xemu/ui/vnc-enc-zrle.c
Cameron Esfahani 557ba0e572 vnc: prioritize ZRLE compression over ZLIB
In my investigation, ZRLE always compresses better than ZLIB so
prioritize ZRLE over ZLIB, even if the client hints that ZLIB is
preferred.

zlib buffer is always reset in zrle_compress_data(), so using offset to
calculate next_out and avail_out is useless.

Signed-off-by: Cameron Esfahani <dirty@apple.com>
Message-Id: <b5d129895d08a90d0a2a6183b95875bacfa998b8.1579582674.git.dirty@apple.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2020-01-21 07:29:03 +01:00

367 lines
10 KiB
C

/*
* 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 "qemu/osdep.h"
#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;
zstream->avail_out = vs->zrle->zlib.capacity;
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;
}
}
}
}
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.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 15
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 16
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 32
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#define ZRLE_COMPACT_PIXEL 24a
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_COMPACT_PIXEL
#define ZRLE_COMPACT_PIXEL 24b
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.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->client_be;
size_t bytes;
int zywrle_level;
if (vs->zrle->type == VNC_ENCODING_ZYWRLE) {
if (!vs->vd->lossy || vs->tight->quality == (uint8_t)-1
|| 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->client_pf.bytes_per_pixel) {
case 1:
zrle_encode_8ne(vs, x, y, w, h, zywrle_level);
break;
case 2:
if (vs->client_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->client_pf.rmax << vs->client_pf.rshift) < (1 << 24) &&
(vs->client_pf.gmax << vs->client_pf.gshift) < (1 << 24) &&
(vs->client_pf.bmax << vs->client_pf.bshift) < (1 << 24));
fits_in_ms3bytes = (vs->client_pf.rshift > 7 &&
vs->client_pf.gshift > 7 &&
vs->client_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);
}