hal: Add support for Fluence Far Field Voice

Add support for 6mic Fluence pre-processing of
captured stream using Far Field Voice (FFV) algorithm.

Change-Id: I7a643014f3e090482db7772dce2fc812fd469b2d
diff --git a/hal/audio_extn/ffv.c b/hal/audio_extn/ffv.c
new file mode 100644
index 0000000..fa55b5a
--- /dev/null
+++ b/hal/audio_extn/ffv.c
@@ -0,0 +1,891 @@
+/*
+ * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of The Linux Foundation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define LOG_TAG "audio_hw_ffv"
+/*#define LOG_NDEBUG 0*/
+#define LOG_NDDEBUG 0
+/*#define VERY_VERY_VERBOSE_LOGGING*/
+#ifdef VERY_VERY_VERBOSE_LOGGING
+#define ALOGVV ALOGV
+#else
+#define ALOGVV(a...) do { } while(0)
+#endif
+
+#include <errno.h>
+#include <cutils/properties.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <cutils/str_parms.h>
+#include <cutils/log.h>
+#include <pthread.h>
+#include <sys/resource.h>
+
+#include "audio_hw.h"
+#include "platform.h"
+#include "platform_api.h"
+
+#include "ffv_interface.h"
+
+#define AUDIO_PARAMETER_FFV_MODE_ON "ffvOn"
+#define AUDIO_PARAMETER_FFV_SPLIT_EC_REF_DATA "ffv_split_ec_ref_data"
+#define AUDIO_PARAMETER_FFV_EC_REF_CHANNEL_COUNT "ffv_ec_ref_channel_count"
+#define AUDIO_PARAMETER_FFV_EC_REF_DEVICE "ffv_ec_ref_dev"
+#define AUDIO_PARAMETER_FFV_CHANNEL_INDEX "ffv_channel_index"
+
+#define FFV_LIB "libffv.so"
+#define FFV_CONFIG_FILE_PATH "/etc/BF_1out.cfg"
+#define FFV_SAMPLING_RATE_16000 16000
+#define FFV_EC_REF_LOOPBACK_DEVICE_MONO "ec-ref-loopback-mono"
+#define FFV_EC_REF_LOOPBACK_DEVICE_STEREO "ec-ref-loopback-stereo"
+
+#define FFV_CHANNEL_MODE_MONO 1
+#define FFV_CHANNEL_MODE_STEREO 2
+#define FFV_CHANNEL_MODE_HEX 6
+#define FFV_CHANNEL_MODE_OCT 8
+
+#define FFV_PCM_BUFFER_DURATION_MS 160
+#define FFV_PCM_PERIOD_COUNT (8)
+#define FFV_PCM_PERIOD_SIZE \
+    ((((FFV_SAMPLING_RATE_16000 * FFV_PCM_BUFFER_DURATION_MS) \
+       /(FFV_PCM_PERIOD_COUNT * 1000)) + 0x1f) & ~0x1f)
+
+#define ALIGN(number, align) \
+        ((number + align - 1) & ~(align - 1))
+#define CALCULATE_PERIOD_SIZE(duration_ms, sample_rate, period_cnt, align) \
+       (ALIGN(((sample_rate * duration_ms) /(period_cnt * 1000)), align))
+
+#define FFV_PCM_MAX_RETRY 10
+#define FFV_PCM_SLEEP_WAIT 1000
+
+#define DLSYM(handle, name, err) \
+do {\
+    const char* error; \
+    *(void**)&name##_fn = dlsym(handle, #name);\
+    if ((error = dlerror())) {\
+        ALOGE("%s: dlsym failed for %s error %s", __func__, #name, error);\
+        err = -ENODEV;\
+    }\
+} while(0)\
+
+/* uncomment to collect pcm dumps */
+//#define FFV_PCM_DUMP
+
+static FfvStatusType (*ffv_init_fn)(void** handle, int num_tx_in_ch,
+    int num_out_ch, int num_ec_ref_ch, int frame_len, int sample_rate,
+    const char *config_file_name, char *svaModelBuffer,
+    uint32_t svaModelSize, int* totMemSize);
+static void (*ffv_deinit_fn)(void* handle);
+static void (*ffv_process_fn)(void *handle, const int16_t *in_pcm,
+    int16_t *out_pcm, const int16_t *ec_ref_pcm);
+static int (*ffv_read_fn)(void* handle, int16_t *buf_pcm,
+    int max_buf_len);
+static FfvStatusType (*ffv_get_param_fn)(void *handle, char *params_buffer_ptr,
+    int param_id, int buffer_size, int *param_size_ptr);
+static FfvStatusType (*ffv_set_param_fn)(void *handle, char *params_buffer_ptr,
+    int param_id, int param_size);
+static FfvStatusType (*ffv_register_event_callback_fn)(void *handle,
+    ffv_event_callback_fn_t *fun_ptr);
+
+struct ffvmodule {
