gl: add support for GBR and GBRA

example pipeline:
gst-launch-1.0 videotestsrc ! video/x-raw,format=GBR ! glimagesink

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/789>

gst-libs/gst/gl/glprototypes/gstgl_gles2compat.h

@@ -42,6 +42,9 @@ G_BEGIN_DECLS
 #ifndef GL_COLOR_ATTACHMENT2
 #define GL_COLOR_ATTACHMENT2 0x8CE2
 #endif
+#ifndef GL_COLOR_ATTACHMENT3
+#define GL_COLOR_ATTACHMENT3 0x8CE3
+#endif
 #ifndef GL_TEXTURE_ENV
 #define GL_TEXTURE_ENV 0
 #endif

gst-libs/gst/gl/gstglcolorconvert.c

@@ -129,6 +129,7 @@ static const gfloat from_rgb_bt709_vcoeff[] = {0.440654f, -0.400285f, -0.040370f
     "uniform vec2 tex_scale0;\n" \
     "uniform vec2 tex_scale1;\n" \
     "uniform vec2 tex_scale2;\n" \
+    "uniform vec2 tex_scale3;\n" \
     "uniform float width;\n"     \
     "uniform float height;\n"    \
     "uniform float poffset_x;\n" \
@@ -391,6 +392,57 @@ static const struct shader_templ templ_RGB_to_YUY2_UYVY =
     GST_GL_TEXTURE_TARGET_2D
   };
 
+/* PLANAR RGB to PACKED RGB conversion */
+static const gchar templ_PLANAR_RGB_to_PACKED_RGB_BODY[] =
+    "vec4 rgba;\n"
+    "rgba.r = texture2D(Rtex, texcoord * tex_scale0).r;\n"
+    "rgba.g = texture2D(Gtex, texcoord * tex_scale1).r;\n"
+    "rgba.b = texture2D(Btex, texcoord * tex_scale2).r;\n"
+    "%s\n" /* alpha channel */
+    "gl_FragColor=vec4(rgba.%c,rgba.%c,rgba.%c,rgba.%c);\n";
+
+static const struct shader_templ templ_PLANAR_RGB_to_PACKED_RGB =
+  { NULL,
+    DEFAULT_UNIFORMS "uniform sampler2D Rtex, Gtex, Btex, Atex;\n",
+    { NULL, },
+    GST_GL_TEXTURE_TARGET_2D
+  };
+
+/* PACKED RGB to PLANAR RGB conversion */
+static const gchar templ_PACKED_RGB_to_PLANAR_RGB_BODY[] =
+    "vec4 rgba;\n"
+    "rgba = texture2D(tex, texcoord).%c%c%c%c;\n"
+    "gl_FragData[0] = vec4(rgba.r, 0, 0, 1.0);\n"
+    "gl_FragData[1] = vec4(rgba.g, 0, 0, 1.0);\n"
+    "gl_FragData[2] = vec4(rgba.b, 0, 0, 1.0);\n"
+    "%s\n";
+
+static const struct shader_templ templ_PACKED_RGB_to_PLANAR_RGB =
+  { NULL,
+    DEFAULT_UNIFORMS "uniform sampler2D tex;\n",
+    { NULL, },
+    GST_GL_TEXTURE_TARGET_2D
+  };
+
+/* PLANAR RGB to PLANAR RGB conversion */
+static const gchar templ_PLANAR_RGB_to_PLANAR_RGB_BODY[] =
+    "vec4 rgba;\n"
+    "rgba.r = texture2D(Rtex, texcoord * tex_scale0).r;\n"
+    "rgba.g = texture2D(Gtex, texcoord * tex_scale1).r;\n"
+    "rgba.b = texture2D(Btex, texcoord * tex_scale2).r;\n"
+    "%s\n" /* alpha channel */
+    "gl_FragData[0] = vec4(rgba.%c, 0, 0, 1.0);\n"
+    "gl_FragData[1] = vec4(rgba.%c, 0, 0, 1.0);\n"
+    "gl_FragData[2] = vec4(rgba.%c, 0, 0, 1.0);\n"
+    "%s\n";
+
+static const struct shader_templ templ_PLANAR_RGB_to_PLANAR_RGB =
+  { NULL,
+    DEFAULT_UNIFORMS "uniform sampler2D Rtex, Gtex, Btex, Atex;\n",
+    { NULL, },
+    GST_GL_TEXTURE_TARGET_2D
+  };
+
 static const gchar text_vertex_shader[] =
     "attribute vec4 a_position;   \n"
     "attribute vec2 a_texcoord;   \n"
@@ -912,8 +964,8 @@ _init_supported_formats (GstGLContext * context, gboolean output,
 
