[vlc-devel] [PATCH v2 2/9] Add utilities for parsing equalizer band strings
Ronald Wright
logiconcepts819 at gmail.com
Sun Nov 29 00:11:16 CET 2015
---
include/vlc_eqz_util.h | 92 +++++++++++++++
src/misc/eqz_util.c | 296 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 388 insertions(+)
create mode 100644 include/vlc_eqz_util.h
create mode 100644 src/misc/eqz_util.c
diff --git a/include/vlc_eqz_util.h b/include/vlc_eqz_util.h
new file mode 100644
index 0000000..9245242
--- /dev/null
+++ b/include/vlc_eqz_util.h
@@ -0,0 +1,92 @@
+/*****************************************************************************
+ * vlc_eqz_util.h: Equalizer utility functions
+ *****************************************************************************
+ * Copyright (C) 2015 Ronald Wright
+ * $Id$
+ *
+ * Author: Ronald Wright <logiconcepts819 at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef VLC_EQZ_UTIL_H
+#define VLC_EQZ_UTIL_H
+
+/**
+ * \file
+ * \brief This file is the interface definition of several useful equalizer
+ * utility functions (implementation in src/misc/eqz_util.c)
+ */
+
+/*****************************************************************************
+ * Documentation
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Type definitions
+ *****************************************************************************/
+
+/**
+ * The preset interpolation data type. This is a pointer to a private structure
+ * defined in misc/eqz_util.c.
+ */
+typedef struct _vlc_band_parser_t vlc_band_parser_t;
+
+/*****************************************************************************
+ * Interpolation routines
+ *****************************************************************************/
+
+/**
+ * Start a new band parser.
+ *
+ * \param p_obj The object that holds VLC object data
+ * \param pp_parse_ctx The object that shall hold band parse data
+ * \param psz_bands The bands string (e.g. "2 0 -2 -4 -2 0 2 4 2 0")
+ * \param i_type The current equalizer type
+ * \param pf_amp An optional memory location to store interpolated values
+ * \retval VLC_SUCCESS Success
+ * \retval VLC_ENOMEM Memory failure
+ *
+ * \note If pf_amp is NULL, then memory is automatically allocated in the
+ * preset parser data context according to the given equalizer type. If
+ * the provided bands string provides a valid number of bands (i.e. 10,
+ * 15, or 31), then the preset values are interpolated according to the
+ * current equalizer type. Otherwise, each value is mapped to the
+ * corresponding band of the current equalizer type, starting at the
+ * lowest band, until there are no more spaces or values left.
+ */
+VLC_API int vlc_eqz_util_band_parser_init( vlc_object_t * p_obj,
+ vlc_band_parser_t ** pp_parse_ctx,
+ const char * psz_bands, int i_type,
+ float * pf_amp );
+
+/**
+ * Find the amplification factors from the given band parse context.
+ *
+ * \param p_parse_ctx The object that holds band parse data
+ * \return A pointer to the amplification array in the context
+ */
+VLC_API const float *
+vlc_eqz_util_get_amp_array( const vlc_band_parser_t * p_parse_ctx );
+
+/**
+ * Destroy the band parse context.
+ *
+ * \param p_parse_ctx The object that holds band parse data
+ */
+VLC_API void
+vlc_eqz_util_band_parser_destroy( vlc_band_parser_t * p_parse_ctx );
+
+#endif
diff --git a/src/misc/eqz_util.c b/src/misc/eqz_util.c
new file mode 100644
index 0000000..d55e225
--- /dev/null
+++ b/src/misc/eqz_util.c
@@ -0,0 +1,296 @@
+/*****************************************************************************
+ * vlc_eqz_util.h: Equalizer utility functions
+ *****************************************************************************
+ * Copyright (C) 2015 Ronald Wright
+ * $Id$
+ *
+ * Author: Ronald Wright <logiconcepts819 at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <math.h>
+#include <vlc_common.h>
+#include <vlc_charset.h>
+#include <vlc_interpolation.h>
+#include <vlc_eqz_util.h>
+
+#define EQZ_INCLUDE_MATH_ROUTINES 1
+#include "../../modules/audio_filter/equalizer_presets.h"
+
+/*****************************************************************************
+ * Documentation : Read vlc_interpolation.h
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private types.
+ *****************************************************************************/
+
+struct _vlc_band_parser_t
+{
+ int i_orig_bands;
+ vlc_interpolant_t * p_itp;
+ float * pf_amp;
+ int i_type;
+ float f_orig_amp[];
+};
+
+/*****************************************************************************
+ * Implementation of routines.