+    void *ffv_lib_handle;
+    unsigned char *in_buf;
+    unsigned int in_buf_size;
+    unsigned char *ec_ref_buf;
+    unsigned int ec_ref_buf_size;
+    unsigned char *split_in_buf;
+    unsigned int split_in_buf_size;
+    unsigned char *out_buf;
+    unsigned int out_buf_size;
+
+    struct pcm_config capture_config;
+    struct pcm_config out_config;
+    struct pcm_config ec_ref_config;
+
+    int ec_ref_pcm_id;
+    struct pcm *ec_ref_pcm;
+    int ec_ref_ch_cnt;
+    audio_devices_t ec_ref_dev;
+    bool split_ec_ref_data;
+
+    bool is_ffv_enabled;
+    bool buffers_allocated;
+    struct stream_in *in;
+    bool is_ffvmode_on;
+    void *handle;
+    pthread_mutex_t init_lock;
+    bool capture_started;
+    int target_ch_idx;
+
+#ifdef FFV_PCM_DUMP
+    FILE *fp_input;
+    FILE *fp_ecref;
+    FILE *fp_split_input;
+    FILE *fp_output;
+#endif
+};
+
+static struct ffvmodule ffvmod = {
+    .ffv_lib_handle = NULL,
+    .in_buf = NULL,
+    .in_buf_size = 0,
+    .ec_ref_buf = NULL,
+    .ec_ref_buf_size = 0,
+    .split_in_buf = NULL,
+    .split_in_buf_size = 0,
+    .out_buf = NULL,
+    .out_buf_size = 0,
+
+    .ec_ref_pcm = NULL,
+    .ec_ref_ch_cnt = 1,
+    .ec_ref_dev = AUDIO_DEVICE_OUT_SPEAKER,
+    .is_ffv_enabled = false,
+    .buffers_allocated = false,
+    .in = NULL,
+    .is_ffvmode_on = false,
+    .handle = NULL,
+    .capture_started = false,
+    .target_ch_idx = -1,
+};
+
+static struct pcm_config ffv_pcm_config = {
+    .channels = FFV_CHANNEL_MODE_MONO,
+    .rate = FFV_SAMPLING_RATE_16000,
+    .period_size = FFV_PCM_PERIOD_SIZE,
+    .period_count = FFV_PCM_PERIOD_COUNT,
+    .format = PCM_FORMAT_S16_LE,
+};
+
+static int32_t ffv_init_lib()
+{
+    int status = 0;
+
+    if (ffvmod.ffv_lib_handle) {
+        ALOGE("%s: FFV library is already initialized", __func__);
+        return 0;
+    }
+
+    ffvmod.ffv_lib_handle = dlopen(FFV_LIB, RTLD_NOW);
+    if (!ffvmod.ffv_lib_handle) {
+        ALOGE("%s: Unable to open %s, error %s", __func__, FFV_LIB,
+            dlerror());
+        status = -ENOENT;
+        goto exit;
+    }
+
+    dlerror(); /* clear errors */
+    DLSYM(ffvmod.ffv_lib_handle, ffv_init, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_deinit, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_process, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_read, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_get_param, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_set_param, status);
+    if (status)
+        goto exit;
+    DLSYM(ffvmod.ffv_lib_handle, ffv_register_event_callback, status);
+    if (status)
+        goto exit;
+
+    return status;
+
+exit:
+    if (ffvmod.ffv_lib_handle)
+        dlclose(ffvmod.ffv_lib_handle);
+    ffvmod.ffv_lib_handle = NULL;
+
+    return status;
+}
+
+static int deallocate_buffers()
+{
+    if (ffvmod.in_buf) {
+        free(ffvmod.in_buf);
+        ffvmod.in_buf = NULL;
+    }
+
+    if (ffvmod.split_in_buf) {
+        free(ffvmod.split_in_buf);
+        ffvmod.split_in_buf = NULL;
+    }
+
+    if (ffvmod.ec_ref_buf) {
+        free(ffvmod.ec_ref_buf);
+        ffvmod.ec_ref_buf = NULL;
+    }
+
+    if (ffvmod.out_buf) {
+        free(ffvmod.out_buf);
+        ffvmod.out_buf = NULL;
+    }
+
+    ffvmod.buffers_allocated = false;
+    return 0;
+}
+
+static int allocate_buffers()
+{
+    int status = 0;
+
+    /* in_buf - buffer read from capture session */
