BPI-CM9-Linux/aml-comp/multimedia/aml_audio_hal/utils/aml_audio_limiter.c

/*
 * Copyright (C) 2025 Amlogic Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "audio_hw_limiter"

#include <math.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <system/audio.h>
#include <audio_utils/primitives.h>
#include "aml_malloc_debug.h"
#include "aml_dump_debug.h"
#include "audio_data_process.h"
#include "aml_audio_limiter.h"
#include "aml_volume_utils.h"
#include "aml_audio_log.h"
#include "format.h"


// NTS AUDIO-LIMITER-HEAAC-HEAAC :
// will detect sample max vule, left small room to avoid reach clipping detect range.
#define  LIMITER_INT32_0DB      ((INT32_MAX - 128 * INT16_MAX) & 0xFFFF0000)


typedef union {
    int32_t i;
    float   f;
} limiter_value;

typedef enum limiter_ease_type {
    LimEase_Linear = 0,   // small gain
    LimEase_InOutQuad,    // large gain
    LimEase_InOutCubic,   // not used it
    LimEase_InOutQuart,   // not used it
    LimEase_Max
} limiter_ease_type_e;

typedef struct limiter_curve {
    limiter_ease_type_e type;
    float *data_buf_ptr;
    size_t data_buf_size;
    int    data_len;
} limiter_curve_st;


typedef struct aml_audio_limiter {
    int            enable;
    audio_format_t format;
    int            process_frames;
    limiter_value  last_sample_max;
    float          curr_gain;
    float          last_gain;
    float          peak_float;
    int32_t        peak_int32;
    float          release_factor;
    float          response_factor;
    int            release_delay;
    int            release_delay_count;

    // data limit gain apply part
    // input data --> delay_buf -> output
    //float          pre_gain;
    float          post_gain;
    void          *delay_buf_ptr;
    void          *src_temp_buf;
    size_t         src_temp_buf_size;
    size_t         delay_buf_size;

    aml_planar_buf_st delay_planar_buf;
    aml_planar_buf_st temp_planar_buf;

    // when process_frames is small,
    // use these member to improve waveform
    float          average_gain;
    float          out_curr_gain;
    float          out_last_gain;
    int            out_lazy_count;

    limiter_curve_st curves[LimEase_Max];
} aml_audio_limiter_st;

// function declare
static int limiter_gen_curve_data(aml_audio_limiter_st *lim, limiter_ease_type_e ease_type, int proc_frames);

void* aml_audio_limiter_new(audio_format_t data_format)
{
    aml_audio_limiter_st *limiter = NULL;

    limiter = (aml_audio_limiter_st *)aml_audio_calloc(1, sizeof(aml_audio_limiter_st));
    if (limiter == NULL) {
        AM_LOGE("malloc limiter failed!");
        return NULL;
    }
    if (data_format != AUDIO_FORMAT_PCM_32_BIT && data_format != AUDIO_FORMAT_PCM_FLOAT && data_format != AUDIO_FORMAT_PCM_16_BIT) {
        AM_LOGE("not support data_format %d", data_format);
        aml_audio_free(limiter);
        limiter = NULL;
        return NULL;
    }

    if (data_format == AUDIO_FORMAT_PCM_16_BIT) {
        data_format = AUDIO_FORMAT_PCM_32_BIT;
    }
    if (data_format == AUDIO_FORMAT_PCM_FLOAT) {
        limiter->last_sample_max.f = 0.0f;
    } else {
        limiter->last_sample_max.i = 0;
    }
    limiter->format = data_format;

    limiter->curr_gain = 1.0f;
    limiter->last_gain = 1.0f;
    limiter->out_curr_gain = 1.0f;
    limiter->out_last_gain = 1.0f;
    limiter->peak_float = 1.0f;
    limiter->peak_int32 = LIMITER_INT32_0DB;
    limiter->average_gain = 0.0f;
    limiter->post_gain = 1.0f;
    limiter->delay_buf_ptr = NULL;
    limiter->delay_buf_size = 0;
    limiter->src_temp_buf = NULL;
    limiter->src_temp_buf_size = 0;

