Add an audio demuxer

Add a demuxer which will read the stream from the audio socket.

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

app/src/demuxer.c

@@ -23,6 +23,7 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
 #define SC_CODEC_ID_H264 UINT32_C(0x68323634) // "h264" in ASCII
 #define SC_CODEC_ID_H265 UINT32_C(0x68323635) // "h265" in ASCII
 #define SC_CODEC_ID_AV1 UINT32_C(0x00617631) // "av1" in ASCII
+#define SC_CODEC_ID_OPUS UINT32_C(0x6f707573) // "opus" in ASCII
     switch (codec_id) {
         case SC_CODEC_ID_H264:
             return AV_CODEC_ID_H264;
@@ -30,6 +31,8 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
             return AV_CODEC_ID_HEVC;
         case SC_CODEC_ID_AV1:
             return AV_CODEC_ID_AV1;
+        case SC_CODEC_ID_OPUS:
+            return AV_CODEC_ID_OPUS;
         default:
             LOGE("Unknown codec id 0x%08" PRIx32, codec_id);
             return AV_CODEC_ID_NONE;
@@ -233,6 +236,8 @@ end:
 void
 sc_demuxer_init(struct sc_demuxer *demuxer, const char *name, sc_socket socket,
                 const struct sc_demuxer_callbacks *cbs, void *cbs_userdata) {
+    assert(socket != SC_SOCKET_NONE);
+
     demuxer->name = name; // statically allocated
     demuxer->socket = socket;
     demuxer->sink_count = 0;

app/src/scrcpy.c

@@ -41,6 +41,7 @@ struct scrcpy {
     struct sc_server server;
     struct sc_screen screen;
     struct sc_demuxer video_demuxer;
+    struct sc_demuxer audio_demuxer;
     struct sc_decoder decoder;
     struct sc_recorder recorder;
 #ifdef HAVE_V4L2
@@ -225,6 +226,16 @@ sc_video_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
     }
 }
 
+static void
+sc_audio_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos,
+                          void *userdata) {
+    (void) demuxer;
+    (void) eos;
+    (void) userdata;
+
+    // Contrary to the video demuxer, keep mirroring if only the audio fails
+}
+
 static void
 sc_server_on_connection_failed(struct sc_server *server, void *userdata) {
     (void) server;
@@ -283,6 +294,7 @@ scrcpy(struct scrcpy_options *options) {
     bool v4l2_sink_initialized = false;
 #endif
     bool video_demuxer_started = false;
+    bool audio_demuxer_started = false;
 #ifdef HAVE_USB
     bool aoa_hid_initialized = false;
     bool hid_keyboard_initialized = false;
@@ -390,6 +402,14 @@ scrcpy(struct scrcpy_options *options) {
     sc_demuxer_init(&s->video_demuxer, "video", s->server.video_socket,
                     &video_demuxer_cbs, NULL);
 
+    if (options->audio) {
+        static const struct sc_demuxer_callbacks audio_demuxer_cbs = {
+            .on_ended = sc_audio_demuxer_on_ended,
+        };
+        sc_demuxer_init(&s->audio_demuxer, "audio", s->server.audio_socket,
+                        &audio_demuxer_cbs, NULL);
+    }
+
     bool needs_decoder = options->display;
 #ifdef HAVE_V4L2
     needs_decoder |= !!options->v4l2_device;
@@ -629,6 +649,13 @@ aoa_hid_end:
     }
     video_demuxer_started = true;
 
+    if (options->audio) {
+        if (!sc_demuxer_start(&s->audio_demuxer)) {
+            goto end;
+        }
+        audio_demuxer_started = true;
+    }
+
     ret = event_loop(s);
     LOGD("quit...");
 
@@ -678,6 +705,10 @@ end:
         sc_demuxer_join(&s->video_demuxer);
     }
 
+    if (audio_demuxer_started) {
+        sc_demuxer_join(&s->audio_demuxer);
+    }
+
 #ifdef HAVE_V4L2
     if (v4l2_sink_initialized) {
         sc_v4l2_sink_destroy(&s->v4l2_sink);