+    ffvmod.in_buf_size = ffvmod.capture_config.period_size * ffvmod.capture_config.channels *
+                              (pcm_format_to_bits(ffvmod.capture_config.format) >> 3);
+    ffvmod.in_buf = (unsigned char *)calloc(1, ffvmod.in_buf_size);
+    if (!ffvmod.in_buf) {
+        ALOGE("%s: ERROR. Can not allocate in buffer size %d", __func__, ffvmod.in_buf_size);
+        status = -ENOMEM;
+        goto error_exit;
+    }
+    ALOGD("%s: Allocated in buffer size bytes =%d",
+          __func__, ffvmod.in_buf_size);
+
+    /* ec_buf - buffer read from ec ref capture session */
+    ffvmod.ec_ref_buf_size = ffvmod.ec_ref_config.period_size * ffvmod.ec_ref_config.channels *
+                              (pcm_format_to_bits(ffvmod.ec_ref_config.format) >> 3);
+    ffvmod.ec_ref_buf = (unsigned char *)calloc(1, ffvmod.ec_ref_buf_size);
+    if (!ffvmod.ec_ref_buf) {
+        ALOGE("%s: ERROR. Can not allocate ec ref buffer size %d",
+               __func__, ffvmod.ec_ref_buf_size);
+        status = -ENOMEM;
+        goto error_exit;
+    }
+    ALOGD("%s: Allocated ec ref buffer size bytes =%d",
+          __func__, ffvmod.ec_ref_buf_size);
+
+    if (ffvmod.split_ec_ref_data) {
+        ffvmod.split_in_buf_size = ffvmod.in_buf_size - ffvmod.ec_ref_buf_size;
+        ffvmod.split_in_buf = (unsigned char *)calloc(1, ffvmod.split_in_buf_size);
+        if (!ffvmod.split_in_buf) {
+            ALOGE("%s: ERROR. Can not allocate split in buffer size %d",
+                   __func__, ffvmod.split_in_buf_size);
+            status = -ENOMEM;
+            goto error_exit;
+        }
+        ALOGD("%s: Allocated split in buffer size bytes =%d",
+               __func__, ffvmod.split_in_buf_size);
+    }
+
+    /* out_buf - output buffer from FFV + SVA library */
+    ffvmod.out_buf_size = ffvmod.out_config.period_size * ffvmod.out_config.channels *
+                              (pcm_format_to_bits(ffvmod.out_config.format) >> 3);
+    ffvmod.out_buf = (unsigned char *)calloc(1, ffvmod.out_buf_size);
+    if (!ffvmod.out_buf) {
+        ALOGE("%s: ERROR. Can not allocate out buffer size %d", __func__, ffvmod.out_buf_size);
+        status = -ENOMEM;
+        goto error_exit;
+    }
+    ALOGD("%s: Allocated out buffer size bytes =%d",
+          __func__, ffvmod.out_buf_size);
+
+    ffvmod.buffers_allocated = true;
+    return 0;
+
+error_exit:
+    deallocate_buffers();
+    return status;
+}
+
+void audio_extn_ffv_update_enabled()
+{
+    char ffv_enabled[PROPERTY_VALUE_MAX] = "false";
+
+    property_get("ro.qc.sdk.audio.ffv", ffv_enabled, "0");
+    if (!strncmp("true", ffv_enabled, 4)) {
+        ALOGD("%s: ffv is supported", __func__);
+        ffvmod.is_ffv_enabled = true;
+    } else {
+        ALOGD("%s: ffv is not supported", __func__);
+        ffvmod.is_ffv_enabled = false;
+    }
+}
+
+bool audio_extn_ffv_get_enabled()
+{
+    ALOGV("%s: is_ffv_enabled:%d is_ffvmode_on:%d ", __func__, ffvmod.is_ffv_enabled, ffvmod.is_ffvmode_on);
+
+    if(ffvmod.is_ffv_enabled && ffvmod.is_ffvmode_on)
+        return true;
+
+    return false;
+}
+
+bool  audio_extn_ffv_check_usecase(struct stream_in *in) {
+    int ret = false;
+    int channel_count = audio_channel_count_from_in_mask(in->channel_mask);
+    audio_devices_t devices = in->device;
+    audio_source_t source = in->source;
+
+    if ((audio_extn_ffv_get_enabled()) &&
+            (channel_count == 1) &&
+            (AUDIO_SOURCE_MIC == source) &&
+            ((AUDIO_DEVICE_IN_BUILTIN_MIC == devices) || (AUDIO_DEVICE_IN_BACK_MIC == devices)) &&
