Fix jpeg quality setting

The encoding identifiers are supposed to be interpreted as a range. I
interpreted the upper and lower limits as two discrete quality settings
instead, which is wrong.

include/common.h

@@ -90,6 +90,7 @@ struct nvnc_client {
 	bool is_qemu_key_ext_notified;
 	struct encoder* encoder;
 	uint32_t cursor_seq;
+	int quality;
 };
 
 LIST_HEAD(nvnc_client_list, nvnc_client);

include/encoder.h

@@ -43,7 +43,7 @@ struct encoder_impl {
 
 	void (*set_output_format)(struct encoder*,
 			const struct rfb_pixel_format*);
-	void (*set_tight_quality)(struct encoder*, int quality);
+	void (*set_quality)(struct encoder*, int quality);
 
 	int (*resize)(struct encoder*, uint16_t width, uint16_t height);
 
@@ -78,7 +78,7 @@ enum encoder_kind encoder_get_kind(const struct encoder* self);
 
 void encoder_set_output_format(struct encoder* self,
 		const struct rfb_pixel_format*);
-void encoder_set_tight_quality(struct encoder* self, int value);
+void encoder_set_quality(struct encoder* self, int value);
 
 int encoder_resize(struct encoder* self, uint16_t width, uint16_t height);
 

include/rfb-proto.h

@@ -63,12 +63,13 @@ enum rfb_encodings {
 	RFB_ENCODING_OPEN_H264 = 50,
 	RFB_ENCODING_CURSOR = -239,
 	RFB_ENCODING_DESKTOPSIZE = -223,
-	RFB_ENCODING_JPEG_HIGHQ = -23,
-	RFB_ENCODING_JPEG_LOWQ = -32,
 	RFB_ENCODING_QEMU_EXT_KEY_EVENT = -258,
 	RFB_ENCODING_PTS = -1000,
 };
 
+#define RFB_ENCODING_JPEG_HIGHQ -23
+#define RFB_ENCODING_JPEG_LOWQ -32
+
 enum rfb_server_to_client_msg_type {
 	RFB_SERVER_TO_CLIENT_FRAMEBUFFER_UPDATE = 0,
 	RFB_SERVER_TO_CLIENT_SET_COLOUR_MAP_ENTRIES = 1,

include/tight.h

@@ -1,25 +0,0 @@
-/*
- * Copyright (c) 2019 - 2021 Andri Yngvason
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
- * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
- * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
- * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- * PERFORMANCE OF THIS SOFTWARE.
- */
-
-#pragma once
-
-enum tight_quality {
-	TIGHT_QUALITY_UNSPEC = 0,
-	TIGHT_QUALITY_LOSSLESS,
-	TIGHT_QUALITY_LOW,
-	TIGHT_QUALITY_HIGH,
-};
-

src/encoder.c

@@ -93,10 +93,10 @@ void encoder_set_output_format(struct encoder* self,
 		self->impl->set_output_format(self, pixfmt);
 }
 
-void encoder_set_tight_quality(struct encoder* self, int value)
+void encoder_set_quality(struct encoder* self, int value)
 {
-	if (self->impl->set_tight_quality)
-		self->impl->set_tight_quality(self, value);
+	if (self->impl->set_quality)
+		self->impl->set_quality(self, value);
 }
 
 int encoder_resize(struct encoder* self, uint16_t width, uint16_t height)

src/server.c

@@ -26,7 +26,6 @@
 #include "config.h"
 #include "usdt.h"
 #include "encoder.h"
-#include "tight.h"
 #include "enc-util.h"
 #include "cursor.h"
 #include "logging.h"
@@ -74,7 +73,6 @@ static int send_desktop_resize(struct nvnc_client* client, struct nvnc_fb* fb);
 static int send_qemu_key_ext_frame(struct nvnc_client* client);
 static enum rfb_encodings choose_frame_encoding(struct nvnc_client* client,
 		struct nvnc_fb*);
-static enum tight_quality client_get_tight_quality(struct nvnc_client* client);
 static void on_encode_frame_done(struct encoder*, struct rcbuf*, uint64_t pts);
 static bool client_has_encoding(const struct nvnc_client* client,
 		enum rfb_encodings encoding);
@@ -500,6 +498,8 @@ static int on_client_set_encodings(struct nvnc_client* client)
 	    sizeof(*msg) + n_encodings * 4)
 		return 0;
 
+	client->quality = 10;
+
 	for (size_t i = 0; i < n_encodings; ++i) {
 		enum rfb_encodings encoding = htonl(msg->encodings[i]);
 
