Fix sound volume editing in ffmpeg mode

1. Handle sound volume changing signal.
2. Handle muted state of audio output instead of auto-muting flag.
3. Dont't use auto-muting for playback rates out of range [0.5; 2.].
   Checked: other backends don't do it as well.
   Auto-muting is a user's responsibility.

Note, it's pretty hard to implement tests for it now,
since audio output is not mocked,
and ffmpeg part is to be refactored after 6.4.

Task-number: QTBUG-105619
Change-Id: I51a2f353275d4ba3c1dc4678e34f0b31f1030264
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
(cherry picked from commit c9fb537f3687e9cbe3c86c8ea8704db27007d81f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 14 insertions, 6 deletions

diff --git a/src/plugins/multimedia/ffmpeg/qffmpegdecoder.cpp b/src/plugins/multimedia/ffmpeg/qffmpegdecoder.cpp
index 0b406e5a9..ad6ddc53d 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpegdecoder.cpp
+++ b/src/plugins/multimedia/ffmpeg/qffmpegdecoder.cpp
@@ -740,6 +740,7 @@ AudioRenderer::AudioRenderer(Decoder *decoder, QAudioOutput *output)
     , output(output)
 {
     connect(output, &QAudioOutput::deviceChanged, this, &AudioRenderer::updateAudio);
+    connect(output, &QAudioOutput::volumeChanged, this, &AudioRenderer::setSoundVolume);
 }
 
 void AudioRenderer::syncTo(qint64 usecs)
@@ -769,10 +770,9 @@ void AudioRenderer::updateOutput(const Codec *codec)
     format = QFFmpegMediaFormatInfo::audioFormatFromCodecParameters(audioStream->codecpar);
     format.setChannelConfig(dev.channelConfiguration());
 
-    if (playbackRate() < 0.5 || playbackRate() > 2)
-        audioMuted = true;
-
     audioSink = new QAudioSink(dev, format);
+    audioSink->setVolume(output->volume());
+
     audioSink->setBufferSize(format.bytesForDuration(100000));
     audioDevice = audioSink->start();
     latencyUSecs = format.durationForBytes(audioSink->bufferSize()); // ### ideally get full latency
@@ -798,7 +798,7 @@ void AudioRenderer::freeOutput()
         audioSink = nullptr;
         audioDevice = nullptr;
     }
-    audioMuted = false;
+
     bufferedData = {};
     bufferWritten = 0;
 
@@ -867,7 +867,7 @@ void AudioRenderer::loop()
         if (!paused) {
             auto buffer = resampler->resample(frame.avFrame());
 
-            if (audioMuted)
+            if (output->isMuted())
                 // This is somewhat inefficient, but it'll work
                 memset(buffer.data<char>(), 0, buffer.byteCount());
 
@@ -909,6 +909,14 @@ void AudioRenderer::updateAudio()
     deviceChanged = true;
 }
 
+void AudioRenderer::setSoundVolume(float volume)
+{
+    QMutexLocker locker(&mutex);
+
+    if (audioSink)
+        audioSink->setVolume(volume);
+}
+
 Decoder::Decoder()
 {
 }
diff --git a/src/plugins/multimedia/ffmpeg/qffmpegdecoder_p.h b/src/plugins/multimedia/ffmpeg/qffmpegdecoder_p.h
index 2993ace56..0ca069105 100644
--- a/src/plugins/multimedia/ffmpeg/qffmpegdecoder_p.h
+++ b/src/plugins/multimedia/ffmpeg/qffmpegdecoder_p.h
@@ -470,6 +470,7 @@ public:
 
 private slots:
     void updateAudio();
+    void setSoundVolume(float volume);
 
 private:
     void updateOutput(const Codec *codec);
@@ -492,7 +493,6 @@ private:
 
     bool deviceChanged = false;
     QAudioOutput *output = nullptr;
-    bool audioMuted = false;
     qint64 writtenUSecs = 0;
     qint64 latencyUSecs = 0;