Commit aa7d73fd authored by Corentin Chary's avatar Corentin Chary Committed by Anthony Liguori
Browse files

vnc: tight: add palette encoding



Add palette tight encoding. Palette encoding will try to count the number
of colors for a given rectangle, and if this number is low enough
(< 256) it will send the palette + the rectangle with indexed colors.
Signed-off-by: default avatarCorentin Chary <corentincj@iksaif.net>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent b4bea3f2
......@@ -28,6 +28,8 @@
#include <stdbool.h>
#include "qdict.h"
#include "qint.h"
#include "vnc.h"
#include "vnc-encoding-tight.h"
......@@ -55,6 +57,285 @@ static const struct {
{ 65536, 2048, 32, 8192, 9, 9, 9, 6, 200, 500, 96, 80, 200, 500 }
};
/*
* Code to determine how many different colors used in rectangle.
*/
static void tight_palette_rgb2buf(uint32_t rgb, int bpp, uint8_t buf[6])
{
memset(buf, 0, 6);
if (bpp == 32) {
buf[0] = ((rgb >> 24) & 0xFF);
buf[1] = ((rgb >> 16) & 0xFF);
buf[2] = ((rgb >> 8) & 0xFF);
buf[3] = ((rgb >> 0) & 0xFF);
buf[4] = ((buf[0] & 1) == 0) << 3 | ((buf[1] & 1) == 0) << 2;
buf[4]|= ((buf[2] & 1) == 0) << 1 | ((buf[3] & 1) == 0) << 0;
buf[0] |= 1;
buf[1] |= 1;
buf[2] |= 1;
buf[3] |= 1;
}
if (bpp == 16) {
buf[0] = ((rgb >> 8) & 0xFF);
buf[1] = ((rgb >> 0) & 0xFF);
buf[2] = ((buf[0] & 1) == 0) << 1 | ((buf[1] & 1) == 0) << 0;
buf[0] |= 1;
buf[1] |= 1;
}
}
static uint32_t tight_palette_buf2rgb(int bpp, const uint8_t *buf)
{
uint32_t rgb = 0;
if (bpp == 32) {
rgb |= ((buf[0] & ~1) | !((buf[4] >> 3) & 1)) << 24;
rgb |= ((buf[1] & ~1) | !((buf[4] >> 2) & 1)) << 16;
rgb |= ((buf[2] & ~1) | !((buf[4] >> 1) & 1)) << 8;
rgb |= ((buf[3] & ~1) | !((buf[4] >> 0) & 1)) << 0;
}
if (bpp == 16) {
rgb |= ((buf[0] & ~1) | !((buf[2] >> 1) & 1)) << 8;
rgb |= ((buf[1] & ~1) | !((buf[2] >> 0) & 1)) << 0;
}
return rgb;
}
static int tight_palette_insert(QDict *palette, uint32_t rgb, int bpp, int max)
{
uint8_t key[6];
int idx = qdict_size(palette);
bool present;
tight_palette_rgb2buf(rgb, bpp, key);
present = qdict_haskey(palette, (char *)key);
if (idx >= max && !present) {
return 0;
}
if (!present) {
qdict_put(palette, (char *)key, qint_from_int(idx));
}
return qdict_size(palette);
}
#define DEFINE_FILL_PALETTE_FUNCTION(bpp) \
\
static int \
tight_fill_palette##bpp(VncState *vs, int x, int y, \
int max, size_t count, \
uint32_t *bg, uint32_t *fg, \
struct QDict **palette) { \
uint##bpp##_t *data; \
uint##bpp##_t c0, c1, ci; \
int i, n0, n1; \
\
data = (uint##bpp##_t *)vs->tight.buffer; \
\
c0 = data[0]; \
i = 1; \
while (i < count && data[i] == c0) \
i++; \
if (i >= count) { \
*bg = *fg = c0; \
return 1; \
} \
\
if (max < 2) { \
return 0; \
} \
\
n0 = i; \
c1 = data[i]; \
n1 = 0; \
for (i++; i < count; i++) { \
ci = data[i]; \
if (ci == c0) { \
n0++; \
} else if (ci == c1) { \
n1++; \
} else \
break; \
} \
if (i >= count) { \
if (n0 > n1) { \
