Method allowing compression and protection parameters to be determined for the transmission of multimedia data over a wireless data channel
A method allowing operating parameters, such as the compression ratio and/or the protection ratio for a multimedia data transmission channel to be determined, wherein it includes at least one step during which several values of sensitivity are determined for pairs of values fixed source bit-rate, desired compression ratio, a step where the different values obtained for an operating point of the fixed channel are compared with one another, and a step where the optimum sensitivity value is selected, the sensitivity value being defined taking the desired source bit-rate and the compression ratio into account.
1. A method of determining operating parameters for a multimedia data transmission channel, comprising the steps of:
receiving information about a state of the channel;
utilizing the received information to determine sensitivity values for a plurality of predetermined pairs of compression ratio and protection ratio, for a given overall fixed source bit-rate of the channel;
comparing the sensitivity values obtained for the given overall fixed source bit-rate of the channel; and
selecting a preferred sensitivity value, the preferred sensitivity value taking into account a desired source bit-rate and a compression ratio;
wherein the sensitivity value is determined according to the following relationship:
D
^
gop
=
∏
i
=
0
N
(
1
-
P
e
)
β
i
n
i
·
D
o
+
∑
i
=
0
N
[
∏
j
=
0
i
-
1
(
1
-
P
e
)
β
j
·
n
j
·
(
1
-
(
1
-
P
e
)
β
i
·
n
i
)
·
D
loss
i
]
wherein {circumflex over (D)} gop is a distortion of a group of pictures, P e is a probability of error for a bit, β i is a correction factor for an i th frame, β j is a correction factor for an j th frame, N is a number of frames, n i is a size of an i th frame, n j is a size of an j th frame, D o is distortion observed when a frame is correct, and D loss i is distortion observed when an i th frame is lost.
2. A method of determining operating parameters for a multimedia data transmission channel, comprising the steps of:
receiving information about a state of the channel;
determining sensitivity values for a plurality of predetermined pairs of compression ratio and protection ratio, for a given overall fixed source bit-rate of the channel;
comparing the sensitivity values obtained for the given overall fixed source bit-rate of the channel;
selecting a preferred sensitivity value, the preferred sensitivity value taking into account a desired source bit-rate and a compression ratio;
separating the data into partitions; and
determining preferred compression and protection ratios for at least a portion of the partitions according to the following relationship:
D
^
gop
DP
=
∏
i
=
0
N
∏
k
=
1
3
(
1
-
P
e
)
(
1
-
β
i
,
k
)
·
n
i
,
k
·
D
o
+
∑
i
=
0
N
∑
k
=
1
3
[
∏
j
=
0
N
∏
l
=
1
k
-
1
(
1
-
P
e
)
β
j
,
l
n
j
,
l
∏
j
=
0
i
-
1
(
1
-
P
e
)
β
j
,
k
n
j
,
k
(
1
-
(
1
-
P
e
)
(
1
-
β
i
,
k
)
·
n
i
,
k
)
·
D
loss
l
,
k
]
,
wherein {circumflex over (D)} gop DP is a distortion of a group of pictures for the partitions, P e is a probability of error for a bit, β i,k is a correction factor for an i th frame of a k th partition, β j,l is a correction factor for a j th frame of an l th partition, β j,k is a correction factor for a j th frame of an k th partition, N is a number of frames, D o is distortion observed when a frame is correct, n i,k is a length of an i th frame of a k th partition, n j,l is a length of an j th frame of an l th partition, n j,k is a length of an j th frame of an k th partition, D loss i,k is a distortion observed if an i th frame of a k th partition is lost, and
n
i
=
∑
k
=
1
3
n
i
,
k
.
3. The method as claimed in claim 2 , wherein a predicted frame is transmitted in at most three slices.
4. A method of determining operating parameters for a multimedia data transmission channel, comprising the steps of:
receiving information about a state of the channel;
determining sensitivity values for a plurality of predetermined pairs of compression ratio and protection ratio, for a given overall fixed source bit-rate of the channel;
comparing the sensitivity values obtained for the given overall fixed source bit-rate of the channel;
selecting a preferred sensitivity value, the preferred sensitivity value taking into account a desired source bit-rate and a compression ratio;
separating the data into partitions; and
determining the compression ratio and the protection ratio for at least a portion of the partitions according to the following relationship:
D
^
gop
=
∏
i
=
0
N
(
1
-
P
e
)
β
i
n
i
·
D
o
+
∑
i
=
0
N
[
∏
j
,
j
∈
FS
i
(
1
-
P
e
)
β
j
·
n
j
·
(
1
-
(
1
-
P
e
)
β
i
n
i
)
·
D
loss
i
]
wherein {circumflex over (D)} gop is a distortion of a group of pictures, P e is a probability of error for a bit, β i is a correction factor for an i th frame, β j is a correction factor for a j th frame, N is a number of frames, n i is a size of an i th frame, n j is a size of an j th frame, D o is distortion observed when a frame is correct, and D loss i is distortion observed when an i th frame is lost, and wherein data are shuffled by a frame shuffle process of a frame shuffle mode; and FS i is a set of the frames on which a frame i depends, the set being defined by a shuffle matrix of the frame shuffle mode.
