Golang と FFmpeg: リアルタイム ビデオ ストリーミングのトランスコーディングとカプセル化のためのテクノロジー

package main

// 导入FFmpeg相关的头文件
/*
#cgo LDFLAGS: -lavformat -lavcodec -lavutil
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
*/
import "C"

import (
    "fmt"
)

func main() {
    // 输入文件名和输出文件名
    inputFileName := "input.mp4"
    outputFileName := "output.mp4"

    // 打开输入文件流
    var inputFormatCtx *C.AVFormatContext
    if C.avformat_open_input(&inputFormatCtx, C.CString(inputFileName), nil, nil) != 0 {
        fmt.Printf("Failed to open input file
")
        return
    }

    // 查找视频流信息
    if C.avformat_find_stream_info(inputFormatCtx, nil) < 0 {
        fmt.Printf("Failed to find stream information
")
        return
    }

    // 打开输出文件流
    var outputFormatCtx *C.AVFormatContext
    C.avformat_alloc_output_context2(&outputFormatCtx, nil, nil, C.CString(outputFileName))
    if outputFormatCtx == nil {
        fmt.Printf("Failed to allocate output format context
")
        return
    }

    // 复制视频流信息到输出流
    for i := C.uint(0); i < inputFormatCtx.nb_streams; i++ {
        stream := inputFormatCtx.streams[i]
        outputStream := C.avformat_new_stream(outputFormatCtx, stream.codec.codec)
        if outputStream == nil {
            fmt.Printf("Failed to allocate output stream
")
            return
        }

        // 复制流的参数
        if C.avcodec_parameters_copy(outputStream.codecpar, stream.codecpar) < 0 {
            fmt.Printf("Failed to copy codec parameters
")
            return
        }
    }

    // 打开输出文件
    if C.avio_open(&outputFormatCtx.pb, C.CString(outputFileName), C.AVIO_FLAG_WRITE) < 0 {
        fmt.Printf("Failed to open output file
")
        return
    }

    // 写入文件头部
    if C.avformat_write_header(outputFormatCtx, nil) < 0 {
        fmt.Printf("Failed to write header
")
        return
    }

    // 读取视频流数据并进行编码处理
    packet := C.AVPacket{}
    for C.av_read_frame(inputFormatCtx, &packet) == 0 {
        stream := inputFormatCtx.streams[packet.stream_index]
        outStream := outputFormatCtx.streams[packet.stream_index]

        // 编码帧数据
        if C.avcodec_send_packet(stream.codec, &packet) < 0 || C.avcodec_receive_packet(stream.codec, &packet) < 0 {
            fmt.Printf("Error while encoding
")
            return
        }

        packet.stream_index = outStream.index
        packet.pts = C.AV_NOPTS_VALUE
        packet.dts = C.AV_NOPTS_VALUE

        // 封装编码后的数据
        if C.av_interleaved_write_frame(outputFormatCtx, &packet) < 0 {
            fmt.Printf("Error while writing frame
")
            return
        }

        C.av_packet_unref(&packet)
    }

    // 结束封装
    C.av_write_trailer(outputFormatCtx)

    // 关闭输入输出流
    C.avformat_close_input(&inputFormatCtx)
    if outputFormatCtx != nil && outputFormatCtx.pb != nil {
        C.avio_close(outputFormatCtx.pb)
    }
    C.avformat_free_context(outputFormatCtx)

    fmt.Printf("Done
")
}