context)) {
      gl->PixelStorei (GL_UNPACK_ALIGNMENT, tex[i].unpack_length);
    }
#endif

    GST_LOG ("data transfer for texture no %u, id:%u, %ux%u %u", i,
        upload->in_texture[i], tex[i].width, tex[i].height, data_i);

    gl->BindTexture (GL_TEXTURE_2D, upload->in_texture[i]);
    gl->TexSubImage2D (GL_TEXTURE_2D, 0, 0, 0, tex[i].width, tex[i].height,
        tex[i].format, tex[i].type, upload->data[data_i]);
  }

  /* Reset to default values */
#if GST_GL_HAVE_OPENGL || GST_GL_HAVE_GLES3
  if (USING_OPENGL (context) || USING_GLES3 (context)) {
    gl->PixelStorei (GL_UNPACK_ROW_LENGTH, 0);
  }
#endif
#if GST_GL_HAVE_GLES2
  if (USING_GLES2 (context)) {
    gl->PixelStorei (GL_UNPACK_ALIGNMENT, 4);
  }
#endif

  /* make sure no texture is in use in our opengl context 
   * in case we want to use the upload texture in an other opengl context
   */
  gl->BindTexture (GL_TEXTURE_2D, 0);

  return TRUE;
}

static gboolean
_do_upload_draw (GstGLContext * context, GstGLUpload * upload)
{
  GstGLFuncs *gl;
  struct TexData *tex = upload->priv->texture_info;
  guint out_width, out_height;
  const gfloat *cms_offset;
  const gfloat *cms_rcoeff;
  const gfloat *cms_gcoeff;
  const gfloat *cms_bcoeff;
  gint i;

  GLint viewport_dim[4];

  const GLfloat vVertices[] = { 1.0f, -1.0f, 0.0f,
    1.0f, 0.0f,
    -1.0f, -1.0f, 0.0f,
    0.0f, 0.0f,
    -1.0f, 1.0f, 0.0f,
    0.0f, 1.0f,
    1.0f, 1.0f, 0.0f,
    1.0f, 1.0f
  };

  GLushort indices[] = { 0, 1, 2, 0, 2, 3 };

  gl = context->gl_vtable;

  out_width = GST_VIDEO_INFO_WIDTH (&upload->out_info);
  out_height = GST_VIDEO_INFO_HEIGHT (&upload->out_info);

  if (gst_video_colorimetry_matches (&upload->in_info.colorimetry,
          GST_VIDEO_COLORIMETRY_BT709)) {
    cms_offset = bt709_offset;
    cms_rcoeff = bt709_rcoeff;
    cms_gcoeff = bt709_gcoeff;
    cms_bcoeff = bt709_bcoeff;
  } else if (gst_video_colorimetry_matches (&upload->in_info.colorimetry,
          GST_VIDEO_COLORIMETRY_BT601)) {
    cms_offset = bt601_offset;
    cms_rcoeff = bt601_rcoeff;
    cms_gcoeff = bt601_gcoeff;
    cms_bcoeff = bt601_bcoeff;
  } else {
    /* defaults */
    cms_offset = bt601_offset;
    cms_rcoeff = bt601_rcoeff;
    cms_gcoeff = bt601_gcoeff;
    cms_bcoeff = bt601_bcoeff;
  }

  gl->BindFramebuffer (GL_FRAMEBUFFER, upload->fbo);

  /* setup a texture to render to */
  gl->BindTexture (GL_TEXTURE_2D, upload->out_texture);

  /* attach the texture to the FBO to renderer to */
  gl->FramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
      GL_TEXTURE_2D, upload->out_texture, 0);

  gst_gl_context_clear_shader (context);

  gl->GetIntegerv (GL_VIEWPORT, viewport_dim);

  gl->Viewport (0, 0, out_width, out_height);

  gl->ClearColor (0.0, 0.0, 0.0, 0.0);
  gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  gst_gl_shader_use (upload->shader);

  gl->VertexAttribPointer (upload->shader_attr_position_loc, 3,
      GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), vVertices);
  gl->VertexAttribPointer (upload->shader_attr_texture_loc, 2,
      GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), &vVertices[3]);

  gl->EnableVertexAttribArray (upload->shader_attr_position_loc);
  gl->EnableVertexAttribArray (upload->shader_attr_texture_loc);

  gst_gl_shader_set_uniform_3fv (upload->shader, "offset", 1,
      (gfloat *) cms_offset);
  gst_gl_shader_set_uniform_3fv (upload->shader, "rcoeff", 1,
      (gfloat *) cms_rcoeff);
  gst_gl_shader_set_uniform_3fv (upload->shader, "gcoeff", 1,
      (gfloat *) cms_gcoeff);
  gst_gl_shader_set_uniform_3fv (upload->shader, "bcoeff", 1,
      (gfloat *) cms_bcoeff);

  for (i = upload->priv->n_textures - 1; i >= 0; i--) {
    gchar *scale_name = g_strdup_printf ("tex_scale%u", i);

    gl->ActiveTexture (GL_TEXTURE0 + i);
    gst_gl_shader_set_uniform_1i (upload->shader, tex[i].shader_name, i);
    gst_gl_shader_set_uniform_2fv (upload->shader, scale_name, 1,
        &tex[i].tex_scaling[0]);

    g_free (scale_name);

    gl->BindTexture (GL_TEXTURE_2D, upload->in_texture[i]);
    gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    gl->TexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  }

  gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);

  /* we are done with the shader */
  gst_gl_context_clear_shader (context);

  gl->Viewport (viewport_dim[0], viewport_dim[1], viewport_dim[2],
      viewport_dim[3]);

  gst_gl_context_check_framebuffer_status (context);

  gl->BindFramebuffer (GL_FRAMEBUFFER, 0);

  return TRUE;
}