@@ -514,12 +514,14 @@ static int on_client_set_encodings(struct nvnc_client* client)
 		case RFB_ENCODING_OPEN_H264:
 		case RFB_ENCODING_CURSOR:
 		case RFB_ENCODING_DESKTOPSIZE:
-		case RFB_ENCODING_JPEG_HIGHQ:
-		case RFB_ENCODING_JPEG_LOWQ:
 		case RFB_ENCODING_QEMU_EXT_KEY_EVENT:
 		case RFB_ENCODING_PTS:
 			client->encodings[n++] = encoding;
 		}
+
+		if (RFB_ENCODING_JPEG_LOWQ <= encoding &&
+				encoding <= RFB_ENCODING_JPEG_HIGHQ)
+			client->quality = encoding - RFB_ENCODING_JPEG_LOWQ;
 	}
 
 	client->n_encodings = n;
@@ -717,8 +719,7 @@ static void process_fb_update_requests(struct nvnc_client* client)
 
 		client_ref(client);
 
-		int q = client_get_tight_quality(client);
-		encoder_set_tight_quality(client->encoder, q);
+		encoder_set_quality(client->encoder, client->quality);
 		encoder_set_output_format(client->encoder, &client->pixfmt);
 
 		client->encoder->on_done = on_encode_frame_done;
@@ -1109,6 +1110,7 @@ static void on_connection(void* obj)
 
 	client->ref = 1;
 	client->server = server;
+	client->quality = 10; /* default to lossless */
 
 	int fd = accept(server->fd, NULL, 0);
 	if (fd < 0) {
@@ -1367,22 +1369,6 @@ static enum rfb_encodings choose_frame_encoding(struct nvnc_client* client,
 	return RFB_ENCODING_RAW;
 }
 
-static enum tight_quality client_get_tight_quality(struct nvnc_client* client)
-{
-	if (client->pixfmt.bits_per_pixel != 16 &&
-	    client->pixfmt.bits_per_pixel != 32)
-		return TIGHT_QUALITY_LOSSLESS;
-
-	for (size_t i = 0; i < client->n_encodings; ++i)
-		switch (client->encodings[i]) {
-		case RFB_ENCODING_JPEG_HIGHQ: return TIGHT_QUALITY_HIGH;
-		case RFB_ENCODING_JPEG_LOWQ: return TIGHT_QUALITY_LOW;
-		default:;
-		}
-
-	return TIGHT_QUALITY_LOSSLESS;
-}
-
 static bool client_has_encoding(const struct nvnc_client* client,
 		enum rfb_encodings encoding)
 {

src/tight.c

@@ -19,7 +19,6 @@
 #include "common.h"
 #include "pixels.h"
 #include "vec.h"
-#include "tight.h"
 #include "config.h"
 #include "enc-util.h"
 #include "fb.h"
@@ -66,7 +65,7 @@ struct tight_encoder {
 	uint32_t height;
 	uint32_t grid_width;
 	uint32_t grid_height;
-	enum tight_quality quality;
+	int quality;
 
 	struct tight_tile* grid;
 
@@ -350,13 +349,7 @@ static int tight_encode_tile_jpeg(struct tight_encoder* self,
 	unsigned char* buffer = NULL;
 	unsigned long size = 0;
 
-	int quality; /* 1 - 100 */
-
-	switch (self->quality) {
-	case TIGHT_QUALITY_HIGH: quality = 66; break;
-	case TIGHT_QUALITY_LOW: quality = 33; break;
-	default: abort();
-	}
+	int quality = 11 * self->quality + 1;
 
 	uint32_t fourcc = nvnc_fb_get_fourcc_format(self->fb);
 	enum TJPF tjfmt = tight_get_jpeg_pixfmt(fourcc);
@@ -411,17 +404,10 @@ static void tight_encode_tile(struct tight_encoder* self,
 	tile->size = 0;
 
 #ifdef HAVE_JPEG
-	switch (self->quality) {
-	case TIGHT_QUALITY_LOSSLESS:
+	if (self->quality >= 10) {
 		tight_encode_tile_basic(self, tile, x, y, width, height, gx % 4);
-		break;
-	case TIGHT_QUALITY_HIGH:
-	case TIGHT_QUALITY_LOW:
-		// TODO: Use more workers for jpeg
+	} else {
 		tight_encode_tile_jpeg(self, tile, x, y, width, height);
-		break;
-	case TIGHT_QUALITY_UNSPEC:
-		abort();
 	}
 #else
 	tight_encode_tile_basic(self, tile, x, y, width, height, gx % 4);
@@ -620,7 +606,7 @@ static int tight_encoder_encode(struct encoder* encoder, struct nvnc_fb* fb,
 struct encoder_impl encoder_impl_tight = {
 	.destroy = tight_encoder_destroy_wrapper,
 	.set_output_format = tight_encoder_set_output_format,
-	.set_tight_quality = tight_encoder_set_quality,
+	.set_quality = tight_encoder_set_quality,
 	.resize = tight_encoder_resize_wrapper,
 	.encode = tight_encoder_encode,
 };