   /* Always supported input formats or output with multiple draw buffers */
   if (!output || (!context || context->gl_vtable->DrawBuffers))
-    _append_value_string_list (supported_formats, "Y444", "I420", "YV12",
-        "Y42B", "Y41B", "NV12", "NV21", "NV16", "NV61", NULL);
+    _append_value_string_list (supported_formats, "GBRA", "GBR", "Y444",
+        "I420", "YV12", "Y42B", "Y41B", "NV12", "NV21", "NV16", "NV61", NULL);
 
   /* Requires reading from a RG/LA framebuffer... */
   if (!context || (USING_GLES3 (context) || USING_OPENGL (context)))
@@ -1411,6 +1463,26 @@ _is_RGBx (GstVideoFormat v_format)
   }
 }
 
+static inline gboolean
+_is_planar_rgb (GstVideoFormat v_format)
+{
+  switch (v_format) {
+    case GST_VIDEO_FORMAT_GBR:
+    case GST_VIDEO_FORMAT_GBR_10BE:
+    case GST_VIDEO_FORMAT_GBR_10LE:
+    case GST_VIDEO_FORMAT_GBRA:
+    case GST_VIDEO_FORMAT_GBRA_10BE:
+    case GST_VIDEO_FORMAT_GBRA_10LE:
+    case GST_VIDEO_FORMAT_GBR_12BE:
+    case GST_VIDEO_FORMAT_GBR_12LE:
+    case GST_VIDEO_FORMAT_GBRA_12BE:
+    case GST_VIDEO_FORMAT_GBRA_12LE:
+      return TRUE;
+    default:
+      return FALSE;
+  }
+}
+
 static inline gchar
 _index_to_shader_swizzle (int idx)
 {
@@ -1572,15 +1644,129 @@ _get_n_textures (GstVideoFormat v_format)
     case GST_VIDEO_FORMAT_Y42B:
     case GST_VIDEO_FORMAT_Y41B:
     case GST_VIDEO_FORMAT_YV12:
+    case GST_VIDEO_FORMAT_GBR:
       return 3;
+    case GST_VIDEO_FORMAT_GBRA:
+      return 4;
     default:
       g_assert_not_reached ();
       return 0;
   }
 }
 