+            (in->format == AUDIO_FORMAT_PCM_16_BIT) &&
+            (in->sample_rate == FFV_SAMPLING_RATE_16000)) {
+        in->config.channels = channel_count;
+        in->config.period_count = FFV_PCM_PERIOD_COUNT;
+        in->config.period_size = FFV_PCM_PERIOD_SIZE;
+        ALOGD("%s: FFV enabled", __func__);
+        ret = true;
+    }
+    return ret;
+}
+
+int audio_extn_ffv_set_usecase(struct stream_in *in)
+{
+    int ret = -EINVAL;
+
+    if (audio_extn_ffv_check_usecase(in)) {
+        if (!audio_extn_ffv_stream_init(in)) {
+            ALOGD("%s: Created FFV session succesfully", __func__);
+            ret = 0;
+        } else {
+            ALOGE("%s: Unable to start FFV record session", __func__);
+        }
+    }
+    return ret;
+}
+
+struct stream_in *audio_extn_ffv_get_stream()
+{
+    return ffvmod.in;
+}
+
+void audio_extn_ffv_update_pcm_config(struct pcm_config *config)
+{
+    config->channels = ffvmod.capture_config.channels;
+    config->period_count = ffvmod.capture_config.period_count;
+    config->period_size = ffvmod.capture_config.period_size;
+}
+
+int32_t audio_extn_ffv_init(struct audio_device *adev)
+{
+    int ret = 0;
+
+    ret = ffv_init_lib();
+    if (ret)
+        ALOGE("%s: ERROR. ffv_init_lib ret %d", __func__, ret);
+
+    pthread_mutex_init(&ffvmod.init_lock, NULL);
+    return ret;
+}
+
+int32_t audio_extn_ffv_deinit()
+{
+    pthread_mutex_destroy(&ffvmod.init_lock);
+    if (ffvmod.ffv_lib_handle) {
+        dlclose(ffvmod.ffv_lib_handle);
+        ffvmod.ffv_lib_handle = NULL;
+    }
+    return 0;
+}
+
+int32_t audio_extn_ffv_stream_init(struct stream_in *in)
+{
+    uint32_t ret = -EINVAL;
+    int num_tx_in_ch, num_out_ch, num_ec_ref_ch;
+    int frame_len;
+    int sample_rate;
+    const char *config_file_path = FFV_CONFIG_FILE_PATH;
+    int total_mem_size;
+    FfvStatusType status_type;
+    const char *sm_buffer = "DISABLE_KEYWORD_DETECTION";
+    ffv_target_channel_index_param_t ch_index_param;
+    char *params_buffer_ptr = NULL;
+    int param_size = 0;
+    int param_id;
+
+    if (!audio_extn_ffv_get_enabled()) {
+        ALOGE("Rejecting FFV -- init is called without enabling FFV");
+        goto fail;
+    }
+
+    if (ffvmod.handle != NULL) {
+        ALOGV("%s: reinitializing ffv library", __func__);
+        audio_extn_ffv_stream_deinit();
+    }
+
+    ffvmod.capture_config = ffv_pcm_config;
+    ffvmod.ec_ref_config = ffv_pcm_config;
+    ffvmod.out_config = ffv_pcm_config;
+    /* configure capture session with 6/8 channels */
+    ffvmod.capture_config.channels = ffvmod.split_ec_ref_data ?
+        FFV_CHANNEL_MODE_OCT : FFV_CHANNEL_MODE_HEX;
+    ffvmod.capture_config.period_size =
+                   CALCULATE_PERIOD_SIZE(FFV_PCM_BUFFER_DURATION_MS,
+                                         ffvmod.capture_config.rate,
+                                         FFV_PCM_PERIOD_COUNT, 32);
+
+    /* Update channels with ec ref channel count */
+    ffvmod.ec_ref_config.channels = ffvmod.ec_ref_ch_cnt;
+    ffvmod.ec_ref_config.period_size =
+               CALCULATE_PERIOD_SIZE(FFV_PCM_BUFFER_DURATION_MS,
+                                     ffvmod.ec_ref_config.rate,
+                                     FFV_PCM_PERIOD_COUNT, 32);
+    ret = allocate_buffers();
+    if (ret)
+        goto fail;
+
+    num_ec_ref_ch = ffvmod.ec_ref_config.channels;
+    num_tx_in_ch = ffvmod.split_ec_ref_data ?
