Class TechSmithCodec

java.lang.Object
org.monte.media.av.AbstractCodec
org.monte.media.av.codec.video.AbstractVideoCodec
org.monte.media.av.codec.video.TechSmithCodec
All Implemented Interfaces:
Codec
public class TechSmithCodec extends AbstractVideoCodec
TechSmithCodec (tscc) encodes a BufferedImage as a byte[] array.

The TechSmith codec works with AVI and QuickTime.

This codec supports encoding from a BufferedImage into the file format, and decoding from the file format to a BufferedImage.

This codec does not encode the color palette of an image. This must be done separately.

Supported input formats:

  • Format with BufferedImage.class, any width, any height, depth=8,16 or 24.
Supported output formats:
  • Format with byte[].class, same width and height as input format, depth=8,16 or 24.
The codec supports lossless delta- and key-frame encoding of images with 8, 16 or 24 bits per pixel.

Compression of a frame is performed in two steps: In the first, step a frame is compressed line by line from bottom to top. In the second step the resulting data is compressed again using zlib compression.

Apart from the second compression step and the support for 16- and 24-bit data, this encoder is identical to the RunLengthCodec.

Each line of a frame is compressed individually. A line consists of two-byte op-codes optionally followed by data. The end of the line is marked with the EOL op-code.

The following op-codes are supported:

  • 0x00 0x00
    Marks the end of a line.
  • 0x00 0x01
    Marks the end of the bitmap.
  • 0x00 0x02 x y
    Marks a delta (skip). x and y indicate the horizontal and vertical offset from the current position. x and y are unsigned 8-bit values.
  • 0x00 n pixel{n} 0x00?
    Marks a literal run. n gives the number of 8-, 16- or 24-bit pixels that follow. n must be between 3 and 255. If n is odd and 8-bit pixels are used, a pad byte with the value 0x00 must be added.
  • n pixel
    Marks a repetition. n gives the number of times the given pixel is repeated. n must be between 1 and 255.
Example: 
 Compressed data         Expanded data

 03 04                   04 04 04
 05 06                   06 06 06 06 06
 00 03 45 56 67 00       45 56 67
 02 78                   78 78
 00 02 05 01             Move 5 right and 1 down
 02 78                   78 78
 00 00                   End of line
 09 1E                   1E 1E 1E 1E 1E 1E 1E 1E 1E
 00 01                   End of RLE bitmap

References:
http://wiki.multimedia.cx/index.php?title=TechSmith_Screen_Capture_Codec

Author:
Werner Randelshofer

  • Constructor Details

    • TechSmithCodec

      public TechSmithCodec()

  • Method Details

    • setOutputFormat

      public Format setOutputFormat(Format f)
      Description copied from interface: Codec
      Sets the output format. Returns the format that was actually set. This is the closest format that the Codec supports. Returns null if the specified format is not supported and no reasonable match could be found.
      Specified by:
      setOutputFormat in interface Codec
      Overrides:
      setOutputFormat in class AbstractCodec

    • reset

      public void reset()
      Description copied from class: AbstractCodec
      Empty implementation of the reset method. Don't call super.
      Specified by:
      reset in interface Codec
      Overrides:
      reset in class AbstractCodec

    • process

      public int process(Buffer in, Buffer out)
      Description copied from interface: Codec
      Performs the media processing defined by this codec.

      Copies the data from the input buffer into the output buffer.

      Returns:
      A combination of processing flags.

    • decode

      public int decode(Buffer in, Buffer out)

    • encode

      public int encode(Buffer in, Buffer out)