libtgvoip/controller/media/MediaStreamItf.cpp

//
// libtgvoip is free and unencumbered public domain software.
// For more information, see http://unlicense.org or the UNLICENSE file
// you should have received with this source code distribution.
//

#include "tools/logging.h"
#include "controller/MediaStreamItf.h"
#include "controller/audio/EchoCanceller.h"
#include <stdint.h>
#include <algorithm>
#include <math.h>
#include <assert.h>

using namespace tgvoip;

void MediaStreamItf::SetCallback(size_t (*f)(unsigned char *, size_t, void *), void *param)
{
	callback = f;
	callbackParam = param;
}

size_t MediaStreamItf::InvokeCallback(unsigned char *data, size_t length)
{
	if (callback)
		return (*callback)(data, length, callbackParam);
	return 0;
}

AudioMixer::AudioMixer() : processedQueue(16), semaphore(16, 0)
{
	running = false;
}

AudioMixer::~AudioMixer()
{
}

void AudioMixer::SetOutput(MediaStreamItf *output)
{
	output->SetCallback(OutputCallback, this);
}

void AudioMixer::Start()
{
	assert(!running);
	running = true;
	thread = new Thread(std::bind(&AudioMixer::RunThread, this));
	thread->SetName("AudioMixer");
	thread->Start();
}

void AudioMixer::Stop()
{
	if (!running)
	{
		LOGE("Tried to stop AudioMixer that wasn't started");
		return;
	}
	running = false;
	semaphore.Release();
	thread->Join();
	delete thread;
	thread = NULL;
}

void AudioMixer::DoCallback(unsigned char *data, size_t length)
{
	//memset(data, 0, 960*2);
	//LOGD("audio mixer callback, %d inputs", inputs.size());
	if (processedQueue.Size() == 0)
		semaphore.Release(2);
	else
		semaphore.Release();
	Buffer buf = processedQueue.GetBlocking();
	memcpy(data, *buf, 960 * 2);
}

size_t AudioMixer::OutputCallback(unsigned char *data, size_t length, void *arg)
{
	((AudioMixer *)arg)->DoCallback(data, length);
	return 960 * 2;
}

void AudioMixer::AddInput(std::shared_ptr<MediaStreamItf> input)
{
	MutexGuard m(inputsMutex);
	MixerInput in;
	in.multiplier = 1;
	in.source = input;
	inputs.push_back(in);
}

void AudioMixer::RemoveInput(std::shared_ptr<MediaStreamItf> input)
{
	MutexGuard m(inputsMutex);
	for (std::vector<MixerInput>::iterator i = inputs.begin(); i != inputs.end(); ++i)
	{
		if (i->source == input)
		{
			inputs.erase(i);
			return;
		}
	}
}

void AudioMixer::SetInputVolume(std::shared_ptr<MediaStreamItf> input, float volumeDB)
{
	MutexGuard m(inputsMutex);
	for (std::vector<MixerInput>::iterator i = inputs.begin(); i != inputs.end(); ++i)
	{
		if (i->source == input)
		{
			if (volumeDB == -INFINITY)
				i->multiplier = 0;
			else
				i->multiplier = expf(volumeDB / 20.0f * logf(10.0f));
			return;
		}
	}
}

void AudioMixer::RunThread()
{
	LOGV("AudioMixer thread started");
	while (running)
	{
		semaphore.Acquire();
		if (!running)
			break;

		try
		{
			Buffer data = bufferPool.Get();
			//LOGV("Audio mixer processing a frame");
			MutexGuard m(inputsMutex);
			int16_t *buf = reinterpret_cast<int16_t *>(*data);
			int16_t input[960];
			float out[960];
			memset(out, 0, 960 * 4);
			int usedInputs = 0;
			for (std::vector<MixerInput>::iterator in = inputs.begin(); in != inputs.end(); ++in)
			{
				size_t res = in->source->InvokeCallback(reinterpret_cast<unsigned char *>(input), 960 * 2);
				if (!res || in->multiplier == 0)
				{
					//LOGV("AudioMixer: skipping silent packet");
					continue;
				}
				usedInputs++;
				float k = in->multiplier;
				if (k != 1)
				{
					for (size_t i = 0; i < 960; i++)
					{
						out[i] += (float)input[i] * k;
					}
				}
				else
				{
					for (size_t i = 0; i < 960; i++)
					{
						out[i] += (float)input[i];
					}
				}
			}
			if (usedInputs > 0)
			{
				for (size_t i = 0; i < 960; i++)
				{
					if (out[i] > 32767.0f)
						buf[i] = INT16_MAX;
					else if (out[i] < -32768.0f)
						buf[i] = INT16_MIN;
					else
						buf[i] = (int16_t)out[i];
				}
			}
			else
			{
				memset(*data, 0, 960 * 2);
			}
			if (echoCanceller)
				echoCanceller->SpeakerOutCallback(*data, 960 * 2);
			processedQueue.Put(std::move(data));
		}
		catch (std::bad_alloc &x)
		{
			LOGE("AudioMixer: no buffers left");
			continue;
		}
	}
	LOGI("======== audio mixer thread exiting =========");
}

void AudioMixer::SetEchoCanceller(EchoCanceller *aec)
{
	echoCanceller = aec;
}

AudioLevelMeter::AudioLevelMeter()
{
	absMax = 0;
	count = 0;
	currentLevel = 0;
	currentLevelFullRange = 0;
}

float AudioLevelMeter::GetLevel()
{
	return currentLevel / 9.0f;
}

void AudioLevelMeter::Update(int16_t *samples, size_t count)
{
	// Number of bars on the indicator.
	// Note that the number of elements is specified because we are indexing it
	// in the range of 0-32
	const int8_t permutation[33] = {0, 1, 2, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9};
	int16_t absValue = 0;
	for (unsigned int k = 0; k < count; k++)
	{
		int16_t absolute = (int16_t)abs(samples[k]);
		if (absolute > absValue)
			absValue = absolute;
	}

	if (absValue > absMax)
		absMax = absValue;
	// Update level approximately 10 times per second
	if (this->count++ == 10)
	{
		currentLevelFullRange = absMax;
		this->count = 0;
		// Highest value for a int16_t is 0x7fff = 32767
		// Divide with 1000 to get in the range of 0-32 which is the range of
		// the permutation vector
		int32_t position = absMax / 1000;
		// Make it less likely that the bar stays at position 0. I.e. only if
		// its in the range 0-250 (instead of 0-1000)
		/*if ((position==0) && (absMax>250)){
			position=1;
		}*/
		currentLevel = permutation[position];
		// Decay the absolute maximum (divide by 4)
		absMax >>= 2;
	}
}