implemented opus encoder

FrameCapturer/Assets/UTJ/FrameCapturer/Scripts/Encoder/fcAPI.cs

@@ -411,7 +411,7 @@ public enum fcWebMVideoEncoder
         public enum fcWebMAudioEncoder
         {
             Vorbis,
-            //Opus, // not implemented yet
+            Opus,
         };
 
         [Serializable]

Plugin/fccore/Encoder/WebM/fcOpusEncoder.cpp

@@ -29,25 +29,49 @@ class fcOpusEncoder : public fcIWebMAudioEncoder
 
 private:
     fcOpusEncoderConfig m_conf;
-    Buffer m_codec_private;
-    RawVector<float> m_samples;
-    Buffer m_buf_encoded;
+    Buffer              m_codec_private;
+    RawVector<float>    m_samples;
+    Buffer              m_buf_encoded;
 
-    OpusEncoder *m_op_encoder = nullptr;
+    OpusEncoder *m_opus = nullptr;
+    int m_preskip = 0;
+    uint64_t m_total_samples = 0;
 };
 
 
 fcOpusEncoder::fcOpusEncoder(const fcOpusEncoderConfig& conf)
     : m_conf(conf)
 {
     int err;
-    m_op_encoder = opus_encoder_create(conf.sample_rate, conf.num_channels, OPUS_APPLICATION_RESTRICTED_LOWDELAY, &err);
-    opus_encoder_ctl(m_op_encoder, OPUS_SET_BITRATE(conf.target_bitrate));
+    m_opus = opus_encoder_create(conf.sample_rate, conf.num_channels, OPUS_APPLICATION_RESTRICTED_LOWDELAY, &err);
+    opus_encoder_ctl(m_opus, OPUS_SET_BITRATE(conf.target_bitrate));
+
+    {
+        m_codec_private.resize(19);
+        auto *cp = (uint8_t*)m_codec_private.data();
+
+        memcpy(cp, "OpusHead", 8);
+        cp[8] = 1; // version
+        cp[9] = (uint8_t)conf.num_channels;
+
+        // pre-skip
+        opus_encoder_ctl(m_opus, OPUS_GET_LOOKAHEAD(&m_preskip));
+        (uint16_t&)cp[10] = m_preskip;
+
+        // sample rate
+        (uint32_t&)cp[12] = conf.sample_rate;
+
+        // output gain (set to 0)
+        cp[16] = cp[17] = 0;
+
+        // channel mapping
+        cp[18] = 0;
+    }
 }
 
 fcOpusEncoder::~fcOpusEncoder()
 {
-    opus_encoder_destroy(m_op_encoder);
+    opus_encoder_destroy(m_opus);
 }
 
 const char* fcOpusEncoder::getMatroskaCodecID() const
@@ -62,32 +86,38 @@ const Buffer& fcOpusEncoder::getCodecPrivate() const
 
 bool fcOpusEncoder::encode(fcWebMFrameData& dst, const float *samples, size_t num_samples)
 {
-    if (!m_op_encoder || !samples) { return false; }
-
-    return false;
-    // todo: implement
+    if (!m_opus || !samples) { return false; }
 
     m_samples.append(samples, num_samples);
 
-    int block_size = m_conf.sample_rate * m_conf.num_channels / 10;
+    bool result = true;
+    int frame_size = m_conf.sample_rate / 100;
     int processed_size = 0;
-    m_buf_encoded.resize(block_size);
-    while (processed_size + block_size <= num_samples) {
-        auto n = opus_encode_float(m_op_encoder,
-            m_samples.data() + processed_size, block_size / m_conf.num_channels,
+    m_buf_encoded.resize(m_conf.sample_rate);
+
+    while (processed_size + frame_size * m_conf.num_channels <= m_samples.size()) {
+        opus_int32 n = opus_encode_float(m_opus,
+            m_samples.data() + processed_size, frame_size,
             (uint8_t*)m_buf_encoded.data(), (int)m_buf_encoded.size());
         if (n > 0) {
-            m_buf_encoded.resize(n);
-            dst.data.append(m_buf_encoded.data(), m_buf_encoded.size());
+            dst.data.append(m_buf_encoded.data(), n);
+            processed_size += frame_size * m_conf.num_channels;
+            m_total_samples += frame_size;
+
+            double timestamp = (double)m_total_samples / (double)m_conf.sample_rate;
+            dst.packets.push_back({ (uint32_t)n, timestamp, 1 });
         }
         else if (n == 0) {
             break;
         }
         else {
-            return false;
+            result = false;
+            break;
         }
     }
-    return true;
+
+    m_samples.erase(m_samples.begin(), m_samples.begin() + processed_size);
+    return result;
 }
 
 bool fcOpusEncoder::flush(fcWebMFrameData& dst)

Plugin/fccore/Encoder/WebM/fcWebMContext.cpp

@@ -121,7 +121,7 @@ fcWebMContext::~fcWebMContext()
     m_video_tasks.wait();
     m_audio_tasks.wait();
 
-    if (m_conf.video) {
+    if (m_conf.video && m_conf.audio) {
         writeOut(m_video_last_timestamp);
     }
     m_mkv_frames.clear();