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Diffstat (limited to 'libao2/pl_volnorm.c')
| -rw-r--r-- | libao2/pl_volnorm.c | 250 |
1 files changed, 0 insertions, 250 deletions
diff --git a/libao2/pl_volnorm.c b/libao2/pl_volnorm.c deleted file mode 100644 index 4a4823a244..0000000000 --- a/libao2/pl_volnorm.c +++ /dev/null @@ -1,250 +0,0 @@ -/* Normalizer plugin - * - * Limitations: - * - only AFMT_S16_LE supported - * - no parameters yet => tweak the values by editing the #defines - * - * License: GPLv2 - * Author: pl <p_l@gmx.fr> (c) 2002 and beyond... - * - * Sources: some ideas from volnorm plugin for xmms - * - * */ - -#define PLUGIN - -/* Values for AVG: - * 1: uses a 1 value memory and coefficients new=a*old+b*cur (with a+b=1) - * - * 2: uses several samples to smooth the variations (standard weighted mean - * on past samples) - * - * */ -#define AVG 1 - -#include <stdio.h> -#include <stdlib.h> -#include <inttypes.h> -#include <math.h> // for sqrt() - -#include "audio_out.h" -#include "audio_plugin.h" -#include "audio_plugin_internal.h" -#include "libaf/af_format.h" - -static ao_info_t info = { - "Volume normalizer", - "volnorm", - "pl <p_l@gmx.fr>", - "" -}; - -LIBAO_PLUGIN_EXTERN(volnorm) - -// mul is the value by which the samples are scaled -// and has to be in [MUL_MIN, MUL_MAX] -#define MUL_INIT 1.0 -#define MUL_MIN 0.1 -#define MUL_MAX 5.0 -static float mul; - - -#if AVG==1 -// "history" value of the filter -static float lastavg; - -// SMOOTH_* must be in ]0.0, 1.0[ -// The new value accounts for SMOOTH_MUL in the value and history -#define SMOOTH_MUL 0.06 -#define SMOOTH_LASTAVG 0.06 - - -#elif AVG==2 -// Size of the memory array -// FIXME: should depend on the frequency of the data (should be a few seconds) -#define NSAMPLES 128 - -// Indicates where to write (in 0..NSAMPLES-1) -static int idx; -// The array -static struct { - float avg; // average level of the sample - int32_t len; // sample size (weight) -} mem[NSAMPLES]; - -// If summing all the mem[].len is lower than MIN_SAMPLE_SIZE bytes, then we -// choose to ignore the computed value as it's not significant enough -// FIXME: should depend on the frequency of the data (0.5s maybe) -#define MIN_SAMPLE_SIZE 32000 - -#else -// Kab00m ! -#error "Unknown AVG" -#endif - - -// Some limits -#define MIN_S16 -32768 -#define MAX_S16 32767 - -// "Ideal" level -#define MID_S16 (MAX_S16 * 0.25) - -// Silence level -// FIXME: should be relative to the level of the samples -#define SIL_S16 (MAX_S16 * 0.01) - - -// Local data -static struct { - int inuse; // This plugin is in use TRUE, FALSE - int format; // sample fomat -} pl_volnorm = {0, 0}; - - -// minimal interface -static int control(int cmd,void *arg){ - switch(cmd){ - case AOCONTROL_PLUGIN_SET_LEN: - return CONTROL_OK; - } - return CONTROL_UNKNOWN; -} - -// minimal interface -// open & setup audio device -// return: 1=success 0=fail -static int init(){ - switch(ao_plugin_data.format){ - case(AF_FORMAT_S16_NE): - break; - default: - fprintf(stderr,"[pl_volnorm] Audio format not yet supported.\n"); - return 0; - } - - pl_volnorm.format = ao_plugin_data.format; - pl_volnorm.inuse = 1; - - reset(); - - printf("[pl_volnorm] Normalizer plugin in use.\n"); - return 1; -} - -// close plugin -static void uninit(){ - pl_volnorm.inuse=0; -} - -// empty buffers -static void reset(){ - int i; - mul = MUL_INIT; - switch(ao_plugin_data.format) { - case(AF_FORMAT_S16_NE): -#if AVG==1 - lastavg = MID_S16; -#elif AVG==2 - for(i=0; i < NSAMPLES; ++i) { - mem[i].len = 0; - mem[i].avg = 0; - } - idx = 0; -#endif - - break; - default: - fprintf(stderr,"[pl_volnorm] internal inconsistency - bugreport !\n"); - *(char *) 0 = 0; - } -} - -// processes 'ao_plugin_data.len' bytes of 'data' -// called for every block of data -static int play(){ - - switch(pl_volnorm.format){ - case(AF_FORMAT_S16_NE): { -#define CLAMP(x,m,M) do { if ((x)<(m)) (x) = (m); else if ((x)>(M)) (x) = (M); } while(0) - - int16_t* data=(int16_t*)ao_plugin_data.data; - int len=ao_plugin_data.len / 2; // 16 bits samples - - int32_t i, tmp; - float curavg, newavg; - -#if AVG==1 - float neededmul; -#elif AVG==2 - float avg; - int32_t totallen; -#endif - - // Evaluate current samples average level - curavg = 0.0; - for (i = 0; i < len ; ++i) { - tmp = data[i]; - curavg += tmp * tmp; - } - curavg = sqrt(curavg / (float) len); - - // Evaluate an adequate 'mul' coefficient based on previous state, current - // samples level, etc -#if AVG==1 - if (curavg > SIL_S16) { - neededmul = MID_S16 / ( curavg * mul); - mul = (1.0 - SMOOTH_MUL) * mul + SMOOTH_MUL * neededmul; - - // Clamp the mul coefficient - CLAMP(mul, MUL_MIN, MUL_MAX); - } -#elif AVG==2 - avg = 0.0; - totallen = 0; - - for (i = 0; i < NSAMPLES; ++i) { - avg += mem[i].avg * (float) mem[i].len; - totallen += mem[i].len; - } - - if (totallen > MIN_SAMPLE_SIZE) { - avg /= (float) totallen; - if (avg >= SIL_S16) { - mul = (float) MID_S16 / avg; - CLAMP(mul, MUL_MIN, MUL_MAX); - } - } -#endif - - // Scale & clamp the samples - for (i = 0; i < len ; ++i) { - tmp = mul * data[i]; - CLAMP(tmp, MIN_S16, MAX_S16); - data[i] = tmp; - } - - // Evaluation of newavg (not 100% accurate because of values clamping) - newavg = mul * curavg; - - // Stores computed values for future smoothing -#if AVG==1 - lastavg = (1.0 - SMOOTH_LASTAVG) * lastavg + SMOOTH_LASTAVG * newavg; - //printf("\rmul=%02.1f ", mul); -#elif AVG==2 - mem[idx].len = len; - mem[idx].avg = newavg; - idx = (idx + 1) % NSAMPLES; - //printf("\rmul=%02.1f (%04dKiB) ", mul, totallen/1024); -#endif - //fflush(stdout); - - break; - } - default: - return 0; - } - return 1; - -} - |