我正在练习UDP套接字编程。我的代码的功能如下。
将视频文件传输到客户端正在工作。但它是用二进制编写的，所以我无法打开视频。
所以我尝试使用ffmpeg来转换视频，但是不起作用。
我的代码有问题吗？如何将接收到的文件转换为视频文件？
我的环境是MacOs。
Server.c（服务器代码）：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/socket.h>
#define PORT 8888
#define BUF_SIZE 256
int main(){
int serv_sock;
char message[BUF_SIZE];
char buf[BUF_SIZE];
int str_len;
socklen_t clnt_adr_sz;
struct sockaddr_in serv_adr, clnt_adr;
//create socket
serv_sock=socket(PF_INET, SOCK_DGRAM, 0);
if(serv_sock == -1){
perror("socket() error");
exit(1);
}
//socket address
memset(&serv_adr, 0, sizeof(serv_adr));
serv_adr.sin_family=AF_INET;
serv_adr.sin_addr.s_addr=htonl(INADDR_ANY);
serv_adr.sin_port=htons(PORT);
//binding socket
if(bind(serv_sock, (struct sockaddr*)&serv_adr, sizeof(serv_adr)) == -1){
perror("bind() error");
exit(1);
}
while(1){
clnt_adr_sz=sizeof(clnt_adr);
str_len=recvfrom(serv_sock, message, BUF_SIZE, 0, (struct sockaddr *)&clnt_adr, &clnt_adr_sz);
if (str_len < 0) {
perror("recvfrom error");
exit(1);
}
char hello_message[] = "hello i am server";
if (sendto(serv_sock, hello_message, strlen(hello_message), 0, (struct sockaddr *)&clnt_adr, clnt_adr_sz) < 0) {
perror("sendto error");
exit(1);
}
//print message
message[str_len] = '\0';
printf("client say: %s\n", message);
char buf[BUF_SIZE];
ssize_t bytes_read;
// sending viedo file
printf("sending video file...\n");
size_t fsize;
//video file
FILE *file;
char *filename = "video.mp4";
// open video file
file = fopen(filename, "rb");
if (file == NULL) {
perror("File opening failed");
exit(EXIT_FAILURE);
}
//calculate video file memory
fseek(file, 0, SEEK_END);
fsize = ftell(file);
fseek(file,0,SEEK_SET);
size_t size = htonl(fsize);
int nsize =0;
while(nsize!=fsize){
int fpsize = fread(buf,1, BUF_SIZE, file);
nsize += fpsize;
if (sendto(serv_sock, &size, sizeof(size), 0, (struct sockaddr *)&clnt_adr, clnt_adr_sz) < 0) {
perror("sendto");
exit(EXIT_FAILURE);
}
fclose(file);
/*
while ((bytes_read = fread(buf, 1, BUF_SIZE, file)) > 0) {
if (sendto(serv_sock, buf, bytes_read, 0,
(struct sockaddr *)&clnt_adr, clnt_adr_sz) < 0) {
perror("sendto");
exit(EXIT_FAILURE);
}
}
*/
}
}
close(serv_sock);
return 0;
}
Client.c（客户端代码）
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/socket.h>
#define BUFSIZE 256
#define PORT 8888
int main(){
int sock;
char message[BUFSIZE];
int str_len;
socklen_t adr_sz;
struct sockaddr_in serv_addr, client_addr;
sock = socket(PF_INET, SOCK_DGRAM, 0);
if(sock == -1){
printf("socket() error\n");
exit(1);
}
memset(&serv_addr, 0, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
serv_addr.sin_port = htons(PORT);
char hello_message[] = "hello i am client";
sendto(sock, hello_message, strlen(hello_message), 0, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
adr_sz = sizeof(client_addr);
str_len=recvfrom(sock,message,BUFSIZE,0,(struct sockaddr*)&client_addr,&adr_sz);
message[str_len] = '\0';
printf("client say: %s\n", message);
/*
char buf[BUFSIZE];
ssize_t bytes_received;
socklen_t serv_len = sizeof(serv_addr);
while ((bytes_received = recvfrom(sock, buf, BUFSIZE, 0,
(struct sockaddr *)&serv_addr, &serv_len)) > 0) {
fwrite(buf, 1, bytes_received, file);
}
*/
FILE *file = fopen("received_test.mp4", "wb");
int nbyte = BUFSIZE;
while(nbyte>= BUFSIZE){
nbyte = recvfrom(sock, message, BUFSIZE, 0, (struct sockaddr*)&serv_addr, &adr_sz);
fwrite(message, sizeof(char), nbyte, file);
}
if (file == NULL) {
perror("File opening failed");
exit(EXIT_FAILURE);
}
fclose(file);
close(sock);
printf("File received successfully\n");
return 0;
}
我尝试使用 ffmpeg 将二进制文件转换为
.mp4ffmpeg -i received_test.mp4 output.mp4
ffmpeg version 7.0 Copyright (c) 2000-2024 the FFmpeg developers
built with Apple clang version 15.0.0 (clang-1500.3.9.4)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.0 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopenvino --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
libavutil 59. 8.100 / 59. 8.100
libavcodec 61. 3.100 / 61. 3.100
libavformat 61. 1.100 / 61. 1.100
libavdevice 61. 1.100 / 61. 1.100
libavfilter 10. 1.100 / 10. 1.100
libswscale 8. 1.100 / 8. 1.100
libswresample 5. 1.100 / 5. 1.100
libpostproc 58. 1.100 / 58. 1.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x12a62bdb0] Format mov,mp4,m4a,3gp,3g2,mj2 detected only with low score of 1, misdetection possible!
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x12a62bdb0] moov atom not found
[in#0 @ 0x12b0043c0] Error opening input: Invalid data found when processing input
Error opening input file received_test.mp4.
Error opening input files: Invalid data found when processing input
在服务器端，您不会将文件的字节发送到客户端，而是一遍又一遍地发送
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