Add --list-encoders

Add an option to list the device encoders properly.

PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>

README.md

@@ -273,12 +273,10 @@ may cause issues or crash. It is possible to select a different encoder:
 scrcpy --video-encoder=OMX.qcom.video.encoder.avc
 ```
 
-To list the available encoders, you can pass an invalid encoder name; the
-error will give the available encoders:
+To list the available encoders:
 
 ```bash
-scrcpy --video-encoder=_                     # for the default codec
-scrcpy --video-codec=h265 --video-encoder=_  # for a specific codec
+scrcpy --list-encoders
 ```
 
 ### Capture

app/data/bash-completion/scrcpy

@@ -19,6 +19,7 @@ _scrcpy() {
         -K --hid-keyboard
         -h --help
         --legacy-paste
+        --list-encoders
         --lock-video-orientation
         --lock-video-orientation=
         --max-fps=

app/data/zsh-completion/_scrcpy

@@ -26,6 +26,7 @@ arguments=(
     {-K,--hid-keyboard}'[Simulate a physical keyboard by using HID over AOAv2]'
     {-h,--help}'[Print the help]'
     '--legacy-paste[Inject computer clipboard text as a sequence of key events on Ctrl+v]'
+    '--list-encoders[List video and audio encoders available on the device]'
     '--lock-video-orientation=[Lock video orientation]:orientation:(unlocked initial 0 1 2 3)'
     '--max-fps=[Limit the frame rate of screen capture]'
     {-M,--hid-mouse}'[Simulate a physical mouse by using HID over AOAv2]'

app/scrcpy.1

@@ -45,6 +45,8 @@ The list of possible codec options is available in the Android documentation
 .BI "\-\-audio\-encoder " name
 Use a specific MediaCodec audio encoder (depending on the codec provided by \fB\-\-audio\-codec\fR).
 
+The available encoders can be listed by \-\-list\-encoders.
+
 .TP
 .BI "\-b, \-\-video\-bit\-rate " value
 Encode the video at the given bit\-rate, expressed in bits/s. Unit suffixes are supported: '\fBK\fR' (x1000) and '\fBM\fR' (x1000000).
@@ -128,6 +130,10 @@ Inject computer clipboard text as a sequence of key events on Ctrl+v (like MOD+S
 
 This is a workaround for some devices not behaving as expected when setting the device clipboard programmatically.
 
+.TP
+.B \-\-list\-encoders
+List video and audio encoders available on the device.
+
 .TP
 \fB\-\-lock\-video\-orientation\fR[=\fIvalue\fR]
 Lock video orientation to \fIvalue\fR. Possible values are "unlocked", "initial" (locked to the initial orientation), 0, 1, 2 and 3. Natural device orientation is 0, and each increment adds a 90 degrees rotation counterclockwise.
@@ -355,6 +361,8 @@ The list of possible codec options is available in the Android documentation
 .BI "\-\-video\-encoder " name
 Use a specific MediaCodec video encoder (depending on the codec provided by \fB\-\-video\-codec\fR).
 
+The available encoders can be listed by \-\-list\-encoders.
+
 .TP
 .B \-w, \-\-stay-awake
 Keep the device on while scrcpy is running, when the device is plugged in.

