imgutils: add a function for copying image data from GPU mapped memory

See https://software.intel.com/en-us/articles/copying-accelerated-video-decode-frame-buffers

doc/APIchanges

@@ -13,6 +13,10 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2016-08-24 - xxxxxxx - lavu 55.21.0 - imgutils.h
+  Add av_image_copy_uc_from(), a version of av_image_copy() for copying
+  from GPU mapped memory.
+
 2016-xx-xx - xxxxxxx - lavc 59.26.0 - vaapi.h
   Deprecate struct vaapi_context and the vaapi.h installed header.
   Callers should set AVCodecContext.hw_frames_ctx instead.

libavutil/imgutils.c

@@ -23,6 +23,7 @@
 
 #include "common.h"
 #include "imgutils.h"
+#include "imgutils_internal.h"
 #include "internal.h"
 #include "intreadwrite.h"
 #include "log.h"
@@ -252,9 +253,9 @@ int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
     return AVERROR(EINVAL);
 }
 
-void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
-                         const uint8_t *src, int src_linesize,
-                         int bytewidth, int height)
+static void image_copy_plane(uint8_t       *dst, ptrdiff_t dst_linesize,
+                             const uint8_t *src, ptrdiff_t src_linesize,
+                             ptrdiff_t bytewidth, int height)
 {
     if (!dst || !src)
         return;
@@ -265,9 +266,33 @@ void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
     }
 }
 
-void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
-                   const uint8_t *src_data[4], const int src_linesizes[4],
-                   enum AVPixelFormat pix_fmt, int width, int height)
+static void image_copy_plane_uc_from(uint8_t       *dst, ptrdiff_t dst_linesize,
+                                     const uint8_t *src, ptrdiff_t src_linesize,
+                                     ptrdiff_t bytewidth, int height)
+{
+    int ret = -1;
+
+#if ARCH_X86
+    ret = ff_image_copy_plane_uc_from_x86(dst, dst_linesize, src, src_linesize,
+                                          bytewidth, height);
+#endif
+
+    if (ret < 0)
+        image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
+}
+
+void av_image_copy_plane(uint8_t       *dst, int dst_linesize,
+                         const uint8_t *src, int src_linesize,
+                         int bytewidth, int height)
+{
+    image_copy_plane(dst, dst_linesize, src, src_linesize, bytewidth, height);
+}
+
+static void image_copy(uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4],
+                       const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
+                       enum AVPixelFormat pix_fmt, int width, int height,
+                       void (*copy_plane)(uint8_t *, ptrdiff_t, const uint8_t *,
+                                          ptrdiff_t, ptrdiff_t, int))
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
 
@@ -276,9 +301,9 @@ void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
 
     if (desc->flags & AV_PIX_FMT_FLAG_PAL ||
         desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL) {
-        av_image_copy_plane(dst_data[0], dst_linesizes[0],
-                            src_data[0], src_linesizes[0],
-                            width, height);
+        copy_plane(dst_data[0], dst_linesizes[0],
+                   src_data[0], src_linesizes[0],
+                   width, height);
         /* copy the palette */
         memcpy(dst_data[1], src_data[1], 4*256);
     } else {
@@ -289,17 +314,41 @@ void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
 
         for (i = 0; i < planes_nb; i++) {
             int h = height;
-            int bwidth = av_image_get_linesize(pix_fmt, width, i);
+            ptrdiff_t bwidth = av_image_get_linesize(pix_fmt, width, i);
             if (i == 1 || i == 2) {
                 h = AV_CEIL_RSHIFT(height, desc->log2_chroma_h);
             }
-            av_image_copy_plane(dst_data[i], dst_linesizes[i],
-                                src_data[i], src_linesizes[i],
-                                bwidth, h);
+            copy_plane(dst_data[i], dst_linesizes[i],
+                       src_data[i], src_linesizes[i],
+                       bwidth, h);
         }
     }
 }
 
+void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
+                   const uint8_t *src_data[4], const int src_linesizes[4],
+                   enum AVPixelFormat pix_fmt, int width, int height)
+{
+    ptrdiff_t dst_linesizes1[4], src_linesizes1[4];
+    int i;
+
+    for (i = 0; i < 4; i++) {
+        dst_linesizes1[i] = dst_linesizes[i];
+        src_linesizes1[i] = src_linesizes[i];
+    }
+
+    image_copy(dst_data, dst_linesizes1, src_data, src_linesizes1, pix_fmt,
+               width, height, image_copy_plane);
+}
+
+void av_image_copy_uc_from(uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4],
+                           const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
+                           enum AVPixelFormat pix_fmt, int width, int height)
+{
+    image_copy(dst_data, dst_linesizes, src_data, src_linesizes, pix_fmt,
+               width, height, image_copy_plane_uc_from);
+}
+
 int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
                          const uint8_t *src, enum AVPixelFormat pix_fmt,
                          int width, int height, int align)

libavutil/imgutils.h

@@ -117,6 +117,24 @@ void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
                    const uint8_t *src_data[4], const int src_linesizes[4],
                    enum AVPixelFormat pix_fmt, int width, int height);
 