*bg = (uint32_t)c0; \
*fg = (uint32_t)c1; \
} else { \
*bg = (uint32_t)c1; \
*fg = (uint32_t)c0; \
} \
return 2; \
} \
\
if (max == 2) { \
return 0; \
} \
\
*palette = qdict_new(); \
tight_palette_insert(*palette, c0, bpp, max); \
tight_palette_insert(*palette, c1, bpp, max); \
\
for (i++; i < count; i++) { \
if (data[i] == ci) { \
continue; \
} else { \
if (!tight_palette_insert(*palette, (uint32_t)ci, \
bpp, max)) { \
return 0; \
} \
ci = data[i]; \
} \
} \
\
return qdict_size(*palette); \
}
DEFINE_FILL_PALETTE_FUNCTION(8)
DEFINE_FILL_PALETTE_FUNCTION(16)
DEFINE_FILL_PALETTE_FUNCTION(32)
static int tight_fill_palette(VncState *vs, int x, int y,
size_t count, uint32_t *bg, uint32_t *fg,
struct QDict **palette)
{
int max;
max = count / tight_conf[vs->tight_compression].idx_max_colors_divisor;
if (max < 2 &&
count >= tight_conf[vs->tight_compression].mono_min_rect_size) {
max = 2;
}
if (max >= 256) {
max = 256;
}
switch(vs->clientds.pf.bytes_per_pixel) {
case 4:
return tight_fill_palette32(vs, x, y, max, count, bg, fg, palette);
case 2:
return tight_fill_palette16(vs, x, y, max, count, bg, fg, palette);
default:
max = 2;
return tight_fill_palette8(vs, x, y, max, count, bg, fg, palette);
}
return 0;
}
/* Callback to dump a palette with qdict_iter
static void print_palette(const char *key, QObject *obj, void *opaque)
{
uint8_t idx = qint_get_int(qobject_to_qint(obj));
uint32_t rgb = tight_palette_buf2rgb(32, (uint8_t *)key);
fprintf(stderr, "%.2x ", (unsigned char)*key);
while (*key++)
fprintf(stderr, "%.2x ", (unsigned char)*key);
fprintf(stderr, ": idx: %x rgb: %x\n", idx, rgb);
}
*/
/*
* Converting truecolor samples into palette indices.
*/
#define DEFINE_IDX_ENCODE_FUNCTION(bpp) \
\
static void \
tight_encode_indexed_rect##bpp(uint8_t *buf, int count, \
struct QDict *palette) { \
uint##bpp##_t *src; \
uint##bpp##_t rgb; \
uint8_t key[6]; \
int rep = 0; \
uint8_t idx; \
\
src = (uint##bpp##_t *) buf; \
\
count -= 1; \
while (count--) { \
rgb = *src++; \
rep = 0; \
while (count && *src == rgb) { \
rep++, src++, count--; \
} \
tight_palette_rgb2buf(rgb, bpp, key); \
if (!qdict_haskey(palette, (char *)key)) { \
/* \
* Should never happen, but don't break everything \
* if it does, use the first color instead \
*/ \
idx = 0; \
} else { \
idx = qdict_get_int(palette, (char *)key); \
} \
while (rep >= 0) { \
*buf++ = idx; \
rep--; \
} \
} \
}
DEFINE_IDX_ENCODE_FUNCTION(16)
DEFINE_IDX_ENCODE_FUNCTION(32)
#define DEFINE_MONO_ENCODE_FUNCTION(bpp) \
\
static void \
tight_encode_mono_rect##bpp(uint8_t *buf, int w, int h, \
uint##bpp##_t bg, uint##bpp##_t fg) { \
uint##bpp##_t *ptr; \
unsigned int value, mask; \
int aligned_width; \
int x, y, bg_bits; \
\
ptr = (uint##bpp##_t *) buf; \
aligned_width = w - w % 8; \
\
for (y = 0; y < h; y++) { \
for (x = 0; x < aligned_width; x += 8) { \
for (bg_bits = 0; bg_bits < 8; bg_bits++) { \
if (*ptr++ != bg) { \
break; \
