Modifying a coded bitstream

An apparatus comprising:

• an entropy decoder to decode variable-length encoded data including an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value;
• and
• a watermark generator, coupled to the entropy decoder, to determine an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, wherein the alternative value is for use in watermarking the variable-length encoded data.

An apparatus comprising:

• means for accessing variable-length encoded data including an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value;
• and
• means for determining an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, wherein the alternative value is for use in watermarking the variable-length encoded data.

A processor configured to perform at least the following:

• accessing variable-length encoded data including an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value;
• and
• determining an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, wherein the alternative value is for use in watermarking the variable-length encoded data.

A processor-readable medium having stored thereon instructions for performing at least the following:

• accessing variable-length encoded data including an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value;
• and
• determining an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, wherein the alternative value is for use in watermarking the variable-length encoded data.

A processor-readable medium having watermark data stored thereon,

• the watermark data for use in watermarking variable-length encoded data that includes an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value, and
• the watermark data including an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, the alternative value being a substitute for the particular value for use in watermarking the variable-length encoded data.

A signal formatted to include watermark data for use in watermarking variable-length encoded data that includes an encoding of information identifying an actual reference used to predictively encode an image, the encoding of the information having a particular value,

• the watermark data including an alternative value that is different from the particular value, such that the alternative value is an encoding of alternative information that identifies a different reference from the actual reference, the alternative value being a substitute for the particular value for use in watermarking the variable-length encoded data.

The method of 27 wherein:

• accessing the variable-length encoded data occurs in response to a request for presentation of the variable-length encoded data, and
• processing operations to determine the alternative value have been performed prior to the accessing of the variable-length encoded data, such that upon receiving the request for presentation of the variable-length encoded data and subsequently accessing the variable-length encoded data, the alternative value may be inserted without needing to determine the alternative value.

The method of 27 further comprising performing processing operations to determine the alternative value, prior to accessing the alternative value.

A processor-readable medium having stored thereon variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from the actual reference used to predictively encode the image, wherein the information identifying the alternative reference provides a watermark for the image.

A signal formatted to include variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from the actual reference used to predictively encode the image, the alternative reference providing a watermark for the image.

A method comprising:

• decoding variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provides a watermark for the image.

An apparatus comprising a decoder configured to decode variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provides a watermark for the image.

An apparatus comprising:

• means for decoding variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provides a watermark for the image.

A processor configured to decode variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provides a watermark for the image.

A processor-readable medium having stored thereon instructions for decoding variable-length encoded data for an encoding of an image, the variable-length encoded data comprising an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provides a watermark for the image.

A processor-readable medium having stored thereon a pixel-domain image that includes a detectable feature arising from a watermark of a variable-length encoding of one or more syntax elements from a predictive encoding of the image, the variable-length encoding having included an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provided the watermark for the image.

A method comprising providing for display a pixel-domain image that includes a detectable feature arising from a watermark of a variable-length encoding of one or more syntax elements from a predictive encoding of the image, the variable-length encoding having included an encoding of information identifying an alternative reference that is different from an actual reference used in predictively encoding the image, wherein the information identifying the alternative reference provided the watermark for the image.

A method comprising:

• variable-length encoding a predictive encoding of a watermarked version of an image, the variable-length encoded data comprising an indicator of a current reference used in encoding the watermarked version of the image and an indicator of a resulting residue, the watermarked version of the image having a detectable characteristic that provides a watermark,
• wherein the detectable characteristic results from (1) modifying a previous variable-length encoding of a previous predictive-encoding of the image, the previous predictive-encoding being based on a previous reference and including information identifying the previous reference, wherein the modifying includes distorting the information in order to indicate an alternative reference and to provide the detectable characteristic for the image, and (2) decoding the previous variable-length encoding and the previous predictive-encoding of the image to produce the watermarked version of the image in which the detectable characteristic is present.

A processor-readable medium having stored thereon:

• variable-length encoded data from a variable-length encoding of a predictive encoding of a watermarked version of an image, the variable-length encoded data comprising an indicator of a current reference used in encoding the watermarked version of the image and an indicator of a resulting residue, the watermarked version of the image having a detectable characteristic that provides a watermark,
• wherein the detectable characteristic results from (1) modifying a previous variable-length encoding of a previous predictive-encoding of the image, the previous predictive-encoding being based on a previous reference and including information identifying the previous reference, wherein the modifying includes distorting the information in order to indicate an alternative reference and to provide the detectable characteristic for the image, and (2) decoding the previous variable-length encoding and the previous predictive-encoding of the image to produce the watermarked version of the image in which the detectable characteristic is present.

A method comprising decoding variable-length encoded data from a variable-length encoding of a predictive encoding of a watermarked version of an image, the variable-length encoded data comprising an indicator of a current reference used in encoding the watermarked version of the image and an indicator of a resulting residue, the watermarked version of the image having a detectable characteristic that provides a watermark,

• wherein the detectable characteristic results from (1) modifying a previous variable-length encoding of a previous predictive-encoding of the image, the previous predictive-encoding being based on a previous reference and including information identifying the previous reference, wherein the modifying includes distorting the information in order to indicate an alternative reference and to provide the detectable characteristic for the image, and (2) decoding the previous variable-length encoding and the previous predictive-encoding of the image to produce the watermarked version of the image in which the detectable characteristic is present.

A processor-readable medium having stored thereon pixel-domain image data resulting from decoding variable-length encoded data from a variable-length encoding of a predictive encoding of a watermarked version of an image, the variable-length encoded data comprising an indicator of a current reference used in encoding the watermarked version of the image and an indicator of a resulting residue, the watermarked version of the image having a detectable characteristic that provides a watermark,

• wherein the detectable characteristic results from (1) modifying a previous variable-length encoding of a previous predictive-encoding of the image, the previous predictive-encoding being based on a previous reference and including information identifying the previous reference, wherein the modifying includes distorting the information in order to indicate an alternative reference and to provide the detectable characteristic for the image, and (2) decoding the previous variable-length encoding and the previous predictive-encoding of the image to produce the watermarked version of the image in which the detectable characteristic is present.

A method comprising providing for display pixel-domain image data resulting from decoding variable-length encoded data from a variable-length encoding of a predictive encoding of a watermarked version of an image, the variable-length encoded data comprising an indicator of a current reference used in encoding the watermarked version of the image and an indicator of a resulting residue, the watermarked version of the image having a detectable characteristic that provides a watermark,

• wherein the detectable characteristic results from (1) modifying a previous variable-length encoding of a previous predictive-encoding of the image, the previous predictive-encoding being based on a previous reference and including information identifying the previous reference, wherein the modifying includes distorting the information in order to indicate an alternative reference and to provide the detectable characteristic for the image, and (2) decoding the previous variable-length encoding and the previous predictive-encoding of the image to produce the watermarked version of the image in which the detectable characteristic is present.