+ *****************************************************************************/
+
+/* Determine the most valid equalizer identifier from the number of bands and
+ * a string with a possibly invalid identifier */
+static char GetValidIdentifier( vlc_object_t *p_obj, int i_cur_type,
+ const char * psz_identifier, int i_bands )
+{
+ char eqz_identifier;
+ switch( i_bands )
+ {
+ case EQZ_ISO10_BANDS_MAX:
+ /* fall-through */
+ case EQZ_ISO15_BANDS_MAX:
+ /* fall-through */
+ case EQZ_ISO31_BANDS_MAX:
+ {
+ size_t i_id_len = psz_identifier ? strlen( psz_identifier ) : 0;
+ if( i_id_len != 1 ||
+ ( psz_identifier[0] != EQZ_VLC_IDENTIFIER &&
+ psz_identifier[0] != EQZ_ISO_IDENTIFIER ) )
+ {
+ eqz_identifier = EqzGetDefaultIdentifier( i_bands );
+ if( i_id_len == 0 )
+ {
+ /* No identifier specified in string */
+ if( i_bands == EQZ_ISO10_BANDS_MAX )
+ {
+ msg_Warn( p_obj, "equalizer identifier not specified "
+ "for 10 bands; assuming VLC bands" );
+ }
+ }
+ else
+ {
+ /* Found invalid identifier */
+ msg_Warn( p_obj, "invalid equalizer identifier '%s'; "
+ "assuming default equalizer type for %d bands ('%c')",
+ psz_identifier, i_bands, eqz_identifier );
+ }
+ }
+ else if( i_bands != EQZ_ISO10_BANDS_MAX &&
+ psz_identifier[0] == EQZ_VLC_IDENTIFIER )
+ {
+ /* Found VLC equalizer type for 15 and 31 bands, but we only
+ * provide ISO bands in these cases */
+ eqz_identifier = EQZ_ISO_IDENTIFIER;
+ msg_Warn( p_obj, "equalizer identifier '%s' not defined for "
+ "%d bands; assuming ISO bands", psz_identifier, i_bands );
+ }
+ else
+ {
+ /* Found VLC or ISO identifier for 10 bands and ISO identifier
+ * for 15 and 31 bands */
+ eqz_identifier = psz_identifier[0];
+ }
+ break;
+ }
+ default:
+ {
+ /* Default is to assume current mode */
+ int i_cur_bands = EqzGetNumBandsByType( i_cur_type );
+ int i_smallest_bands = __MIN( i_cur_bands, i_bands );
+ eqz_identifier = EqzGetIdentifier( i_cur_type );
+ if( i_smallest_bands == 1 )
+ {
+ msg_Warn( p_obj, "found only one band (which is not 10, 15, "
+ "or 31, as it ought to be); assuming it corresponds to "
+ "the first band of the currently active equalizer type "
+ "(%d-band %s equalizer)", i_cur_bands,
+ EqzGetStringIdentifier( eqz_identifier ) );
+ }
+ else
+ {
+ msg_Warn( p_obj, "found unexpected number of bands (%d, which "
+ "is not 10, 15, or 31, as it ought to be); assuming the "
+ "%s%d bands correspond to the %s%d bands of the currently "
+ "active equalizer type (%d-band %s equalizer)", i_bands,
+ i_cur_bands < i_bands ? "first " : "", i_smallest_bands,
+ i_cur_bands > i_bands ? "first " : "", i_smallest_bands,
+ i_cur_bands, EqzGetStringIdentifier( eqz_identifier ) );
+ }
+ break;
+ }
+ }
+ return eqz_identifier;
+}
+
+/* Try setting up an interpolant */
+static int SetUpInterpolant( int i_bands, int i_type, float * pf_amp,
+ vlc_interpolant_t ** itp )
+{
+ int i_ret_val = VLC_ENOMEM;
+ float * pf_freq = malloc( i_bands * sizeof( *pf_freq ) );
+ if( likely( pf_freq != NULL ) )
+ {
+ for( int k = 0; k < i_bands; k++ )
+ pf_freq[k] = EqzGetTrueFrequency( i_type, k );
+ i_ret_val = vlc_interpolant_create( itp, pf_freq, pf_amp, i_bands );
+ free( pf_freq );
+ }
+ return i_ret_val;
+}
+
+int vlc_eqz_util_band_parser_init( vlc_object_t * p_obj,
+ vlc_band_parser_t ** pp_parse_ctx,
+ const char * psz_bands, int i_type,
+ float * pf_amp )
+{
+ vlc_band_parser_t * p_parse_ctx;
+ vlc_interpolant_t * p_itp = NULL;
+ float * pf_orig_amp;
+ int i = 0, i_toks = 0;
