cras_stream_apm: Apply aecdump to future APM

When we enable aecdump via chrome://webrtc-internals, it is only applied
to the current active APM on that stream. The APM may be removed and a
new one is created, or the active APM can be changed due to iodev
switching. This cause the future APM to not have aecdump applied.

Store the aecdump state on the cras_stream_apm and apply it to the
future APM.

BUG=b:333982642
TEST=Manual test:
     1. Go to chrome://webrtc-internals and start aecdump
     2. Start Meet
     3. Stop aecdump
     4. Unpack the dump and verify that the last stream has
        aec_enabled=1 and the reverse.wav is not empty
TEST=Manual test (Switching device):
     1. Start aecdump
     2. Select internal mic
     3. Start Meet
     4. Switch input to 3.5mm mic jack
     5. Stop aecdump
     6. Check that there is a dump for each input, unpack and check the
        dump
TEST=tast run $DUT audio.ChromeAECDump

Change-Id: I4a807ba3a612d0a4ac19d5761aceebff0d2f7c89
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/5524641
Commit-Queue: Pattara Teerapong <[email protected]>
Tested-by: [email protected] <[email protected]>
Reviewed-by: Li-Yu Yu <[email protected]>

Author: Pattara Teerapong

cras/src/server/cras_stream_apm.c

@@ -111,6 +111,9 @@ struct cras_apm {
   // The time when the apm started.
   struct timespec start_ts;
   struct cras_apm *prev, *next;
+  // Indicate if AEC dump is active on this APM. If this APM is
+  // stopped while AEC dump is active, the dump will be stopped.
+  bool aec_dump_active;
 };
 
 /*
@@ -123,7 +126,7 @@ struct cras_apm {
  * Access with cautious from audio thread.
  */
 struct cras_stream_apm {
-  // The effecets bit map of APM.
+  // The effects bit map of APM.
   uint64_t effects;
   // List of APMs for stream processing. It is a list because
   // multiple input devices could be configured by user.
@@ -132,6 +135,13 @@ struct cras_stream_apm {
   // used as echo ref for this apm. When set to NULL it means to
   // follow what the default_rmod provides as echo ref.
   struct cras_iodev* echo_ref;
+  // Indicate if AEC dump is running or not. AEC dump can be
+  // started and stopped via cras_stream_apm_set_aec_dump.
+  bool aec_dump_enabled;
+  // fd to the AEC dump file if it is running.
+  int aec_dump_fd;
+  // Reference to the APM with AEC dump active.
+  struct cras_apm* aec_dump_active_apm;
 };
 
 static struct actx_apm {
@@ -433,6 +443,64 @@ static inline bool apm_needed_for_effects(uint64_t effects,
   return false;
 }
 
+// Start AEC dump for the APM. Caller must ensure that the stream contains the
+// APM.
+void possibly_start_apm_aec_dump(struct cras_stream_apm* stream,
+                                 struct cras_apm* apm) {
+  if (!stream->aec_dump_enabled) {
+    return;
+  }
+  if (stream->aec_dump_active_apm) {
+    return;
+  }
+
+  // Create or append to the dump file fd.
+  //
+  // aecdump format is appendable. It consists of events in the
+  // third_party/webrtc/modules/audio_processing/debug.proto file.
+  //
+  // Example of aecdump file:
+  //  [CONFIG] [INIT] [REVERSE_STREAM] [STREAM] [REVERSE_STREAM] [STREAM] ...
+  //
+  // unpack_aecdump read through the events. It will create a new set of wave
+  // files on INIT event, and append REVERSE_STREAM and STREAM data to them.
+  //
+  // Appended aecdump content will be in different wave files due to the INIT
+  // event. The frame counter will be continued from the previous aecdump
+  // instead of starting from 0, but the data will be correct.
+  FILE* handle = fdopen(dup(stream->aec_dump_fd), "w");
+  if (handle == NULL) {
+    syslog(LOG_WARNING, "Create dump handle failed, errno %d", errno);
+    return;
+  }
+
+  // webrtc apm will own the FILE handle and close it.
+  int rc = webrtc_apm_aec_dump(apm->apm_ptr, &apm->work_queue, 1, handle);
+  if (rc) {
+    syslog(LOG_WARNING, "Start apm aec dump failed, rc %d", rc);
+  }
+
+  apm->aec_dump_active = true;
+  stream->aec_dump_active_apm = apm;
+}
+
+// Stop AEC dump for the APM. Caller must ensure that the stream contains the
+// APM.
+void possibly_stop_apm_aec_dump(struct cras_stream_apm* stream,
+                                struct cras_apm* apm) {
+  if (!apm->aec_dump_active) {
+    return;
+  }
+
+  int rc = webrtc_apm_aec_dump(apm->apm_ptr, &apm->work_queue, 0, NULL);
+  if (rc) {
+    syslog(LOG_WARNING, "Stop apm aec dump failed, rc %d", rc);
+  }
+
+  apm->aec_dump_active = false;
+  stream->aec_dump_active_apm = NULL;
+}
+
 struct cras_stream_apm* cras_stream_apm_create(uint64_t effects) {
   if (!apm_needed_for_effects(
           effects,
@@ -456,6 +524,9 @@ struct cras_stream_apm* cras_stream_apm_create(uint64_t effects) {
   stream->effects = effects;
   stream->apms = NULL;
   stream->echo_ref = NULL;
+  stream->aec_dump_enabled = false;
+  stream->aec_dump_fd = -1;
+  stream->aec_dump_active_apm = NULL;
 
