王纲保存图片
作者：互联网
#ifndef PCH_H
#define PCH_H
extern "C"
{
#include "libavutil/opt.h"
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavutil/mathematics.h"
#include "libavutil/samplefmt.h"
#include "libavutil/time.h"
#include "libavutil/fifo.h"
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavformat/avio.h"
//#include "libavfilter/avfiltergraph.h"
#include "libavfilter/avfilter.h"
#include "libavfilter/buffersink.h"
#include "libavfilter/buffersrc.h"
#include "libswscale/swscale.h"
#include "libswresample/swresample.h"
}
#endif
pch.h
// CGFileCut.cpp : 定义控制台应用程序的入口点。
//
/* Copyright [c] 2018-2028 By www.chungen90.com Allrights Reserved
This file give a simple example of getting picture form
real stream. Any questions, you can join QQ group for
help, QQ Group number:127903734 or 766718184.
*/
//#include "stdafx.h"
#include <string>
#include <memory>
#include <thread>
#include <iostream>
#include <iostream>
using namespace std;
#include "pch.h"
AVFormatContext *inputContext = nullptr;
AVFormatContext * outputContext;
int64_t lastReadPacktTime ;
static int interrupt_cb(void *ctx)
{
int timeout = 3;
if(av_gettime() - lastReadPacktTime > timeout *1000 *1000)
{
return -1;
}
return 0;
}
int OpenInput(string inputUrl)
{
inputContext = avformat_alloc_context();
lastReadPacktTime = av_gettime();
inputContext->interrupt_callback.callback = interrupt_cb;
int ret = avformat_open_input(&inputContext, inputUrl.c_str(), nullptr,nullptr);
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "Input file open input failed\n");
return ret;
}
ret = avformat_find_stream_info(inputContext,nullptr);
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "Find input file stream inform failed\n");
}
else
{
av_log(NULL, AV_LOG_FATAL, "Open input file %s success\n",inputUrl.c_str());
}
return ret;
}
shared_ptr<AVPacket> ReadPacketFromSource()
{
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());
lastReadPacktTime = av_gettime();
int ret = av_read_frame(inputContext, packet.get());
if(ret >= 0)
{
return packet;
}
else
{
return nullptr;
}
}
int OpenOutput(string outUrl)
{
int ret = avformat_alloc_output_context2(&outputContext, nullptr, "singlejpeg", outUrl.c_str());
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "open output context failed\n");
goto Error;
}
ret = avio_open2(&outputContext->pb, outUrl.c_str(), AVIO_FLAG_WRITE,nullptr, nullptr);
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "open avio failed");
goto Error;
}
for(int i = 0; i < inputContext->nb_streams; i++)
{
if(inputContext->streams[i]->codec->codec_type == AVMediaType::AVMEDIA_TYPE_AUDIO)
{
continue;
}
AVStream * stream = avformat_new_stream(outputContext, inputContext->streams[i]->codec->codec);
ret = avcodec_copy_context(stream->codec, inputContext->streams[i]->codec);
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "copy coddec context failed");
goto Error;
}
}
ret = avformat_write_header(outputContext, nullptr);
if(ret < 0)
{
av_log(NULL, AV_LOG_ERROR, "format write header failed");
goto Error;
}
av_log(NULL, AV_LOG_FATAL, " Open output file success %s\n",outUrl.c_str());
return ret ;
Error:
if(outputContext)
{
for(int i = 0; i < outputContext->nb_streams; i++)
{
avcodec_close(outputContext->streams[i]->codec);
}
avformat_close_input(&outputContext);
}
return ret ;
