1. A method comprising:
accessing encoded data including at least a first portion and a second portion, wherein the second portion is decodable to produce a result that is based on the first portion as well as the second portion; and
determining a modified first portion such that the second portion is decodable to produce the result based on the second portion and the modified first portion.
2. The method of claim 1 further comprising replacing the first portion with the modified first portion.
3. The method of claim 1 wherein the modified first portion comprises a value having a bit length equal to that of the first portion.
4. The method of claim 1 wherein determining comprises determining a modified first portion that generates a CABAC state value that is the same as a state value for the first portion.
5. The method of claim 1 wherein decoding of the first portion produces a first result, decoding of the modified first portion produces a modified first result that is different from the first result.
6. The method of claim 1 wherein determining the modified first portion is based on providing a modified first result having a difference from the first result that is (1) imperceptible, from a viewer’s standpoint, and (2) detectable by a processing device.
7. The method of claim 6 wherein the modified first portion is suitable for watermarking the encoded data by replacing the first portion with the modified first portion.
8. The method of claim 1 wherein the result is based on the first portion by being based on a state produced from an encoding of the first portion.
9. The method of claim 1 wherein the first portion comprises a syntax element in a CABAC coded bitstream.
10. The method of claim 9 wherein determining further comprises:
determining all possible alternative replacement values for the syntax element; and
determining for each possible alternative replacement value, whether the replacement value generates the same state variable value for the syntax element; and
saving a list of alternative replacement values that do generate the same state variable value for the syntax element.
11. The method of claim 10 further comprising encoding the alternative replacement value before determining whether the replacement value generates the same state variable.
12. The method of claim 1 wherein the first portion comprises coded syntax elements, and wherein the modified first portion comprises a value having a bit length equal to that of the first portion, the modified first portion generating an L value in an CABAC encoder that is equal to the L value that would have been generated by the first portion.
13. The method of claim 1 wherein the second portion comprises more than one coded syntax element each having a corresponding state variable value, wherein the modified first portion maintains the state variable values for all decoding of all subsequent second portion syntax elements.
14. The method of claim 13 wherein the modified first portion does not affect the value of any other coded syntax element in the set of data.
15. The method of claim 1 wherein:
the encoded data comprises entropy encoded data,
the first portion comprises a syntax element, and
the modified first portion comprises a modification of the syntax element.
16. An apparatus comprising:
an accessing unit to access encoded data including at least two portions, wherein the second portion is decodable to produce a result, the result is based on the first portion as well as the second portion; and
a modification unit to determine a modified first portion such that the second portion is decodable to produce the result based on the second portion and the modified first portion.
17. An apparatus comprising:
means for accessing encoded data including at least two portions, wherein the second portion is decodable to produce a result, the result is based on the first portion as well as the second portion; and
means for determining a modified first portion such that the second portion is decodable to produce the result based on the second portion and the modified first portion.
18. An apparatus comprising a processor-readable medium including instructions stored on the processor-readable medium for performing at least the following:
accessing encoded data including at least two portions, wherein the second portion is decodable to produce a result, the result is based on the first portion as well as the second portion; and
determining a modified first portion such that the second portion is decodable to produce the result based on the second portion and the modified first portion.
19. An apparatus comprising a processor-readable medium including information stored on the processor-readable medium identifying a replacement value for a first portion of an encoded set of data, the encoded set of data also including a second portion, and decoding of the second portion being based on the second portion and on the first portion, wherein the replacement value has a property such that:
decoding of the second portion produces a particular decoded result if decoding is performed on the encoded set of data including the first portion, and
decoding of the second portion produces the particular decoded result if decoding is performed on the encoded set of data including the replacement value instead of the first portion.
20. A signal formatted to include information identifying a replacement value for a first portion of an encoded set of data, the encoded set of data also including a second portion, and decoding of the second portion being based on the second portion and on the first portion, wherein the replacement value has a property such that:
decoding of the second portion produces a particular decoded result if decoding is performed on the encoded set of data including the first portion, and
decoding of the second portion produces the particular decoded result if decoding is performed on the encoded set of data including the replacement value instead of the first portion.
21. The signal of claim 20 wherein the signal represents digital information.
22. The signal of claim 20 wherein the signal is a modulated electromagnetic wave.
23. A method comprising:
accessing a coded bitstream that includes at least a first portion and a second portion, the second portion being decodable to produce a result that is based on the first portion as well as the second portion; and
replacing the first portion with a replacement value to produce a modified coded bitstream for which a decoding of the second portion will still produce the result.
