直播软件开发中的音视频编码转换怎么实现

2.1、下载ffmpeg。 下载网址：[url]http://www.ffmpeg.org/download.html[/url] 2.2、解压缩

tar -zxvf ffmpeg-2.0.1.tar.gz

2.3、编辑profile文件： vi /etc/profile 在文件末尾加上两句话：

export FFMPEG_HOME=/usr/local/ffmpeg export PATH=$FFMPEG_HOME/bin:$PATH

2.4、配置安装路径之类的：

./configure --enable-shared --prefix=/usr/local/ffmpeg --enable-shared 参数据说是允许其编译产生动态库，在以后的编程中要用到这个几个动态库，我也没考证，就直接用了。 如果出现异常，提示因为缺少yasm，需要添加参数，再执行以下命令： ./configure --enable-shared --disable-yasm --prefix=/usr/local/ffmpeg 如果执行结果不对，可以根据提示信息，并查看帮助，解决问题 ./configure --help

2.5、编译安装

make make install

2.6、安装之后在/usr/local/ffmpeg会看到有三个目录

bin 执行文件目录 lib 静态，动态链接库目录 include 编程用到的头文件

2.7、为了防止执行程序找不到库文件，

可以将/usr/local/ffmpeg/lib目录设置到LD_LIBRARY_PATH环境变量

8、若出现error while loading shared libraries: libavdevice.so.52的错误

修改/etc/ld.so.conf 在最后一行加上/usr/local/ffmpeg/lib ldconfig -v 并修改 /usr/local/ffmpeg/lib目录下的文件权限为777

[b]3.shell脚本命令转换[/b]

./ffmpeg -i source.amr dest.mp3

[b]4.ffmpeg自带转换[/b]

/** * useFfmpegToMp3 * * @param ffmpeg * @param source * @param target */ public static void useFfmpegToMp3(String ffmpeg, String source, String target){ Runtime run = null; try { long start=System.currentTimeMillis(); run = Runtime.getRuntime(); //设置文件运行权限 run.exec(new String[] { "/bin/chmod", "755", ffmpeg}); String runCmd = ffmpeg + " -i " + source + " " + target; //运行命令 Process proc = run.exec(runCmd); proc.getOutputStream().flush(); proc.getOutputStream().close(); proc.getInputStream().close(); LOGGER.info("Dest File Size:{}", new File(target).length()); long end=System.currentTimeMillis(); LOGGER.info("useFfmpegToMp3 Complete:{} -> {}, cost ms:{}", source, target, end-start); } catch (Exception e) { LOGGER.error("useJaveToMp3 Exception: ", e); } finally{ //run调用lame解码器最后释放内存 run.freeMemory(); } }

[b]5.Jave转换[/b] 下载地址:[url]http://www.sauronsoftware.it/projects/jave/download.php[/url]

/** * jave 转换mp3 * * @param source * @param target */ public static void useJaveToMp3(String source, String target) { try { long start=System.currentTimeMillis(); File sourceFile = new File(source); File targetFile = new File(target); AudioAttributes audio = new AudioAttributes(); Encoder encoder = new Encoder(); audio.setCodec("libmp3lame"); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("mp3"); attrs.setAudioAttributes(audio); encoder.encode(sourceFile, targetFile, attrs); LOGGER.info("Dest File Size:{}", targetFile.length()); long end=System.currentTimeMillis(); LOGGER.info("useJaveToMp3 Complete:{} -> {}, cost ms:{}", source, target, end-start); }catch (Exceptio){ LOGGER.error("useJaveToMp3 Exception: ", e); } }

备注: 如果自带的FFmpeg转码报错，编译最新的ffmpeg，执行就可以了 官方示例：

//From a generic AVI to a youtube-like FLV movie, with an embedded MP3 audio stream: File source = new File("source.avi"); File target = new File("target.flv"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("libmp3lame"); audio.setBitRate(new Integer(64000)); audio.setChannels(new Integer(1)); audio.setSamplingRate(new Integer(22050)); VideoAttributes video = new VideoAttributes(); video.setCodec("flv"); video.setBitRate(new Integer(160000)); video.setFrameRate(new Integer(15)); video.setSize(new VideoSize(400, 300)); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("flv"); attrs.setAudioAttributes(audio); attrs.setVideoAttributes(video); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs); //Next lines extracts audio informations from an AVI and store them in a plain WAV file: File source = new File("source.avi"); File target = new File("target.wav"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("pcm_s16le"); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("wav"); attrs.setAudioAttributes(audio); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs); // Next example takes an audio WAV file and generates a 128 kbit/s, stereo, 44100 Hz MP3 file: File source = new File("source.wav"); File target = new File("target.mp3"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("libmp3lame"); audio.setBitRate(new Integer(128000)); audio.setChannels(new Integer(2)); audio.setSamplingRate(new Integer(44100)); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("mp3"); attrs.setAudioAttributes(audio); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs); // Next one decodes a generic AVI file and creates another one with the same video stream of the source and a re-encoded low quality MP3 audio stream: File source = new File("source.avi"); File target = new File("target.avi"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("libmp3lame"); audio.setBitRate(new Integer(56000)); audio.setChannels(new Integer(1)); audio.setSamplingRate(new Integer(22050)); VideoAttributes video = new VideoAttributes(); video.setCodec(VideoAttributes.DIRECT_STREAM_COPY); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("avi"); attrs.setAudioAttributes(audio); attrs.setVideoAttributes(video); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs); //Next one generates an AVI with MPEG 4/DivX video and OGG Vorbis audio: File source = new File("source.avi"); File target = new File("target.avi"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("libvorbis"); VideoAttributes video = new VideoAttributes(); video.setCodec("mpeg4"); video.setTag("DIVX"); video.setBitRate(new Integer(160000)); video.setFrameRate(new Integer(30)); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("mpegvideo"); attrs.setAudioAttributes(audio); attrs.setVideoAttributes(video); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs); // A smartphone suitable video: File source = new File("source.avi"); File target = new File("target.3gp"); AudioAttributes audio = new AudioAttributes(); audio.setCodec("libfaac"); audio.setBitRate(new Integer(128000)); audio.setSamplingRate(new Integer(44100)); audio.setChannels(new Integer(2)); VideoAttributes video = new VideoAttributes(); video.setCodec("mpeg4"); video.setBitRate(new Integer(160000)); video.setFrameRate(new Integer(15)); video.setSize(new VideoSize(176, 144)); EncodingAttributes attrs = new EncodingAttributes(); attrs.setFormat("3gp"); attrs.setAudioAttributes(audio); attrs.setVideoAttributes(video); Encoder encoder = new Encoder(); encoder.encode(source, target, attrs);