# Ubuntu/Debian
sudo apt-get install lib*codec-dev lib*format-dev lib*util-dev libswscale-dev
<h1>macOS (使用 Homebrew)</h1><p>brew install ffmpeg</p><p><span>立即学习</span>“<a href="https://pan.quark.cn/s/6e7abc4abb9f" style="text-decoration: underline !important; color: blue; font-weight: bolder;" rel="nofollow" target="_blank">C++免费学习笔记（深入）</a>”；</p>

extern "C" {
#include <lib*format/*format.h>
#include <lib*codec/*codec.h>
#include <lib*util/*util.h>
#include <libswscale/swscale.h>
}

g++ main.cpp -l*format -l*codec -l*util -lswscale

*format_open_input(&formatContext, "input.mp4", nullptr, nullptr);
*format_find_stream_info(formatContext, nullptr);
<p>int videoStreamIndex = -1;
for (int i = 0; i < formatContext->nb_streams; i++) {
if (formatContext->streams[i]->codecpar->codec_type == *MEDIA_TYPE_VIDEO) {
videoStreamIndex = i;
break;
}
}</p><p>*Codec<em> codec = *codec_find_decoder(formatContext->streams[videoStreamIndex]->codecpar->codec_id);
*CodecContext</em> codecContext = *codec_alloc_context3(codec);
*codec_parameters_to_context(codecContext, formatContext->streams[videoStreamIndex]->codecpar);
*codec_open2(codecContext, codec, nullptr);</p><p>*Frame* frame = *_frame_alloc();
*Packet packet;
while (*_read_frame(formatContext, &packet) >= 0) {
if (packet.stream_index == videoStreamIndex) {
*codec_send_packet(codecContext, &packet);
while (*codec_receive_frame(codecContext, frame) == 0) {
// frame->data 包含YUV数据，可进一步转换或保存
// 使用 swscale 可将 YUV 转为 RGB
}
}
*_packet_unref(&packet);
}</p>

*format_open_input(&formatContext, "rtsp://example.com/stream", nullptr, nullptr);