+      (ffvmod.capture_config.channels - num_ec_ref_ch) :
+      ffvmod.capture_config.channels;
+    num_out_ch = ffvmod.out_config.channels;
+    frame_len = ffvmod.capture_config.period_size;
+    sample_rate = ffvmod.capture_config.rate;
+
+    ALOGD("%s: ec_ref_ch %d, tx_in_ch %d, out_ch %d, frame_len %d, sample_rate %d",
+           __func__, num_ec_ref_ch, num_tx_in_ch, num_out_ch, frame_len, sample_rate);
+    ALOGD("%s: config file path %s", __func__, config_file_path);
+    status_type = ffv_init_fn(&ffvmod.handle, num_tx_in_ch, num_out_ch, num_ec_ref_ch,
+                      frame_len, sample_rate, config_file_path, sm_buffer, 0,
+                      &total_mem_size);
+    if (status_type) {
+        ALOGE("%s: ERROR. ffv_init returned %d", __func__, status_type);
+        ret = -EINVAL;
+        goto fail;
+    }
+    ALOGD("%s: ffv_init success %p", __func__, ffvmod.handle);
+
+    /* set target channel index if received as part of setparams */
+    if (ffvmod.target_ch_idx != -1) {
+        ALOGD("%s: target channel index %d", __func__, ffvmod.target_ch_idx);
+        ch_index_param.target_chan_idx = ffvmod.target_ch_idx;
+        params_buffer_ptr = (char *)&ch_index_param;
+        param_size = sizeof(ch_index_param);
+        param_id = FFV_TARGET_CHANNEL_INDEX_PARAM;
+        status_type = ffv_set_param_fn(ffvmod.handle, params_buffer_ptr,
+                                       param_id, param_size);
+        if (status_type) {
+            ALOGE("%s: ERROR. ffv_set_param_fn ret %d", __func__, status_type);
+            ret = -EINVAL;
+            goto fail;
+        }
+    }
+
+    ffvmod.in = in;
+
+#ifdef FFV_PCM_DUMP
+    if (!ffvmod.fp_input) {
+        ALOGD("%s: Opening input dump file \n", __func__);
+        ffvmod.fp_input = fopen("/data/misc/audio/ffv_input.pcm", "wb");
+    }
+    if (!ffvmod.fp_ecref) {
+        ALOGD("%s: Opening ecref dump file \n", __func__);
+        ffvmod.fp_ecref = fopen("/data/misc/audio/ffv_ecref.pcm", "wb");
+    }
+    if (!ffvmod.fp_split_input && ffvmod.split_ec_ref_data) {
+        ALOGD("%s: Opening split input dump file \n", __func__);
+        ffvmod.fp_split_input = fopen("/data/misc/audio/ffv_split_input.pcm", "wb");
+    }
+    if (!ffvmod.fp_output) {
+        ALOGD("%s: Opening output dump file \n", __func__);
+        ffvmod.fp_output = fopen("/data/misc/audio/ffv_output.pcm", "wb");
+    }
+#endif
+    ALOGV("%s: exit", __func__);
+    return 0;
+
+fail:
+    audio_extn_ffv_stream_deinit();
+    return ret;
+}
+
+int32_t audio_extn_ffv_stream_deinit()
+{
+    ALOGV("%s: entry", __func__);
+
+#ifdef FFV_PCM_DUMP
+    if (ffvmod.fp_input)
+        fclose(ffvmod.fp_input);
+
+    if (ffvmod.fp_ecref)
+        fclose(ffvmod.fp_ecref);
+
+    if (ffvmod.fp_split_input)
+        fclose(ffvmod.fp_split_input);
+
+    if (ffvmod.fp_output)
+        fclose(ffvmod.fp_output);
+#endif
+
+    if (ffvmod.handle)
+        ffv_deinit_fn(ffvmod.handle);
+
+    if (ffvmod.buffers_allocated)
+        deallocate_buffers();
+
+    ffvmod.in = NULL;
+    ALOGV("%s: exit", __func__);
+    return 0;
+}
+
+snd_device_t audio_extn_ffv_get_capture_snd_device()
+{
+    if (ffvmod.capture_config.channels == FFV_CHANNEL_MODE_OCT) {
+        return SND_DEVICE_IN_HANDSET_8MIC;
+    } else if (ffvmod.capture_config.channels == FFV_CHANNEL_MODE_HEX) {
+        return SND_DEVICE_IN_HANDSET_6MIC;
+    } else {
+        ALOGE("%s: Invalid channels configured for capture", __func__);
+        return SND_DEVICE_NONE;
+    }
+}
+
+int audio_extn_ffv_init_ec_ref_loopback(struct audio_device *adev,
+                                        snd_device_t snd_device)
+{
+    struct audio_usecase *uc_info_tx = NULL;
+    snd_device_t in_snd_device;