    AM_LOGI("success ,limiter->format =%d", limiter->format);
    return limiter;
}

void aml_audio_limiter_free(void *limiter)
{
    int i = 0;
    limiter_curve_st *p_curve = NULL;
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    if (lim == NULL) {
        AM_LOGE("limiter is NULL");
        return;
    }
    if (lim->src_temp_buf != NULL) {
        AM_LOGI("free delay_buf_ptr %p, bytes %zu", lim->delay_buf_ptr, lim->src_temp_buf_size);
        aml_audio_free(lim->src_temp_buf);
        lim->src_temp_buf = NULL;
        lim->src_temp_buf_size = 0;
    }
    if (lim->delay_buf_ptr != NULL) {
        AM_LOGI("free delay_buf_ptr %p, bytes %zu", lim->delay_buf_ptr, lim->delay_buf_size);
        aml_audio_free(lim->delay_buf_ptr);
        lim->delay_buf_ptr = NULL;
        lim->delay_buf_size = 0;
    }
    aml_planar_free_buf(&lim->delay_planar_buf);
    aml_planar_free_buf(&lim->temp_planar_buf);
    for (i = 0; i < LimEase_Max; i++) {
        p_curve = &lim->curves[i];
        if (p_curve->data_buf_ptr) {
            AM_LOGI("free curves type %d, bytes %zu", p_curve->type, p_curve->data_buf_size);
            aml_audio_free(p_curve->data_buf_ptr);
            p_curve->data_buf_ptr = NULL;
            p_curve->data_buf_size = 0;
            p_curve->data_len = 0;
        }
    }

    lim->enable = 0;
    aml_audio_free(lim);
    AM_LOGI("success");
}

static void limiter_smooth_output_gain(aml_audio_limiter_st *lim)
{
    int percent = 0;
    float gain_step = 0.0f;
    float last_average = 0.0f;
    float diff_value = 0.0f;
    float out_curr_gain = 0.0f;
    const float AVERAGE_FACTOR = 0.05;

    if (lim == NULL || lim->process_frames <= 0) return;
    // when process_frames >=256 frames, output gain is good enough to handle extreme case.
    if (lim->process_frames >= 256) {
        lim->out_last_gain = lim->out_curr_gain;
        lim->out_curr_gain = lim->curr_gain;
        return;
    }
    lim->out_last_gain = lim->out_curr_gain;
    out_curr_gain = lim->curr_gain;

    if (is_float_equal(lim->last_gain, 1.0f) && is_float_equal(lim->curr_gain, 1.0f)) {
        lim->out_curr_gain = 1.0f;
        lim->average_gain = 0;
        lim->out_lazy_count = 0;
        return;
    }

    last_average = lim->average_gain;
    gain_step = (lim->curr_gain - lim->last_gain) / lim->process_frames;
    lim->average_gain = lim->average_gain * (1 - AVERAGE_FACTOR) + lim->curr_gain * AVERAGE_FACTOR;
    diff_value = lim->average_gain - last_average;
    percent = (diff_value * 100 / AVERAGE_FACTOR);

    // sinetone sample is stable, avoid tiny jitter
    //AM_LOGV("percent %d, __gain_step %f,", percent, gain_step);
    if (percent == 0) {
        if (gain_step > 0.000001) {
            lim->out_lazy_count += 1;
        } else if (gain_step < 0) {
            lim->out_lazy_count = 0;
        }

        if (gain_step > 0.000001 && lim->out_lazy_count <= 2 && (lim->curr_gain - lim->last_gain < 0.005)) {
            out_curr_gain = lim->out_last_gain;
        }
    }

    lim->out_curr_gain = out_curr_gain;
}

static float limiter_find_sample_max_float(const float *buffer, const int count)
{
    int i = 0;
    float sample_max = 0.0f;
    float sample_abs = 0.0f;

    for (i = 0; i < count; i++) {
        sample_abs = (buffer[i] < 0 ? -(buffer[i]) : buffer[i]);
        if (sample_max < sample_abs) {
            sample_max = sample_abs;
        }
    }
    return sample_max;
}

static int32_t limiter_find_sample_max_int32(const int32_t *buffer, const int count)
{
    int i = 0;
    int32_t sample_max = 0;
    int32_t sample_abs = 0;

    for (i = 0; i < count; i++) {
        sample_abs = (buffer[i] < 0 ? -(buffer[i]) : buffer[i]);
        if (sample_max < sample_abs) {
            sample_max = sample_abs;
        }
    }
    return sample_max;
}


static float limiter_planar_find_sample_max_float(
        const aml_planar_buf_st *p_planar_buf, int frame_offset, int proc_frames)
{
    int i = 0;
    int j = 0;
    float sample_max = 0.0f;
    float sample_abs = 0.0f;
    const float *pch = NULL;
    const float **ppdata = (const float **)p_planar_buf->ch_data;
    int ch_num = p_planar_buf->ch_num;
    int buf_frames = p_planar_buf->per_ch_frames;

    if (frame_offset + proc_frames > buf_frames) {
        AM_LOGW("offset %d + proc %d > buf_frames %d", frame_offset, proc_frames, buf_frames);
        proc_frames = buf_frames - frame_offset;
        if (proc_frames < 0) {
            proc_frames = 0;
        }
    }

    for (i = 0; i < ch_num; i++) {
        pch = ppdata[i] + frame_offset;
        for (j = 0; j < proc_frames; j++) {
            sample_abs = (pch[j] < 0 ? -(pch[j]) : pch[j]);
            if (sample_max < sample_abs) {
                sample_max = sample_abs;
            }
        }
    }
    return sample_max;
}

