WebGL & 16-bit video stream: upload to FLOAT texture.

media/renderers/skcanvas_video_renderer.cc

Index: media/renderers/skcanvas_video_renderer.cc
diff --git a/media/renderers/skcanvas_video_renderer.cc b/media/renderers/skcanvas_video_renderer.cc
index e6ee9d1e12ca16cb01957acd649cdc6034556451..cacee0d44f7b9fbdec9608c74e4ee4c5e170063d 100644
--- a/media/renderers/skcanvas_video_renderer.cc
+++ b/media/renderers/skcanvas_video_renderer.cc
@@ -4,12 +4,14 @@
 
 #include "media/renderers/skcanvas_video_renderer.h"
 
+#include <GLES3/gl3.h>
 #include <limits>
 
 #include "base/macros.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
+#include "media/base/data_buffer.h"
 #include "media/base/video_frame.h"
 #include "media/base/yuv_convert.h"
 #include "skia/ext/texture_handle.h"
@@ -522,24 +524,46 @@ scoped_refptr<VideoFrame> DownShiftHighbitVideoFrame(
   return ret;
 }
 
-// We take the upper 8 bits of 16-bit data and convert it as luminance to ARGB.
-// We loose the precision here, but it is important not to render Y16 as RG_88.
-// To get the full precision use float textures with WebGL1 and e.g. R16UI or
-// R32F textures with WebGL2.
-void ConvertY16ToARGB(const VideoFrame* video_frame,
-                      void* argb_pixels,
-                      size_t argb_row_bytes) {
+void FlipAndConvertY16(const VideoFrame* video_frame,

[hubbe, 2016/11/07 22:16:55]

Add comment.

[aleksandar.stojiljkovic, 2016/11/16 20:01:24]

Done.

+                       uint8_t* out,
+                       unsigned format,
+                       unsigned type,
+                       bool flip_y,
+                       size_t output_row_bytes) {
   const uint8_t* row_head = video_frame->visible_data(0);
-  uint8_t* out = static_cast<uint8_t*>(argb_pixels);
   const size_t stride = video_frame->stride(0);
-  for (int i = 0; i < video_frame->visible_rect().height(); ++i) {
-    uint32_t* rgba = reinterpret_cast<uint32_t*>(out);
-    const uint8_t* row_end = row_head + video_frame->visible_rect().width() * 2;
-    for (const uint8_t* row = row_head; row < row_end; ++row) {
-      uint32_t gray_value = *++row;
-      *rgba++ = SkColorSetRGB(gray_value, gray_value, gray_value);
+  const int height = video_frame->visible_rect().height();
+  for (int i = 0; i < height; ++i) {
+    uint8_t* out_row_head = flip_y ? out + output_row_bytes * (height - i - 1)
+                                   : out + output_row_bytes * i;
+    const uint16_t* row = reinterpret_cast<const uint16_t*>(row_head);
+    const uint16_t* row_end = row + video_frame->visible_rect().width();
+    if (type == GL_FLOAT && format == GL_RGBA) {
+      float* out_row = reinterpret_cast<float*>(out_row_head);
+      while (row < row_end) {
+        float gray_value = *row++ / 65535.f;
+        *out_row++ = gray_value;
+        *out_row++ = gray_value;
+        *out_row++ = gray_value;
+        *out_row++ = 1.0f;
+      }
+    } else if (type == GL_UNSIGNED_BYTE) {
+      // We take the upper 8 bits of 16-bit data and convert it as luminance to
+      // ARGB.  We loose the precision here, but it is important not to render
+      // Y16 as RG_88.  To get the full precision use float textures with WebGL1
+      // and e.g. R16UI or R32F textures with WebGL2.
+      DCHECK(format == GL_RGBA) << "Unsupported Y16 conversion for format: 0x"
+                                << std::hex << format << " and type: 0x"
+                                << std::hex << type;
+      uint32_t* rgba = reinterpret_cast<uint32_t*>(out_row_head);
+      while (row < row_end) {
+        uint32_t gray_value = *row++ >> 8;
+        *rgba++ = SkColorSetRGB(gray_value, gray_value, gray_value);
+      }
+    } else {
+      NOTREACHED() << "Unsupported Y16 conversion for format: 0x" << std::hex
+                   << format << " and type: 0x" << std::hex << type;
     }
-    out += argb_row_bytes;
     row_head += stride;
   }
 }
@@ -648,7 +672,10 @@ void SkCanvasVideoRenderer::ConvertVideoFrameToRGBPixels(
     }
 
