JAVE 视音频转码

官方参考文档： http://www.sauronsoftware.it/projects/jave/manual.php

一、什么是JAVE

    JAVE(Java Audio Video Encoder),是一个包涵ffmpeg项目库。开发这可以运用它去实现音频（Audio）与视频（Video）文件的转码。例如你要把AVI格式文件转为MPEG文件、WAV格式文件转为MP3格式文件，同时你还能调整文件大小与比例。JAVE兼容和支持很多格式之间的转码……

二、典型案例分析

    近期在做微信开发时，需要获取用户发给公众服务号的语音留言。而从微信服务端下载来的语音格式却是amr的格式，同样的你手机录音、Android语音等也都是生成amr格式文件。但当你想在web页面去播放此文件时，就困难了。因为无论是当前HTML5的<audio>标签，还是众多的播放插件都不支持amr格式文件的播放。所以，你不得不先把它转码为常见的MP3等类型文件。

三、所需环境与配置

    JAVE requires a J2SE environment 1.4 or later and a Windows or Linux OS on a i386 / 32 bit hardware architecture. JAVE can also be easily ported to other OS and hardware configurations, see the JAVE manual for details。 嗯，你应该看得懂~:D

    

    噢~差点忘了，你在使用时当然还必须引入它的jar包，请猛戳这里点击下载：jave-1.0.2.zip

四、具体用法与文档说明：

    1.JAVE中有个最重要的类Encoder,它暴露了很多的方法，总之你在使用JAVE时，你总是要创建Encoder的实例。

    Encoder encoder = new Encoder();

    让后转码时调用 encode()方法：

public void encode(java.io.File source,
                   java.io.File target,
                   it.sauronsoftware.jave.EncodingAttributes attributes)
            throws java.lang.IllegalArgumentException,
                   it.sauronsoftware.jave.InputFormatException,
                   it.sauronsoftware.jave.EncoderException

    第一个参数source：需要转码的源文件

    第二个参数target：需转型成的目标文件

    第三个参数attributes：是一个包含编码所需数据的参数

    2.Encoding attributes

    如上所述的encoder()方法，第三个参数是很重要的，所以，你得实例化出一个EncodingAttributes即EncodingAttributes attrs = new EncodingAttributes();

    接下来看看attrs都包含了些什么方法：

public void setAudioAttributes(it.sauronsoftware.jave.AudioAttributes audioAttributes)

从方法名可以看出是在转码音频时需要用到的方法，可以说是添加音频转码时所需音频属性。

public void setVideoAttributes(it.sauronsoftware.jave.AudioAttributes videoAttributes)

从方法名可以看出是在转码视频时需要用到的方法，可以说是添加视频转码时所需视频属性。

public void setFormat(java.lang.String format)

这个则是设置转码格式的方法。

public void setOffset(java.lang.Float offset)

设置转码偏移位置的方法，例如你想在5秒后开始转码源文件则setOffset(5)。

public void setDuration(java.lang.Float duration)

设置转码持续时间的方法，例如你想持续30秒的转码则setDuration(30)。

 3.Audio encoding attributes

    同样的我们也需设置Audio的属***：AudioAttributes audio = new AudioAttributes();

    看看它的方法：

public void setCodec(java.lang.String codec)//设置编码器

public void setBitRate(java.lang.Integer bitRate)//设置比特率

public void setSamplingRate(java.lang.Integer bitRate)//设置节录率

public void setChannels(java.lang.Integer channels)//设置声音频道

public void setVolume(java.lang.Integer volume)//设置音量

4.Video encoding attributes

public void setCodec(java.lang.String codec)//设置编码器
	
public void setTag(java.lang.String tag)//设置标签（通常用多媒体播放器所选择的视频解码）
	
public void setBitRate(java.lang.Integer bitRate)//设置比特率
	
public void setFrameRate(java.lang.Integer bitRate)//设置帧率
	
public void setSize(it.sauronsoftware.jave.VideoSize size)//设置大小

5.Monitoring the transcoding operation

    你可以用listener监测转码操作。JAVE定义了一个EncoderProgressListener的接口。

public void encode(java.io.File source,
                   java.io.File target,
                   it.sauronsoftware.jave.EncodingAttributes attributes,
                   it.sauronsoftware.jave.EncoderProgressListener listener)
            throws java.lang.IllegalArgumentException,
                   it.sauronsoftware.jave.InputFormatException,
                   it.sauronsoftware.jave.EncoderException

