vnc: Add ZRLE and ZYWRLE encodings.

Add ZRLE [1] and ZYWRLE [2] encodings. The code is inspire^W stolen
from libvncserver (again), but have been rewriten to match QEMU coding
style.

[1] http://www.realvnc.com/docs/rfbproto.pdf
[2] http://micro-vnc.jp/research/remote_desktop_ng/ZYWRLE/publications/

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 365 insertions, 0 deletions

diff --git a/ui/vnc-enc-zrle.c b/ui/vnc-enc-zrle.c
new file mode 100644
index 0000000000..016a406eec
--- /dev/null
+++ b/ui/vnc-enc-zrle.c
@@ -0,0 +1,365 @@
+/*
+ * QEMU VNC display driver: Zlib Run-length Encoding (ZRLE)
+ *
+ * From libvncserver/libvncserver/zrle.c
+ * Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
+ * Copyright (C) 2003 Sun Microsystems, Inc.
+ *
+ * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "vnc.h"
+#include "vnc-enc-zrle.h"
+
+static const int bits_per_packed_pixel[] = {
+  0, 1, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
+};
+
+
+static void vnc_zrle_start(VncState *vs)
+{
+    buffer_reset(&vs->zrle.zrle);
+
+    /* make the output buffer be the zlib buffer, so we can compress it later */
+    vs->zrle.tmp = vs->output;
+    vs->output = vs->zrle.zrle;
+}
+
+static void vnc_zrle_stop(VncState *vs)
+{
+    /* switch back to normal output/zlib buffers */
+    vs->zrle.zrle = vs->output;
+    vs->output = vs->zrle.tmp;
+}
+
+static void *zrle_convert_fb(VncState *vs, int x, int y, int w, int h,
+                             int bpp)
+{
+    Buffer tmp;
+
+    buffer_reset(&vs->zrle.fb);
+    buffer_reserve(&vs->zrle.fb, w * h * bpp + bpp);
+
+    tmp = vs->output;
+    vs->output = vs->zrle.fb;
+
+    vnc_raw_send_framebuffer_update(vs, x, y, w, h);
+
+    vs->zrle.fb = vs->output;
+    vs->output = tmp;
+    return vs->zrle.fb.buffer;
+}
+
+static int zrle_compress_data(VncState *vs, int level)
+{
+    z_streamp zstream = &vs->zrle.stream;
+
+    buffer_reset(&vs->zrle.zlib);
+
+    if (zstream->opaque != vs) {
+        int err;
+
+        zstream->zalloc = vnc_zlib_zalloc;
+        zstream->zfree = vnc_zlib_zfree;
+
+        err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
+                           MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+
+        if (err != Z_OK) {
+            fprintf(stderr, "VNC: error initializing zlib\n");
+            return -1;
+        }
+
+        zstream->opaque = vs;
+    }
+
+    /* reserve memory in output buffer */
+    buffer_reserve(&vs->zrle.zlib, vs->zrle.zrle.offset + 64);
+
+    /* set pointers */
+    zstream->next_in = vs->zrle.zrle.buffer;
+    zstream->avail_in = vs->zrle.zrle.offset;
+    zstream->next_out = vs->zrle.zlib.buffer + vs->zrle.zlib.offset;
+    zstream->avail_out = vs->zrle.zlib.capacity - vs->zrle.zlib.offset;
+    zstream->data_type = Z_BINARY;
+
+    /* start encoding */
+    if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
+        fprintf(stderr, "VNC: error during zrle compression\n");
+        return -1;
+    }
+
+    vs->zrle.zlib.offset = vs->zrle.zlib.capacity - zstream->avail_out;
+    return vs->zrle.zlib.offset;
+}
+
+/* Try to work out whether to use RLE and/or a palette.  We do this by
+ * estimating the number of bytes which will be generated and picking the
+ * method which results in the fewest bytes.  Of course this may not result
+ * in the fewest bytes after compression... */
+static void zrle_choose_palette_rle(VncState *vs, int w, int h,
+                                    VncPalette *palette, int bpp_out,