     case PIXEL_FORMAT_Y16:
-      ConvertY16ToARGB(video_frame, rgb_pixels, row_bytes);
+      // Since it is grayscale conversion, we disregard SK_PMCOLOR_BYTE_ORDER
+      // and always use GL_RGBA.
+      FlipAndConvertY16(video_frame, static_cast<uint8_t*>(rgb_pixels), GL_RGBA,
+                        GL_UNSIGNED_BYTE, false /*flip_y*/, row_bytes);
       break;
 
     case PIXEL_FORMAT_NV12:
@@ -772,6 +799,73 @@ bool SkCanvasVideoRenderer::CopyVideoFrameTexturesToGLTexture(
   return true;
 }
 
+bool SkCanvasVideoRenderer::TexImageImpl(const char* functionID,
+                                         unsigned target,
+                                         gpu::gles2::GLES2Interface* gl,
+                                         VideoFrame* frame,
+                                         int level,
+                                         int internalformat,
+                                         unsigned format,
+                                         unsigned type,
+                                         int xoffset,
+                                         int yoffset,
+                                         int zoffset,
+                                         bool flip_y,
+                                         bool premultiplyAlpha) {
+  DCHECK(frame);
+  DCHECK(!frame->HasTextures());
+
+  bool has_alpha = false;
+  unsigned output_bytes_per_pixel;

[hubbe, 2016/11/07 22:16:55]

Please initialize to something.

[aleksandar.stojiljkovic, 2016/11/16 20:01:24]

Done.

+  switch (frame->format()) {
+    case PIXEL_FORMAT_Y16:
+      // Converting single component unsigned short here to FLOAT luminance.
+      switch (format) {
+        case GL_RGBA:
+          if (type == GL_FLOAT) {
+            output_bytes_per_pixel = 4 * sizeof(GLfloat);
+            break;
+          }
+        // Pass through.
+        default:
+          return false;
+      }
+      break;
+    default:
+      return false;
+  }
+
+  if (has_alpha && premultiplyAlpha) {
+    NOTREACHED() << "Premultiply alpha is not supported.";
+    return false;
+  }
+  if (xoffset || yoffset || zoffset) {
+    NOTREACHED() << "Offsets are not supported.";

[hubbe, 2016/11/07 22:16:55]

If they are not supported, why even have those arguments?

[aleksandar.stojiljkovic, 2016/11/16 20:01:24]

Done. Split the method and now supported in texSubImage2d.

+    return false;
+  }
+
+  const size_t width = frame->visible_rect().width();
+  const size_t height = frame->visible_rect().height();
+  size_t output_row_bytes = width * output_bytes_per_pixel;
+  scoped_refptr<DataBuffer> temp_buffer =
+      new DataBuffer(output_row_bytes * height);
+  uint8_t* data = temp_buffer->writable_data();
+
+  FlipAndConvertY16(frame, data, format, type, flip_y, output_row_bytes);
+
+  if (!strcmp(functionID, "texImage2D")) {
+    gl->TexImage2D(target, level, internalformat, width, height, 0, format,
+                   type, data);
+  } else if (!strcmp(functionID, "texSubImage2D")) {
+    gl->TexSubImage2D(target, level, xoffset, yoffset, width, height, format,
+                      type, data);
+  } else {
+    DCHECK(false) << functionID << " isn't implemented for format: "
+                  << VideoPixelFormatToString(frame->format());
+  }
+  return true;
+}
+
 void SkCanvasVideoRenderer::ResetCache() {
   DCHECK(thread_checker_.CalledOnValidThread());
   // Clear cached values.