gldownload: Add support for downloading multi-planar formats to GLES2download-planar

https://bugzilla.gnome.org/show_bug.cgi?id=704222

2 files changed, 88 insertions, 13 deletions

diff --git a/gst-libs/gst/gl/gstgldownload.c b/gst-libs/gst/gl/gstgldownload.c
index 7439282..3681393 100644
--- a/gst-libs/gst/gl/gstgldownload.c
+++ b/gst-libs/gst/gl/gstgldownload.c
@@ -163,10 +163,29 @@ static const gchar *text_shader_YUY2_UYVY_gles2 =
     "  gl_FragColor=vec4(%s);\n"
     "}\n";
 
-/* no OpenGL ES 2.0 support because for now it's not possible
- * to attach multiple textures to a frame buffer object
- */
-#define text_shader_I420_YV12_gles2 NULL
+static const gchar *text_shader_I420_YV12_gles2 =
+    "precision mediump float;\n"
+    "varying vec2 v_texCoord;\n"
+    "uniform sampler2D tex;\n"
+    "uniform float w, h;\n"
+    RGB_TO_YUV_COEFFICIENTS
+    "void main(void) {\n"
+    "  vec3 rgb1, rgb2;\n"
+    "  float fx,fy,y,u,v;\n"
+    "  fx = v_texCoord.x;\n"
+    "  fy = v_texCoord.y;\n"
+    "  rgb1=texture2D(tex,vec2(fx, fy)).rgb;\n"
+    "  rgb2=texture2D(tex,vec2(fx*2.0, fy*2.0)).rgb;\n"
+    "  y=dot(rgb1, ycoeff);\n"
+    "  u=dot(rgb2, ucoeff);\n"
+    "  v=dot(rgb2, vcoeff);\n"
+    "  y+=offset.x;\n"
+    "  u+=offset.y;\n"
+    "  v+=offset.z;\n"
+    "  gl_FragData[0] = vec4(y, 0.0, 0.0, 1.0);\n"
+    "  gl_FragData[1] = vec4(u, 0.0, 0.0, 1.0);\n"
+    "  gl_FragData[2] = vec4(v, 0.0, 0.0, 1.0);\n"
+    "}\n";
 
 static const gchar *text_shader_AYUV_gles2 =
     "precision mediump float;\n"
@@ -566,6 +585,15 @@ _init_download (GstGLDisplay * display, GstGLDownload * download)
       }
       GST_INFO ("Context, EXT_framebuffer_object supported: yes");
 
+      /* Need the NV extension for multi-planar formats with GLES2,
+       * or need GLES3 */
+      if (USING_GLES2 (display) && GST_VIDEO_INFO_N_PLANES (&download->info)
+          && (!gl->DrawBuffers || !gl->ReadBuffer)) {
+        gst_gl_display_set_error (display,
+            "No glDrawBuffers or glReadBuffer support");
+        goto error;
+      }
+
       /* setup FBO */
       gl->GenFramebuffers (1, &download->fbo);
       gl->BindFramebuffer (GL_FRAMEBUFFER, download->fbo);
@@ -663,10 +691,10 @@ _init_download (GstGLDisplay * display, GstGLDownload * download)
     }
       break;
     default:
-      break;
       gst_gl_display_set_error (display, "Unsupported download video format %d",
           v_format);
       g_assert_not_reached ();
+      break;
   }
 
 no_convert:
@@ -794,8 +822,17 @@ _init_download_shader (GstGLDisplay * display, GstGLDownload * download)
     case GST_VIDEO_FORMAT_I420:
     case GST_VIDEO_FORMAT_YV12:
     {
-      _create_shader (display, download->priv->vert_shader,
-          download->priv->I420_YV12, &download->shader);
+      if (_create_shader (display, download->priv->vert_shader,
+              download->priv->I420_YV12, &download->shader)) {
+        if (USING_GLES2 (display)) {
+          download->shader_attr_position_loc =
+              gst_gl_shader_get_attribute_location (download->shader,
+              "a_position");
+          download->shader_attr_texture_loc =
+              gst_gl_shader_get_attribute_location (download->shader,
+              "a_texCoord");
+        }
+      }
       break;
     }
     case GST_VIDEO_FORMAT_AYUV:
@@ -1167,9 +1204,9 @@ _do_download_draw_yuv_opengl (GstGLDisplay * display, GstGLDownload * download)
       break;
 
     default:
-      break;
       gst_gl_display_set_error (display,
           "Download video format inconsistensy %d", v_format);
+      break;
   }
 
   gl->ClientActiveTexture (GL_TEXTURE0);
@@ -1262,10 +1299,10 @@ _do_download_draw_yuv_opengl (GstGLDisplay * display, GstGLDownload * download)
     }
       break;
     default:
-      break;
       gst_gl_display_set_error (display,
           "Download video format inconsistensy %d", v_format);
       g_assert_not_reached ();
+      break;
   }
   gl->ReadBuffer (GL_NONE);
 
@@ -1285,6 +1322,18 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
 
   GLint viewport_dim[4];
 
+  GLenum singleRT[] = {
+    GL_COLOR_ATTACHMENT0
+  };
+  GLenum multipleRT[] = {
+    GL_COLOR_ATTACHMENT0,
+    GL_COLOR_ATTACHMENT1,
+    GL_COLOR_ATTACHMENT2
+  };
+  GLenum noneRT[] = {
+    GL_NONE
+  };
+
   const GLfloat vVertices[] = { 1.0f, -1.0f, 0.0f,
     1.0f, 0.0f,
     -1.0f, -1.0f, 0.0f,
@@ -1318,6 +1367,9 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
     case GST_VIDEO_FORMAT_UYVY:
     case GST_VIDEO_FORMAT_AYUV:
     {
+      if (gl->DrawBuffers)
+        gl->DrawBuffers (1, singleRT);
+
       gl->ClearColor (0.0, 0.0, 0.0, 0.0);
       gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
@@ -1340,11 +1392,21 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
     case GST_VIDEO_FORMAT_I420:
     case GST_VIDEO_FORMAT_YV12:
     {
+      gl->DrawBuffers (3, multipleRT);
+
       gl->ClearColor (0.0, 0.0, 0.0, 0.0);
       gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
       gst_gl_shader_use (download->shader);
 