实现 EncoderProgressListener接口，需定义的方法：

public void sourceInfo(it.sauronsoftware.jave.MultimediaInfo info)//源文件信息
	
public void progress(int permil)//增长千分率

public void message(java.lang.String message)//转码信息提示

6.Getting informations about a multimedia file

    获取多媒体文件转码时的信息：

public it.sauronsoftware.jave.MultimediaInfo getInfo(java.io.File source)
                                             throws it.sauronsoftware.jave.InputFormatException,
                                                    it.sauronsoftware.jave.EncoderException

五、例子：

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);

总结下，以上例子看上去都大同小异，步骤就那几步固定死了。

首先，源文件与目标文件。

其次，设置视音频转码钱的属***数据。

      其中setCodec()方法中的参数要对应你所转码的格式的编码encoders。

最后，设置attrs并转码。

六、支持包含在内的格式：

Supported container formats

The JAVE built-in ffmpeg executable gives support for the following multimedia container formats:

Decoding

Formato	Descrizione
4xm	4X Technologies format
MTV	MTV format
RoQ	Id RoQ format
aac	ADTS AAC
ac3	raw ac3
aiff	Audio IFF
alaw	pcm A law format
amr	3gpp amr file format
apc	CRYO APC format
ape	Monkey's Audio
asf	asf format
au	SUN AU Format
avi	avi format
avs	AVISynth
bethsoftvid	Bethesda Softworks 'Daggerfall' VID format
c93	Interplay C93
daud	D-Cinema audio format
dsicin	Delphine Software International CIN format
dts	raw dts
dv	DV video format
dxa	dxa
ea	Electronic Arts Multimedia Format
ea_cdata	Electronic Arts cdata
ffm	ffm format
film_cpk	Sega FILM/CPK format
flac	raw flac
flic	FLI/FLC/FLX animation format
flv	flv format
gif	GIF Animation
gxf	GXF format
h261	raw h261
h263	raw h263
h264	raw H264 video format
idcin	Id CIN format
image2	image2 sequence
image2pipe	piped image2 sequence
ingenient	Ingenient MJPEG
ipmovie	Interplay MVE format
libnut	nut format
m4v	raw MPEG4 video format
matroska	Matroska File Format
mjpeg	MJPEG video
mm	American Laser Games MM format
mmf	mmf format
mov,mp4,m4a,3gp,3g2,mj2	QuickTime/MPEG4/Motion JPEG 2000 format
mp3	MPEG audio layer 3
mpc	musepack
mpc8	musepack8
mpeg	MPEG1 System format
mpegts	MPEG2 transport stream format
mpegtsraw	MPEG2 raw transport stream format
mpegvideo	MPEG video
mulaw	pcm mu law format
mxf	MXF format
nsv	NullSoft Video format
nut	nut format
nuv	NuppelVideo format
ogg	Ogg format
psxstr	Sony Playstation STR format
rawvideo	raw video format
redir	Redirector format
rm	rm format
rtsp	RTSP input format
s16be	pcm signed 16 bit big endian format
s16le	pcm signed 16 bit little endian format
s8	pcm signed 8 bit format
sdp	SDP
shn	raw shorten
siff	Beam Software SIFF
smk	Smacker Video
sol	Sierra SOL Format
swf	Flash format
thp	THP
tiertexseq	Tiertex Limited SEQ format
tta	true-audio
txd	txd format
u16be	pcm unsigned 16 bit big endian format
u16le	pcm unsigned 16 bit little endian format
u8	pcm unsigned 8 bit format
vc1	raw vc1
vmd	Sierra VMD format
voc	Creative Voice File format
wav	wav format
wc3movie	Wing Commander III movie format
wsaud	Westwood Studios audio format
wsvqa	Westwood Studios VQA format
wv	WavPack
yuv4mpegpipe	YUV4MPEG pipe format