} \
} \
if (bg_bits == 8) { \
*buf++ = 0; \
continue; \
} \
mask = 0x80 >> bg_bits; \
value = mask; \
for (bg_bits++; bg_bits < 8; bg_bits++) { \
mask >>= 1; \
if (*ptr++ != bg) { \
value |= mask; \
} \
} \
*buf++ = (uint8_t)value; \
} \
\
mask = 0x80; \
value = 0; \
if (x >= w) { \
continue; \
} \
\
for (; x < w; x++) { \
if (*ptr++ != bg) { \
value |= mask; \
} \
mask >>= 1; \
} \
*buf++ = (uint8_t)value; \
} \
}
DEFINE_MONO_ENCODE_FUNCTION(8)
DEFINE_MONO_ENCODE_FUNCTION(16)
DEFINE_MONO_ENCODE_FUNCTION(32)
/*
* Check if a rectangle is all of the same color. If needSameColor is
* set to non-zero, then also check that its color equals to the
......@@ -288,14 +569,12 @@ static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
/*
* Subencoding implementations.
*/
static void tight_pack24(VncState *vs, size_t count)
static void tight_pack24(VncState *vs, uint8_t *buf, size_t count, size_t *ret)
{
unsigned char *buf;
uint32_t *buf32;
uint32_t pix;
int rshift, gshift, bshift;
buf = vs->tight.buffer;
buf32 = (uint32_t *)buf;
if ((vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) ==
......@@ -309,7 +588,9 @@ static void tight_pack24(VncState *vs, size_t count)
bshift = 24 - vs->clientds.pf.bshift;
}
vs->tight.offset = count * 3;
if (ret) {
*ret = count * 3;
}
while (count--) {
pix = *buf32++;
......@@ -327,7 +608,7 @@ static int send_full_color_rect(VncState *vs, int w, int h)
vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
if (vs->tight_pixel24) {
tight_pack24(vs, w * h);
tight_pack24(vs, vs->tight.buffer, w * h, &vs->tight.offset);
bytes = 3;
} else {
bytes = vs->clientds.pf.bytes_per_pixel;
......@@ -347,7 +628,7 @@ static int send_solid_rect(VncState *vs)
vnc_write_u8(vs, VNC_TIGHT_FILL << 4); /* no flushing, no filter */
if (vs->tight_pixel24) {
tight_pack24(vs, 1);
tight_pack24(vs, vs->tight.buffer, 1, &vs->tight.offset);
bytes = 3;
} else {
bytes = vs->clientds.pf.bytes_per_pixel;
......@@ -357,6 +638,126 @@ static int send_solid_rect(VncState *vs)
return 1;
}
static int send_mono_rect(VncState *vs, int w, int h, uint32_t bg, uint32_t fg)
{
size_t bytes;
int stream = 1;
int level = tight_conf[vs->tight_compression].mono_zlib_level;
bytes = ((w + 7) / 8) * h;
vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
vnc_write_u8(vs, 1);
switch(vs->clientds.pf.bytes_per_pixel) {
case 4:
{
uint32_t buf[2] = {bg, fg};
size_t ret = sizeof (buf);
if (vs->tight_pixel24) {
tight_pack24(vs, (unsigned char*)buf, 2, &ret);
}
vnc_write(vs, buf, ret);
tight_encode_mono_rect32(vs->tight.buffer, w, h, bg, fg);
break;
}
case 2:
vnc_write(vs, &bg, 2);
vnc_write(vs, &fg, 2);
tight_encode_mono_rect16(vs->tight.buffer, w, h, bg, fg);
break;
default:
vnc_write_u8(vs, bg);
vnc_write_u8(vs, fg);
tight_encode_mono_rect8(vs->tight.buffer, w, h, bg, fg);
break;
}
vs->tight.offset = bytes;
bytes = tight_compress_data(vs, stream, bytes, level, Z_DEFAULT_STRATEGY);