+/**
+ * Copy image data located in uncacheable (e.g. GPU mapped) memory. Where
+ * available, this function will use special functionality for reading from such
+ * memory, which may result in greatly improved performance compared to plain
+ * av_image_copy().
+ *
+ * The data pointers and the linesizes must be aligned to the maximum required
+ * by the CPU architecture.
+ *
+ * @note The linesize parameters have the type ptrdiff_t here, while they are
+ *       int for av_image_copy().
+ * @note On x86, the linesizes currently need to be aligned to the cacheline
+ *       size (i.e. 64) to get improved performance.
+ */
+void av_image_copy_uc_from(uint8_t *dst_data[4],       const ptrdiff_t dst_linesizes[4],
+                           const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
+                           enum AVPixelFormat pix_fmt, int width, int height);
+
 /**
  * Setup the data pointers and linesizes based on the specified image
  * parameters and the provided array.

libavutil/imgutils_internal.h

@@ -0,0 +1,30 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_IMGUTILS_INTERNAL_H
+#define AVUTIL_IMGUTILS_INTERNAL_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+int ff_image_copy_plane_uc_from_x86(uint8_t       *dst, ptrdiff_t dst_linesize,
+                                    const uint8_t *src, ptrdiff_t src_linesize,
+                                    ptrdiff_t bytewidth, int height);
+
+
+#endif /* AVUTIL_IMGUTILS_INTERNAL_H */

libavutil/version.h

@@ -54,7 +54,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 20
+#define LIBAVUTIL_VERSION_MINOR 21
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

libavutil/x86/Makefile

@@ -1,8 +1,10 @@
 OBJS += x86/cpu.o                                                       \
         x86/float_dsp_init.o                                            \
+        x86/imgutils_init.o                                             \
         x86/lls_init.o                                                  \
 
 YASM-OBJS += x86/cpuid.o                                                \
              x86/emms.o                                                 \
              x86/float_dsp.o                                            \
+             x86/imgutils.o                                             \
              x86/lls.o                                                  \

libavutil/x86/imgutils.asm

@@ -0,0 +1,53 @@
+;*****************************************************************************
+;* Copyright 2016 Anton Khirnov
+;*
+;* This file is part of Libav.
+;*
+;* Libav is free software; you can redistribute it and/or
+;* modify it under the terms of the GNU Lesser General Public
+;* License as published by the Free Software Foundation; either
+;* version 2.1 of the License, or (at your option) any later version.
+;*
+;* Libav 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
+;* Lesser General Public License for more details.
+;*
+;* You should have received a copy of the GNU Lesser General Public
+;* License along with Libav; if not, write to the Free Software
+;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;******************************************************************************
+
+%include "libavutil/x86/x86util.asm"
+
+SECTION .text
+
+INIT_XMM sse4
+cglobal image_copy_plane_uc_from, 6, 7, 4, dst, dst_linesize, src, src_linesize, bw, height, rowpos
+    add dstq, bwq
+    add srcq, bwq
+    neg bwq
+
+.row_start
+    mov rowposq, bwq
+
+.loop
+    movntdqa m0, [srcq + rowposq + 0 * mmsize]
+    movntdqa m1, [srcq + rowposq + 1 * mmsize]
+    movntdqa m2, [srcq + rowposq + 2 * mmsize]
+    movntdqa m3, [srcq + rowposq + 3 * mmsize]
+
+    mova [dstq + rowposq + 0 * mmsize], m0
+    mova [dstq + rowposq + 1 * mmsize], m1
+    mova [dstq + rowposq + 2 * mmsize], m2
+    mova [dstq + rowposq + 3 * mmsize], m3
+
+    add rowposq, 4 * mmsize
+    jnz .loop
+
+    add srcq, src_linesizeq
+    add dstq, dst_linesizeq
+    dec heightd
+    jnz .row_start
+
+    RET

libavutil/x86/imgutils_init.c

@@ -0,0 +1,49 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "libavutil/cpu.h"
+#include "libavutil/error.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/imgutils_internal.h"
+#include "libavutil/internal.h"
+
+#include "cpu.h"
+
+void ff_image_copy_plane_uc_from_sse4(uint8_t *dst, ptrdiff_t dst_linesize,
+                                      const uint8_t *src, ptrdiff_t src_linesize,
+                                      ptrdiff_t bytewidth, int height);
+
+int ff_image_copy_plane_uc_from_x86(uint8_t       *dst, ptrdiff_t dst_linesize,
+                                    const uint8_t *src, ptrdiff_t src_linesize,
+                                    ptrdiff_t bytewidth, int height)
+{
+    int cpu_flags = av_get_cpu_flags();
+    ptrdiff_t bw_aligned = FFALIGN(bytewidth, 64);
+
+    if (EXTERNAL_SSE4(cpu_flags) &&
+        bw_aligned <= dst_linesize && bw_aligned <= src_linesize)
+        ff_image_copy_plane_uc_from_sse4(dst, dst_linesize, src, src_linesize,
+                                         bw_aligned, height);
+    else
+        return AVERROR(ENOSYS);
+
+    return 0;
+}