Encoding

Formato	Descrizione
3g2	3gp2 format
3gp	3gp format
RoQ	Id RoQ format
ac3	raw ac3
adts	ADTS AAC
aiff	Audio IFF
alaw	pcm A law format
amr	3gpp amr file format
asf	asf format
asf_stream	asf format
au	SUN AU Format
avi	avi format
crc	crc testing format
dv	DV video format
dvd	MPEG2 PS format (DVD VOB)
ffm	ffm format
flac	raw flac
flv	flv format
framecrc	framecrc testing format
gif	GIF Animation
gxf	GXF format
h261	raw h261
h263	raw h263
h264	raw H264 video format
image2	image2 sequence
image2pipe	piped image2 sequence
libnut	nut format
m4v	raw MPEG4 video format
matroska	Matroska File Format
mjpeg	MJPEG video
mmf	mmf format
mov	mov format
mp2	MPEG audio layer 2
mp3	MPEG audio layer 3
mp4	mp4 format
mpeg	MPEG1 System format
mpeg1video	MPEG video
mpeg2video	MPEG2 video
mpegts	MPEG2 transport stream format
mpjpeg	Mime multipart JPEG format
mulaw	pcm mu law format
null	null video format
nut	nut format
ogg	Ogg format
psp	psp mp4 format
rawvideo	raw video format
rm	rm format
rtp	RTP output format
s16be	pcm signed 16 bit big endian format
s16le	pcm signed 16 bit little endian format
s8	pcm signed 8 bit format
svcd	MPEG2 PS format (VOB)
swf	Flash format
u16be	pcm unsigned 16 bit big endian format
u16le	pcm unsigned 16 bit little endian format
u8	pcm unsigned 8 bit format
vcd	MPEG1 System format (VCD)
vob	MPEG2 PS format (VOB)
voc	Creative Voice File format
wav	wav format
yuv4mpegpipe	YUV4MPEG pipe format

Built-in decoders and encoders

The JAVE built-in ffmpeg executable contains the following decoders and encoders:

Audio decoders

adpcm_4xm	adpcm_adx	adpcm_ct	adpcm_ea	adpcm_ea_r1
adpcm_ea_r2	adpcm_ea_r3	adpcm_ea_xas	adpcm_ima_amv	adpcm_ima_dk3
adpcm_ima_dk4	adpcm_ima_ea_eacs	adpcm_ima_ea_sead	adpcm_ima_qt	adpcm_ima_smjpeg
adpcm_ima_wav	adpcm_ima_ws	adpcm_ms	adpcm_sbpro_2	adpcm_sbpro_3
adpcm_sbpro_4	adpcm_swf	adpcm_thp	adpcm_xa	adpcm_yamaha
alac	ape	atrac 3	cook	dca
dsicinaudio	flac	g726	imc	interplay_dpcm
liba52	libamr_nb	libamr_wb	libfaad	libgsm
libgsm_ms	mace3	mace6	mp2	mp3
mp3adu	mp3on4	mpc sv7	mpc sv8	mpeg4aac
nellymoser	pcm_alaw	pcm_mulaw	pcm_s16be	pcm_s16le
pcm_s16le_planar	pcm_s24be	pcm_s24daud	pcm_s24le	pcm_s32be
pcm_s32le	pcm_s8	pcm_u16be	pcm_u16le	pcm_u24be
pcm_u24le	pcm_u32be	pcm_u32le	pcm_u8	pcm_zork
qdm2	real_144	real_288	roq_dpcm	shorten
smackaud	sol_dpcm	sonic	truespeech	tta
vmdaudio	vorbis	wavpack	wmav1	wmav2
ws_snd1	xan_dpcm

Audio encoders

ac3	adpcm_adx	adpcm_ima_wav	adpcm_ms	adpcm_swf
adpcm_yamaha	flac	g726	libamr_nb	libamr_wb
libfaac	libgsm	libgsm_ms	libmp3lame	libvorbis
mp2	pcm_alaw	pcm_mulaw	pcm_s16be	pcm_s16le
pcm_s24be	pcm_s24daud	pcm_s24le	pcm_s32be	pcm_s32le
pcm_s8	pcm_u16be	pcm_u16le	pcm_u24be	pcm_u24le
pcm_u32be	pcm_u32le	pcm_u8	pcm_zork	roq_dpcm
sonic	sonicls	vorbis	wmav1	wmav2