+    char *params_buffer_ptr = NULL;
+    int param_id = FFV_RESET_AEC_PARAM;
+    int param_size = 0;
+    FfvStatusType status_type;
+    int ret = 0;
+
+    ALOGV("%s: entry", __func__);
+    /* notify library to reset AEC during each start */
+    status_type = ffv_set_param_fn(ffvmod.handle, params_buffer_ptr,
+                      param_id, param_size);
+    if (status_type) {
+        ALOGE("%s: ERROR. ffv_set_param_fn ret %d", __func__, status_type);
+        return -EINVAL;
+    }
+
+    if (ffvmod.split_ec_ref_data) {
+        ALOGV("%s: Ignore ec ref loopback init", __func__);
+        return 0;
+    }
+
+    in_snd_device = platform_get_ec_ref_loopback_snd_device(ffvmod.ec_ref_ch_cnt);
+    uc_info_tx = (struct audio_usecase *)calloc(1, sizeof(struct audio_usecase));
+    if (!uc_info_tx) {
+        return -ENOMEM;
+    }
+
+    pthread_mutex_lock(&ffvmod.init_lock);
+    uc_info_tx->id = USECASE_AUDIO_EC_REF_LOOPBACK;
+    uc_info_tx->type = PCM_CAPTURE;
+    uc_info_tx->in_snd_device = in_snd_device;
+    uc_info_tx->out_snd_device = SND_DEVICE_NONE;
+    ffvmod.ec_ref_pcm = NULL;
+    list_add_tail(&adev->usecase_list, &uc_info_tx->list);
+    enable_snd_device(adev, in_snd_device);
+    enable_audio_route(adev, uc_info_tx);
+
+    ffvmod.ec_ref_pcm_id = platform_get_pcm_device_id(uc_info_tx->id, PCM_CAPTURE);
+    if (ffvmod.ec_ref_pcm_id < 0) {
+        ALOGE("%s: Invalid pcm device for usecase (%d)",
+              __func__, uc_info_tx->id);
+        ret = -ENODEV;
+        goto exit;
+    }
+
+    ffvmod.ec_ref_pcm = pcm_open(adev->snd_card,
+                             ffvmod.ec_ref_pcm_id,
+                             PCM_IN, &ffvmod.ec_ref_config);
+    if (ffvmod.ec_ref_pcm && !pcm_is_ready(ffvmod.ec_ref_pcm)) {
+        ALOGE("%s: %s", __func__, pcm_get_error(ffvmod.ec_ref_pcm));
+        ret = -EIO;
+        goto exit;
+    }
+
+    if (pcm_prepare(ffvmod.ec_ref_pcm) < 0) {
+        ALOGE("%s: pcm prepare for ec ref loopback failed", __func__);
+        ret = -EINVAL;
+    }
+
+    ffvmod.capture_started = false;
+    pthread_mutex_unlock(&ffvmod.init_lock);
+    ALOGV("%s: exit", __func__);
+    return 0;
+
+exit:
+    if (ffvmod.ec_ref_pcm) {
+        pcm_close(ffvmod.ec_ref_pcm);
+        ffvmod.ec_ref_pcm = NULL;
+    }
+    list_remove(&uc_info_tx->list);
+    disable_snd_device(adev, in_snd_device);
+    disable_audio_route(adev, uc_info_tx);
+    free(uc_info_tx);
+    pthread_mutex_unlock(&ffvmod.init_lock);
+    return ret;
+}
+
+void audio_extn_ffv_append_ec_ref_dev_name(char *device_name)
+{
+    if (ffvmod.ec_ref_dev == AUDIO_DEVICE_OUT_AUX_LINE)
+        strlcat(device_name, " lineout",  DEVICE_NAME_MAX_SIZE);
+    ALOGD("%s: ec ref dev name %s", __func__, device_name);
+}
+
+int audio_extn_ffv_deinit_ec_ref_loopback(struct audio_device *adev,
+                                          snd_device_t snd_device)
+{
+    struct audio_usecase *uc_info_tx = NULL;
+    snd_device_t in_snd_device;
+    int ret = 0;
+
+    ALOGV("%s: entry", __func__);
+    if (ffvmod.split_ec_ref_data) {
+        ALOGV("%s: Ignore ec ref loopback init", __func__);
+        return 0;
+    }
+
+    in_snd_device = platform_get_ec_ref_loopback_snd_device(ffvmod.ec_ref_ch_cnt);
+    uc_info_tx = get_usecase_from_list(adev, USECASE_AUDIO_EC_REF_LOOPBACK);
+    pthread_mutex_lock(&ffvmod.init_lock);
+    if (ffvmod.ec_ref_pcm) {
+        pcm_close(ffvmod.ec_ref_pcm);
+        ffvmod.ec_ref_pcm = NULL;
+    }
+    disable_snd_device(adev, in_snd_device);
+    if (uc_info_tx) {
+        list_remove(&uc_info_tx->list);
+        disable_audio_route(adev, uc_info_tx);
+        free(uc_info_tx);
+    }
+    pthread_mutex_unlock(&ffvmod.init_lock);
+    ALOGV("%s: exit", __func__);
+    return ret;