static int32_t limiter_planar_find_sample_max_int32(
        const aml_planar_buf_st *p_planar_buf, int frame_offset, int proc_frames)
{
    int i = 0;
    int j = 0;
    int32_t sample_max = 0;
    int32_t sample_abs = 0;
    const int32_t *pch = NULL;
    const int32_t **ppdata = (const int32_t **)p_planar_buf->ch_data;
    int ch_num = p_planar_buf->ch_num;
    int buf_frames = p_planar_buf->per_ch_frames;

    if (frame_offset + proc_frames > buf_frames) {
        AM_LOGW("offset %d + proc %d > buf_frames %d", frame_offset, proc_frames, buf_frames);
        proc_frames = buf_frames - frame_offset;
        if (proc_frames < 0) {
            proc_frames = 0;
        }
    }

    for (i = 0; i < ch_num; i++) {
        pch = ppdata[i] + frame_offset;
        for (j = 0; j < proc_frames; j++) {
            sample_abs = (pch[j] < 0 ? -(pch[j]) : pch[j]);
            if (sample_max < sample_abs) {
                sample_max = sample_abs;
            }
        }
    }
    return sample_max;
}

static limiter_value limiter_planar_get_block_max_value(void *limiter,
            const aml_planar_buf_st *p_planar_buf, int frame_offset, int proc_frames)
{
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;
    limiter_value max_value;

    memset(&max_value, 0, sizeof(max_value));
    if (lim->format == AUDIO_FORMAT_PCM_FLOAT) {
        max_value.f = limiter_planar_find_sample_max_float(p_planar_buf, frame_offset, proc_frames);
    } else {
        max_value.i = limiter_planar_find_sample_max_int32(p_planar_buf, frame_offset, proc_frames);
    }
    return max_value;
}

static void limiter_calculate_gain_from_max(void *limiter, limiter_value current_max)
{
    float gain_new = 1.0f;
    const float PRECISION = 1e-04;
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;
    int debug_value = get_debug_value(AML_DEBUG_AUDIOHAL_LIMITER);

    float f_sample_max = 0.0f;
    float f_current_max = 0.0f;
    int   i_sample_max = 0;
    int   i_current_max = 0;

    if (lim == NULL || lim->enable == 0) {
        return;
    }

    if (lim->format == AUDIO_FORMAT_PCM_FLOAT) {
        f_current_max = current_max.f;
        f_sample_max = f_current_max;
        if (f_sample_max < lim->last_sample_max.f) {
            f_sample_max = lim->last_sample_max.f;
        }
        lim->last_sample_max.f = f_current_max;
        if (debug_value) {
            AM_LOGI("f_current_max %f, f_sample_max %f", f_current_max, f_sample_max);
        }
    } else {
        i_current_max = current_max.i;
        i_sample_max = i_current_max;
        if (i_sample_max < lim->last_sample_max.i) {
            i_sample_max = lim->last_sample_max.i;
        }
        lim->last_sample_max.i = i_current_max;
        if (debug_value) {
            AM_LOGI("i_current_max %d, i_sample_max %d", i_current_max, i_sample_max);
        }
    }
    lim->last_gain = lim->curr_gain;

    if (lim->format == AUDIO_FORMAT_PCM_FLOAT) {
        if (f_sample_max > lim->peak_float && f_sample_max != 0) {
            gain_new = lim->peak_float / f_sample_max;
        }
    } else {
        if (i_sample_max > lim->peak_int32 && i_sample_max != 0) {
            gain_new = ((float)lim->peak_int32) / i_sample_max;
        }
    }

    if (!is_float_equal(gain_new, 1.0f) || !is_float_equal(lim->last_gain, 1.0f)) {
        if (gain_new <= lim->curr_gain) {
            lim->curr_gain = gain_new;
            lim->release_delay_count = 0;
        } else {
            if (lim->release_delay_count < lim->release_delay) {
                lim->release_delay_count += 1;
            } else {
                lim->curr_gain += (gain_new - lim->curr_gain) * lim->release_factor;
            }
        }
    }

    if (lim->curr_gain > 1.0f) {
        lim->curr_gain = 1.0f;
    }
    if ((fabs(lim->curr_gain - 1.0f) < PRECISION)) {
        lim->curr_gain = 1.0f;
    }
    if (debug_value) {
        AM_LOGI("lim %p curr_gain %f", lim, lim->curr_gain);
    }

    limiter_smooth_output_gain(lim);
}

static void limiter_calculate_gain(void *limiter, const void *buffer, const int sample_count)
{
    limiter_value current_max;
    float *float_buf = (float *)buffer;
    int   *int32_buf = (int *)buffer;
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    memset(&current_max, 0, sizeof(current_max));
    if (lim == NULL || lim->enable == 0) {
        return;
    }