 static void
-_RGB_to_RGB (GstGLColorConvert * convert)
+_PLANAR_RGB_to_PLANAR_RGB (GstGLColorConvert * convert)
+{
+  struct ConvertInfo *info = &convert->priv->convert_info;
+  GstVideoFormat in_format = GST_VIDEO_INFO_FORMAT (&convert->in_info);
+  const gchar *in_format_str = gst_video_format_to_string (in_format);
+  GstVideoFormat out_format = GST_VIDEO_INFO_FORMAT (&convert->out_info);
+  const gchar *out_format_str = gst_video_format_to_string (out_format);
+  gchar *pixel_order = _RGB_pixel_order (in_format_str, out_format_str);
+  const gchar *in_alpha = NULL;
+  gchar *out_alpha = NULL;
+
+  info->frag_prog = NULL;
+
+  if (GST_VIDEO_INFO_HAS_ALPHA (&convert->in_info)) {
+    in_alpha = "rgba.a = texture2D(Atex, texcoord * tex_scale3).r;";
+    info->shader_tex_names[0] = "Rtex";
+    info->shader_tex_names[1] = "Gtex";
+    info->shader_tex_names[2] = "Btex";
+    info->shader_tex_names[3] = "Atex";
+  } else {
+    in_alpha = "rgba.a = 1.0;";
+    info->shader_tex_names[0] = "Rtex";
+    info->shader_tex_names[1] = "Gtex";
+    info->shader_tex_names[2] = "Btex";
+  }
+
+  if (GST_VIDEO_INFO_HAS_ALPHA (&convert->out_info)) {
+    out_alpha =
+        g_strdup_printf ("gl_FragData[3] = vec4(rgba.%c, 0, 0, 1.0);",
+        pixel_order[3]);
+    info->out_n_textures = 4;
+  } else {
+    out_alpha = g_strdup_printf ("\n");
+    info->out_n_textures = 3;
+  }
+
+  info->templ = &templ_PLANAR_RGB_to_PLANAR_RGB;
+  info->frag_body =
+      g_strdup_printf (templ_PLANAR_RGB_to_PLANAR_RGB_BODY, in_alpha,
+      pixel_order[0], pixel_order[1], pixel_order[2], out_alpha);
+
+  g_free (out_alpha);
+  g_free (pixel_order);
+}
+
+static void
+_PLANAR_RGB_to_PACKED_RGB (GstGLColorConvert * convert)
+{
+  struct ConvertInfo *info = &convert->priv->convert_info;
+  GstVideoFormat in_format = GST_VIDEO_INFO_FORMAT (&convert->in_info);
+  const gchar *in_format_str = gst_video_format_to_string (in_format);
+  GstVideoFormat out_format = GST_VIDEO_INFO_FORMAT (&convert->out_info);
+  const gchar *out_format_str = gst_video_format_to_string (out_format);
+  gchar *pixel_order = _RGB_pixel_order (in_format_str, out_format_str);
+  const gchar *alpha = NULL;
+
+  info->frag_prog = NULL;
+
+  if (GST_VIDEO_INFO_HAS_ALPHA (&convert->in_info)) {
+    alpha = "rgba.a = texture2D(Atex, texcoord * tex_scale3).r;";
+    info->shader_tex_names[0] = "Rtex";
+    info->shader_tex_names[1] = "Gtex";
+    info->shader_tex_names[2] = "Btex";
+    info->shader_tex_names[3] = "Atex";
+  } else {
+    alpha = "rgba.a = 1.0;";
+    info->shader_tex_names[0] = "Rtex";
+    info->shader_tex_names[1] = "Gtex";
+    info->shader_tex_names[2] = "Btex";
+  }
+
+  info->out_n_textures = 1;
+
+  info->templ = &templ_PLANAR_RGB_to_PACKED_RGB;
+  info->frag_body = g_strdup_printf (templ_PLANAR_RGB_to_PACKED_RGB_BODY, alpha,
+      pixel_order[0], pixel_order[1], pixel_order[2], pixel_order[3]);
+
+  g_free (pixel_order);
+}
+
+static void
+_PACKED_RGB_to_PLANAR_RGB (GstGLColorConvert * convert)
+{
+  struct ConvertInfo *info = &convert->priv->convert_info;
+  GstVideoFormat in_format = GST_VIDEO_INFO_FORMAT (&convert->in_info);
+  const gchar *in_format_str = gst_video_format_to_string (in_format);
+  GstVideoFormat out_format = GST_VIDEO_INFO_FORMAT (&convert->out_info);
+  const gchar *out_format_str = gst_video_format_to_string (out_format);
+  gchar *pixel_order = _RGB_pixel_order (in_format_str, out_format_str);
+  const gchar *alpha;
+
+  info->frag_prog = NULL;
+  info->shader_tex_names[0] = "tex";
+
+  if (GST_VIDEO_INFO_HAS_ALPHA (&convert->out_info)) {
+    alpha = "gl_FragData[3] = vec4(rgba.a, 0, 0, 1.0);";
+    info->out_n_textures = 4;
+  } else {
+    alpha = "";
+    info->out_n_textures = 3;
+  }
+
+  info->templ = &templ_PACKED_RGB_to_PLANAR_RGB;
+  info->frag_body = g_strdup_printf (templ_PACKED_RGB_to_PLANAR_RGB_BODY,
+      pixel_order[0], pixel_order[1], pixel_order[2], pixel_order[3], alpha);
+  info->shader_tex_names[0] = "tex";
+
+  g_free (pixel_order);
+}
+
+static void
+_PACKED_RGB_to_PACKED_RGB (GstGLColorConvert * convert)
 {
   struct ConvertInfo *info = &convert->priv->convert_info;
   GstVideoFormat in_format = GST_VIDEO_INFO_FORMAT (&convert->in_info);
@@ -1610,6 +1796,25 @@ _RGB_to_RGB (GstGLColorConvert * convert)
   g_free (pixel_order);
 }
 