app/src/cli.c

@@ -68,6 +68,7 @@ enum {
     OPT_AUDIO_CODEC,
     OPT_AUDIO_CODEC_OPTIONS,
     OPT_AUDIO_ENCODER,
+    OPT_LIST_ENCODERS,
 };
 
 struct sc_option {
@@ -141,7 +142,8 @@ static const struct sc_option options[] = {
         .longopt = "audio-encoder",
         .argdesc = "name",
         .text = "Use a specific MediaCodec audio encoder (depending on the "
-                "codec provided by --audio-codec).",
+                "codec provided by --audio-codec).\n"
+                "The available encoders can be listed by --list-encoders.",
     },
     {
         .shortopt = 'b',
@@ -270,6 +272,11 @@ static const struct sc_option options[] = {
                 "This is a workaround for some devices not behaving as "
                 "expected when setting the device clipboard programmatically.",
     },
+    {
+        .longopt_id = OPT_LIST_ENCODERS,
+        .longopt = "list-encoders",
+        .text = "List video and audio encoders available on the device.",
+    },
     {
         .longopt_id = OPT_LOCK_VIDEO_ORIENTATION,
         .longopt = "lock-video-orientation",
@@ -586,7 +593,8 @@ static const struct sc_option options[] = {
         .longopt = "video-encoder",
         .argdesc = "name",
         .text = "Use a specific MediaCodec video encoder (depending on the "
-                "codec provided by --video-codec).",
+                "codec provided by --video-codec).\n"
+                "The available encoders can be listed by --list-encoders.",
     },
     {
         .shortopt = 'w',
@@ -1792,6 +1800,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
                 LOGE("V4L2 (--v4l2-buffer) is only available on Linux.");
                 return false;
 #endif
+            case OPT_LIST_ENCODERS:
+                opts->list_encoders = true;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/options.c

@@ -72,4 +72,5 @@ const struct scrcpy_options scrcpy_options_default = {
     .start_fps_counter = false,
     .power_on = true,
     .audio = true,
+    .list_encoders = false,
 };

app/src/options.h

@@ -154,6 +154,7 @@ struct scrcpy_options {
     bool start_fps_counter;
     bool power_on;
     bool audio;
+    bool list_encoders;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/scrcpy.c

@@ -183,12 +183,16 @@ await_for_server(bool *connected) {
     while (SDL_WaitEvent(&event)) {
         switch (event.type) {
             case SDL_QUIT:
-                *connected = false;
+                if (connected) {
+                    *connected = false;
+                }
                 return true;
             case SC_EVENT_SERVER_CONNECTION_FAILED:
                 return false;
             case SC_EVENT_SERVER_CONNECTED:
-                *connected = true;
+                if (connected) {
+                    *connected = true;
+                }
                 return true;
             default:
                 break;
@@ -339,6 +343,7 @@ scrcpy(struct scrcpy_options *options) {
         .tcpip_dst = options->tcpip_dst,
         .cleanup = options->cleanup,
         .power_on = options->power_on,
+        .list_encoders = options->list_encoders,
     };
 
     static const struct sc_server_callbacks cbs = {
@@ -356,6 +361,12 @@ scrcpy(struct scrcpy_options *options) {
 
     server_started = true;
 
+    if (options->list_encoders) {
+        bool ok = await_for_server(NULL);
+        ret = ok ? SCRCPY_EXIT_SUCCESS : SCRCPY_EXIT_FAILURE;
+        goto end;
+    }
+
     if (options->display) {
         sdl_set_hints(options->render_driver);
     }

app/src/server.c

@@ -300,6 +300,9 @@ execute_server(struct sc_server *server,
         // By default, power_on is true
         ADD_PARAM("power_on=false");
     }
+    if (params->list_encoders) {
+        ADD_PARAM("list_encoders=true");
+    }
 
 #undef ADD_PARAM
 
@@ -848,6 +851,25 @@ run_server(void *data) {
     assert(serial);
     LOGD("Device serial: %s", serial);
 
+    ok = push_server(&server->intr, serial);
+    if (!ok) {
+        goto error_connection_failed;
+    }
+
+    // If --list-encoders is passed, then the server just prints the encoders
+    // then exits.
