调整视频的分辨率

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已于 2024-08-20 14:15:52 修改 · 755 阅读

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CC 4.0 BY-SA版权

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#音视频 #c++ #ffmpeg

于 2024-07-23 18:09:32 首次发布

main.cpp

extern "C" {
    #include <libavformat/avformat.h>
    #include <libavcodec/avcodec.h>
    #include <libavutil/avutil.h>
    #include <libavutil/imgutils.h>
    #include <libswscale/swscale.h>
}

#include <iostream>
#include <string>

int resize_video(const std::string &input_filename, const std::string &output_filename, int width, int height) {
    av_register_all();

    AVFormatContext *input_format_context = nullptr;
    if (avformat_open_input(&input_format_context, input_filename.c_str(), nullptr, nullptr) < 0) {
        std::cerr << "Could not open input file." << std::endl;
        return -1;
    }

    if (avformat_find_stream_info(input_format_context, nullptr) < 0) {
        std::cerr << "Could not find stream information." << std::endl;
        return -1;
    }

    AVCodec *decoder = nullptr;
    int video_stream_index = av_find_best_stream(input_format_context, AVMEDIA_TYPE_VIDEO, -1, -1, &decoder, 0);
    if (video_stream_index < 0) {
        std::cerr << "Could not find video stream in the input file." << std::endl;
        return -1;
    }

    AVCodecContext *decoder_context = avcodec_alloc_context3(decoder);
    if (!decoder_context) {
        std::cerr << "Could not allocate decoder context." << std::endl;
        return -1;
    }

    if (avcodec_parameters_to_context(decoder_context, input_format_context->streams[video_stream_index]->codecpar) < 0) {
        std::cerr << "Could not copy decoder parameters to decoder context." << std::endl;
        return -1;
    }

    if (avcodec_open