FreeCalypso > hg > gsm-codec-lib
view libgsmefr/basicops.c @ 581:e2d5cad04cbf
libgsmhr1 RxFE: store CN R0+LPC separately from speech
In the original GSM 06.06 code the ECU for speech mode is entirely
separate from the CN generator, maintaining separate state. (The
main intertie between them is the speech vs CN state variable,
distinguishing between speech and CN BFIs, in addition to the
CN-specific function of distinguishing between initial and update
SIDs.)
In the present RxFE implementation I initially thought that we could
use the same saved_frame buffer for both ECU and CN, overwriting
just the first 4 params (R0 and LPC) when a valid SID comes in.
However, I now realize it was a bad idea: the original code has a
corner case (long sequence of speech-mode BFIs to put the ECU in
state 6, then SID and CN-mode BFIs, then a good speech frame) that
would be broken by that buffer reuse approach. We could eliminate
this corner case by resetting the ECU state when passing through
a CN insertion period, but doing so would needlessly increase
the behavioral diffs between GSM 06.06 and our version.
Solution: use a separate CN-specific buffer for CN R0+LPC parameters,
and match the behavior of GSM 06.06 code in this regard.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Thu, 13 Feb 2025 10:02:45 +0000 |
| parents | 1c514150c033 |
| children |
line wrap: on
line source
/* * This C module is a stripped-down version made from ETSI basicop2.c, * reduced to just those functions which we are not inlining. */ /*___________________________________________________________________________ | | | Include-Files | |___________________________________________________________________________| */ #include <stdint.h> #include "typedef.h" #include "namespace.h" #include "basic_op.h" /*___________________________________________________________________________ | | | Functions | |___________________________________________________________________________| */ /*___________________________________________________________________________ | | | Function Name : L_macNs | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Add the 32 bit | | result to L_var3 without saturation, return a 32 bit result. Generate | | carry and overflow values : | | L_macNs(L_var3,var1,var2) = L_add_c(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_macNs (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; L_var_out = L_mult (var1, var2); L_var_out = L_add_c (L_var3, L_var_out); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_msuNs | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Subtract the 32 | | bit result from L_var3 without saturation, return a 32 bit result. Ge- | | nerate carry and overflow values : | | L_msuNs(L_var3,var1,var2) = L_sub_c(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_msuNs (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; L_var_out = L_mult (var1, var2); L_var_out = L_sub_c (L_var3, L_var_out); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_add_c | | | | Purpose : | | | | Performs 32 bits addition of the two 32 bits variables (L_var1+L_var2+C)| | with carry. No saturation. Generate carry and Overflow values. The car- | | ry and overflow values are binary variables which can be tested and as- | | signed values. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_add_c (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; Word32 L_test; Flag carry_int = 0; L_var_out = L_var1 + L_var2 + Carry; L_test = L_var1 + L_var2; if ((L_var1 > 0) && (L_var2 > 0) && (L_test < 0)) { Overflow = 1; carry_int = 0; } else { if ((L_var1 < 0) && (L_var2 < 0)) { if (L_test >= 0) { Overflow = 1; carry_int = 1; } else { Overflow = 0; carry_int = 1; } } else { if (((L_var1 ^ L_var2) < 0) && (L_test >= 0)) { Overflow = 0; carry_int = 1; } else { Overflow = 0; carry_int = 0; } } } if (Carry) { if (L_test == MAX_32) { Overflow = 1; Carry = carry_int; } else { if (L_test == (Word32) 0xFFFFFFFFL) { Carry = 1; } else { Carry = carry_int; } } } else { Carry = carry_int; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_sub_c | | | | Purpose : | | | | Performs 32 bits subtraction of the two 32 bits variables with carry | | (borrow) : L_var1-L_var2-C. No saturation. Generate carry and Overflow | | values. The carry and overflow values are binary variables which can | | be tested and assigned values. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_sub_c (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; Word32 L_test; Flag carry_int = 0; if (Carry) { Carry = 0; if (L_var2 != MIN_32) { L_var_out = L_add_c (L_var1, -L_var2); } else { L_var_out = L_var1 - L_var2; if (L_var1 > 0L) { Overflow = 1; Carry = 0; } } } else { L_var_out = L_var1 - L_var2 - (Word32) 0X00000001L; L_test = L_var1 - L_var2; if ((L_test < 0) && (L_var1 > 0) && (L_var2 < 0)) { Overflow = 1; carry_int = 0; } else if ((L_test > 0) && (L_var1 < 0) && (L_var2 > 0)) { Overflow = 1; carry_int = 1; } else if ((L_test > 0) && ((L_var1 ^ L_var2) > 0)) { Overflow = 0; carry_int = 1; } if (L_test == MIN_32) { Overflow = 1; Carry = carry_int; } else { Carry = carry_int; } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : shr_r | | | | Purpose : | | | | Same as shr(var1,var2) but with rounding. Saturate the result in case of| | underflows or overflows : | | - If var2 is greater than zero : | | if (sub(shl(shr(var1,var2),1),shr(var1,sub(var2,1)))) | | is equal to zero | | then | | shr_r(var1,var2) = shr(var1,var2) | | else | | shr_r(var1,var2) = add(shr(var1,var2),1) | | - If var2 is less than or equal to zero : | | shr_r(var1,var2) = shr(var1,var2). | | | | Complexity weight : 2 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 shr_r (Word16 var1, Word16 var2) { Word16 var_out; if (var2 > 15) { var_out = 0; } else { var_out = shr (var1, var2); if (var2 > 0) { if ((var1 & ((Word16) 1 << (var2 - 1))) != 0) { var_out++; } } } return (var_out); } /*___________________________________________________________________________ | | | Function Name : mac_r | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Add the 32 bit | | result to L_var3 with saturation. Round the LS 16 bits of the result | | into the MS 16 bits with saturation and shift the result right by 16. | | Return a 16 bit result. | | mac_r(L_var3,var1,var2) = round(L_mac(L_var3,var1,var2)) | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 8000 <= L_var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 mac_r (Word32 L_var3, Word16 var1, Word16 var2) { Word16 var_out; L_var3 = L_mac (L_var3, var1, var2); L_var3 = L_add (L_var3, (Word32) 0x00008000L); var_out = extract_h (L_var3); return (var_out); } /*___________________________________________________________________________ | | | Function Name : msu_r | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Subtract the 32 | | bit result to L_var3 with saturation. Round the LS 16 bits of the res- | | ult into the MS 16 bits with saturation and shift the result right by | | 16. Return a 16 bit result. | | msu_r(L_var3,var1,var2) = round(L_msu(L_var3,var1,var2)) | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 8000 <= L_var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 msu_r (Word32 L_var3, Word16 var1, Word16 var2) { Word16 var_out; L_var3 = L_msu (L_var3, var1, var2); L_var3 = L_add (L_var3, (Word32) 0x00008000L); var_out = extract_h (L_var3); return (var_out); } /*___________________________________________________________________________ | | | Function Name : L_shr_r | | | | Purpose : | | | | Same as L_shr(L_var1,var2) but with rounding. Saturate the result in | | case of underflows or overflows : | | - If var2 is greater than zero : | | if (L_sub(L_shl(L_shr(L_var1,var2),1),L_shr(L_var1,sub(var2,1))))| | is equal to zero | | then | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2) | | else | | L_shr_r(L_var1,var2) = L_add(L_shr(L_var1,var2),1) | | - If var2 is less than or equal to zero : | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2). | | | | Complexity weight : 3 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ Word32 L_shr_r (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (var2 > 31) { L_var_out = 0; } else { L_var_out = L_shr (L_var1, var2); if (var2 > 0) { if ((L_var1 & ((Word32) 1 << (var2 - 1))) != 0) { L_var_out++; } } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_sat | | | | Purpose : | | | | 32 bit L_var1 is set to 2147483647 if an overflow occured or to | | -2147483648 if an underflow occured on the most recent L_add_c, | | L_sub_c, L_macNs or L_msuNs operations. The carry and overflow values | | are binary values which can be tested and assigned values. | | | | Complexity weight : 4 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ Word32 L_sat (Word32 L_var1) { Word32 L_var_out; L_var_out = L_var1; if (Overflow) { if (Carry) { L_var_out = MIN_32; } else { L_var_out = MAX_32; } Carry = 0; Overflow = 0; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : div_s | | | | Purpose : | | | | Produces a result which is the fractional integer division of var1 by | | var2; var1 and var2 must be positive and var2 must be greater or equal | | to var1; the result is positive (leading bit equal to 0) and truncated | | to 16 bits. | | If var1 = var2 then div(var1,var2) = 32767. | | | | Complexity weight : 18 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var1 <= var2 and var2 != 0. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : var1 <= var2 <= 0x0000 7fff and var2 != 0. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 7fff. | | It's a Q15 value (point between b15 and b14). | |___________________________________________________________________________| */ Word16 div_s (Word16 var1, Word16 var2) { Word16 var_out = 0; Word16 iteration; Word32 L_num; Word32 L_denom; #if 0 if ((var1 > var2) || (var1 < 0) || (var2 < 0)) { printf ("Division Error var1=%d var2=%d\n", var1, var2); exit (0); } if (var2 == 0) { printf ("Division by 0, Fatal error \n"); exit (0); } #endif if (var1 == 0) { var_out = 0; } else { if (var1 == var2) { var_out = MAX_16; } else { L_num = L_deposit_l (var1); L_denom = L_deposit_l (var2); for (iteration = 0; iteration < 15; iteration++) { var_out <<= 1; L_num <<= 1; if (L_num >= L_denom) { L_num = L_sub (L_num, L_denom); var_out = add (var_out, 1); } } } } return (var_out); }