前言
这篇是几年前整理的老文章了,当时在调研流视频推送及播放相关技术,并在项目中应用,使用到ffmpeg,所以整理了这篇文章,但并未发布。最近又有相关的技术需求,所以整理出来,作为一个新的开始。
一 ffmpeg安装
1.1 基于源码进行编译安装
wget http://www.ffmpeg.org/releases/ffmpeg-3.1.tar.gz
tar -zxvf ffmpeg-3.1.tar.gz
cd ffmpeg-3.1
./configure --prefix=/usr/local/ffmpeg
make && make install
等待安装完成...
配置环境变量:
vi /etc/profile
在最后PATH添加环境变量:PATH=$PATH:/usr/local/ffmpeg/binexport PATH保存退出
source /ect/profile 设置生效
ffmpeg -version 查看版本
1.2 yasm
若安装过程中出现以下错误:
yasm/nasm not found or too old. Use –disable-yasm for a crippled build.
If you think configure made a mistake, make sure you are using the latestversion from Git. If the latest version fails, report the problem to theffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.Include the log file “config.log” produced by configure as this will helpsolve the problem.
如错误提示,yasm未安装或者版本太老了,需要安装新版的yasm
yasm安装方法:
代码语言:javascript复制wget http://www.tortall.net/projects/yasm/releases/yasm-1.3.0.tar.gz
tar -zxvf yasm-1.3.0.tar.gz
cd yasm-1.3.0
./configure
make && make install
1.3 其他问题
问题:在其他机器安装时,还遇到了下面的几个问题,可供参考:
1、使用./configure 时,出现:
If gcc is a cross-compiler, use the --enable-cross-compile option.Only do this if you know what cross compiling means.C compiler test failed.If you think configure made a mistake, make sure you are using the latestversion from Git. If the latest version fails, report the problem to theffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.Include the log file "config.log" produced by configure as this will helpsolve the problem.提示是gcc的问题,并提示了可以查看config.log。cat config.log 查看错误信息如下【这里只粘贴最后的错误信息】:
END /tmp/ffconf.A6YIvVF3.cgcc -c -o /tmp/ffconf.kvhyNUCz.o /tmp/ffconf.A6YIvVF3.c./configure: line 875: gcc: command not foundC compiler test failed.显然,是没有找到gcc命令。。通过yum 或 apt-get命令安装即可,之后再进行./configure ,便可以继续安装
2、运行./configure 会报错,错误提示为: configure: error: C preprocessor “/lib/cpp” sanity check check See `config.log’ for more details
解决办法:出现该情况是由于c 编译器的相关package没有安装,在终端上执行: $ sudo yum install glibc-headers gcc-c
windows下的编译步骤,参考:http://blog.csdn.net/zhouyongku/article/details/44961447
二 视频转码命令
由于需求的来源是要把h264裸流转换成mp4,好供前端页面进行播放(js的视频播放器支持的格式比较有限。。由于开发时间紧张,所以也没有足够的精力自己开发或找到现成的播放器,所以暂时只能采用编码的方案)。
2.1 ffmpeg命令:264转mp4
ffmpeg -i slamtv60.264 -vcodec copy -f mp4 test.mp4
执行中打印的信息如下:
ffmpeg version 3.1 Copyright (c) 2000-2016 the FFmpeg developersbuilt with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-11)configuration: --prefix=/usr/local/ffmpeglibavutil 55. 27.100 / 55. 27.100libavcodec 57. 48.101 / 57. 48.101libavformat 57. 40.101 / 57. 40.101libavdevice 57. 0.101 / 57. 0.101libavfilter 6. 46.102 / 6. 46.102libswscale 4. 1.100 / 4. 1.100libswresample 2. 1.100 / 2. 1.100Input #0, h264, from 'slamtv60.264':Duration: N/A, bitrate: N/AStream #0:0: Video: h264 (Main), yuv420p, 384x288, 25.50 fps, 25.50 tbr, 1200k tbn, 51 tbcFile 'test.mp4' already exists. Overwrite ? [y/N] y[mp4 @ 0x3913260] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.Output #0, mp4, to 'test.mp4':Metadata:encoder : Lavf57.40.101Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 384x288, q=2-31, 25.50 fps, 25.50 tbr, 1200k tbn, 1200k tbcStream mapping:Stream #0:0 -> #0:0 (copy)Press [q] to stop, [?] for help[mp4 @ 0x3913260] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properlyframe= 1479 fps=0.0 q=-1.0 Lsize= 4890kB time=00:00:58.31 bitrate= 687.0kbits/s speed=2.41e 03x
video:4884kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.139057%
转换速度还是很快的,5M的一个.264文件,转换成mp4耗时在毫秒级。【不过是在配置较高的机器,x86_64,8核内存20G的服务器】
2.2 提取视频缩略图
代码语言:javascript复制ffmpeg -i 001709270738_1514337636497_3393223176.H264 -y -f image2 -t 0.001 -s 352x240 a.jpg
上述指令,是从H264文件中,提取一个尺寸为352x240大小的jpg图片文件,作为缩略图。
三 Java代码调用命令
使用的还是简单的java中执行shell命令的方法,考虑到都在java中实现的话可以在一个任务中完成操作,不必在使用shell衔接,增加复杂度。
代码如下:
代码语言:javascript复制package schedule;
import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;
public class FfmpegTranscode {
public static void runCmd(String command) {
try {
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
InputStream stderr = proc.getErrorStream();
InputStreamReader isr = new InputStreamReader(stderr);
BufferedReader br = new BufferedReader(isr);
String line = null;
System.out.println("<LogInfo>");
while ((line = br.readLine()) != null){
System.out.println(line);
}
System.out.println("</LogInfo>");
int exitVal = proc.waitFor();
System.out.println("Process exitValue: " exitVal);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
if(args.length<2) {
System.out.println("请输入源文件和输出文件位置,源文件为264,输出mp4! ");
return;
}
String h264Path = args[0];
String mp4Path = args[1];
System.out.println("执行转码:" h264Path " " mp4Path);
String videoCommand = "ffmpeg -i "
h264Path
" -vcodec copy -f mp4 "
mp4Path;
System.out.println(videoCommand);
runCmd(videoCommand);
}
}
代码语言:javascript复制
执行时,需要在有ffmpeg的环境下运行。可以打成jar包后,上传到上面已安装ffmpeg的机器,通过命令:
java -jar ffmpegtools.jar ./slamtv60.264 ./slamtv60.mp4 的方式执行(slamtv60.264替换成自己的264文件)
四 流数据转换【待续-研究中】
虽然上面已经实现了文件的转换,但更希望可以直接针对流数据进行处理,可以减少存储文件和读取的时间;直接把h264的流处理成mp4流后再写入指定位置。这个后续再继续调研,包括H265编码。