+    if (params->list_encoders) {
+        sc_pid pid = execute_server(server, params);
+        if (pid == SC_PROCESS_NONE) {
+            goto error_connection_failed;
+        }
+        sc_process_wait(pid, NULL); // ignore exit code
+        sc_process_close(pid);
+        // Wake up await_for_server()
+        server->cbs->on_connected(server, server->cbs_userdata);
+        return 0;
+    }
+
     int r = asprintf(&server->device_socket_name, SC_SOCKET_NAME_PREFIX "%08x",
                      params->scid);
     if (r == -1) {
@@ -857,11 +879,6 @@ run_server(void *data) {
     assert(r == sizeof(SC_SOCKET_NAME_PREFIX) - 1 + 8);
     assert(server->device_socket_name);
 
-    ok = push_server(&server->intr, serial);
-    if (!ok) {
-        goto error_connection_failed;
-    }
-
     ok = sc_adb_tunnel_open(&server->tunnel, &server->intr, serial,
                             server->device_socket_name, params->port_range,
                             params->force_adb_forward);

app/src/server.h

@@ -55,6 +55,7 @@ struct sc_server_params {
     bool select_tcpip;
     bool cleanup;
     bool power_on;
+    bool list_encoders;
 };
 
 struct sc_server {

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

@@ -334,7 +334,7 @@ public final class AudioEncoder {
             try {
                 return MediaCodec.createByCodecName(encoderName);
             } catch (IllegalArgumentException e) {
-                Ln.e(CodecUtils.buildUnknownEncoderMessage(codec, encoderName));
+                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + CodecUtils.buildAudioEncoderListMessage());
                 throw new ConfigurationException("Unknown encoder: " + encoderName);
             }
         }

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

@@ -139,7 +139,7 @@ public final class CleanUp {
         builder.start();
     }
 
-    private static void unlinkSelf() {
+    public static void unlinkSelf() {
         try {
             new File(SERVER_PATH).delete();
         } catch (Exception e) {

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

@@ -10,6 +10,24 @@ import java.util.List;
 
 public final class CodecUtils {
 
+    public static final class DeviceEncoder {
+        private final Codec codec;
+        private final MediaCodecInfo info;
+
+        DeviceEncoder(Codec codec, MediaCodecInfo info) {
+            this.codec = codec;
+            this.info = info;
+        }
+
+        public Codec getCodec() {
+            return codec;
+        }
+
+        public MediaCodecInfo getInfo() {
+            return info;
+        }
+    }
+
     private CodecUtils() {
         // not instantiable
     }
@@ -26,28 +44,63 @@ public final class CodecUtils {
         }
     }
 
-    public static String buildUnknownEncoderMessage(Codec codec, String encoderName) {
-        StringBuilder msg = new StringBuilder("Encoder '").append(encoderName).append("' for ").append(codec.getName()).append(" not found");
-        MediaCodecInfo[] encoders = listEncoders(codec.getMimeType());
-        if (encoders != null && encoders.length > 0) {
-            msg.append("\nTry to use one of the available encoders:");
-            String codecOption = codec.getType() == Codec.Type.VIDEO ? "video-codec" : "audio-codec";
-            for (MediaCodecInfo encoder : encoders) {
-                msg.append("\n    scrcpy --").append(codecOption).append("=").append(codec.getName());
-                msg.append(" --encoder='").append(encoder.getName()).append("'");
+    public static String buildVideoEncoderListMessage() {
+        StringBuilder builder = new StringBuilder("List of video encoders:");
+        List<CodecUtils.DeviceEncoder> videoEncoders = CodecUtils.listVideoEncoders();
+        if (videoEncoders.isEmpty()) {
+            builder.append("\n    (none)");
+        } else {
+            for (CodecUtils.DeviceEncoder encoder : videoEncoders) {
+                builder.append("\n    --video-codec=").append(encoder.getCodec().getName());
+                builder.append(" --video-encoder='").append(encoder.getInfo().getName()).append("'");
             }
         }
-        return msg.toString();
+        return builder.toString();
     }
 
-    private static MediaCodecInfo[] listEncoders(String mimeType) {
+    public static String buildAudioEncoderListMessage() {
+        StringBuilder builder = new StringBuilder("List of audio encoders:");
+        List<CodecUtils.DeviceEncoder> audioEncoders = CodecUtils.listAudioEncoders();
+        if (audioEncoders.isEmpty()) {
