org.monte.media.av.codec.video.AbstractVideoCodecCore

org.monte.media.av.codec.video.TechSmithCodecCore

public class TechSmithCodecCore extends AbstractVideoCodecCore

TechSmithCodec (tscc) encodes a BufferedImage as a byte[] array.

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 dx dy
Marks a delta (skip). dx and dy indicate the horizontal and vertical offset from the current position. dx and dy 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

Palette colors

In an AVI file, palette changes are stored in chunks with id's with the suffix "pc". "pc" chunks contain an AVIPALCHANGE struct as shown below.

 /* ------------------
  * AVI Palette Change
  * ------------------
  * /

 // Values for this enum have been taken from:
 // http://biodi.sdsc.edu/Doc/GARP/garp-1.1/define.h
 enum {
     PC_EXPLICIT = 0x02,
     // Specifies that the low-order word of the logical palette entry
     // designates a hardware palette index. This flag allows the application to
     // show the contents of the display device palette.
     PC_NOCOLLAPSE = 0x04,
     // Specifies that the color be placed in an unused entry in the system
     // palette instead of being matched to an existing color in the system
     // palette. If there are no unused entries in the system palette, the color
     // is matched normally. Once this color is in the system palette, colors in
     // other logical palettes can be matched to this color.
     PC_RESERVED = 0x01
     // Specifies that the logical palette entry be used for palette animation.
     // This flag prevents other windows from matching colors to the palette
     // entry since the color frequently changes. If an unused system-palette
     // entry is available, the color is placed in that entry. Otherwise, the
     // color is not available for animation.
 } peFlagsEnum;
 /*
  * The PALETTEENTRY structure specifies the color and usage of an entry in a
  * logical palette. A logical palette is defined by a LOGPALETTE structure.
  * /
 typedef struct {
   BYTE peRed; // Specifies a red intensity value for the palette entry.
   BYTE peGreen; // Specifies a green intensity value for the palette entry.
   BYTE peBlue; // Specifies a blue intensity value for the palette entry.
   BYTE enum peFlagsEnum peFlags; // Specifies how the palette entry is to be used.
 } PALETTEENTRY;

 typedef struct {
   AVIPALCHANGE avipalchange;
 } AVIPALCHANGE0;

 typedef struct {
     PALETTEENTRY  p[256];
 } PALETTEENTRY_ALLENTRIES;

 typedef struct {
     BYTE          firstEntry;
         // Specifies the index of the first palette entry to change.
     BYTE          numEntries;
         // Specifies the number of palette entries to change, or zero to change
         // all 256 palette entries.
     WORD          flags;
         // Reserved.
     PALETTEENTRY  peNew[numEntries];
         // Specifies an array of PALETTEENTRY structures, of size "numEntries".
     PALETTEENTRY_ALLENTRIES  all[numEntries==0];
 } AVIPALCHANGE;

Author:: Werner Randelshofer

Constructor Summary

Constructors

Constructor

Description

TechSmithCodecCore()
Method Summary

Modifier and Type

Method

Description

boolean

decode16(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe)

Decodes from 16-bit to 24-bit RGB.

boolean

decode24(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe)

Decodes to 24-bit RGB.

boolean

decode8(byte[] inDat, int off, int length, byte[] outDat, byte[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe)

Decodes to 8-bit palettised.

boolean

decode8(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe)

Decodes to 24-bit direct color.

void

decodePalette(byte[] inDat, int off, int len)

Decodes an AVI palette change chunk.

void

encodeDelta16(OutputStream out, short[] data, short[] prev, int width, int height, int offset, int scanlineStride)

Encodes a 16-bit delta frame.

void

encodeDelta24(OutputStream out, int[] data, int[] prev, int width, int height, int offset, int scanlineStride)

Encodes a 24-bit delta frame.

void

encodeDelta8(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride)

Encodes an 8-bit delta frame with indexed colors.

void

encodeDelta8to24(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride)

Encodes an 8-bit delta frame with indexed colors to 24-bit.

void

encodeKey16(OutputStream out, short[] data, int width, int height, int offset, int scanlineStride)

Encodes a 16-bit key frame.

void

encodeKey24(OutputStream out, int[] data, int width, int height, int offset, int scanlineStride)

Encodes a 24-bit key frame.

void

encodeKey8(OutputStream out, byte[] data, int width, int height, int offset, int scanlineStride)

Encodes a 8-bit key frame with indexed colors.

void

encodeKey8to24(OutputStream out, byte[] data, int width, int height, int offset, int scanlineStride)

Encodes a 8-bit key frame with indexed colors to 24-bit.

void

encodeSameDelta16(OutputStream out, short[] data, short[] prev, int width, int height, int offset, int scanlineStride)

Encodes a delta frame which is known to have the same content than the previous frame.

void

encodeSameDelta24(OutputStream out, int[] data, int[] prev, int width, int height, int offset, int scanlineStride)

Encodes a delta frame which is known to have the same content than the previous frame.

void

encodeSameDelta8(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride)

Encodes a delta frame which is known to have the same content than the previous frame.

int[]

getPalette()

void

reset()

void

setPalette(byte[] redValues, byte[] greenValues, byte[] blueValues)

void

setPalette(int[] rgbValues)

Methods inherited from class org.monte.media.av.codec.video.AbstractVideoCodecCore
readInt24LE, readInt24LE, readInts24LE, readInts24LE, readRGB555to24, readRGB555to24, readRGB565to24, readRGBs555to24, readRGBs555to24, readRGBs565to24, writeInt24LE, writeInts16LE, writeInts24LE

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- TechSmithCodecCore
  
  public TechSmithCodecCore()
Method Details
- reset
  
  public void reset()
- getPalette
  
  public int[] getPalette()
- decodePalette
  
  public void decodePalette(byte[] inDat, int off, int len) throws IOException
  
  Decodes an AVI palette change chunk. FIXME - This could be moved out into a separate class.
  
