embox

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#define __STDCPP_WANT_MATH_SPEC_FUNCS__ 1
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#include <iostream>
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#include <fstream>
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extern "C" {
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libswscale/swscale.h>
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}
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int main() {
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    const char* filename = "test.mp4";
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    // Check if the file exists
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    std::ifstream file(filename);
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    if (!file.good()) {
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        std::cout << "File does not exist: " << filename << std::endl;
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        return -1;
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    }
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    file.close();
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    avformat_network_init();
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    AVFormatContext* pFormatContext = nullptr;
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    int ret = avformat_open_input(&pFormatContext, filename, nullptr, nullptr);
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    if (ret < 0) {
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        char errbuf[256];
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        av_strerror(ret, errbuf, sizeof(errbuf));
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        std::cout << "Error opening video file: " << errbuf << std::endl;
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        return -1;
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    }
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    if (avformat_find_stream_info(pFormatContext, nullptr) < 0) {
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        std::cout << "Error finding stream information" << std::endl;
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        return -1;
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    }
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    int videoStreamIndex = av_find_best_stream(pFormatContext, AVMEDIA_TYPE_VIDEO, -1, -1, nullptr, 0);
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    if (videoStreamIndex < 0) {
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        std::cout << "No video stream found" << std::endl;
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        return -1;
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    }
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    AVCodecParameters* pCodecParameters = pFormatContext->streams[videoStreamIndex]->codecpar;
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    AVCodec* pCodec = avcodec_find_decoder(pCodecParameters->codec_id);
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    if (pCodec == nullptr) {
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        std::cout << "Unsupported codec" << std::endl;
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        return -1;
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    }
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    AVCodecContext* pCodecContext = avcodec_alloc_context3(pCodec);
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    if (avcodec_parameters_to_context(pCodecContext, pCodecParameters) < 0) {
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        std::cout << "Failed to copy codec parameters to codec context" << std::endl;
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        return -1;
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    }
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    if (avcodec_open2(pCodecContext, pCodec, nullptr) < 0) {
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        std::cout << "Failed to open codec" << std::endl;
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        return -1;
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    }
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    AVFrame* pFrame = av_frame_alloc();
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    if (pFrame == nullptr) {
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        std::cout << "Failed to allocate frame" << std::endl;
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        return -1;
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    }
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    AVPacket packet;
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    while (av_read_frame(pFormatContext, &packet) >= 0) {
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        if (packet.stream_index == videoStreamIndex) {
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            if (avcodec_send_packet(pCodecContext, &packet) < 0) {
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                std::cout << "Error sending packet for decoding" << std::endl;
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                return -1;
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            }
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            while (avcodec_receive_frame(pCodecContext, pFrame) == 0) {
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                // Process the decoded frame
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                std::cout << "Frame decoded: " << pFrame->width << "x" << pFrame->height << std::endl;
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            }
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        }
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        av_packet_unref(&packet);
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    }
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    av_frame_free(&pFrame);
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    avcodec_free_context(&pCodecContext);
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    avformat_close_input(&pFormatContext);
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    avformat_network_deinit();
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    return 0;
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}