+}
+
+int32_t audio_extn_ffv_read(struct audio_stream_in *stream,
+                       void *buffer, size_t bytes)
+{
+    int status = 0;
+    int16_t *in_ptr = NULL, *process_in_ptr = NULL, *process_out_ptr = NULL;
+    int16_t *process_ec_ref_ptr = NULL;
+    size_t in_buf_size, out_buf_size, bytes_to_copy;
+    int retry_num = 0;
+    int i, j, ch;
+    int total_in_ch, in_ch, ec_ref_ch;
+
+    if (!ffvmod.ffv_lib_handle) {
+        ALOGE("%s: ffv_lib_handle not initialized", __func__);
+        return -EINVAL;
+    }
+
+    if (!ffvmod.handle) {
+        ALOGE("%s: ffv module handle not initialized", __func__);
+        return -EINVAL;
+    }
+
+    if (!ffvmod.in || !ffvmod.in->pcm) {
+        ALOGE("%s: capture session not initiliazed", __func__);
+        return -EINVAL;
+    }
+
+    if (!ffvmod.split_ec_ref_data && !ffvmod.ec_ref_pcm) {
+        ALOGE("%s: ec ref session not initiliazed", __func__);
+        return -EINVAL;
+    }
+
+    if (!ffvmod.capture_started) {
+        /* pcm_start of capture and ec ref session before read to reduce drift */
+        pcm_start(ffvmod.in->pcm);
+        while (status && (retry_num < FFV_PCM_MAX_RETRY)) {
+            usleep(FFV_PCM_SLEEP_WAIT);
+            retry_num++;
+            ALOGI("%s: pcm_start retrying..status %d errno %d, retry cnt %d",
+                   __func__, status, errno, retry_num);
+            status = pcm_start(ffvmod.in->pcm);
+        }
+        if (status) {
+            ALOGE("%s: ERROR. pcm_start failed, returned status %d - %s",
+                  __func__, status, pcm_get_error(ffvmod.in->pcm));
+            return status;
+        }
+        retry_num = 0;
+
+        if (!ffvmod.split_ec_ref_data) {
+            pcm_start(ffvmod.ec_ref_pcm);
+            while (status && (retry_num < FFV_PCM_MAX_RETRY)) {
+                usleep(FFV_PCM_SLEEP_WAIT);
+                retry_num++;
+                ALOGI("%s: pcm_start retrying..status %d errno %d, retry cnt %d",
+                      __func__, status, errno, retry_num);
+                status = pcm_start(ffvmod.ec_ref_pcm);
+            }
+            if (status) {
+                ALOGE("%s: ERROR. pcm_start failed, returned status %d - %s",
+                       __func__, status, pcm_get_error(ffvmod.ec_ref_pcm));
+                return status;
+            }
+        }
+        ffvmod.capture_started = true;
+    }
+
+    ALOGVV("%s: pcm_read reading bytes=%d", __func__, ffvmod.in_buf_size);
+    status = pcm_read(ffvmod.in->pcm, ffvmod.in_buf, ffvmod.in_buf_size);
+    if (status) {
+        ALOGE("%s: pcm read failed status %d - %s", __func__, status,
+              pcm_get_error(ffvmod.in->pcm));
+        goto exit;
+    }
+    ALOGVV("%s: pcm_read done", __func__);
+
+    if (!ffvmod.split_ec_ref_data) {
+        /* read EC ref data */
+        ALOGVV("%s: ec ref pcm_read reading bytes=%d", __func__, ffvmod.ec_ref_buf_size);
+        status = pcm_read(ffvmod.ec_ref_pcm, ffvmod.ec_ref_buf, ffvmod.ec_ref_buf_size);
+        if (status) {
+            ALOGE("%s: ec ref pcm read failed status %d - %s", __func__, status,
+                   pcm_get_error(ffvmod.ec_ref_pcm));
+            goto exit;
+        }
+        ALOGVV("%s: ec ref pcm_read done", __func__);
+        process_in_ptr = (int16_t *)ffvmod.in_buf;
+        process_ec_ref_ptr = (int16_t *)ffvmod.ec_ref_buf;
+        in_buf_size = ffvmod.in_buf_size;
+    } else {
+        /* split input buffer into actual input channels and EC ref channels */
+        in_ptr = (int16_t *)ffvmod.in_buf;
+        process_in_ptr = (int16_t *)ffvmod.split_in_buf;
+        process_ec_ref_ptr = (int16_t *)ffvmod.ec_ref_buf;
+        total_in_ch = ffvmod.capture_config.channels;
+        ec_ref_ch = ffvmod.ec_ref_config.channels;
