Encoding Attributes

Audio encoding attributes

Audio encoding attributes are represented by the instances of the ws.schild.jave.AudioAttributes class. The available methods on this kind of objects are:

public void setCodec(java.lang.String codec)

It sets the name of the codec that will be used for the transcoding of the audio stream. You have to choose a value from the list returned by the getAudioEncoders() method of the current Encoder instance. Otherwise you can pass the AudioAttributes.DIRECT_STREAM_COPY special value, that requires the copy of the original audio stream from the source file.

public void setBitRate(java.lang.Integer bitRate)

It sets the bitrate value for the new re-encoded audio stream. If no bitrate value is set, a default one will be picked by the encoder. The value should be expressed in bits per second. In example if you want a 128 kb/s bitrate you should call setBitRate(new Integer(128000)).

public void setSamplingRate(java.lang.Integer bitRate)

It sets the sampling rate for the new re-encoded audio stream. If no sampling-rate value is set, a default one will be picked by the encoder. The value should be expressed in hertz. In example if you want a CD-like 44100 Hz sampling-rate, you should call setSamplingRate(new Integer(44100)).

public void setChannels(java.lang.Integer channels)

It sets the number of the audio channels that will be used in the re-encoded audio stream (1 = mono, 2 = stereo). If no channels value is set, a default one will be picked by the encoder.

public void setVolume(java.lang.Integer volume)

This method can be called to alter the volume of the audio stream. A value of 256 means no volume change. So a value less than 256 is a volume decrease, while a value greater than 256 will increase the volume of the audio stream.

Video encoding attributes

Video encoding attributes are represented by the instances of the ws.schild.jave.VideoAttributes class. The available methods on this kind of objects are:

public void setCodec(java.lang.String codec)

It sets the name of the codec that will be used for the transcoding of the video stream. You have to choose a value from the list returned by the getVideoEncoders() method of the current Encoder instance. Otherwise you can pass the VideoAttributes.DIRECT_STREAM_COPY special value, that requires the copy of the original video stream from the source file.

public void setTag(java.lang.String tag)

It sets the tag/fourcc value associated to the re-encoded video stream. If no value is set a default one will be picked by the encoder. The tag value is often used by multimedia players to choose which video decoder run on the stream. In example a MPEG 4 video stream with a "DIVX" tag value will be decoded with the default DivX decoder used by the player. And, by the way, this is exactly what a DivX is: a MPEG 4 video stream with an attached "DIVX" tag/fourcc value!

public void setBitRate(java.lang.Integer bitRate)

It sets the bitrate value for the new re-encoded video stream. If no bitrate value is set, a default one will be picked by the encoder. The value should be expressed in bits per second. In example if you want a 360 kb/s bitrate you should call setBitRate(new Integer(360000)).

public void setFrameRate(java.lang.Integer bitRate)

It sets the frame rate value for the new re-encoded audio stream. If no bitrate frame-rate is set, a default one will be picked by the encoder. The value should be expressed in frames per second. In example if you want a 30 f/s frame-rate you should call setFrameRate(new Integer(30)). public void setSize(ws.schild.jave.VideoSize size)

It sets the size and the proportion of the images in the video stream. If no value is set, the encoder will preserve the original size and proportion. Otherwise you can pass a ws.schild.java.VideoSize instance, with your preferred size. You can set the width and the height of the new encoded video, with pixel values, scaling the original one. In example if you want to scale the video to 512 px in width and 384px in height you should call setSize(new VideoSize(512, 384)).

To limit CPU usage to 1 or more threads (cores) use this:

EncodingAttributes attrs= new EncodingAttributes();
attrs.setDecodingThreads(2);
attrs.setEncodingThreads(2);