Quit on audio configuration failure

When audio capture fails on the device, scrcpy continue mirroring the
video stream. This allows to enable audio by default only when
supported.

However, if an audio configuration occurs (for example the user
explicitly selected an unknown audio encoder), this must be treated as
an error and scrcpy must exit.

PR #3757 <Genymobile/scrcpy#3757>

Author: rom1v

app/src/demuxer.c

@@ -195,6 +195,12 @@ run_demuxer(void *data) {
         goto end;
     }
 
+    if (raw_codec_id == 1) {
+        LOGE("Demuxer '%s': stream configuration error on the device",
+             demuxer->name);
+        goto end;
+    }
+
     enum AVCodecID codec_id = sc_demuxer_to_avcodec_id(raw_codec_id);
     if (codec_id == AV_CODEC_ID_NONE) {
         LOGE("Demuxer '%s': stream disabled due to unsupported codec",

app/src/scrcpy.c

@@ -231,10 +231,19 @@ 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
+    // Contrary to the video demuxer, keep mirroring if only the audio fails.
+    // 'eos' is true on end-of-stream, including when audio capture is not
+    // possible on the device (so that scrcpy continue to mirror video without
+    // failing).
+    // However, if an audio configuration failure occurs (for example the user
+    // explicitly selected an unknown audio encoder), 'eos' is false and scrcpy
+    // must exit.
+
+    if (!eos) {
+        PUSH_EVENT(SC_EVENT_DEMUXER_ERROR);
+    }
 }
 
 static void

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

@@ -222,7 +222,7 @@ private synchronized void waitEnded() {
     public void encode() throws IOException, ConfigurationException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
             Ln.w("Audio disabled: it is not supported before Android 11");
-            streamer.writeDisableStream();
+            streamer.writeDisableStream(false);
             return;
         }
 
@@ -279,9 +279,13 @@ public void encode() throws IOException, ConfigurationException {
             outputThread.start();
 
             waitEnded();
+        } catch (ConfigurationException e) {
+            // Notify the error to make scrcpy exit
+            streamer.writeDisableStream(true);
+            throw e;
         } catch (Throwable e) {
             // Notify the client that the audio could not be captured
-            streamer.writeDisableStream();
+            streamer.writeDisableStream(false);
             throw e;
         } finally {
             // Cleanup everything (either at the end or on error at any step of the initialization)

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

@@ -40,10 +40,15 @@ public void writeHeader() throws IOException {
         }
     }
 
-    public void writeDisableStream() throws IOException {
-        // Writing 0 (32-bit) as codec-id means that the device disables the stream (because it could not capture)
-        byte[] zeros = new byte[4];
-        IO.writeFully(fd, zeros, 0, zeros.length);
+    public void writeDisableStream(boolean error) throws IOException {
+        // Writing a specific code as codec-id means that the device disables the stream
+        //   code 0: it explicitly disables the stream (because it could not capture audio), scrcpy should continue mirroring video only
+        //   code 1: a configuration error occurred, scrcpy must be stopped
+        byte[] code = new byte[4];
+        if (error) {
+            code[3] = 1;
+        }
+        IO.writeFully(fd, code, 0, code.length);
     }
 
     public void writePacket(ByteBuffer buffer, long pts, boolean config, boolean keyFrame) throws IOException {