Add bit-rate command-line option

Add a command-line option (-b/--bit-rate) to customize the video
bit-rate.

app/src/main.c

@@ -6,13 +6,15 @@
 #include <SDL2/SDL.h>
 
 #define DEFAULT_LOCAL_PORT 27183
-#define DEFAULT_MAX_SIZE 0
+#define DEFAULT_MAX_SIZE 0 // unlimited
+#define DEFAULT_BIT_RATE 4000000 // 4Mbps
 
 struct args {
     const char *serial;
     SDL_bool help;
     Uint16 port;
     Uint16 max_size;
+    Uint32 bit_rate;
 };
 
 static void usage(const char *arg0) {
@@ -25,6 +27,11 @@ static void usage(const char *arg0) {
         "\n"
         "Options:\n"
         "\n"
+        "    -b, --bit-rate value\n"
+        "        Encode the video at the given bit-rate, expressed in bits/s.\n"
+        "        Unit suffixes are supported: 'K' (x1000) and 'M' (x1000000).\n"
+        "        Default is %d.\n"
+        "\n"
         "    -h, --help\n"
         "        Print this help.\n"
         "\n"
@@ -45,6 +52,7 @@ static void usage(const char *arg0) {
         "    Ctrl+x: resize window to optimal size (remove black borders)\n"
         "\n",
         arg0,
+        DEFAULT_BIT_RATE,
         DEFAULT_MAX_SIZE, DEFAULT_MAX_SIZE ? "" : " (unlimited)",
         DEFAULT_LOCAL_PORT);
 }
@@ -54,10 +62,11 @@ static int parse_args(struct args *args, int argc, char *argv[]) {
         {"help",     no_argument,       NULL, 'h'},
         {"port",     required_argument, NULL, 'p'},
         {"max-size", required_argument, NULL, 'm'},
+        {"bit-rate", required_argument, NULL, 'b'},
         {NULL,       0,                 NULL, 0  },
     };
     int c;
-    while ((c = getopt_long(argc, argv, "hp:m:", long_options, NULL)) != -1) {
+    while ((c = getopt_long(argc, argv, "hp:m:b:", long_options, NULL)) != -1) {
         switch (c) {
             case 'h': {
                 args->help = SDL_TRUE;
@@ -99,6 +108,35 @@ static int parse_args(struct args *args, int argc, char *argv[]) {
                 args->max_size = (Uint16) value;
                 break;
             }
+            case 'b': {
+                char *endptr;
+                if (*optarg == '\0') {
+                    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Bit-rate parameter is empty");
+                    return -1;
+                }
+                long value = strtol(optarg, &endptr, 0);
+                int mul = 1;
+                if (*endptr != '\0') {
+                    if (optarg == endptr) {
+                        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Invalid bit-rate: %s", optarg);
+                        return -1;
+                    }
+                    if ((*endptr == 'M' || *endptr == 'm') && endptr[1] == '\0') {
+                        mul = 1000000;
+                    } else if ((*endptr == 'K' || *endptr == 'k') && endptr[1] == '\0') {
+                        mul = 1000;
+                    } else {
+                        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Invalid bit-rate unit: %s", optarg);
+                        return -1;
+                    }
+                }
+                if (value < 0 || ((Uint32) -1) / mul < value) {
+                    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Bitrate must be positive and less than 2^32: %s", optarg);
+                    return -1;
+                }
+                args->bit_rate = (Uint32) value * mul;
+                break;
+            }
             default:
                 // getopt prints the error message on stderr
                 return -1;
@@ -120,10 +158,11 @@ int main(int argc, char *argv[]) {
     int res;
 
     struct args args = {
-        .help = SDL_FALSE,
         .serial = NULL,
-        .max_size = DEFAULT_MAX_SIZE,
+        .help = SDL_FALSE,
         .port = DEFAULT_LOCAL_PORT,
+        .max_size = DEFAULT_MAX_SIZE,
+        .bit_rate = DEFAULT_BIT_RATE,
     };
     if (parse_args(&args, argc, argv)) {
         usage(argv[0]);
@@ -143,7 +182,7 @@ int main(int argc, char *argv[]) {
 
     SDL_LogSetAllPriority(SDL_LOG_PRIORITY_DEBUG);
 
-    res = scrcpy(args.serial, args.port, args.max_size) ? 0 : 1;
+    res = scrcpy(args.serial, args.port, args.max_size, args.bit_rate) ? 0 : 1;
 
     avformat_network_deinit(); // ignore failure
 

app/src/scrcpy.c

@@ -417,7 +417,7 @@ void event_loop(void) {
     }
 }
 
-SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size) {
+SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size, Uint32 bit_rate) {
     SDL_bool ret = 0;
 
     process_t push_proc = push_server(serial);
@@ -437,7 +437,7 @@ SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size) {
     }
 