+      gl->VertexAttribPointer (download->shader_attr_position_loc, 3,
+          GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), vVertices);
+      gl->VertexAttribPointer (download->shader_attr_texture_loc, 2,
+          GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), &vVertices[3]);
+
+      gl->EnableVertexAttribArray (download->shader_attr_position_loc);
+      gl->EnableVertexAttribArray (download->shader_attr_texture_loc);
+
       gl->ActiveTexture (GL_TEXTURE0);
       gst_gl_shader_set_uniform_1i (download->shader, "tex", 0);
       gst_gl_shader_set_uniform_1f (download->shader, "w", (gfloat) out_width);
@@ -1354,14 +1416,17 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
       break;
 
     default:
-      break;
       gst_gl_display_set_error (display,
           "Download video format inconsistensy %d", v_format);
+      break;
 
   }
 
   gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
 
+  if (gl->DrawBuffers)
+    gl->DrawBuffers (1, noneRT);
+
   /* don't check if GLSL is available
    * because download yuv is not available
    * without GLSL (whereas rgb is)
@@ -1371,6 +1436,9 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
   gl->Viewport (viewport_dim[0], viewport_dim[1], viewport_dim[2],
       viewport_dim[3]);
 
+  if (gl->ReadBuffer)
+    gl->ReadBuffer (GL_COLOR_ATTACHMENT0);
+
   switch (v_format) {
     case GST_VIDEO_FORMAT_AYUV:
 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
@@ -1396,10 +1464,12 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
       gl->ReadPixels (0, 0, out_width, out_height, GL_LUMINANCE,
           GL_UNSIGNED_BYTE, download->data[0]);
 
+      gl->ReadBuffer (GL_COLOR_ATTACHMENT1);
       gl->ReadPixels (0, 0, GST_ROUND_UP_2 (out_width) / 2,
           GST_ROUND_UP_2 (out_height) / 2, GL_LUMINANCE, GL_UNSIGNED_BYTE,
           download->data[1]);
 
+      gl->ReadBuffer (GL_COLOR_ATTACHMENT2);
       gl->ReadPixels (0, 0, GST_ROUND_UP_2 (out_width) / 2,
           GST_ROUND_UP_2 (out_height) / 2, GL_LUMINANCE, GL_UNSIGNED_BYTE,
           download->data[2]);
@@ -1410,22 +1480,27 @@ _do_download_draw_yuv_gles2 (GstGLDisplay * display, GstGLDownload * download)
       gl->ReadPixels (0, 0, out_width, out_height, GL_LUMINANCE,
           GL_UNSIGNED_BYTE, download->data[0]);
 
+      gl->ReadBuffer (GL_COLOR_ATTACHMENT1);
       gl->ReadPixels (0, 0, GST_ROUND_UP_2 (out_width) / 2,
           GST_ROUND_UP_2 (out_height) / 2, GL_LUMINANCE, GL_UNSIGNED_BYTE,
           download->data[2]);
 
+      gl->ReadBuffer (GL_COLOR_ATTACHMENT2);
       gl->ReadPixels (0, 0, GST_ROUND_UP_2 (out_width) / 2,
           GST_ROUND_UP_2 (out_height) / 2, GL_LUMINANCE, GL_UNSIGNED_BYTE,
           download->data[1]);
     }
       break;
     default:
-      break;
       gst_gl_display_set_error (display,
           "Download video format inconsistensy %d", v_format);
       g_assert_not_reached ();
+      break;
   }
 
+  if (gl->ReadBuffer)
+    gl->ReadBuffer (GL_NONE);
+
   gst_gl_display_check_framebuffer_status (display);
   gl->BindFramebuffer (GL_FRAMEBUFFER, 0);
 }
diff --git a/gst-libs/gst/gl/gstgles2.h b/gst-libs/gst/gl/gstgles2.h
index 49e744b..01948c3 100644
--- a/gst-libs/gst/gl/gstgles2.h
+++ b/gst-libs/gst/gl/gstgles2.h
@@ -35,6 +35,8 @@ G_BEGIN_DECLS
 #define GL_BGR GL_RGB
 #define GL_UNSIGNED_INT_8_8_8_8 GL_UNSIGNED_BYTE
 #define GL_UNSIGNED_INT_8_8_8_8_REV GL_UNSIGNED_BYTE
+#define GL_COLOR_ATTACHMENT1 0x8CE1
+#define GL_COLOR_ATTACHMENT2 0x8CE2
 //END FIXME
 
 #define GL_TEXTURE_RECTANGLE_ARB GL_TEXTURE_2D
@@ -46,8 +48,6 @@ G_BEGIN_DECLS
 #define GL_UNSIGNED_SHORT_8_8_MESA 0
 #define GL_UNSIGNED_SHORT_8_8_REV_MESA 0
 
-#define GL_COLOR_ATTACHMENT1 0
-#define GL_COLOR_ATTACHMENT2 0
 #define GL_TEXTURE_ENV 0
 #define GL_TEXTURE_ENV_MODE 0
 #define GL_DEPTH24_STENCIL8 0