+
+ /* Duplicate memory of bands string value */
+ char *p = strdup( psz_bands ), *q = NULL, *saved;
+ if( unlikely( !p ) )
+ return VLC_ENOMEM;
+
+ /* Allocate memory for storing the context data */
+ int i_ret_val = VLC_ENOMEM;
+ int i_size = EQZ_BANDS_MAX;
+ if( !pf_amp )
+ i_size += EqzGetNumBandsByType( i_type );
+ p_parse_ctx = malloc( sizeof( *p_parse_ctx ) + i_size * sizeof( *pf_amp ) );
+ if( likely( p_parse_ctx != NULL ) )
+ {
+ pf_orig_amp = p_parse_ctx->f_orig_amp;
+ if( !pf_amp )
+ pf_amp = pf_orig_amp + EQZ_BANDS_MAX;
+
+ for( char *tok = strtok_r( p, " ", &saved ); tok != NULL;
+ tok = strtok_r( NULL, " ", &saved ) )
+ {
+ if( i < EQZ_BANDS_MAX )
+ {
+ char *r = tok;
+ float f = us_strtof( tok, &r );
+ if( r == tok || *r != '\0' || isnan( f ) )
+ pf_orig_amp[i++] = 0.f;
+ else
+ pf_orig_amp[i++] = f;
+ }
+
+ /* Even if we exceed EQZ_BANDS_MAX or encounter malformed tokens,
+ * keep counting the number of tokens */
+ i_toks++;
+ q = tok;
+ }
+
+ /* Check whether we have a potential identifier at the end of the
+ * string. One way to check is if the last token is numeric. If not,
+ * then we consider it as a potential identifier. */
+ if( q ) /* q is non-NULL if we have at least one token */
+ {
+ char *r = q;
+ float f = us_strtof( q, &r );
+ if( r == q || *r != '\0' || isnan( f ) )
+ {
+ /* In this case, the last token could not be converted into a
+ * float, so we treat it as a potential identifier by excluding
+ * it from all counts */
+ if( i <= EQZ_BANDS_MAX )
+ i--; /* potential identifier found within bounds */
+ i_toks--;
+ }
+ else
+ q = NULL; /* don't treat any tokens as potential identifiers */
+ }
+
+ i_ret_val = VLC_SUCCESS;
+ if( i > 0 )
+ {
+ /* Should there be a mismatch in the number or type of bands,
+ * interpolate */
+ char id = GetValidIdentifier( p_obj, i_type, q, i_toks );
+ if( i != EqzGetNumBandsByType( i_type ) ||
+ id != EqzGetIdentifier( i_type ) )
+ {
+ int i_bands_type = EqzGetTypeByNumBands( i_toks, id );
+ if( i_bands_type != EQZ_UNKNOWN_TYPE )
+ /* Try creating the interpolant */
+ i_ret_val = SetUpInterpolant( i, i_bands_type, pf_orig_amp,
+ &p_itp );
+ }
+ }
+ }
+
+ /* Check status of i_ret_val. If it is not equal to VLC_SUCCESS, then
+ * clean up. Otherwise, set up structure */
+ if( i_ret_val == VLC_SUCCESS )
+ {
+ p_parse_ctx->p_itp = p_itp;
+ p_parse_ctx->i_orig_bands = i;
+ p_parse_ctx->pf_amp = pf_amp;
+ p_parse_ctx->i_type = i_type;
+ *pp_parse_ctx = p_parse_ctx;
+ }
+ else
+ {
+ free( p_parse_ctx );
+ }
+
+ free( p );
+ return i_ret_val;
+}
+
+const float * vlc_eqz_util_get_amp_array( const vlc_band_parser_t * p_parse_ctx )
+{
+ int i_band = EqzGetNumBandsByType( p_parse_ctx->i_type );
+ if( p_parse_ctx->p_itp )
+ {
+ /* Construct the interpolated set of bands */
+ for( int k = 0; k < i_band; k++ )
+ {
+ float f_freq = EqzGetTrueFrequency( p_parse_ctx->i_type, k );
+ p_parse_ctx->pf_amp[k] = vlc_interpolate( p_parse_ctx->p_itp, f_freq );
+ }
+ }
+ else
+ {
+ /* Read bands as they are */
+ int k;
+ for( k = 0; k < p_parse_ctx->i_orig_bands; k++ )
+ p_parse_ctx->pf_amp[k] = p_parse_ctx->f_orig_amp[k];
+ while( k < i_band )
+ p_parse_ctx->pf_amp[k++] = 0.f;
+ }
+ return p_parse_ctx->pf_amp;
+}
+
+void vlc_eqz_util_band_parser_destroy( vlc_band_parser_t * p_parse_ctx )
+{
+ if( likely( p_parse_ctx ) )
+ {
+ free( p_parse_ctx->p_itp );
+ free( p_parse_ctx );
+ }
+}
--
1.9.1
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