diff options
| author | Jacob Erlbeck <jerlbeck@sysmocom.de> | 2016-02-03 18:31:19 +0100 |
|---|---|---|
| committer | Jacob Erlbeck <jerlbeck@sysmocom.de> | 2016-02-08 00:45:39 +0100 |
| commit | fbd82e4e9f38ed6885e94ccf8d0297bba65b50de (patch) | |
| tree | 86525081883cdc40473bdb0130cd1ba170e92882 | |
| parent | b55f31373554394092bb923acca723cc7808cd49 (diff) | |
rlc: Add gprs_rlc_mcs_cps_decode
To access EGPRS data blocks, the optional padding must be taken into
account. Whether padding has been used must be dervied from the CPS
field in the header of the RLC EGPRS data message.
Add this function to decode the CPS value and extract that
information.
Sponsored-by: On-Waves ehf
| -rw-r--r-- | src/rlc.cpp | 29 | ||||
| -rw-r--r-- | src/rlc.h | 2 |
2 files changed, 31 insertions, 0 deletions
diff --git a/src/rlc.cpp b/src/rlc.cpp index ca12e919..79d8f48a 100644 --- a/src/rlc.cpp +++ b/src/rlc.cpp @@ -356,3 +356,32 @@ unsigned int gprs_rlc_mcs_cps(GprsCodingScheme cs, int punct, int punct2, return -1; } + +void gprs_rlc_mcs_cps_decode(unsigned int cps, + GprsCodingScheme cs, int *punct, int *punct2, int *with_padding) +{ + *punct2 = -1; + *with_padding = 0; + + switch (GprsCodingScheme::Scheme(cs)) { + case GprsCodingScheme::MCS1: + cps -= 0b1011; *punct = cps % 2; break; + case GprsCodingScheme::MCS2: + cps -= 0b1001; *punct = cps % 2; break; + case GprsCodingScheme::MCS3: + cps -= 0b0011; *punct = cps % 3; *with_padding = cps >= 3; break; + case GprsCodingScheme::MCS4: + cps -= 0b0000; *punct = cps % 3; break; + case GprsCodingScheme::MCS5: + cps -= 0b100; *punct = cps % 2; break; + case GprsCodingScheme::MCS6: + cps -= 0b000; *punct = cps % 2; *with_padding = cps >= 2; break; + case GprsCodingScheme::MCS7: + cps -= 0b10100; *punct = cps / 3; *punct2 = cps % 3; break; + case GprsCodingScheme::MCS8: + cps -= 0b01011; *punct = cps / 3; *punct2 = cps % 3; break; + case GprsCodingScheme::MCS9: + cps -= 0b00000; *punct = cps / 4; *punct2 = cps % 3; break; + default: ; + } +} @@ -109,6 +109,8 @@ void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, GprsCodingScheme cs, bool with_padding); unsigned int gprs_rlc_mcs_cps(GprsCodingScheme cs, int punct, int punct2, int with_padding); +void gprs_rlc_mcs_cps_decode(unsigned int cps, GprsCodingScheme cs, + int *punct, int *punct2, int *with_padding); /* * I hold the currently transferred blocks and will provide |