5. The method as claimed in claim 4 , wherein the shuffle mode is a mode offering “Tree” granularity.
6. The method as claimed in claim 1 , wherein an RCPC protection code is used for transmitted data.
7. The method as claimed in claim 1 , wherein a H.264/AVC video standard is used for the data transmission.
8. A device to determine operating parameters for a multimedia data transmission channel, comprising at least one adaptation module, wherein the adaptation module is configured:
to receive information on a state of the multimedia data transmission channel and information on efficiency available for coders; and
to generate coding rules, including values of a video compression ratio and of a protection ratio, by implementing a method according to claim 4 .
9. A device to determine operating parameters for a multimedia data transmission channel, comprising at least one adaptation module, wherein the adaptation module is configured:
to receive information on a state of the multimedia data transmission channel and information on efficiency available for coders; and
to generate coding rules, including values of a video compression ratio and of a protection ratio, by implementing a method according to claim 1 .
10. A device to determine operating parameters for a multimedia data transmission channel, comprising at least one adaptation module, wherein the adaptation module is configured:
to receive information on a state of the multimedia data transmission channel and information on efficiency available for coders; and
to generate coding rules, including values of a video compression ratio and of a protection ratio, by implementing a method according to claim 2 .
11. The method as claimed in claim 2 , wherein an RCPC protection code is used for transmitted data.
12. The method as claimed in claim 2 , wherein a H.264/AVC video standard is used for the data transmission.
13. The method as claimed in claim 4 , wherein an RCPC protection code is used for transmitted data.
14. The method as claimed in claim 4 , wherein a H.264/AVC video standard is used for the data transmission.
15. The method as claimed in claim 2 , wherein the sensitivity value is determined according to the following relationship:
D
^
gop
=
∏
i
=
0
N
(
1
-
P
e
)
β
i
n
i
·
D
o
+
∑
i
=
0
N
[
∏
j
=
0
i
-
1
(
1
-
P
e
)
β
j
·
n
j
·
(
1
-
(
1
-
P
e
)
β
i
·
n
i
)
·
D
loss
i
]
wherein {circumflex over (D)} gop is a distortion of a group of pictures, P e is a probability of error for a bit, β i is a correction factor for an i th frame, β j is a correction factor for a j th frame, N is a number of frames, n i is a size of an i th frame, n j is a size of an j th frame, D o is distortion observed when a frame is correct, and D loss i is distortion observed when an i th frame is lost.
16. The method as claimed in claim 4 , wherein the sensitivity value is determined according to the following relationship:
D
^
gop
=
∏
i
=
0
N
(
1
-
P
e
)
β
i
n
i
·
D
o
+
∑
i
=
0
N
[
∏
j
=
0
i
-
1
(
1
-
P
e
)
β
j
·
n
j
·
(
1
-
(
1
-
P
e
)
β
i
·
n
i
)
·
D
loss
i
]
wherein {circumflex over (D)} gop is a distortion of a group of pictures, P e is a probability of error for a bit, β i is a correction factor for an i th frame, β j is a correction factor for a j th frame, N is a number of frames, n i is a size of an i th frame, n j is a size of an j th frame, D o is distortion observed when a frame is correct, and D loss i is distortion observed when an i th frame is lost.
17. The method as claimed in claim 1 , further comprising the steps of:
separating the data into partitions; and
determining preferred compression and protection ratios for at least a portion of the partitions according to the following relationship:
D
^
gop
DP
=
∏
i
=
0
N
∏
k
=
1
3
(
1
-
P
e
)
(
1
-
β
i
,
k
)
·
n
i
,
k
·
D
o
+
∑
i
=
0
N
∑
k
=
1
3
[
∏
j
=
0
N
∏
l
=
1
k
-
1
(
1
-
P
e
)
β
j
,
l
n
j
,
l
∏
j
=
0
i
-
1
(
1
-
P
e
)
β
j
,
k
n
j
,
k
(
1
-
(
1
-
P
e
)
(
1
-
β
i
,
k
)
·
n
i
,
k
)
·
D
loss
l
,
k
]
,
wherein {circumflex over (D)} gop DP is a distortion of a group of pictures for the partitions, P e is a probability of error for a bit, β i,k is a correction factor for an i th frame of a k th partition, β j,l is a correction factor for a j th frame of an l th partition, β j,k is a correction factor for a j th frame of an k th partition, N is a number of frames, D o is distortion observed when a frame is correct, n i,k is a length of an i th frame of a k th partition, n j,l is a length of an j th frame of an l th partition, n j,k is a length of an j th frame of an k th partition, D loss i,k is a distortion observed if an i th frame of a k th partition is lost, and
n
i
=
∑
k
=
1
3
n
i
,
k
.
18. The method as claimed in claim 1 , further comprising the step of:
separating the data into partitions; and
determining the compression ratio and the protection ratio for at least a portion of the partitions according to the following relationship:
D
^
gop
=
∏
i
=
0
N
(
1
-
P
e
)
β
i
n
i
·
D
o
+
∑
i
=
0
N
[
∏
j
,
j
∈
FS
i
(
1
-
P
e
)
β
j
·
n
j
·
(
1
-
(
1
-
P
e
)
β
i
n
i
)
·
D
loss
i
]
wherein {circumflex over (D)} gop is a distortion of a group of pictures, P e is a probability of error for a bit, β i is a correction factor for an i th frame, β j is a correction factor for a j th frame, N is a number of frames, n i is a size of an i th frame, n j is a size of an j th frame, D o is distortion observed when a frame is correct, and D loss i is distortion observed when an i th frame is lost, and wherein data are shuffled by a frame shuffle process of a frame shuffle mode; and FS i is a set of the frames on which a frame i depends, the set being defined by a shuffle matrix of the frame shuffle mode.