Add dynamic bitrate update for pyrowave encode.

Author: Themaister

video/ffmpeg_encode.cpp

@@ -133,9 +133,13 @@ struct VideoEncoder::Impl final
 	bool init_video_codec_av(const AVCodec *codec);
 	bool init_video_codec_pyro(PyroEnc::Profile profile);
 	bool init_video_codec_pyrowave();
+	bool init_video_codec_pyrowave_buffers(unsigned bitrate_kbits);
 	bool init_video_codec();
 	bool init_audio_codec();
 
+	bool update_bitrate_async();
+	std::atomic<unsigned> update_bitrate_kbits = {};
+
 	std::vector<int16_t> audio_buffer_s16;
 
 	struct
@@ -460,10 +464,21 @@ void VideoEncoder::Impl::write_frames_interleaved_f32(const float *data, size_t
 }
 #endif
 
+bool VideoEncoder::Impl::update_bitrate_async()
+{
+	auto new_value = update_bitrate_kbits.exchange(0, std::memory_order_acq_rel);
+	if (new_value)
+		options.bitrate_kbits = new_value;
+	return new_value != 0;
+}
+
 bool VideoEncoder::Impl::encode_frame(const PyroWave::ViewBuffers &views, int64_t pts, int compensate_audio_us)
 {
 	assert(mux_stream_callback);
 
+	if (update_bitrate_async() && !init_video_codec_pyrowave_buffers(options.bitrate_kbits))
+		return false;
+
 	auto cmd = device->request_command_buffer(Vulkan::CommandBuffer::Type::AsyncCompute);
 	pyrowave_encoder.encode(*cmd, views, pyrowave.buffers);
 	cmd->barrier(VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT, VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT,
@@ -1335,42 +1350,17 @@ bool VideoEncoder::Impl::init_video_codec_av(const AVCodec *codec)
 	return true;
 }
 
-bool VideoEncoder::Impl::init_video_codec_pyrowave()
+bool VideoEncoder::Impl::init_video_codec_pyrowave_buffers(unsigned bitrate_kbits)
 {
-	if (!pyrowave_encoder.init(device, int(options.width), int(options.height),
-	                           format_needs_downsample(options.format) ?
-	                           PyroWave::ChromaSubsampling::Chroma420 :
-	                           PyroWave::ChromaSubsampling::Chroma444))
-		return false;
-
-	pyro_codec.video_codec = PYRO_VIDEO_CODEC_PYROWAVE;
-	pyro_codec.width = options.width;
-	pyro_codec.height = options.height;
-	pyro_codec.frame_rate_num = options.frame_timebase.den;
-	pyro_codec.frame_rate_den = options.frame_timebase.num;
-
-	if (format_needs_downsample(options.format))
-	{
-		pyro_codec.video_color_profile = options.hdr10 ?
-		                                 PYRO_VIDEO_COLOR_BT2020NCL_PQ_FULL_CENTER_CHROMA_420 :
-		                                 PYRO_VIDEO_COLOR_BT709_FULL_CENTER_CHROMA_420;
-	}
-	else
-	{
-		pyro_codec.video_color_profile = options.hdr10 ?
-		                                 PYRO_VIDEO_COLOR_BT2020NCL_PQ_FULL_CHROMA_444 :
-		                                 PYRO_VIDEO_COLOR_BT709_FULL_CHROMA_444;
-	}
-
-	pyrowave.payload_size = (1000ull * options.bitrate_kbits * options.frame_timebase.num) /
+	pyrowave.payload_size = (1000ull * bitrate_kbits * options.frame_timebase.num) /
 	                        (options.frame_timebase.den * 8);
 
 	pyrowave.payload_size &= ~3;
 
 	Vulkan::BufferCreateInfo bufinfo = {};
 	bufinfo.usage = VK_BUFFER_USAGE_STORAGE_BUFFER_BIT |
-	                VK_BUFFER_USAGE_TRANSFER_DST_BIT |
-	                VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
+					VK_BUFFER_USAGE_TRANSFER_DST_BIT |
+					VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
 
 	bufinfo.size = pyrowave.payload_size + pyrowave_encoder.get_meta_required_size();
 	bufinfo.domain = Vulkan::BufferDomain::Device;
@@ -1394,7 +1384,37 @@ bool VideoEncoder::Impl::init_video_codec_pyrowave()
 
 	pyrowave.bitstream.resize(pyrowave.payload_size);
 
-	return true;
+	return pyrowave.bitstream_gpu && pyrowave.bitstream_cpu && pyrowave.meta_gpu && pyrowave.meta_cpu;
+}
+
+bool VideoEncoder::Impl::init_video_codec_pyrowave()
+{
+	if (!pyrowave_encoder.init(device, int(options.width), int(options.height),
+	                           format_needs_downsample(options.format) ?
+	                           PyroWave::ChromaSubsampling::Chroma420 :
+	                           PyroWave::ChromaSubsampling::Chroma444))
+		return false;
+
+	pyro_codec.video_codec = PYRO_VIDEO_CODEC_PYROWAVE;
+	pyro_codec.width = options.width;
+	pyro_codec.height = options.height;
+	pyro_codec.frame_rate_num = options.frame_timebase.den;
+	pyro_codec.frame_rate_den = options.frame_timebase.num;
+
+	if (format_needs_downsample(options.format))
+	{
+		pyro_codec.video_color_profile = options.hdr10 ?
+		                                 PYRO_VIDEO_COLOR_BT2020NCL_PQ_FULL_CENTER_CHROMA_420 :
+		                                 PYRO_VIDEO_COLOR_BT709_FULL_CENTER_CHROMA_420;
+	}
+	else
+	{
+		pyro_codec.video_color_profile = options.hdr10 ?
+		                                 PYRO_VIDEO_COLOR_BT2020NCL_PQ_FULL_CHROMA_444 :
+		                                 PYRO_VIDEO_COLOR_BT709_FULL_CHROMA_444;
+	}
+
+	return init_video_codec_pyrowave_buffers(options.bitrate_kbits);
 }
 
 bool VideoEncoder::Impl::init_video_codec_pyro(PyroEnc::Profile profile)
@@ -1940,6 +1960,11 @@ void VideoEncoder::process_rgb(Vulkan::CommandBuffer &cmd, YCbCrPipeline &pipeli
 	}
 }
 
+void VideoEncoder::update_bitrate_kbits(unsigned bitrate_kbits)
+{
+	impl->update_bitrate_kbits.exchange(bitrate_kbits, std::memory_order_acq_rel);
+}
+
 bool VideoEncoder::encode_frame(YCbCrPipeline &pipeline_ptr, int64_t pts, int compensate_audio_us)
 {
 	auto &pipeline = *pipeline_ptr;

video/ffmpeg_encode.hpp

@@ -125,6 +125,9 @@ class VideoEncoder
 
 	bool encode_frame(YCbCrPipeline &pipeline, int64_t pts, int compensate_audio_us = 0);
 
+	// Only implemented for pyrowave atm, updates bitrate on the fly.
+	void update_bitrate_kbits(unsigned bitrate_kbits);
+
 private:
 	struct Impl;
 	std::unique_ptr<Impl> impl;