+                                    int runs, int single_pixels,
+                                    int zywrle_level,
+                                    bool *use_rle, bool *use_palette)
+{
+    size_t estimated_bytes;
+    size_t plain_rle_bytes;
+
+    *use_palette = *use_rle = false;
+
+    estimated_bytes = w * h * (bpp_out / 8); /* start assuming raw */
+
+    if (bpp_out != 8) {
+        if (zywrle_level > 0 && !(zywrle_level & 0x80))
+            estimated_bytes >>= zywrle_level;
+    }
+
+    plain_rle_bytes = ((bpp_out / 8) + 1) * (runs + single_pixels);
+
+    if (plain_rle_bytes < estimated_bytes) {
+        *use_rle = true;
+        estimated_bytes = plain_rle_bytes;
+    }
+
+    if (palette_size(palette) < 128) {
+        int palette_rle_bytes;
+
+        palette_rle_bytes = (bpp_out / 8) * palette_size(palette);
+        palette_rle_bytes += 2 * runs + single_pixels;
+
+        if (palette_rle_bytes < estimated_bytes) {
+            *use_rle = true;
+            *use_palette = true;
+            estimated_bytes = palette_rle_bytes;
+        }
+
+        if (palette_size(palette) < 17) {
+            int packed_bytes;
+
+            packed_bytes = (bpp_out / 8) * palette_size(palette);
+            packed_bytes += w * h *
+                bits_per_packed_pixel[palette_size(palette)-1] / 8;
+
+            if (packed_bytes < estimated_bytes) {
+                *use_rle = false;
+                *use_palette = true;
+                estimated_bytes = packed_bytes;
+            }
+        }
+    }
+}
+
+static void zrle_write_u32(VncState *vs, uint32_t value)
+{
+    vnc_write(vs, (uint8_t *)&value, 4);
+}
+
+static void zrle_write_u24a(VncState *vs, uint32_t value)
+{
+    vnc_write(vs, (uint8_t *)&value, 3);
+}
+
+static void zrle_write_u24b(VncState *vs, uint32_t value)
+{
+    vnc_write(vs, ((uint8_t *)&value) + 1, 3);
+}
+
+static void zrle_write_u16(VncState *vs, uint16_t value)
+{
+    vnc_write(vs, (uint8_t *)&value, 2);
+}
+
+static void zrle_write_u8(VncState *vs, uint8_t value)
+{
+    vnc_write_u8(vs, value);
+}
+
+#define ENDIAN_LITTLE 0
+#define ENDIAN_BIG    1
+#define ENDIAN_NO     2
+
+#define ZRLE_BPP 8
+#define ZYWRLE_ENDIAN ENDIAN_NO
+#include "vnc-enc-zrle-template.c"
+#undef ZRLE_BPP
+
+#define ZRLE_BPP 15
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_LITTLE
+#include "vnc-enc-zrle-template.c"
+
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_BIG
+#include "vnc-enc-zrle-template.c"
+
+#undef ZRLE_BPP
+#define ZRLE_BPP 16
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_LITTLE
+#include "vnc-enc-zrle-template.c"
+
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_BIG
+#include "vnc-enc-zrle-template.c"
+
+#undef ZRLE_BPP
+#define ZRLE_BPP 32
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_LITTLE
+#include "vnc-enc-zrle-template.c"
+
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_BIG
+#include "vnc-enc-zrle-template.c"
+
+#define ZRLE_COMPACT_PIXEL 24a
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_LITTLE
+#include "vnc-enc-zrle-template.c"
+
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_BIG
+#include "vnc-enc-zrle-template.c"
+
+#undef ZRLE_COMPACT_PIXEL
+#define ZRLE_COMPACT_PIXEL 24b
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_LITTLE
+#include "vnc-enc-zrle-template.c"
+
+#undef ZYWRLE_ENDIAN
+#define ZYWRLE_ENDIAN ENDIAN_BIG
+#include "vnc-enc-zrle-template.c"
+#undef ZRLE_COMPACT_PIXEL
+#undef ZRLE_BPP