     // server will connect to our socket
-    process_t server = start_server(serial, max_size);
+    process_t server = start_server(serial, max_size, bit_rate);
     if (server == PROCESS_NONE) {
         ret = SDL_FALSE;
         SDLNet_TCP_Close(server_socket);

app/src/scrcpy.h

@@ -3,6 +3,6 @@
 
 #include <SDL2/SDL_stdinc.h>
 
-SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size);
+SDL_bool scrcpy(const char *serial, Uint16 local_port, Uint16 max_size, Uint32 bit_rate);
 
 #endif

app/src/server.c

@@ -2,6 +2,7 @@
 
 #include <SDL2/SDL_log.h>
 #include <errno.h>
+#include <stdint.h>
 
 #define SOCKET_NAME "scrcpy"
 
@@ -21,9 +22,11 @@ process_t disable_tunnel(const char *serial) {
     return adb_reverse_remove(serial, SOCKET_NAME);
 }
 
-process_t start_server(const char *serial, Uint16 max_size) {
+process_t start_server(const char *serial, Uint16 max_size, Uint32 bit_rate) {
     char max_size_string[6];
-    sprintf(max_size_string, "%d", max_size);
+    char bit_rate_string[11];
+    sprintf(max_size_string, "%"PRIu16, max_size);
+    sprintf(bit_rate_string, "%"PRIu32, bit_rate);
     const char *const cmd[] = {
         "shell",
         "CLASSPATH=/data/local/tmp/scrcpy.apk",
@@ -31,6 +34,7 @@ process_t start_server(const char *serial, Uint16 max_size) {
         "/", // unused
         "com.genymobile.scrcpy.ScrCpyServer",
         max_size_string,
+        bit_rate_string,
     };
     return adb_execute(serial, cmd, sizeof(cmd) / sizeof(cmd[0]));
 }

app/src/server.h

@@ -4,5 +4,5 @@ process_t push_server(const char *serial);
 process_t enable_tunnel(const char *serial, Uint16 local_port);
 process_t disable_tunnel(const char *serial);
 
-process_t start_server(const char *serial, Uint16 max_size);
+process_t start_server(const char *serial, Uint16 max_size, Uint32 bit_rate);
 void stop_server(process_t server);

server/src/main/java/com/genymobile/scrcpy/Options.java

@@ -2,6 +2,7 @@ package com.genymobile.scrcpy;
 
 public class Options {
     private int maxSize;
+    private int bitRate;
 
     public int getMaxSize() {
         return maxSize;
@@ -10,4 +11,12 @@ public class Options {
     public void setMaxSize(int maxSize) {
         this.maxSize = maxSize;
     }
+
+    public int getBitRate() {
+        return bitRate;
+    }
+
+    public void setBitRate(int bitRate) {
+        this.bitRate = bitRate;
+    }
 }

server/src/main/java/com/genymobile/scrcpy/ScrCpyServer.java

@@ -7,7 +7,7 @@ public class ScrCpyServer {
     private static void scrcpy(Options options) throws IOException {
         final Device device = new Device(options);
         try (DesktopConnection connection = DesktopConnection.open(device)) {
-            ScreenEncoder screenEncoder = new ScreenEncoder();
+            ScreenEncoder screenEncoder = new ScreenEncoder(options.getBitRate());
 
             // asynchronous
             startEventController(device, connection);
@@ -36,10 +36,18 @@ public class ScrCpyServer {
 
     private static Options createOptions(String... args) {
         Options options = new Options();
-        if (args.length > 0) {
+        if (args.length < 1) {
+            return options;
+        }
         int maxSize = Integer.parseInt(args[0]) & ~7; // multiple of 8
         options.setMaxSize(maxSize);
+
+        if (args.length < 2) {
+            return options;
         }
+        int bitRate = Integer.parseInt(args[1]);
+        options.setBitRate(bitRate);
+
         return options;
     }
 

server/src/main/java/com/genymobile/scrcpy/ScreenEncoder.java

@@ -34,6 +34,10 @@ public class ScreenEncoder implements Device.RotationListener {
         this.iFrameInterval = iFrameInterval;
     }
 
+    public ScreenEncoder(int bitRate) {
+        this(bitRate, DEFAULT_FRAME_RATE, DEFAULT_I_FRAME_INTERVAL);
+    }
+
     public ScreenEncoder() {
         this(DEFAULT_BIT_RATE, DEFAULT_FRAME_RATE, DEFAULT_I_FRAME_INTERVAL);
     }