#include "CVideoSource.h"

#include <process.h>
#include <iostream>
#include <windows.h>

extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavutil/frame.h"
#include "libavcodec/bsf.h"
};

#include "CSyncProc.h"
#include "CVideoDataManager.h"

#pragma comment(lib, "avcodec.lib")
#pragma comment(lib, "avformat.lib")
#pragma comment(lib, "avutil.lib")
#pragma comment(lib, "avdevice.lib")
#pragma comment(lib, "avfilter.lib")
#pragma comment(lib, "postproc.lib")
#pragma comment(lib, "swresample.lib")
#pragma comment(lib, "swscale.lib")

AVHWDeviceType CVideoSource::m_HardType = AV_HWDEVICE_TYPE_NONE;
AVPixelFormat  CVideoSource::m_pixelFormat = AV_PIX_FMT_NONE;
bool CVideoSource::m_bUseHardDecode = true;

CVideoSource::CVideoSource()
{
	
}

CVideoSource::~CVideoSource()
{
	Clear();
}

bool CVideoSource::IsHardDecode()
{
	//return false;
	if (!m_bUseHardDecode)
	{
		return false;
	}
	//已经检测过
	if (m_HardType != AV_HWDEVICE_TYPE_NONE)
	{
		return true;
	}

	m_HardType = av_hwdevice_find_type_by_name("cuda");
	if (m_HardType != AV_HWDEVICE_TYPE_NONE)
	{
		return true;
	}

	while ((m_HardType = av_hwdevice_iterate_types(m_HardType)) != AV_HWDEVICE_TYPE_NONE)
	{
		return true;
	}

	//m_HardType = AV_HWDEVICE_TYPE_VULKAN;
		/*AV_HWDEVICE_TYPE_VDPAU,
		AV_HWDEVICE_TYPE_CUDA,
		AV_HWDEVICE_TYPE_VAAPI,
		AV_HWDEVICE_TYPE_DXVA2,
		AV_HWDEVICE_TYPE_QSV,
		AV_HWDEVICE_TYPE_VIDEOTOOLBOX,
		AV_HWDEVICE_TYPE_D3D11VA,
		AV_HWDEVICE_TYPE_DRM,
		AV_HWDEVICE_TYPE_OPENCL,
		AV_HWDEVICE_TYPE_MEDIACODEC,
		AV_HWDEVICE_TYPE_VULKAN,*/

	return false;
}

AVPixelFormat CVideoSource::GetpPixelFormat(AVCodecContext* ctx, const enum AVPixelFormat* fmts)
{
	const enum AVPixelFormat* p;
	for (p = fmts; *p != AV_PIX_FMT_NONE; p++) {
		if (*p == m_pixelFormat) {
			return *p;
		}
	}

	return AV_PIX_FMT_NONE;
}


bool CVideoSource::Init(const char * szUrl, CVideoDataManager * pDataManager)
{
	m_pDataManager = pDataManager;
	auto memberFunc1 = std::bind(&CVideoDataManager::AlignRecvData, m_pDataManager);
	CSyncProc::getInstance().AddFun(this, memberFunc1);

	int ret;
	AVDictionary* options = NULL;

	av_dict_set(&options, "rtsp_transport", "tcp", 0);
	av_dict_set(&options, "probesize", "10240", 0);

	if (avformat_open_input(&m_pFormatCtx, szUrl, NULL, &options) != 0)
	{
		return false;
	}

	if ((ret = avformat_find_stream_info(m_pFormatCtx, NULL)) < 0)
	{
		return false;
	}
	// 最后一个参数目前未定义，填写0 即可
	// 找到指定流类型的流信息，并且初始化codec(如果codec没有值)
	AVCodec	*decoder = nullptr;
	if ((ret = av_find_best_stream(m_pFormatCtx, AVMEDIA_TYPE_VIDEO, -1, -1, (const AVCodec **)&decoder, 0)) < 0)
	{
		return false;
	}
	m_nVideoIndex = ret;