24. The method of claim 23 further comprising:
accessing an indicator of a location of the first portion; and
accessing a replacement value for the first portion, such that replacing the first portion with the replacement value results in a modified coded bitstream for which a decoding of the second portion will still produce the result.
25. The method of claim 23 further comprising accessing a piece of information, and wherein replacing the first portion comprises replacing the first portion based on the accessed piece of information.
26. The method of claim 25 wherein replacing the first portion is part of watermarking the coded bitstream, and the accessed piece of information comprises payload information.
27. The method of claim 26 wherein the value of the payload information dictates whether or not the first portion is to be replaced.
28. The method of claim 26 wherein the value of the payload information dictates which of multiple potential replacement values, including the replacement value, is to replace the first portion.
29. The method of claim 23 wherein accessing the encoded bitstream comprises accessing a bitstream encoded with an entropy code.
30. The method of claim 29 wherein the entropy code is an arithmetic code.
31. The method of claim 30 wherein the arithmetic code is CABAC.
32. The method of claim 31 wherein the replacement value and the first portion produce the same CABAC state values.
33. The method of claim 31 wherein the accessed coded bitstream comprises a CABAC coded bitstream, and the first portion comprising at least one coded syntax element in the CABAC coded bitstream.
34. The method of claim 24 wherein the accessed indicator comprises metadata.
35. The method of claim 23 wherein:
the second portion comprises more than one syntax element, and each of the more than one syntax elements has a corresponding state variable value that is produced during decoding of the modified coded bitstream, and
the replacement value for the first portion maintains the state variable values for each of the more than one syntax elements the same as if the first portion were used instead of the replacement value in the modified coded bitstream.
36. An apparatus comprising a processor-readable medium including instructions stored on the processor-readable medium for performing at least the following:
accessing a coded bitstream that includes at least two portions, the second portion being decodable to produce a result that is based on the first portion as well as the second portion; and
replacing the first portion with a replacement value to produce a modified coded bitstream for which a decoding of the second portion will still produce the result.
37. An apparatus comprising a processor-readable medium, the processor-readable medium having stored thereon encoded data including a modified first portion and a second portion, the modified first portion being a replacement of a first portion, wherein:
the second portion is decodable to produce a result that is based on the modified first portion as well as the second portion, and
the result is the same as if decoding of the second portion were performed based on the second portion and the first portion rather than the second portion and the modified first portion.
38. The apparatus of claim 37 wherein the modified first portion is at least part of a watermark included in the encoded data.
39. A signal formatted to include encoded data including a modified first portion and a second portion, the modified first portion being a replacement of a first portion, wherein:
the second portion is decodable to produce a result that is based on the modified first portion as well as the second portion, and
the result is the same as if decoding of the second portion were performed based on the second portion and the first portion rather than the second portion and the modified first portion.
40. The signal according to claim 39 wherein the modified first portion comprises at least one coded syntax element in a CABAC encoded bitstream.
41. The signal according to claim 40 wherein the modified first portion has a bit length equal to a bit length of the first portion prior to modification.
42. The signal according to claim 40 wherein the modified first portion produces the same state variables necessary for CABAC decoding of the second portion as the first portion would produce.
43. A method comprising:
accessing a modified set of data including a modified first portion and a second portion, the modified first portion resulting from a modification of a first portion, wherein the second portion is decodable to produce a result, and the result is based on the modified first portion as well as the second portion;
decoding the second portion to produce the result, wherein the result is the same as if decoding of the second portion were performed based on the second portion and the first portion rather than the second portion and the modified first portion; and
decoding the modified first portion.
44. The method of claim 43 wherein the modified first portion reflects a modification that was made based on a value of a piece of information, and the method further comprises determining the value of the piece of information based on the decoding of the modified first portion.
45. The method of claim 43 wherein the modified first portion is at least part of a watermark included in the modified set of data.
46. The method of claim 43 wherein the accessed modified set of data comprises a CABAC encoded bitstream and the first portion comprises at least one coded syntax element.
47. The method of claim 46 wherein the modified first portion comprises a modified syntax element, and the modified syntax element results in the same decoding variables for the CABAC encoded bitstream as does the first portion.