+
+static int zrle_send_framebuffer_update(VncState *vs, int x, int y,
+                                        int w, int h)
+{
+    bool be = !!(vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG);
+    size_t bytes;
+    int zywrle_level;
+
+    if (vs->zrle.type == VNC_ENCODING_ZYWRLE) {
+        if (!vs->vd->lossy || vs->tight.quality < 0 || vs->tight.quality == 9) {
+            zywrle_level = 0;
+            vs->zrle.type = VNC_ENCODING_ZRLE;
+        } else if (vs->tight.quality < 3) {
+            zywrle_level = 3;
+        } else if (vs->tight.quality < 6) {
+            zywrle_level = 2;
+        } else {
+            zywrle_level = 1;
+        }
+    } else {
+        zywrle_level = 0;
+    }
+
+    vnc_zrle_start(vs);
+
+    switch(vs->clientds.pf.bytes_per_pixel) {
+    case 1:
+        zrle_encode_8ne(vs, x, y, w, h, zywrle_level);
+        break;
+
+    case 2:
+        if (vs->clientds.pf.gmax > 0x1F) {
+            if (be) {
+                zrle_encode_16be(vs, x, y, w, h, zywrle_level);
+            } else {
+                zrle_encode_16le(vs, x, y, w, h, zywrle_level);
+            }
+        } else {
+            if (be) {
+                zrle_encode_15be(vs, x, y, w, h, zywrle_level);
+            } else {
+                zrle_encode_15le(vs, x, y, w, h, zywrle_level);
+            }
+        }
+        break;
+
+    case 4:
+    {
+        bool fits_in_ls3bytes;
+        bool fits_in_ms3bytes;
+
+        fits_in_ls3bytes =
+            ((vs->clientds.pf.rmax << vs->clientds.pf.rshift) < (1 << 24) &&
+             (vs->clientds.pf.gmax << vs->clientds.pf.gshift) < (1 << 24) &&
+             (vs->clientds.pf.bmax << vs->clientds.pf.bshift) < (1 << 24));
+
+        fits_in_ms3bytes = (vs->clientds.pf.rshift > 7 &&
+                            vs->clientds.pf.gshift > 7 &&
+                            vs->clientds.pf.bshift > 7);
+
+        if ((fits_in_ls3bytes && !be) || (fits_in_ms3bytes && be)) {
+            if (be) {
+                zrle_encode_24abe(vs, x, y, w, h, zywrle_level);
+            } else {
+                zrle_encode_24ale(vs, x, y, w, h, zywrle_level);
+          }
+        } else if ((fits_in_ls3bytes && be) || (fits_in_ms3bytes && !be)) {
+            if (be) {
+                zrle_encode_24bbe(vs, x, y, w, h, zywrle_level);
+            } else {
+                zrle_encode_24ble(vs, x, y, w, h, zywrle_level);
+            }
+        } else {
+            if (be) {
+                zrle_encode_32be(vs, x, y, w, h, zywrle_level);
+            } else {
+                zrle_encode_32le(vs, x, y, w, h, zywrle_level);
+            }
+        }
+    }
+    break;
+    }
+
+    vnc_zrle_stop(vs);
+    bytes = zrle_compress_data(vs, Z_DEFAULT_COMPRESSION);
+    vnc_framebuffer_update(vs, x, y, w, h, vs->zrle.type);
+    vnc_write_u32(vs, bytes);
+    vnc_write(vs, vs->zrle.zlib.buffer, vs->zrle.zlib.offset);
+    return 1;
+}
+
+int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
+{
+    vs->zrle.type = VNC_ENCODING_ZRLE;
+    return zrle_send_framebuffer_update(vs, x, y, w, h);
+}
+
+int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
+{
+    vs->zrle.type = VNC_ENCODING_ZYWRLE;
+    return zrle_send_framebuffer_update(vs, x, y, w, h);
+}
+
+void vnc_zrle_clear(VncState *vs)
+{
+    if (vs->zrle.stream.opaque) {
+        deflateEnd(&vs->zrle.stream);
+    }
+    buffer_free(&vs->zrle.zrle);
+    buffer_free(&vs->zrle.fb);
+    buffer_free(&vs->zrle.zlib);
+}