diff options
Diffstat (limited to 'libFLAC/window.c')
| -rw-r--r-- | libFLAC/window.c | 83 |
1 files changed, 70 insertions, 13 deletions
diff --git a/libFLAC/window.c b/libFLAC/window.c index cd689c5..4387ef7 100644 --- a/libFLAC/window.c +++ b/libFLAC/window.c @@ -1,5 +1,6 @@ /* libFLAC - Free Lossless Audio Codec library - * Copyright (C) 2006,2007 Josh Coalson + * Copyright (C) 2006-2009 Josh Coalson + * Copyright (C) 2011-2014 Xiph.Org Foundation * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -29,22 +30,18 @@ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -#if HAVE_CONFIG_H +#ifdef HAVE_CONFIG_H # include <config.h> #endif #include <math.h> +#include "share/compat.h" #include "FLAC/assert.h" #include "FLAC/format.h" #include "private/window.h" #ifndef FLAC__INTEGER_ONLY_LIBRARY -#ifndef M_PI -/* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */ -#define M_PI 3.14159265358979323846 -#endif - void FLAC__window_bartlett(FLAC__real *window, const FLAC__int32 L) { @@ -61,7 +58,7 @@ void FLAC__window_bartlett(FLAC__real *window, const FLAC__int32 L) for (n = 0; n <= L/2-1; n++) window[n] = 2.0f * n / (float)N; for (; n <= N; n++) - window[n] = 2.0f - 2.0f * (N-n) / (float)N; + window[n] = 2.0f - 2.0f * n / (float)N; } } @@ -71,7 +68,7 @@ void FLAC__window_bartlett_hann(FLAC__real *window, const FLAC__int32 L) FLAC__int32 n; for (n = 0; n < L; n++) - window[n] = (FLAC__real)(0.62f - 0.48f * fabs((float)n/(float)N+0.5f) + 0.38f * cos(2.0f * M_PI * ((float)n/(float)N+0.5f))); + window[n] = (FLAC__real)(0.62f - 0.48f * fabs((float)n/(float)N-0.5f) - 0.38f * cos(2.0f * M_PI * ((float)n/(float)N))); } void FLAC__window_blackman(FLAC__real *window, const FLAC__int32 L) @@ -176,16 +173,16 @@ void FLAC__window_triangle(FLAC__real *window, const FLAC__int32 L) FLAC__int32 n; if (L & 1) { - for (n = 1; n <= L+1/2; n++) + for (n = 1; n <= (L+1)/2; n++) window[n-1] = 2.0f * n / ((float)L + 1.0f); for (; n <= L; n++) - window[n-1] = - (float)(2 * (L - n + 1)) / ((float)L + 1.0f); + window[n-1] = (float)(2 * (L - n + 1)) / ((float)L + 1.0f); } else { for (n = 1; n <= L/2; n++) - window[n-1] = 2.0f * n / (float)L; + window[n-1] = 2.0f * n / ((float)L + 1.0f); for (; n <= L; n++) - window[n-1] = ((float)(2 * (L - n)) + 1.0f) / (float)L; + window[n-1] = (float)(2 * (L - n + 1)) / ((float)L + 1.0f); } } @@ -210,6 +207,66 @@ void FLAC__window_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__rea } } +void FLAC__window_partial_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__real p, const FLAC__real start, const FLAC__real end) +{ + const FLAC__int32 start_n = (FLAC__int32)(start * L); + const FLAC__int32 end_n = (FLAC__int32)(end * L); + const FLAC__int32 N = end_n - start_n; + FLAC__int32 Np, n, i; + + if (p <= 0.0f) + FLAC__window_partial_tukey(window, L, 0.05f, start, end); + else if (p >= 1.0f) + FLAC__window_partial_tukey(window, L, 0.95f, start, end); + else { + + Np = (FLAC__int32)(p / 2.0f * N); + + for (n = 0; n < start_n && n < L; n++) + window[n] = 0.0f; + for (i = 1; n < (start_n+Np) && n < L; n++, i++) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Np)); + for (; n < (end_n-Np) && n < L; n++) + window[n] = 1.0f; + for (i = Np; n < end_n && n < L; n++, i--) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Np)); + for (; n < L; n++) + window[n] = 0.0f; + } +} + +void FLAC__window_punchout_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__real p, const FLAC__real start, const FLAC__real end) +{ + const FLAC__int32 start_n = (FLAC__int32)(start * L); + const FLAC__int32 end_n = (FLAC__int32)(end * L); + FLAC__int32 Ns, Ne, n, i; + + if (p <= 0.0f) + FLAC__window_punchout_tukey(window, L, 0.05f, start, end); + else if (p >= 1.0f) + FLAC__window_punchout_tukey(window, L, 0.95f, start, end); + else { + + Ns = (FLAC__int32)(p / 2.0f * start_n); + Ne = (FLAC__int32)(p / 2.0f * (L - end_n)); + + for (n = 0, i = 1; n < Ns && n < L; n++, i++) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Ns)); + for (; n < start_n-Ns && n < L; n++) + window[n] = 1.0f; + for (i = Ns; n < start_n && n < L; n++, i--) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Ns)); + for (; n < end_n && n < L; n++) + window[n] = 0.0f; + for (i = 1; n < end_n+Ne && n < L; n++, i++) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Ne)); + for (; n < L - (Ne) && n < L; n++) + window[n] = 1.0f; + for (i = Ne; n < L; n++, i--) + window[n] = (FLAC__real)(0.5f - 0.5f * cos(M_PI * i / Ne)); + } +} + void FLAC__window_welch(FLAC__real *window, const FLAC__int32 L) { const FLAC__int32 N = L - 1; |