    if (lim->format == AUDIO_FORMAT_PCM_FLOAT) {
        current_max.f = limiter_find_sample_max_float(float_buf, sample_count);
    } else {
        current_max.i = limiter_find_sample_max_int32(int32_buf, sample_count);
    }
    limiter_calculate_gain_from_max(limiter, current_max);
}

static inline void limiter_get_gain(aml_audio_limiter_st *limiter, float *last_gain, float *curr_gain)
{
    *last_gain = limiter->out_last_gain;
    *curr_gain = limiter->out_curr_gain;
}


static float limiter_calculate_factor(int time_ms, int proc_frames, int sample_rate)
{
    /*
     * Y = Y * factor + X * (1 - factor)
     * Yn − X = (factor)^n ∗(Y0 - X)
     * (factor)^n = (Yn - X) / (Y0 − X)
     * (factor)^n < target
     *
     * count * log(factor) < log(target)
     * log(factor) < log(target) / count
     *
     * factor = exp(log(target) / count)
    */

    double factor = 1.0f;
    float  count = (float)time_ms * sample_rate / (proc_frames * 1000);
    const float TARGET = 5.0f / 100;    // Diff 0.05 : is regarded attack or release action complete

    AM_LOGI("count %.04f, proc_frames %d, sample_rate %d, time_ms %d, target %f", count, proc_frames, sample_rate, time_ms, TARGET);
    factor = exp(log(TARGET) / count);

    // arrvie 1/2 X :
    int half_index = log(1 - 0.5) / log(factor);
    AM_LOGI("arrive half of target = %d\n", half_index);

    return factor;
}

#if 0
//for debug
static void limiter_verify_factor(float factor, int count)
{
    float X = 2.0f;
    float Y = 1.0f;

    int i = 0;
    for (i = 0; i < count; i++) {
        AM_LOGD("%f", Y);
        Y = Y * factor + X * (1.0f - factor);
    }
}
#endif

int aml_audio_limiter_set(void *limiter, float peak_level, int attack_time, int release_time, int proc_frames, limiter_config_mode_e limiter_type)
{
    char info_buf[32];
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    if (lim == NULL) {
        return -1;
    }

    if (attack_time < 30) {
        attack_time = 30;
    } else if (attack_time > 300) {
        attack_time = 300;
    }

    if (release_time < 60) {
        release_time = 60;
    } else if (release_time > 600) {
        release_time = 600;
    }

    if (peak_level < 0.0f || peak_level > 1.0f) {
        AM_LOGE("fail, invalid peak_level %f !", peak_level);
        return -1;
    }

    lim->release_factor = limiter_calculate_factor(release_time, proc_frames, 48000);
    lim->response_factor = limiter_calculate_factor(attack_time, proc_frames, 48000);
    lim->process_frames = proc_frames;
    lim->release_delay = -1;

    switch (proc_frames) {
        case 384:
            lim->release_delay = 1;
            break;
        case 256:
            lim->release_delay = 2;
            break;
        case 120:
        case 128:
            lim->release_delay = 3;
            break;
        case 64:
            lim->release_delay = 6;
            break;
        default:
            break;
    }
    if (lim->release_delay <= 0) {
        AM_LOGE("fail, not support proc_frames %d !", proc_frames);
        return -1;
    }

    //limiter_gen_curve_data(lim, LimEase_Linear, proc_frames);
    limiter_gen_curve_data(lim, LimEase_InOutQuad, proc_frames);

    memset(info_buf, 0, sizeof(info_buf));
    if (lim->format == AUDIO_FORMAT_PCM_FLOAT) {
        lim->peak_float = peak_level;
        snprintf(info_buf, sizeof(info_buf)-1, "float %.03f", peak_level);
    } else {
        if (is_float_equal(peak_level, 0.125)) {
            lim->peak_int32 = LIMITER_INT32_0DB / 8;
        } else if (is_float_equal(peak_level, 0.25)) {
            lim->peak_int32 = LIMITER_INT32_0DB / 4;
        } else if (is_float_equal(peak_level, 0.5)) {
            lim->peak_int32 = LIMITER_INT32_0DB / 2;
        } else {
            lim->peak_int32 = LIMITER_INT32_0DB * peak_level;
        }
        snprintf(info_buf, sizeof(info_buf)-1, "int32 %d", lim->peak_int32);
    }
    //lim->pre_gain = peak_level;
    if (limiter_type == AML_LIMITER) {
        lim->post_gain = 1.0f / peak_level; //Use limiter
    } else {
        lim->post_gain  = 1.0f; //Use limiter as DRC
    }

    lim->average_gain = 1.0f;
    lim->out_lazy_count = 0;