}
void Init()
{
av_register_all();
avfilter_register_all();
avformat_network_init();
av_log_set_level(AV_LOG_WARNING);
}
void CloseInput()
{
if(inputContext != nullptr)
{
avformat_close_input(&inputContext);
}
}
void CloseOutput()
{
if(outputContext != nullptr)
{
int ret = av_write_trailer(outputContext);
for(int i = 0 ; i < outputContext->nb_streams; i++)
{
AVCodecContext *codecContext = outputContext->streams[i]->codec;
avcodec_close(codecContext);
}
avformat_close_input(&outputContext);
}
}
int WritePacket(shared_ptr<AVPacket> packet)
{
auto inputStream = inputContext->streams[packet->stream_index];
auto outputStream = outputContext->streams[packet->stream_index];
return av_interleaved_write_frame(outputContext, packet.get());
}
int InitDecodeContext(AVStream *inputStream)
{
auto codecId = inputStream->codec->codec_id;
auto codec = avcodec_find_decoder(codecId);
if (!codec)
{
return -1;
}
int ret = avcodec_open2(inputStream->codec, codec, NULL);
return ret;
}
int initEncoderCodec(AVStream* inputStream,AVCodecContext **encodeContext)
{
AVCodec * picCodec;
picCodec = avcodec_find_encoder(AV_CODEC_ID_MJPEG);
(*encodeContext) = avcodec_alloc_context3(picCodec);
(*encodeContext)->codec_id = picCodec->id;
(*encodeContext)->time_base.num = inputStream->codec->time_base.num;
(*encodeContext)->time_base.den = inputStream->codec->time_base.den;
(*encodeContext)->pix_fmt = *picCodec->pix_fmts;
(*encodeContext)->width = inputStream->codec->width;
(*encodeContext)->height =inputStream->codec->height;
int ret = avcodec_open2((*encodeContext), picCodec, nullptr);
if (ret < 0)
{
std::cout<<"open video codec failed"<<endl;
return ret;
}
return 1;
}
bool Decode(AVStream* inputStream,AVPacket* packet, AVFrame *frame)
{
int gotFrame = 0;
auto hr = avcodec_decode_video2(inputStream->codec, frame, &gotFrame, packet);
if (hr >= 0 && gotFrame != 0)
{
return true;
}
return false;
}
std::shared_ptr<AVPacket> Encode(AVCodecContext *encodeContext,AVFrame * frame)
{
int gotOutput = 0;
std::shared_ptr<AVPacket> pkt(static_cast<AVPacket*>(av_malloc(sizeof(AVPacket))), [&](AVPacket *p) { av_packet_free(&p); av_freep(&p); });
av_init_packet(pkt.get());
pkt->data = NULL;
pkt->size = 0;
int ret = avcodec_encode_video2(encodeContext, pkt.get(), frame, &gotOutput);
if (ret >= 0 && gotOutput)
{
return pkt;
}
else
{
return nullptr;
}
}
int main(int argc, char* argv[])
{
Init();
int ret = OpenInput("D:\\test.mp4");
if(ret >= 0)
{
ret = OpenOutput("D:\\test.jpg");
}
if(ret <0) goto Error;
AVCodecContext *encodeContext = nullptr;
InitDecodeContext(inputContext->streams[0]);
AVFrame *videoFrame = av_frame_alloc();
initEncoderCodec(inputContext->streams[0],&encodeContext);
while(true)
{
auto packet = ReadPacketFromSource();
if(packet && packet->stream_index == 0)
{
if(Decode(inputContext->streams[0],packet.get(),videoFrame))
{
auto packetEncode = Encode(encodeContext,videoFrame);
if(packetEncode)
{
ret = WritePacket(packetEncode);
if(ret >= 0)
{
break;
}
}
}
}
}
cout <<"Get Picture End "<<endl;
av_frame_free(&videoFrame);
avcodec_close(encodeContext);
Error:
CloseInput();
CloseOutput();
while(true)
{
this_thread::sleep_for(chrono::seconds(100));
}
return 0;
}
View Code
标签：int,保存,ret,王纲,codec,packet,av,include,图片 来源： https://www.cnblogs.com/zeliangzhang/p/15752447.html