48. The method of claim 46 wherein the modified first portion comprises a modified syntax element having a bit length having equal to a bit length of the first portion, and the modified first portion results in an L value in an CABAC encoder that is equal to an L value that would have been generated by the first portion.
49. An apparatus comprising a processor-readable medium including instructions stored on the processor-readable medium for performing at least the following:
accessing a modified set of data including a modified first portion and a second portion, the modified first portion resulting from a modification of a first portion, wherein the second portion is decodable to produce a result, and the result is based on the modified first portion as well as the second portion;
decoding the second portion to produce the result, wherein the result is the same as if decoding of the second portion were performed based on the second portion and the first portion rather than the second portion and the modified first portion; and
decoding the modified first portion.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A power conversion control apparatus comprising:
a command value output unit that outputs a command value;
a carrier wave output unit that outputs a carrier wave;
a frequency changing unit that changes a frequency of the carrier wave;
a control signal generating unit that compares the command value with the carrier wave and generates a control signal corresponding to the comparison result;
an output unit that outputs an output value based on the control signal; and
a frequency setting unit that sets a target frequency and calculates a specific frequency from the target frequency, wherein
the frequency changing unit changes the frequency of the carrier wave so that the specific frequency matches with a harmonic component of the frequency of the carrier wave.
2. The power conversion control apparatus according to claim 1, wherein the specific frequency is the target frequency plus a predetermined value.
3. The power conversion control apparatus according to claim 2, wherein if a lower limit value to which the frequency of the carrier wave can be set is assumed to be fmin, the predetermined value is more than zero and less than fmin.
4. The power conversion control apparatus according to claim 1, wherein the frequency setting unit selects the frequency of the carrier wave from among those each of which being the specific frequency divided by a natural number nq (q: 1, 2, . . . , r).
5. The power conversion control apparatus according to claim 2, wherein the frequency setting unit comprising a receiving-channel frequency detecting unit that detects a channel frequency of a receiver sets the channel frequency detected by the receiving-channel frequency detecting unit as the target frequency and then calculates the frequency of the carrier wave.
6. The power conversion control apparatus according to claim 5, wherein the frequency setting unit selects the frequency of the carrier wave from among those each of which being the specific frequency calculated from the target frequency divided by the natural number nq (q: 1, 2, . . . , r).
7. The power conversion control apparatus according to claim 2, comprising a frequency map, which is a database in which the frequency of the carrier frequency calculated in advance using the channel frequency of the receiver as the target frequency is stored for each channel of the receiver, wherein
the frequency setting unit extracts the frequency of the carrier wave corresponding to the channel detected from the receiver from the frequency map.
8. The power conversion control apparatus according to claim 5, wherein the frequency setting unit selects the frequency of the carrier wave from those each of which being the channel frequency divided by an integer mq (q: 1, 2, . . . , r) plus a predetermined value \u03b1 (0<\u03b1<1).
9. The power conversion control apparatus according to claim 8, wherein the frequency setting unit comprises a channel band detecting unit that detects a channel band of the channel frequency of the receiver; and
when the channel frequency is denoted by fch, the channel band is denoted by BAND, the lower limit value to which the frequency of the carrier wave can be set is denoted by fch, and an arbitrary integer is denoted by mq (q: 1, 2, . . . , r), the frequency setting unit selects the frequency of the carrier wave from among values fb calculated by fb=(fch\xb1(fmin\u2212BAND)2)(mq+\u03b1.
10. The power conversion control apparatus according to claim 8, wherein the predetermined value \u03b1 is 0.5.
11. A power conversion control method comprising steps of:
outputting a command value;
outputting a carrier wave;
comparing the command value with the carrier wave and then generating a control signal according to the comparison result;
outputting an output value based on the control signal;
setting a target frequency and calculating a specific frequency from the target frequency; and
changing a frequency of the carrier wave so that the specific frequency matches with a harmonic component of the frequency of the carrier wave.
12. A power conversion control apparatus comprising:
a command value output means for outputting a command value;
a carrier wave output means for outputting a carrier wave;
a frequency changing means for changing a frequency of the carrier wave;
a control signal generating means for comparing the command value with the carrier wave and for generating a control signal corresponding to the comparison result;
an output means for outputting an output value based on the control signal; and
a frequency setting means for setting a target frequency and for calculating a specific frequency from the target frequency, wherein
the frequency changing means changes the frequency of the carrier wave so that the specific frequency matches with a harmonic component of the frequency of the carrier wave.