    AM_LOGI("release_factor = %f(release_time %d ms), process_frames = %d, release_delay = %d", lim->release_factor, release_time, lim->process_frames, lim->release_delay);
    AM_LOGI("peak_level: %f (dB %.03f, %s), post_gain %.03f,\n", peak_level, AmplToDb(peak_level), info_buf, lim->post_gain);

    return 0;
}

static inline float limiter_ease_next(limiter_ease_type_e ease, float t, float b, float c, float d)
{
    float result = 0.0f;

    switch (ease) {
        case LimEase_Linear:
            result = (c * t) / d + b;
            break;
        case LimEase_InOutQuad:
            if ((t /= d / 2) < 1) {
                result = ((c / 2) * (t * t)) + b;
            } else {
                --t;
                result = -c / 2 * (((t - 2) * t) - 1) + b;
            }
            break;
        case LimEase_InOutCubic:
            if ((t /= d / 2) < 1) {
                result = c / 2 * t * t * t + b;
            } else {
                t -= 2;
                result = c / 2 * (t * t * t + 2) + b;
            }
            break;
        case LimEase_InOutQuart:
            if ((t /= d / 2) < 1) {
                result = c / 2 * t * t * t * t + b;
            } else {
                t -= 2;
                result = -c / 2 * (t * t * t * t - 2) + b;
            }
            break;
        default:
            break;
    }
    return result;
}

static int limiter_gen_curve_data(aml_audio_limiter_st *lim, limiter_ease_type_e ease_type, int proc_frames)
{
    int i = 0;
    int ret = 0;
    int ease_frames = proc_frames;
    float vol_delta = 1.0f;
    float start_volume = 0.0f;
    float current_volume = 0.0f;
    float ease_frames_elapsed = 0.0f;
    limiter_curve_st *p_curve = NULL;
    size_t req_buf_size = 0;

    if (ease_type < 0 || ease_type >= LimEase_Max) {
        AM_LOGE("invalid ease_type %d", ease_type);
        return -1;
    }
    p_curve = &lim->curves[ease_type];
    req_buf_size = sizeof(float) * proc_frames;

    ret = aml_audio_check_and_realloc((void **)&p_curve->data_buf_ptr, &p_curve->data_buf_size, req_buf_size);
    if ((ret != 0) || (p_curve->data_buf_ptr == NULL)) {
        AM_LOGE("allocate data_buf_ptr(%zu bytes) failed", req_buf_size);
        return -1;
    }
    memset(p_curve->data_buf_ptr, 0, p_curve->data_buf_size);

    for (i = 0; i < proc_frames; i++) {
        current_volume = limiter_ease_next(ease_type, ease_frames_elapsed, start_volume, vol_delta, ease_frames);
        p_curve->data_buf_ptr[i] = current_volume;
        ease_frames_elapsed++;
    }
    p_curve->type = ease_type;
    p_curve->data_len = proc_frames;

    return 0;
}

static inline float * get_curver_data(aml_audio_limiter_st *lim, limiter_ease_type_e ease_type, int proc_frames)
{
    float *p_curve_data = lim->curves[ease_type].data_buf_ptr;

    if (p_curve_data == NULL || lim->curves[ease_type].data_len < proc_frames) {
        if (limiter_gen_curve_data(lim, ease_type, proc_frames) != 0) {
            AM_LOGE("limiter_gen_curve_data type %d fail !", ease_type);
            return NULL;
        }
        p_curve_data = lim->curves[ease_type].data_buf_ptr;
    }
    return p_curve_data;
}


static void limiter_apply_gain_fade(aml_audio_limiter_st *lim, float last_gain, float curr_gain, void *buf, int frame_num, int channels, int format)
{
    int32_t *input32 = (int32_t *)buf;
    float *input_float = (float *)buf;
    unsigned int i = 0, j= 0;
    float gain_step = 0.0f;
    float next_gain = 1.0f;
    float diff_gain = 0.0f;
    float *p_fade_curve = NULL;
    int debug_value = get_debug_value(AML_DEBUG_AUDIOHAL_LIMITER);

    if (buf == NULL || channels == 0 || frame_num == 0) {
        return;
    }
    p_fade_curve = get_curver_data(lim, LimEase_InOutQuad, frame_num);
    if (p_fade_curve == NULL) {
        AM_LOGE("p_fade_curve is NULL");
        return;
    }

    if (!is_float_equal(last_gain, curr_gain)) {
        gain_step = (curr_gain - last_gain)/frame_num;
        diff_gain = curr_gain - last_gain;
    }