+            builder.append("\n    (none)");
+        } else {
+            for (CodecUtils.DeviceEncoder encoder : audioEncoders) {
+                builder.append("\n    --audio-codec=").append(encoder.getCodec().getName());
+                builder.append(" --audio-encoder='").append(encoder.getInfo().getName()).append("'");
+            }
+        }
+        return builder.toString();
+    }
+
+    private static MediaCodecInfo[] getEncoders(MediaCodecList codecs, String mimeType) {
         List<MediaCodecInfo> result = new ArrayList<>();
-        MediaCodecList list = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
-        for (MediaCodecInfo codecInfo : list.getCodecInfos()) {
+        for (MediaCodecInfo codecInfo : codecs.getCodecInfos()) {
             if (codecInfo.isEncoder() && Arrays.asList(codecInfo.getSupportedTypes()).contains(mimeType)) {
                 result.add(codecInfo);
             }
         }
         return result.toArray(new MediaCodecInfo[result.size()]);
     }
+
+    public static List<DeviceEncoder> listVideoEncoders() {
+        List<DeviceEncoder> encoders = new ArrayList<>();
+        MediaCodecList codecs = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
+        for (VideoCodec codec : VideoCodec.values()) {
+            for (MediaCodecInfo info : getEncoders(codecs, codec.getMimeType())) {
+                encoders.add(new DeviceEncoder(codec, info));
+            }
+        }
+        return encoders;
+    }
+
+    public static List<DeviceEncoder> listAudioEncoders() {
+        List<DeviceEncoder> encoders = new ArrayList<>();
+        MediaCodecList codecs = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
+        for (AudioCodec codec : AudioCodec.values()) {
+            for (MediaCodecInfo info : getEncoders(codecs, codec.getMimeType())) {
+                encoders.add(new DeviceEncoder(codec, info));
+            }
+        }
+        return encoders;
+    }
 }

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

@@ -33,6 +33,8 @@ public class Options {
     private boolean cleanup = true;
     private boolean powerOn = true;
 
+    private boolean listEncoders;
+
     // Options not used by the scrcpy client, but useful to use scrcpy-server directly
     private boolean sendDeviceMeta = true; // send device name and size
     private boolean sendFrameMeta = true; // send PTS so that the client may record properly
@@ -239,6 +241,14 @@ public class Options {
         this.powerOn = powerOn;
     }
 
+    public boolean getListEncoders() {
+        return listEncoders;
+    }
+
+    public void setListEncoders(boolean listEncoders) {
+        this.listEncoders = listEncoders;
+    }
+
     public boolean getSendDeviceMeta() {
         return sendDeviceMeta;
     }

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

@@ -202,7 +202,7 @@ public class ScreenEncoder implements Device.RotationListener {
             try {
                 return MediaCodec.createByCodecName(encoderName);
             } catch (IllegalArgumentException e) {
-                Ln.e(CodecUtils.buildUnknownEncoderMessage(codec, encoderName));
+                Ln.e("Encoder '" + encoderName + "' for " + codec.getName() + " not found\n" + CodecUtils.buildVideoEncoderListMessage());
                 throw new ConfigurationException("Unknown encoder: " + encoderName);
             }
         }

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

@@ -291,6 +291,10 @@ public final class Server {
                     boolean powerOn = Boolean.parseBoolean(value);
                     options.setPowerOn(powerOn);
                     break;
+                case "list_encoders":
+                    boolean listEncoders = Boolean.parseBoolean(value);
+                    options.setListEncoders(listEncoders);
+                    break;
                 case "send_device_meta":
                     boolean sendDeviceMeta = Boolean.parseBoolean(value);
                     options.setSendDeviceMeta(sendDeviceMeta);
@@ -350,6 +354,17 @@ public final class Server {
 
         Ln.initLogLevel(options.getLogLevel());
 
+        if (options.getListEncoders()) {
+            if (options.getCleanup()) {
+                CleanUp.unlinkSelf();
+            }
+
+            Ln.i(CodecUtils.buildVideoEncoderListMessage());
+            Ln.i(CodecUtils.buildAudioEncoderListMessage());
+            // Just print the available encoders, do not mirror
+            return;
+        }
+
         try {
             scrcpy(options);
         } catch (ConfigurationException e) {