return (bytes >= 0);
}
struct palette_cb_priv {
VncState *vs;
uint8_t *header;
};
static void write_palette(const char *key, QObject *obj, void *opaque)
{
struct palette_cb_priv *priv = opaque;
VncState *vs = priv->vs;
uint32_t bytes = vs->clientds.pf.bytes_per_pixel;
uint8_t idx = qint_get_int(qobject_to_qint(obj));
if (bytes == 4) {
uint32_t color = tight_palette_buf2rgb(32, (uint8_t *)key);
((uint32_t*)priv->header)[idx] = color;
} else {
uint16_t color = tight_palette_buf2rgb(16, (uint8_t *)key);
((uint16_t*)priv->header)[idx] = color;
}
}
static int send_palette_rect(VncState *vs, int w, int h, struct QDict *palette)
{
int stream = 2;
int level = tight_conf[vs->tight_compression].idx_zlib_level;
int colors;
size_t bytes;
colors = qdict_size(palette);
vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
vnc_write_u8(vs, colors - 1);
switch(vs->clientds.pf.bytes_per_pixel) {
case 4:
{
size_t old_offset, offset;
uint32_t header[qdict_size(palette)];
struct palette_cb_priv priv = { vs, (uint8_t *)header };
old_offset = vs->output.offset;
qdict_iter(palette, write_palette, &priv);
vnc_write(vs, header, sizeof(header));
if (vs->tight_pixel24) {
tight_pack24(vs, vs->output.buffer + old_offset, colors, &offset);
vs->output.offset = old_offset + offset;
}
tight_encode_indexed_rect32(vs->tight.buffer, w * h, palette);
break;
}
case 2:
{
uint16_t header[qdict_size(palette)];
struct palette_cb_priv priv = { vs, (uint8_t *)header };
qdict_iter(palette, write_palette, &priv);
vnc_write(vs, header, sizeof(header));
tight_encode_indexed_rect16(vs->tight.buffer, w * h, palette);
break;
}
default:
return -1; /* No palette for 8bits colors */
break;
}
bytes = w * h;
vs->tight.offset = bytes;
bytes = tight_compress_data(vs, stream, bytes,
level, Z_DEFAULT_STRATEGY);
return (bytes >= 0);
}
static void vnc_tight_start(VncState *vs)
{
buffer_reset(&vs->tight);
......@@ -375,18 +776,30 @@ static void vnc_tight_stop(VncState *vs)
static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
{
struct QDict *palette = NULL;
uint32_t bg = 0, fg = 0;
int colors;
int ret = 0;
vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_TIGHT);
/*
* Convert pixels and store them in vs->tight
* We will probably rework that later, probably
* when adding other sub-encodings
*/
vnc_tight_start(vs);
vnc_raw_send_framebuffer_update(vs, x, y, w, h);
vnc_tight_stop(vs);
return send_full_color_rect(vs, w, h);
colors = tight_fill_palette(vs, x, y, w * h, &fg, &bg, &palette);
if (colors == 0) {
ret = send_full_color_rect(vs, w, h);
} else if (colors == 1) {
ret = send_solid_rect(vs);
} else if (colors == 2) {
ret = send_mono_rect(vs, w, h, bg, fg);
} else if (colors <= 256) {
ret = send_palette_rect(vs, w, h, palette);
}
QDECREF(palette);
return ret;
}
static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
......
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