	AVCodec* decoderVideo = nullptr;
	AVBufferRef* hw_device_ctx = NULL;

	if (IsHardDecode())
	{
		// 根据解码器获取支持此解码方式的硬件加速计
		/** 所有支持的硬件解码器保存在AVCodec的hw_configs变量中。对于硬件编码器来说又是单独的AVCodec
		 */
		if (m_pixelFormat == AV_PIX_FMT_NONE)
		{
			for (int i = 0;; i++)
			{
				const AVCodecHWConfig* hwcodec = avcodec_get_hw_config(decoder, i);
				if (hwcodec == NULL) break;

				// 可能一个解码器对应着多个硬件加速方式，所以这里将其挑选出来
				if (hwcodec->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX && hwcodec->device_type == m_HardType)
				{
					m_pixelFormat = hwcodec->pix_fmt;
					break;
				}
			}
		}

		if ((m_pCodecContextVideo = avcodec_alloc_context3(decoder)) == NULL)
		{
			return false;
		}

		AVStream* video_stream = m_pFormatCtx->streams[m_nVideoIndex];
		// 给解码器赋值解码相关参数
		if (avcodec_parameters_to_context(m_pCodecContextVideo, video_stream->codecpar) < 0) {

			return false;
		}

		// 配置获取硬件加速器像素格式的函数；该函数实际上就是将AVCodec中AVHWCodecConfig中的pix_fmt返回
		//m_pCodecContext->get_format = &CFfmpegProc::GetpPixelFormat;
		// 创建硬件加速器的缓冲区
		if (ret = av_hwdevice_ctx_create(&hw_device_ctx, m_HardType, NULL, NULL, 0) < 0) {

			return false;
		}
		/** 如果使用软解码则默认有一个软解码的缓冲区(获取AVFrame的)，而硬解码则需要额外创建硬件解码的缓冲区
		 *  这个缓冲区变量为hw_frames_ctx，不手动创建，则在调用avcodec_send_packet()函数内部自动创建一个
		 *  但是必须手动赋值硬件解码缓冲区引用hw_device_ctx(它是一个AVBufferRef变量)
		 */
		 // 即hw_device_ctx有值则使用硬件解码
		m_pCodecContextVideo->hw_device_ctx = av_buffer_ref(hw_device_ctx);

		av_buffer_unref(&hw_device_ctx);
		// 初始化并打开解码器上下文
		if (avcodec_open2(m_pCodecContextVideo, decoder, NULL) < 0)
		{
			return false;
		}

	}
	else
	{
		decoderVideo = (AVCodec*)avcodec_find_decoder(m_pFormatCtx->streams[m_nVideoIndex]->codecpar->codec_id);
		if (decoderVideo == nullptr)
		{
			return false;
		}

		m_pCodecContextVideo = avcodec_alloc_context3(decoderVideo);
		//AV_CODEC_ID_PCM_ALAW
		avcodec_parameters_to_context(m_pCodecContextVideo, m_pFormatCtx->streams[m_nVideoIndex]->codecpar);
		//打开解码器
		if (avcodec_open2(m_pCodecContextVideo, 0, 0) < 0)
		{
			return false;
		}
	}
	
	m_nWidth = m_pFormatCtx->streams[m_nVideoIndex]->codecpar->width;
	m_nHeight = m_pFormatCtx->streams[m_nVideoIndex]->codecpar->height ;
	m_eVideoCodec = m_pFormatCtx->streams[m_nVideoIndex]->codecpar->codec_id;

	InitAudio();
	
	_beginthreadex(nullptr, 0, &CVideoSource::RecvThread, this, 0, 0);