   return stream;
 }
@@ -558,6 +629,9 @@ void cras_stream_apm_remove(struct cras_stream_apm* stream,
   DL_FOREACH (stream->apms, apm) {
     if (apm->idev == idev) {
       DL_DELETE(stream->apms, apm);
+      if (stream->aec_dump_active_apm == apm) {
+        stream->aec_dump_active_apm = NULL;
+      }
       apm_destroy(&apm);
     }
   }
@@ -781,6 +855,11 @@ void cras_stream_apm_start(struct cras_stream_apm* stream,
   cras_apm_reverse_state_update();
   update_supported_dsp_effects_activation(actx);
   reconfigure_apm_vad(actx);
+
+  // If AEC dump is running, start AEC dump for this new APM.
+  if (stream->aec_dump_enabled) {
+    possibly_start_apm_aec_dump(stream, apm);
+  }
 }
 
 void cras_stream_apm_stop(struct cras_stream_apm* stream,
@@ -805,6 +884,11 @@ void cras_stream_apm_stop(struct cras_stream_apm* stream,
       apm_state.last_nc_closed = now;
     }
 
+    // If AEC dump is active on this APM, stop it.
+    if (active->apm->aec_dump_active) {
+      possibly_stop_apm_aec_dump(stream, active->apm);
+    }
+
     DL_DELETE(actx->apm->active_apms, active);
     free(active);
   }
@@ -835,6 +919,10 @@ int cras_stream_apm_destroy(struct cras_stream_apm* stream) {
   // Unlink any linked echo ref.
   cras_apm_reverse_link_echo_ref(stream, NULL);
 
+  if (stream->aec_dump_enabled) {
+    close(stream->aec_dump_fd);
+  }
+
   DL_FOREACH (stream->apms, apm) {
     DL_DELETE(stream->apms, apm);
     apm_destroy(&apm);
@@ -1270,31 +1358,41 @@ void cras_stream_apm_set_aec_dump(struct cras_stream_apm* stream,
                                   int start,
                                   int fd) {
   struct cras_apm* apm;
-  char file_name[256];
-  int rc;
-  FILE* handle;
 
   DL_SEARCH_SCALAR(stream->apms, apm, idev, idev);
   if (apm == NULL) {
     return;
   }
 
   if (start) {
-    handle = fdopen(fd, "w");
-    if (handle == NULL) {
-      syslog(LOG_WARNING, "Create dump handle fail, errno %d", errno);
-      return;
-    }
-    // webrtc apm will own the FILE handle and close it.
-    rc = webrtc_apm_aec_dump(apm->apm_ptr, &apm->work_queue, start, handle);
-    if (rc) {
-      syslog(LOG_WARNING, "Fail to dump debug file %s, rc %d", file_name, rc);
+    if (stream->aec_dump_enabled) {
+      // If AEC dump is already running, keep it running. If the new fd is
+      // different, close the previous one.
+      //
+      // If there is an APM with active AEC dump, possibly_start_apm_aec_dump
+      // will fail (do nothing). New APM created after that will use the new fd.
+      syslog(LOG_WARNING,
+             "got aec dump start request, but it is already running");
+      if (fd != stream->aec_dump_fd) {
+        close(stream->aec_dump_fd);
+      }
     }
+    stream->aec_dump_enabled = true;
+    stream->aec_dump_fd = fd;
+    possibly_start_apm_aec_dump(stream, apm);
   } else {
-    rc = webrtc_apm_aec_dump(apm->apm_ptr, &apm->work_queue, 0, NULL);
-    if (rc) {
-      syslog(LOG_WARNING, "Failed to stop apm debug, rc %d", rc);
+    if (!stream->aec_dump_enabled) {
+      syslog(LOG_WARNING, "got aec dump stop request, but it is not running");
+      return;
+    }
+
+    // Stop the AEC dump on the APM with active dump.
+    if (stream->aec_dump_active_apm) {
+      possibly_stop_apm_aec_dump(stream, stream->aec_dump_active_apm);
     }
+
+    stream->aec_dump_enabled = false;
+    close(stream->aec_dump_fd);
   }
 }