// Transcode.cpp : 定义控制台应用程序的入口点。
//
/* Copyright [c] 2016-2026 By Gang.Wang Allrights Reserved 
 this file shows how to compress video. Any questions, you
 can join QQ group for help, QQ
 Group number:127903734.
*/
#include "stdafx.h"

#include "pch.h"
#include <string>
#include <iostream>
#include <thread>
#include <memory>
#include <iostream>
#include<fstream>
#include <Winsock2.h>

#include <condition_variable>
#include <concurrent_queue.h>
using namespace std;
AVFormatContext * context = nullptr;
AVFormatContext* outputContext;
int64_t lastPts = 0;
int64_t lastDts = 0;
int64_t lastFrameRealtime = 0;

int64_t firstPts = AV_NOPTS_VALUE;
int64_t startTime = 0;

AVCodecContext*	outPutEncContext = NULL;
AVCodecContext *decoderContext = NULL;
#define SrcWidth 1920
#define SrcHeight 1080
#define DstWidth 640
#define DstHeight 480

struct SwsContext* pSwsContext;

AVFilterGraph * filter_graph = nullptr;
AVFilterContext *buffersink_ctx = nullptr;;
AVFilterContext *buffersrc_ctx = nullptr;;

int64_t packetCount = 0;
int interrupt_cb(void *ctx)
{
	return 0;
}

string GetLocalIpAddress()
{
	WORD wVersionRequested = MAKEWORD(2, 2);

	WSADATA wsaData;
	if (WSAStartup(wVersionRequested, &wsaData) != 0)
		return "";

	char local[255] = {0};
	gethostname(local, sizeof(local));
	hostent* ph = gethostbyname(local);
	if (ph == NULL)
		return "";

	in_addr addr;
	memcpy(&addr, ph->h_addr_list[0], sizeof(in_addr)); // 这里仅获取第一个ip

	string localIP;
	localIP.assign(inet_ntoa(addr));

	WSACleanup();
	return localIP;
}

void Init()
{
	av_register_all();
	avfilter_register_all();
	avformat_network_init();
	avdevice_register_all();
	av_log_set_level(AV_LOG_ERROR);
}

int OpenInput(char *fileName)
{
	context = avformat_alloc_context();
	context->interrupt_callback.callback = interrupt_cb;
	AVDictionary *format_opts = nullptr;

	int ret = avformat_open_input(&context, fileName, nullptr, &format_opts);
	if(ret < 0)
	{
		return ret;
	}
	ret = avformat_find_stream_info(context,nullptr);
	av_dump_format(context, 0, fileName, 0);
	if(ret >= 0) 
	{
		std::cout <<"open input stream successfully" << endl;
	}
	return ret;
}

shared_ptr<AVPacket> ReadPacketFromSource()
{
	 std::shared_ptr<AVPacket> packet(static_cast<AVPacket*>(av_malloc(sizeof(AVPacket))), [&](AVPacket *p) { av_packet_free(&p); av_freep(&p); });
	av_init_packet(packet.get());
	int ret = av_read_frame(context, packet.get());
	if(ret >= 0)
	{
		return packet;
	}
	else
	{
		return nullptr;
	}
}


int OpenOutput(char *fileName)
{
	int ret = 0;
	ret = avformat_alloc_output_context2(&outputContext, nullptr, "mpegts", fileName);
	if(ret < 0)
	{
		goto Error;
	}
	ret = avio_open2(&outputContext->pb, fileName, AVIO_FLAG_READ_WRITE,nullptr, nullptr);	
	if(ret < 0)
	{
		goto Error;
	}

	for(int i = 0; i < context->nb_streams; i++)
	{
		AVStream * stream = avformat_new_stream(outputContext, outPutEncContext->codec);
		stream->codec = outPutEncContext;
		if(ret < 0)
		{
			goto Error;
		}
	}
	av_dump_format(outputContext, 0, fileName, 1);
	ret = avformat_write_header(outputContext, nullptr);
	if(ret < 0)
	{
		goto Error;
	}
	if(ret >= 0)
		cout <<"open output stream successfully" << endl;
	return ret ;
Error:
	if(outputContext)
	{
		avformat_close_input(&outputContext);
	}
	return ret ;
}

void CloseInput()
{
	if(context != nullptr)
	{
		avformat_close_input(&context);
	}
}

void CloseOutput()
{
	if(outputContext != nullptr)
	{
		for(int i = 0 ; i < outputContext->nb_streams; i++)
		{
			AVCodecContext *codecContext = outputContext->streams[i]->codec;
			avcodec_close(codecContext);
		}
		avformat_close_input(&outputContext);
	}
}

int InitEncoderCodec( int iWidth, int iHeight)
{
	AVCodec * pH264Codec = avcodec_find_encoder(AV_CODEC_ID_H264);
	if(NULL == pH264Codec)
	{
		printf("%s", "avcodec_find_encoder failed");
		return -1;
	}
	outPutEncContext = avcodec_alloc_context3(pH264Codec);
	outPutEncContext->gop_size = 30;
	outPutEncContext->has_b_frames = 0;
	outPutEncContext->max_b_frames = 0;
	outPutEncContext->codec_id = pH264Codec->id;
	outPutEncContext->time_base.num =context->streams[0]->codec->time_base.num;
	outPutEncContext->time_base.den = context->streams[0]->codec->time_base.den;
	outPutEncContext->pix_fmt = *pH264Codec->pix_fmts;
	outPutEncContext->width = iWidth;
	outPutEncContext->height = iHeight;