  Throws:
  
  IOException
- decode8
  
  public boolean decode8(byte[] inDat, int off, int length, byte[] outDat, byte[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe) throws IOException
  
  Decodes to 8-bit palettised. Returns true if a key-frame was decoded.
  
  Parameters:
  
  inDat -
  
  off -
  
  length -
  
  outDat -
  
  prevDat - The pixels decoded in the previous frame. Since no double buffering is used, this can be the same array than outDat.
  
  width -
  
  height -
  
  onlyDecodeIfKeyframe -
  
  Returns:
  
  True if a key-frame was decoded.
  
  Throws:
  
  IOException
- decode8
  
  public boolean decode8(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe) throws IOException
  
  Decodes to 24-bit direct color. Returns true if a key-frame was decoded.
  
  Parameters:
  
  inDat -
  
  off -
  
  length -
  
  outDat -
  
  prevDat - The pixels decoded in the previous frame. Since no double buffering is used, this can be the same array than outDat.
  
  width -
  
  height -
  
  onlyDecodeIfKeyframe -
  
  Returns:
  
  True if a key-frame was decoded.
  
  Throws:
  
  IOException
- decode24
  
  public boolean decode24(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe) throws IOException
  
  Decodes to 24-bit RGB. Returns true if a key-frame was decoded.
  
  Throws:
  
  IOException
- decode16
  
  public boolean decode16(byte[] inDat, int off, int length, int[] outDat, int[] prevDat, int width, int height, boolean onlyDecodeIfKeyframe) throws IOException
  
  Decodes from 16-bit to 24-bit RGB. Returns true if a key-frame was decoded.
  
  Throws:
  
  IOException
- encodeDelta8
  
  public void encodeDelta8(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes an 8-bit delta frame with indexed colors.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  prev - The image data of the previous frame.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeDelta8to24
  
  public void encodeDelta8to24(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes an 8-bit delta frame with indexed colors to 24-bit.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  prev - The image data of the previous frame.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeSameDelta8
  
  public void encodeSameDelta8(OutputStream out, byte[] data, byte[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a delta frame which is known to have the same content than the previous frame.
  
  Parameters:
  
  out -
  
  data -
  
  prev -
  
  width -
  
  height -
  
  offset -
  
  scanlineStride -
  
  Throws:
  
  IOException
- encodeSameDelta24
  
  public void encodeSameDelta24(OutputStream out, int[] data, int[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a delta frame which is known to have the same content than the previous frame.
  
  Parameters:
  
  out -
  
  data -
  
  prev -
  
  width -
  
  height -
  
  offset -
  
  scanlineStride -
  
  Throws:
  
  IOException
- encodeSameDelta16
  
  public void encodeSameDelta16(OutputStream out, short[] data, short[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a delta frame which is known to have the same content than the previous frame.
  
  Parameters:
  
  out -
  
  data -
  
  prev -
  
  width -
  
  height -
  
  offset -
  
  scanlineStride -
  
  Throws:
  
  IOException
- encodeKey8
  
  public void encodeKey8(OutputStream out, byte[] data, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 8-bit key frame with indexed colors.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeKey8to24
  
  public void encodeKey8to24(OutputStream out, byte[] data, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 8-bit key frame with indexed colors to 24-bit.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeDelta16
  
  public void encodeDelta16(OutputStream out, short[] data, short[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 16-bit delta frame.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  prev - The image data of the previous frame.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeKey24
  
  public void encodeKey24(OutputStream out, int[] data, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 24-bit key frame.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeDelta24
  
  public void encodeDelta24(OutputStream out, int[] data, int[] prev, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 24-bit delta frame.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  prev - The image data of the previous frame.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- encodeKey16
  
  public void encodeKey16(OutputStream out, short[] data, int width, int height, int offset, int scanlineStride) throws IOException
  
  Encodes a 16-bit key frame.
  
  Parameters:
  
  out - The output stream.
  
  data - The image data.
  
  width - The width of the image in data elements.
  
  offset - The offset to the first pixel in the data array.
  
  scanlineStride - The number to add to offset to get to the next scanline.
  
  Throws:
  
  IOException
- setPalette
  
  public void setPalette(byte[] redValues, byte[] greenValues, byte[] blueValues)
- setPalette
  
  public void setPalette(int[] rgbValues)

Class TechSmithCodecCore

Constructor Summary

Method Summary

Methods inherited from class org.monte.media.av.codec.video.AbstractVideoCodecCore

Methods inherited from class java.lang.Object

Constructor Details

TechSmithCodecCore

Method Details

reset

getPalette

decodePalette

decode8

decode8

decode24

decode16

encodeDelta8

encodeDelta8to24

encodeSameDelta8

encodeSameDelta24

encodeSameDelta16

encodeKey8

encodeKey8to24

encodeDelta16

encodeKey24

encodeDelta24

encodeKey16

setPalette

setPalette