Video decoders

4xm	8bps	VMware video	aasc	amv
asv1	asv2	avs	bethsoftvid	bmp
c93	camstudio	camtasia	cavs	cinepak
cljr	cyuv	dnxhd	dsicinvideo	dvvideo
dxa	ffv1	ffvhuff	flashsv	flic
flv	fraps	gif	h261	h263
h263i	h264	huffyuv	idcinvideo	indeo2
indeo3	interplayvideo	jpegls	kmvc	loco
mdec	mjpeg	mjpegb	mmvideo	mpeg1video
mpeg2video	mpeg4	mpegvideo	msmpeg4	msmpeg4v1
msmpeg4v2	msrle	msvideo1	mszh	nuv
pam	pbm	pgm	pgmyuv	png
ppm	ptx	qdraw	qpeg	qtrle
rawvideo	roqvideo	rpza	rv10	rv20
sgi	smackvid	smc	snow	sp5x
svq1	svq3	targa	theora	thp
tiertexseqvideo	tiff	truemotion1	truemotion2	txd
ultimotion	vb	vc1	vcr1	vmdvideo
vp3	vp5	vp6	vp6a	vp6f
vqavideo	wmv1	wmv2	wmv3	wnv1
xan_wc3	xl	zlib	zmbv

Video encoders

asv1	asv2	bmp	dnxhd	dvvideo
ffv1	ffvhuff	flashsv	flv	gif
h261	h263	h263p	huffyuv	jpegls
libtheora	libx264	libxvid	ljpeg	mjpeg
mpeg1video	mpeg2video	mpeg4	msmpeg4	msmpeg4v1
msmpeg4v2	pam	pbm	pgm	pgmyuv
png	ppm	qtrle	rawvideo	roqvideo
rv10	rv20	sgi	snow	svq1
targa	tiff	wmv1	wmv2	zlib
zmbv

七、执行ffmpeg的二选一

JAVE is not pure Java: it acts as a wrapper around an ffmpeg (http://ffmpeg.mplayerhq.hu/) executable. ffmpeg is an open source and free software project entirely written in C, so its executables cannot be easily ported from a machine to another. You need a pre-compiled version of ffmpeg in order to run JAVE on your target machine. The JAVE distribution includes two pre-compiled executables of ffmpeg: a Windows one and a Linux one, both compiled for i386/32 bit hardware achitectures. This should be enough in most cases. If it is not enough for your specific situation, you can still run JAVE, but you need to obtain a platform specific ffmpeg executable. Check the Internet for it. You can even build it by yourself getting the code (and the documentation to build it) on the official ffmpeg site. Once you have obtained a ffmpeg executable suitable for your needs, you have to hook it in the JAVE library. That's a plain operation. JAVE gives you an abstract class called it.sauronsoftware.jave.FFMPEGLocator. Extend it. All you have to do is to define the following method:

public java.lang.String getFFMPEGExecutablePath()

This method should return a file system based path to your custom ffmpeg executable.

Once your class is ready, suppose you have called it MyFFMPEGExecutableLocator, you have to create an alternate encoder that uses it instead of the default locator:

Encoder encoder = new Encoder(new MyFFMPEGExecutableLocator())

You can use the same procedure also to switch to other versions of ffmpeg, even if you are on a platform covered by the executables bundled in the JAVE distribution.

Anyway be careful and test ever your application: JAVE it's not guaranteed to work properly with custom ffmpeg executables different from the bundled ones.

    额~天气炎热心情烦躁，上面的就大家自己去翻译吧~

    结语：关于JAVE的资料网络上也比较少，只好去翻阅官方文档，但自己英语水平一般，理解的也许不够透彻，文章中存在着很多漏洞，还望包涵并指正。有些东西不一定别人说的就完全正确，还是看官方的比较靠谱。