    if (format == AUDIO_FORMAT_PCM_32_BIT) {
        for (i = 0; i < frame_num; i++) {
            //next_gain = last_gain + i * gain_step;
            next_gain = last_gain + diff_gain * p_fade_curve[i];
            for (j = 0; j < channels; j ++) {
                input32[i * channels + j] = clamp32((int64_t)(next_gain * input32[i * channels + j]));
            }
        }
    } else if (format == AUDIO_FORMAT_PCM_FLOAT) {
        for (i = 0; i < frame_num; i++) {
            //next_gain = last_gain + i * gain_step;
            next_gain = last_gain + diff_gain * p_fade_curve[i];
            for (j = 0; j < channels; j ++) {
                input_float[i * channels + j] = clamp_float((next_gain * input_float[i * channels + j]));
            }
        }
    }

    if (debug_value) {
        char info_buf[32];

        memset(info_buf, 0, sizeof(info_buf));
        if (format == AUDIO_FORMAT_PCM_32_BIT) {
            int sample_max = limiter_find_sample_max_int32(buf, frame_num * channels);
            snprintf(info_buf, sizeof(info_buf)-1, "%d, %.03f", sample_max, ((float)sample_max)/INT32_MAX);
        } else if (format == AUDIO_FORMAT_PCM_FLOAT) {
            float sample_max = limiter_find_sample_max_float(buf, frame_num * channels);
            snprintf(info_buf, sizeof(info_buf)-1, "%.03f", sample_max);
        }
        AM_LOGI("%p final sample_max %s", lim, info_buf);
    }

    return;
}

static void limiter_planar_apply_gain_fade(aml_audio_limiter_st *lim,
            float last_gain, float curr_gain, aml_planar_buf_st *p_planar_buf, int frame_num)
{
    unsigned int i = 0, j = 0;
    float next_gain = 1.0f;
    float diff_gain = 0.0f;
    float *p_fade_curve = NULL;
    int debug_value = get_debug_value(AML_DEBUG_AUDIOHAL_LIMITER);

    if (p_planar_buf == NULL || frame_num <= 0) {
        return;
    }
    p_fade_curve = get_curver_data(lim, LimEase_InOutQuad, frame_num);
    if (p_fade_curve == NULL) {
        AM_LOGE("p_fade_curve is NULL");
        return;
    }

    if (!is_float_equal(last_gain, curr_gain)) {
        diff_gain = curr_gain - last_gain;
    } else {
        if (is_float_equal(curr_gain, 1.0f)) {
            goto exit;
        }
    }

    if (frame_num > p_planar_buf->per_ch_frames) {
        AM_LOGW("frame_num(%d)  truncate to %d", frame_num, p_planar_buf->per_ch_frames);
        frame_num = p_planar_buf->per_ch_frames;
    }

    for (i = 0; i < (unsigned int)p_planar_buf->ch_num; i++) {
        if (p_planar_buf->format == AUDIO_FORMAT_PCM_32_BIT) {
            int32_t *p_ch_int32 = p_planar_buf->ch_data[i];
            for (j = 0; j < (unsigned int)frame_num; j++) {
                next_gain = last_gain + diff_gain * p_fade_curve[j];
                p_ch_int32[j] = clamp32((int64_t)(next_gain * p_ch_int32[j]));
            }
        } else if (p_planar_buf->format == AUDIO_FORMAT_PCM_FLOAT) {
            float *p_ch_float = p_planar_buf->ch_data[i];
            for (j = 0; j < (unsigned int)frame_num; j++) {
                next_gain = last_gain + diff_gain * p_fade_curve[j];
                p_ch_float[j] = clamp_float((next_gain * p_ch_float[j]));
            }
        }
    }

exit:
    if (debug_value) {
        char info_buf[32];

        memset(info_buf, 0, sizeof(info_buf));
        if (p_planar_buf->format == AUDIO_FORMAT_PCM_32_BIT) {
            int sample_max = limiter_planar_find_sample_max_int32(p_planar_buf, 0, frame_num);
            snprintf(info_buf, sizeof(info_buf)-1, "%d, %.03f", sample_max, ((float)sample_max)/INT32_MAX);
        } else if (p_planar_buf->format == AUDIO_FORMAT_PCM_FLOAT) {
            float sample_max = limiter_planar_find_sample_max_float(p_planar_buf, 0, frame_num);
            snprintf(info_buf, sizeof(info_buf)-1, "%.03f", sample_max);
        }
        AM_LOGI("%p final sample_max %s", lim, info_buf);
    }
}

int aml_audio_limiter_process(void *limiter,
    void *dst_buf, const audio_format_t dst_format,
    void *src_buf, audio_format_t src_format,
    const int channels, const int frame_num)
{
    int ret = 0;
    int block_frames = 0;
    int block_samples = 0;
    int handle_samples = 0;
    const int sample_size = 4;
    size_t block_bytes = 0;
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;
    void *curr_src_ptr = NULL;
    int debug_value = get_debug_value(AML_DEBUG_AUDIOHAL_LIMITER);
    int in_frames = frame_num;
    int in_samples = in_frames * channels;
    int in_bytes = in_samples * sample_size;