+static void
+_RGB_to_RGB (GstGLColorConvert * convert)
+{
+  GstVideoFormat in_format = GST_VIDEO_INFO_FORMAT (&convert->in_info);
+  GstVideoFormat out_format = GST_VIDEO_INFO_FORMAT (&convert->out_info);
+
+  if (_is_planar_rgb (in_format)) {
+    if (_is_planar_rgb (out_format))
+      _PLANAR_RGB_to_PLANAR_RGB (convert);
+    else
+      _PLANAR_RGB_to_PACKED_RGB (convert);
+  } else {
+    if (_is_planar_rgb (out_format))
+      _PACKED_RGB_to_PLANAR_RGB (convert);
+    else
+      _PACKED_RGB_to_PACKED_RGB (convert);
+  }
+}
+
 static void
 _YUV_to_RGB (GstGLColorConvert * convert)
 {
@@ -2699,7 +2904,8 @@ _do_convert_draw (GstGLContext * context, GstGLColorConvert * convert)
   GLenum multipleRT[] = {
     GL_COLOR_ATTACHMENT0,
     GL_COLOR_ATTACHMENT1,
-    GL_COLOR_ATTACHMENT2
+    GL_COLOR_ATTACHMENT2,
+    GL_COLOR_ATTACHMENT3
   };
 
   gl = context->gl_vtable;

gst-libs/gst/gl/gstglcolorconvert.h

@@ -100,7 +100,7 @@ struct _GstGLColorConvertClass
  * The currently supported formats that can be converted
  */
 #define GST_GL_COLOR_CONVERT_FORMATS "{ RGBA, RGB, RGBx, BGR, BGRx, BGRA, xRGB, " \
-                               "xBGR, ARGB, ABGR, Y444, I420, YV12, Y42B, " \
+                               "xBGR, ARGB, ABGR, GBRA, GBR, Y444, I420, YV12, Y42B, " \
                                "Y41B, NV12, NV21, NV16, NV61, YUY2, UYVY, Y210, AYUV, " \
                                "VUYA, Y410, GRAY8, GRAY16_LE, GRAY16_BE, " \
                                "RGB16, BGR16, ARGB64 " \

gst-libs/gst/gl/gstglformat.c

@@ -220,6 +220,9 @@ gst_gl_format_from_video_info (GstGLContext * context, GstVideoInfo * vinfo,
     case GST_VIDEO_FORMAT_Y412_LE:
     case GST_VIDEO_FORMAT_Y412_BE:
       return GST_GL_RGBA16;
+    case GST_VIDEO_FORMAT_GBR:
+    case GST_VIDEO_FORMAT_GBRA:
+      return GST_GL_R8;
     default:
       n_plane_components = 4;
       g_assert_not_reached ();

gst-libs/gst/gl/gstglmemory.h

@@ -62,7 +62,7 @@ GType gst_gl_memory_allocator_get_type(void);
  * List of video formats that are supported by #GstGLMemory
  */
 #define GST_GL_MEMORY_VIDEO_FORMATS_STR \
-    "{ RGBA, BGRA, RGBx, BGRx, ARGB, ABGR, xRGB, xBGR, RGB, BGR, RGB16, BGR16, " \
+    "{ RGBA, BGRA, RGBx, BGRx, ARGB, ABGR, xRGB, xBGR, GBRA, GBR, RGB, BGR, RGB16, BGR16, " \
     "AYUV, VUYA, Y410, I420, YV12, NV12, NV21, NV16, NV61, YUY2, UYVY, Y210, Y41B, " \
     "Y42B, Y444, GRAY8, GRAY16_LE, GRAY16_BE, ARGB64" \
     GST_GL_MEMORY_VIDEO_EXT_FORMATS "}"