}


void CVideoSource::Clear()
{
	if (m_pFormatCtx!=nullptr)
	{
		avformat_close_input(&m_pFormatCtx);
		m_pFormatCtx = nullptr;
	}
	if (m_pCodecContextAudio != nullptr)
	{
		avcodec_close(m_pCodecContextAudio);
		m_pCodecContextAudio = nullptr;
	}
}

unsigned __stdcall CVideoSource::RecvThread(void * param)
{
	CVideoSource* p = (CVideoSource*)param;
	p->RecvThreadProcessor();

	return 0;
}

void CVideoSource::RecvThreadProcessor()
{
	while (true)
	{
		RecvFrameSync();
	}
}

bool CVideoSource::InitAudio()
{
	int ret;
	AVCodec	*decoderAudio = nullptr;
	if ((ret = av_find_best_stream(m_pFormatCtx, AVMEDIA_TYPE_AUDIO, -1, -1, (const AVCodec **)&decoderAudio, 0)) < 0)
	{
		return false;
	}
	m_nAudioIndex = ret;

	decoderAudio = (AVCodec *)avcodec_find_decoder(m_pFormatCtx->streams[m_nAudioIndex]->codecpar->codec_id);
	if (decoderAudio == nullptr)
	{
		return false;
	}

	m_pCodecContextAudio = avcodec_alloc_context3(decoderAudio);
	//AV_CODEC_ID_PCM_ALAW
	avcodec_parameters_to_context(m_pCodecContextAudio, m_pFormatCtx->streams[m_nAudioIndex]->codecpar);
	//打开解码器
	if (avcodec_open2(m_pCodecContextAudio, 0, 0) < 0)
	{
		return false;
	}
}

int CVideoSource::RecvFrameSync()
{
	int nRet = 0;
	
	AVPacket *packet = av_packet_alloc(); 

	nRet = av_read_frame(m_pFormatCtx, packet);

	if (nRet < 0)
	{
		return RECV_FAILED;
	}

	if (packet->stream_index != m_nVideoIndex)
	{
		AudioProc(packet);
		av_packet_free(&packet);
		return RECV_SUCCESS_NOTPROC;
	}

	m_pDataManager->AddRecvData(packet->pts, packet, packet->flags&AV_PKT_FLAG_KEY );

	//av_packet_free(&packet);

	return RECV_SUCCESS;
}

int CVideoSource::AudioProc(AVPacket * pktAudio)
{
	int nRet = 0;
	avcodec_send_packet(m_pCodecContextAudio, pktAudio);

	AVFrame * pFramAudio = av_frame_alloc();
	nRet = avcodec_receive_frame(m_pCodecContextAudio, pFramAudio);
	if (nRet < 0)
	{
		return RECV_FAILED;
	}

	int32_t nSum = 0;
	
	for (int i = 0; i < pFramAudio->linesize[0] * pFramAudio->channels; i = i + 2)
	{
		int16_t word16 = 0;

		word16 = (int16_t)(pFramAudio->data[0][i+1] << 8);
		word16 +=(pFramAudio->data[0][i]);

		if (word16<0)
		{
			word16 = abs(word16);
			word16 = ~word16 + 1;
			//word16 |= 0x8000;
		}
		//OutputDebugPrintf("VideoPlayer  AudioProc word16  1--- %d", word16);
		//word16 = bit_reverse(word16);
		nSum += abs(word16);
	}

	av_frame_free(&pFramAudio);
	//通过多次数据采集分析，能量值大于80000 确保是有同步信号
	if (nSum < 80000)
	{
		return RECV_SUCCESS;
	}

	double pts = 0;
	pts = av_q2d(m_pCodecContextAudio->time_base)* pktAudio->pts;

	//出现 音频的同步信号，3秒以内认为是同一个信号，认为无效
	if (pts - m_curAutdioPts < 3)
	{
		return RECV_SUCCESS;
	}

	m_curAutdioPts = pts;
	m_pDataManager->SetAutdioPts(m_curAutdioPts);

	CSyncProc::getInstance().UpdateTimeQueue(m_pDataManager, m_curAutdioPts);

}