    float last_gain = 1.0f;
    float curr_gain = 1.0f;
    float last_boost = 1.0f;
    float curr_boost = 1.0f;

    if (limiter == NULL || dst_buf == NULL || src_buf == NULL || channels <= 0 || frame_num <= 0) {
        AM_LOGE("invalid param (limiter %p, buffer (%p, %p), channels %d, frame_num %d)", limiter, dst_buf, src_buf, channels, frame_num);
        return -1;
    }
    if (!lim->enable) {
        AM_LOGV("limiter is not enable !");
        return -1;
    }

    ret = aml_audio_check_and_realloc(&lim->src_temp_buf, &lim->src_temp_buf_size, in_bytes);
    if ((ret != 0) || (lim->src_temp_buf == NULL)) {
        AM_LOGE("allocate src_temp_buf_ptr(%d bytes) failed", in_bytes);
        return -1;
    }
    if (src_format == AUDIO_FORMAT_PCM_16_BIT) {
        memcpy_by_audio_format(lim->src_temp_buf, lim->format, src_buf, AUDIO_FORMAT_PCM_16_BIT, in_samples);
        src_format = AUDIO_FORMAT_PCM_32_BIT;;
    } else {
        memcpy_by_audio_format(lim->src_temp_buf, src_format, src_buf, src_format, in_samples);
    }
    if (lim->format != src_format) {
        AM_LOGE("limiter format(%d) does NOT match src format(%d)", lim->format, src_format);
        return -1;
    }

    if ((frame_num % lim->process_frames) != 0) {
        AM_LOGE("not support frame_num %d (limiter process_frames %d)", frame_num, lim->process_frames);
        return -1;
    }

    block_frames = lim->process_frames;
    block_samples = block_frames * channels;
    block_bytes = block_samples * sample_size;
    ret = aml_audio_check_and_realloc(&lim->delay_buf_ptr, &lim->delay_buf_size, block_bytes);
    if ((ret != 0) || (lim->delay_buf_ptr == NULL)) {
        AM_LOGE("allocate delay_buf_ptr(%zu bytes) failed", block_bytes);
        if (lim->src_temp_buf != NULL) {
            aml_audio_free(lim->src_temp_buf);
            lim->src_temp_buf = NULL;
            lim->src_temp_buf_size = 0;
        }
        return -1;
    }

    for (handle_samples = 0; handle_samples < frame_num * channels; handle_samples += block_samples) {
        curr_src_ptr = (uint8_t *)lim->src_temp_buf + (handle_samples * audio_bytes_per_sample(lim->format));
        // calculate gain
        if (debug_value) {
            char name[64] = {0};
            snprintf(name, 64, "audio_before_limiter_cal_%s_lim_%p.pcm", src_format == AUDIO_FORMAT_PCM_32_BIT ? "int32":"float", lim);
            aml_dump_audio_bitstreams(name, curr_src_ptr, block_samples *sizeof(lim->format));
        }
        limiter_calculate_gain(lim, curr_src_ptr, block_samples);
        limiter_get_gain(lim, &last_gain, &curr_gain);
        // apply boost gain to delay buffer
        last_boost = last_gain * lim->post_gain;
        curr_boost = curr_gain * lim->post_gain;
        limiter_apply_gain_fade(lim, last_boost, curr_boost, lim->delay_buf_ptr, block_frames, channels, lim->format);

        // output delay buffer data, then move input buffer data into it
        if (lim->format == dst_format) {
            memcpy(dst_buf, lim->delay_buf_ptr, block_bytes);
        } else {
            memcpy_by_audio_format(dst_buf, dst_format, lim->delay_buf_ptr, lim->format, block_samples);
        }
        memcpy(lim->delay_buf_ptr, curr_src_ptr, block_bytes);
        // update destination and source buffer pointer
        dst_buf = (uint8_t *)dst_buf + (block_samples * audio_bytes_per_sample(dst_format));
    }
    return 0;
}

int aml_audio_limiter_planar_process(void *limiter,
            aml_planar_buf_st *p_src_buf, aml_planar_buf_st *p_dst_buf, audio_format_t dst_format)
{
    int ret = 0;
    int block_frames = 0;
    int handle_frames = 0;
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;
    int ch_num = 0;
    int frame_num = 0;
    audio_format_t src_format;
    int debug_value = get_debug_value(AML_DEBUG_AUDIOHAL_LIMITER);

    float last_gain = 1.0f;
    float curr_gain = 1.0f;
    float last_boost = 1.0f;
    float curr_boost = 1.0f;
    limiter_value block_max_value;

