forked from len0rd/rockbox
Correct DSP_SET_SAMPLE_DEPTH to 29 for mpc (18.14 fixed point samples). Higher precision for fast 32x32=32 multiplication in dewindowing part of synthesis filter.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17708 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann
parent
50763d512c
commit
f52696ef8a
3 changed files with 25 additions and 16 deletions
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@ -44,11 +44,15 @@
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#if defined(MPC_FIXED_POINT)
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#if defined(OPTIMIZE_FOR_SPEED)
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// round to +/- 2^14 as pre-shift before 32=32x32-multiply
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// round at compile time to +/- 2^14 as a pre-shift before 32=32x32-multiply
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#define D(value) (MPC_SHR_RND(value, 3))
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// round to +/- 2^17 as pre-shift before 32=32x32-multiply
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#define MPC_V_PRESHIFT(X) MPC_SHR_RND(X, 14)
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// round at runtime to +/- 2^17 as a pre-shift before 32=32x32-multiply
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// samples are 18.14 fixed point. 30.2 after this shift, whereas the
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// 15.2 bits are significant (not including sign)
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#define MPC_V_PRESHIFT(X) MPC_SHR_RND(X, 12)
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// in this configuration a post-shift by >>1 is needed after synthesis
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#else
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// saturate to +/- 2^31 (= value << (31-17)), D-values are +/- 2^17
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#define D(value) (value << (14))
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@ -65,7 +69,7 @@
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#define MPC_V_PRESHIFT(X) (X)
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#endif
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// Di_opt coefficients are +/- 2^17
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// Di_opt coefficients are +/- 2^17 (pre-shifted by <<16)
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static const MPC_SAMPLE_FORMAT Di_opt [512] ICONST_ATTR = {
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/* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 */
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/* 0 */ D( 0), -D( 29), D( 213), -D( 459), D(2037), -D(5153), D( 6574), -D(37489), D(75038), D(37489), D(6574), D(5153), D(2037), D(459), D(213), D(29),
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@ -462,6 +466,7 @@ mpc_decoder_windowing_D(MPC_SAMPLE_FORMAT * Data,
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+ V[256]*D[ 4] + V[352]*D[ 5] + V[384]*D[ 6] + V[480]*D[ 7]
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+ V[512]*D[ 8] + V[608]*D[ 9] + V[640]*D[10] + V[736]*D[11]
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+ V[768]*D[12] + V[864]*D[13] + V[896]*D[14] + V[992]*D[15];
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*Data >>= 1; // post shift to compensate for pre-shifting
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Data += 1;
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// total: 32 * (16 muls, 15 adds)
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}
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@ -493,6 +498,7 @@ mpc_decoder_windowing_D(MPC_SAMPLE_FORMAT * Data,
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"mac.l %%d2, %%a5, (992*4, %[V]), %%a5, %%acc0\n\t"
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"mac.l %%d3, %%a5, %%acc0 \n\t"
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"movclr.l %%acc0, %%d0 \n\t"
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"lsl.l #1, %%d0 \n\t"
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"move.l %%d0, (%[Data])+ \n"
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: [Data] "+a" (Data)
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: [V] "a" (V), [D] "a" (D)
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@ -500,16 +506,16 @@ mpc_decoder_windowing_D(MPC_SAMPLE_FORMAT * Data,
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}
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#else
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// 64=64x64-multiply (FIXED_POINT) or float=float*float (!FIXED_POINT) in C
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for ( k = 0; k < 32; k++, D += 16, V++ )
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for ( k = 0; k < 32; k++, D += 16, V++ )
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{
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*Data = MPC_MULTIPLY_EX(V[ 0],D[ 0],31) + MPC_MULTIPLY_EX(V[ 96],D[ 1],31)
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+ MPC_MULTIPLY_EX(V[128],D[ 2],31) + MPC_MULTIPLY_EX(V[224],D[ 3],31)
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+ MPC_MULTIPLY_EX(V[256],D[ 4],31) + MPC_MULTIPLY_EX(V[352],D[ 5],31)
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+ MPC_MULTIPLY_EX(V[384],D[ 6],31) + MPC_MULTIPLY_EX(V[480],D[ 7],31)
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+ MPC_MULTIPLY_EX(V[512],D[ 8],31) + MPC_MULTIPLY_EX(V[608],D[ 9],31)
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+ MPC_MULTIPLY_EX(V[640],D[10],31) + MPC_MULTIPLY_EX(V[736],D[11],31)
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+ MPC_MULTIPLY_EX(V[768],D[12],31) + MPC_MULTIPLY_EX(V[864],D[13],31)
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+ MPC_MULTIPLY_EX(V[896],D[14],31) + MPC_MULTIPLY_EX(V[992],D[15],31);
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*Data = MPC_MULTIPLY_EX(V[ 0],D[ 0],30) + MPC_MULTIPLY_EX(V[ 96],D[ 1],30)
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+ MPC_MULTIPLY_EX(V[128],D[ 2],30) + MPC_MULTIPLY_EX(V[224],D[ 3],30)
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+ MPC_MULTIPLY_EX(V[256],D[ 4],30) + MPC_MULTIPLY_EX(V[352],D[ 5],30)
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+ MPC_MULTIPLY_EX(V[384],D[ 6],30) + MPC_MULTIPLY_EX(V[480],D[ 7],30)
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+ MPC_MULTIPLY_EX(V[512],D[ 8],30) + MPC_MULTIPLY_EX(V[608],D[ 9],30)
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+ MPC_MULTIPLY_EX(V[640],D[10],30) + MPC_MULTIPLY_EX(V[736],D[11],30)
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+ MPC_MULTIPLY_EX(V[768],D[12],30) + MPC_MULTIPLY_EX(V[864],D[13],30)
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+ MPC_MULTIPLY_EX(V[896],D[14],30) + MPC_MULTIPLY_EX(V[992],D[15],30);
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Data += 1;
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// total: 16 muls, 15 adds, 16 shifts
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}
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@ -75,7 +75,8 @@ mpc_decoder_windowing_D:
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ldr r11, [r1, #896*4] /* 14 */
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mla r12, r9, r11, r12
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ldr r11, [r1, #992*4] /* 15 */
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mla r12, r10, r11, r12
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mla r12, r10, r11, r12
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mov r12, r12, asr #1 /* post shift to compensate for pre-shifting */
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str r12, [r0], #4 /* store Data */
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add r1, r1, #4 /* V++ */
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@ -142,7 +143,7 @@ mpc_decoder_windowing_D:
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smlal r11, r12, r9, r11
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ldr r11, [r1, #992*4] /* 15 */
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smlal r11, r12, r10, r11
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mov r4, r12, lsl #1 /* get result from hi-part */
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mov r4, r12, lsl #2 /* get result from hi-part, loose 2 bits */
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str r4, [r0], #4 /* store Data */
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add r1, r1, #4 /* V++ */
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@ -76,7 +76,9 @@ enum codec_status codec_main(void)
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mpc_streaminfo info;
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int retval = CODEC_OK;
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ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
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/* musepack's sample representation is 18.14
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* DSP_SET_SAMPLE_DEPTH = 14 (FRACT) + 16 (NATIVE) - 1 (SIGN) = 29 */
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ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
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/* Create a decoder instance */
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reader.read = read_impl;
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