ffmpeg编程查看视频文件信息

效果如下

执行效果打印日志

zh&＃64;zh-lpc:~/project/ffmpeg$ ./frmi test.mp4
open test.mp4 success.Input #0, mov,mp4,m4a,3gp,3g2,mj2, from &＃39;test.mp4&＃39;:Metadata:major_brand : isomminor_version : 512compatible_brands: isomiso2avc1mp41title : BigBuckBunny_115k.movencoder : Lavf58.76.100Duration: 00:05:52.96, bitrate: N/AStream #0:0(und): Video: h264 (avc1 / 0x31637661), none, 240x160, 87 kb/s, 23.88 fps, 24 tbr, 90k tbn (default)Metadata:handler_name : VideoHandlerStream #0:1(und): Audio: aac (mp4a / 0x6134706D), 12000 Hz, 2 channels, 32 kb/s (default)Metadata:handler_name : SoundHandler
zh&＃64;zh-lpc:~/project/ffmpeg$


简单分析

在真正实操之前&＃xff0c;我们先来分析一下&＃xff0c;我们正常使用C语言读取一个文件都需要哪些步骤&＃xff1a;

• 1、打开文件&＃xff1b;
• 2、读取文件信息&＃xff1b;
• 3、关闭文件。

一般就是&＃xff1a;open --> read --> close三步走。那么在ffmpeg中至少也需要这三步。

Linux中原始读取文件的小实验

1、创建一个文件

zh&＃64;zh-lpc:~/project/unixapi$ echo "aaaaa三生三世十里桃花123456" > info.txt


2、创建C语言编程文件

#include
#include #define BUFFSIZE 1024int main()
{int ret &＃61; 0;FILE *file;char buf[BUFFSIZE];char *fileName &＃61; "./info.txt";//open filefile &＃61; fopen(fileName,"r");//read filefread(buf, BUFFSIZE&＃43;1, 1, file);printf("%s\n", buf);//close filefclose(file);return 0;
}


3、编译

zh&＃64;zh-lpc:~/project/unixapi$ make unix_file
cc unix_file.c -o unix_file
zh&＃64;zh-lpc:~/project/unixapi$


4、执行

zh&＃64;zh-lpc:~/project/unixapi$ ./unix_file
aaaaa三生三世十里桃花123456zh&＃64;zh-lpc:~/project/unixapi$


ffmpeg读取视频文件信息—代码

ffmpeg_read_media_info.c:

/*** use ffmpeg codeing read flow file info**/
#include
#include
#include int main(int argc, char *argv[])
{int ret &＃61; 0;const char* fileName &＃61; "";AVFormatContext *ac &＃61; NULL;//set log levelav_log_set_level(AV_LOG_INFO);//diff params &＃61; 2 is params !&＃61; 2if(argc !&＃61; 2){av_log(NULL,AV_LOG_WARNING,"params not enough. \n\n");return -1;}//file name fileName &＃61; argv[1];//open video fileret &＃61; avformat_open_input(&ac,fileName,NULL,NULL);//diff open success or errorif(ret < 0){av_log(NULL,AV_LOG_ERROR,"open %s error. \n\n",fileName);return -1;}else{av_log(NULL,AV_LOG_INFO,"open %s success. \n\n",fileName);}av_dump_format(ac,0,fileName,0);//close file flowavformat_close_input(&ac);return 0;
}


编译&＃xff1a;

gcc -g -o frmi ffmpeg_read_media_info.c -I/usr/local/ffmpeg/include -L/usr/local/ffmpeg/lib -lavformat -lavutil


执行

zh&＃64;zh-lpc:~/project/ffmpeg$ ls -l test.mp4
-rwx------ 1 zh zh 5431627 9月 10 23:05 test.mp4
zh&＃64;zh-lpc:~/project/ffmpeg$
zh&＃64;zh-lpc:~/project/ffmpeg$ ls -l frmi
-rwxrwxr-x 1 zh zh 65152 9月 16 22:00 frmi
zh&＃64;zh-lpc:~/project/ffmpeg$
zh&＃64;zh-lpc:~/project/ffmpeg$ ls -l ffmpeg_read_media_info.c
-rwx------ 1 zh zh 955 9月 16 22:02 ffmpeg_read_media_info.c
zh&＃64;zh-lpc:~/project/ffmpeg$
zh&＃64;zh-lpc:~/project/ffmpeg$
zh&＃64;zh-lpc:~/project/ffmpeg$ ./frmi test.mp4
open test.mp4 success.Input #0, mov,mp4,m4a,3gp,3g2,mj2, from &＃39;test.mp4&＃39;:Metadata:major_brand : isomminor_version : 512compatible_brands: isomiso2avc1mp41title : BigBuckBunny_115k.movencoder : Lavf58.76.100Duration: 00:05:52.96, bitrate: N/AStream #0:0(und): Video: h264 (avc1 / 0x31637661), none, 240x160, 87 kb/s, 23.88 fps, 24 tbr, 90k tbn (default)Metadata:handler_name : VideoHandlerStream #0:1(und): Audio: aac (mp4a / 0x6134706D), 12000 Hz, 2 channels, 32 kb/s (default)Metadata:handler_name : SoundHandler
zh&＃64;zh-lpc:~/project/ffmpeg$