    if (limiter == NULL || p_src_buf == NULL || p_dst_buf == NULL
        || p_src_buf->ch_num <= 0 || p_src_buf->per_ch_frames <= 0) {
        AM_LOGE("invalid param, limiter %p, buffer (src %p, dst %p)",
            limiter, p_src_buf, p_dst_buf);
        return -1;
    }
    if (!lim->enable) {
        AM_LOGV("limiter is not enable !");
        return -1;
    }
    memset(&block_max_value, 0, sizeof(block_max_value));

    ch_num = p_src_buf->ch_num;
    src_format = p_src_buf->format;
    frame_num = p_src_buf->per_ch_frames;

    if (lim->format != src_format) {
        AM_LOGE("limiter format(%d) does NOT match src format(%d)", lim->format, src_format);
        return -1;
    }
    if ((frame_num % lim->process_frames) != 0) {
        AM_LOGE("not support frame_num %d (limiter process_frames %d)", frame_num, lim->process_frames);
        return -1;
    }

    block_frames = lim->process_frames;
    ret = aml_planar_check_and_realloc_buf(&lim->delay_planar_buf, block_frames, ch_num, src_format);
    if (ret != 0) {
        AM_LOGE("allocate delay_planar_buf(%d frames) failed", block_frames);
        return -1;
    }
    ret = aml_planar_check_and_realloc_buf(&lim->temp_planar_buf, block_frames, ch_num, src_format);
    if (ret != 0) {
        AM_LOGE("allocate temp_planar_buf(%d frames) failed", block_frames);
        return -1;
    }

    for (handle_frames = 0; handle_frames < frame_num; handle_frames += block_frames) {
        block_max_value = limiter_planar_get_block_max_value(lim, p_src_buf, handle_frames, block_frames);
        limiter_calculate_gain_from_max(lim, block_max_value);
        limiter_get_gain(lim, &last_gain, &curr_gain);
        if (debug_value) {
            AM_LOGI("limiter %p, last_gain %f, curr_gain %f", lim, last_gain, curr_gain);
        }

        last_boost = last_gain * lim->post_gain;
        curr_boost = curr_gain * lim->post_gain;
        limiter_planar_apply_gain_fade(lim, last_boost, curr_boost, &lim->delay_planar_buf, block_frames);

        if (p_src_buf == p_dst_buf) {
            aml_planar_memcpy_buf(&lim->temp_planar_buf, 0, src_format, p_src_buf, handle_frames, block_frames);
        }

        aml_planar_memcpy_buf(p_dst_buf, handle_frames, dst_format, &lim->delay_planar_buf, 0, block_frames);

        if (p_src_buf == p_dst_buf) {
            p_src_buf->per_ch_frames = frame_num;
            aml_planar_memcpy_buf(&lim->delay_planar_buf, 0, src_format, &lim->temp_planar_buf, 0, block_frames);
        } else {
            aml_planar_memcpy_buf(&lim->delay_planar_buf, 0, src_format, p_src_buf, handle_frames, block_frames);
        }
    }

    return 0;
}

int aml_audio_limiter_enable(void *limiter, bool enable)
{
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    if (lim == NULL) {
        AM_LOGE("fail, limiter is NULL");
        return -1;
    }
    if (lim->enable != enable) {
        aml_audio_limiter_flush(limiter);
    }
    lim->enable = enable;

    AM_LOGI("enable=%d ok", enable);
    return 0;
}

int aml_audio_limiter_get_delay(void *limiter)
{
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    if (lim == NULL || (!lim->enable)) {
        return 0;
    }
    return lim->process_frames;
}

static void limiter_reset(aml_audio_limiter_st *limiter)
{
    limiter->curr_gain = 1.0f;
    limiter->last_gain = 1.0f;
    if (limiter->format == AUDIO_FORMAT_PCM_FLOAT) {
        limiter->last_sample_max.f = 0.0f;
    } else {
        limiter->last_sample_max.i = 0;
    }
    limiter->release_delay_count = 0;

    limiter->average_gain = 1.0f;
    limiter->out_curr_gain = 1.0f;
    limiter->out_last_gain = 1.0f;
    limiter->out_lazy_count = 0;
}

int aml_audio_limiter_flush(void *limiter)
{
    aml_audio_limiter_st *lim = (aml_audio_limiter_st *)limiter;

    if (lim == NULL) {
        return -1;
    }
    if (lim->delay_buf_ptr) {
        memset(lim->delay_buf_ptr, 0, lim->delay_buf_size);
    }
    if (lim->src_temp_buf) {
        memset(lim->src_temp_buf, 0, lim->src_temp_buf_size);
    }
    aml_planar_clear_buf(&lim->delay_planar_buf);
    aml_planar_clear_buf(&lim->temp_planar_buf);
    limiter_reset(lim);

    AM_LOGI("ok");
    return 0;
}