	AVDictionary *options = nullptr;
	outPutEncContext->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

	int ret = avcodec_open2(outPutEncContext, pH264Codec, &options);
	if (ret < 0)
	{
		printf("%s", "open codec failed");
		return ret;
	}
	return 1;
}

int InitDecodeCodec(AVCodecID codecId)
{
	auto codec = avcodec_find_decoder(codecId);
	if(!codec)
	{
		return -1;
	}
	decoderContext = context->streams[0]->codec;
	if (!decoderContext) {
		fprintf(stderr, "Could not allocate video codec context\n");
		exit(1);
	}

	if (codec->capabilities & AV_CODEC_CAP_TRUNCATED)
		decoderContext->flags |= AV_CODEC_FLAG_TRUNCATED; 
	int ret = avcodec_open2(decoderContext, codec, NULL);
	return ret;

}

bool DecodeVideo(AVPacket* packet, AVFrame* frame)
{
	int gotFrame = 0;
	auto hr = avcodec_decode_video2(decoderContext, frame, &gotFrame, packet);
	if(hr >= 0 && gotFrame != 0)
	{
		return true;
	}
	return false;
}

int InitFilter(AVCodecContext * codecContext)
{
	char args[512];
	int ret = 0;	

	AVFilter *buffersrc = avfilter_get_by_name("buffer");
	AVFilter *buffersink = avfilter_get_by_name("buffersink");
	AVFilterInOut *outputs = avfilter_inout_alloc();
	AVFilterInOut *inputs = avfilter_inout_alloc();
	string filters_descr ="scale=640:480";
	enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV420P};

	filter_graph = avfilter_graph_alloc();
	if (!outputs || !inputs || !filter_graph) {
		ret = AVERROR(ENOMEM);
		goto end;
	}

	/* buffer video source: the decoded frames from the decoder will be inserted here. */
	sprintf_s(args, sizeof(args),
		"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
		codecContext->width, codecContext->height, codecContext->pix_fmt,
		codecContext->time_base.num, codecContext->time_base.den,
		codecContext->sample_aspect_ratio.num, codecContext->sample_aspect_ratio.den);

	ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
		args, NULL, filter_graph);
	if (ret < 0) {
		av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
		goto end;
	}

	/* buffer video sink: to terminate the filter chain. */
	ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
		NULL, NULL, filter_graph);
	if (ret < 0) {
		av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
		goto end;
	}

	ret = av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts,
		AV_PIX_FMT_YUV420P, AV_OPT_SEARCH_CHILDREN);
	if (ret < 0) {
		av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
		goto end;
	}

	/* Endpoints for the filter graph. */
	outputs->name = av_strdup("in");
	outputs->filter_ctx = buffersrc_ctx;
	outputs->pad_idx = 0;
	outputs->next = NULL;

	inputs->name = av_strdup("out");
	inputs->filter_ctx = buffersink_ctx;
	inputs->pad_idx = 0;
	inputs->next = NULL; 
	if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr.c_str(),
		&inputs, &outputs, NULL)) < 0)
		goto end;

	if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
		goto end;
	return ret;
end:
	avfilter_inout_free(&inputs);
	avfilter_inout_free(&outputs);
	return ret;
}

int _tmain(int argc, _TCHAR* argv[])
{
	string fileInput = "D:\\test1.ts";
	string fileOutput = "D:\\TranscodedFile.ts";
	Init();
	if(OpenInput((char *)fileInput.c_str()) < 0)
	{
		cout << "Open file Input failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	int ret = InitDecodeCodec(context->streams[0]->codecpar->codec_id);
	if(ret <0)
	{
		cout << "InitDecodeCodec failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	ret = InitEncoderCodec(DstWidth,DstHeight);
	if(ret < 0)
	{
		cout << "open eccoder failed ret is " << ret<<endl;
		cout << "InitEncoderCodec failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	ret = InitFilter(outPutEncContext);
	if(OpenOutput((char *)fileOutput.c_str()) < 0)
	{
		cout << "Open file Output failed!" << endl;
		this_thread::sleep_for(chrono::seconds(10));
		return 0;
	}

	auto pSrcFrame = av_frame_alloc();
	auto filterFrame = av_frame_alloc();
	int got_output = 0;	
	int64_t timeRecord = 0;
	int64_t firstPacketTime = 0;
	int64_t outLastTime = av_gettime();
	int64_t inLastTime = av_gettime();
	int64_t videoCount = 0;
	while(true)
	{
		outLastTime = av_gettime();
		auto packet = ReadPacketFromSource();
		if(packet)
		{
			if(timeRecord == 0)
			{
				firstPacketTime = av_gettime();
				timeRecord++;
			}
			if(DecodeVideo(packet.get(),pSrcFrame))
			{
				if (av_buffersrc_add_frame_flags(buffersrc_ctx, pSrcFrame, AV_BUFFERSRC_FLAG_KEEP_REF) >= 0)
				{
					if (av_buffersink_get_frame(buffersink_ctx, filterFrame) >= 0)
					{
						AVPacket *pTmpPkt = (AVPacket *)av_malloc(sizeof(AVPacket));
						av_init_packet(pTmpPkt);
						pTmpPkt->data = NULL;
						pTmpPkt->size = 0;
						ret = avcodec_encode_video2(outPutEncContext, pTmpPkt, filterFrame, &got_output);
						if (ret >= 0 && got_output)
						{
							pTmpPkt->pts = pTmpPkt->dts = 3600 * packetCount++;
							int ret = av_write_frame(outputContext, pTmpPkt);
							av_packet_unref(pTmpPkt);
						}
					}
				}
			}
		}
		else break;
	}
	CloseInput();
	CloseOutput();
	std::cout <<"Transcode file end!" << endl;
	this_thread::sleep_for(chrono::hours(10));
	return 0;
}