+        in_ch = total_in_ch - ec_ref_ch;
+        for (i = 0; i < ffvmod.capture_config.period_size; i++) {
+            for (ch = 0; ch < in_ch; ch++) {
+                process_in_ptr[i*in_ch+ch] =
+                          in_ptr[i*total_in_ch+ch];
+            }
+            for (ch = 0; ch < ec_ref_ch; ch++) {
+                process_ec_ref_ptr[i*ec_ref_ch+ch] =
+                          in_ptr[i*total_in_ch+in_ch+ch];
+            }
+        }
+        in_buf_size = ffvmod.split_in_buf_size;
+    }
+    process_out_ptr = (int16_t *)ffvmod.out_buf;
+
+    ffv_process_fn(ffvmod.handle, process_in_ptr,
+            process_out_ptr, process_ec_ref_ptr);
+    out_buf_size = ffvmod.out_buf_size;
+    bytes_to_copy = (bytes <= out_buf_size) ? bytes : out_buf_size;
+    memcpy(buffer, process_out_ptr, bytes_to_copy);
+    if (bytes_to_copy != out_buf_size)
+        ALOGD("%s: out buffer data dropped, copied %d bytes",
+               __func__, bytes_to_copy);
+
+#ifdef FFV_PCM_DUMP
+    if (ffvmod.fp_input)
+        fwrite(ffvmod.in_buf, 1, ffvmod.in_buf_size, ffvmod.fp_input);
+    if (ffvmod.fp_ecref)
+        fwrite(ffvmod.ec_ref_buf, 1, ffvmod.ec_ref_buf_size, ffvmod.fp_ecref);
+    if (ffvmod.fp_split_input)
+        fwrite(ffvmod.split_in_buf, 1, ffvmod.split_in_buf_size, ffvmod.fp_split_input);
+    if (ffvmod.fp_output)
+        fwrite(process_out_ptr, 1, bytes_to_copy, ffvmod.fp_output);
+#endif
+
+exit:
+    return status;
+}
+
+void audio_extn_ffv_set_parameters(struct audio_device *adev __unused,
+                                   struct str_parms *parms)
+{
+    int err;
+    int val;
+    int ret = 0;
+    char value[128];
+
+    /* FFV params are required to be set before start of recording */
+    if (!ffvmod.handle) {
+        ret = str_parms_get_str(parms, AUDIO_PARAMETER_FFV_MODE_ON, value,
+                                sizeof(value));
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_FFV_MODE_ON);
+            if (strcmp(value, "true") == 0) {
+                ALOGD("%s: Setting FFV mode to true", __func__);
+                ffvmod.is_ffvmode_on = true;
+            } else {
+                ALOGD("%s: Resetting FFV mode to false", __func__);
+                ffvmod.is_ffvmode_on = false;
+            }
+        }
+
+        ret = str_parms_get_str(parms, AUDIO_PARAMETER_FFV_SPLIT_EC_REF_DATA, value,
+                                sizeof(value));
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_FFV_SPLIT_EC_REF_DATA);
+            if (strcmp(value, "true") == 0) {
+                ALOGD("%s: ec ref is packed with mic captured data", __func__);
+                ffvmod.split_ec_ref_data = true;
+            } else {
+                ALOGD("%s: ec ref is captured separately", __func__);
+                ffvmod.split_ec_ref_data = false;
+            }
+        }
+        ret = str_parms_get_int(parms, AUDIO_PARAMETER_FFV_EC_REF_CHANNEL_COUNT, &val);
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_FFV_EC_REF_CHANNEL_COUNT);
+            if (val == 1) {
+                ALOGD("%s: mono ec ref", __func__);
+                ffvmod.ec_ref_ch_cnt = FFV_CHANNEL_MODE_MONO;
+            } else if (val == 2) {
+                ALOGD("%s: stereo ec ref", __func__);
+                ffvmod.ec_ref_ch_cnt = FFV_CHANNEL_MODE_STEREO;
+            } else {
+                ALOGE("%s: Invalid ec ref", __func__);
+            }
+        }
+
+        ret = str_parms_get_int(parms, AUDIO_PARAMETER_FFV_EC_REF_DEVICE, &val);
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_FFV_EC_REF_DEVICE);
+            if (val & AUDIO_DEVICE_OUT_SPEAKER) {
+                ALOGD("%s: capture ec ref from speaker", __func__);
+                ffvmod.ec_ref_dev = AUDIO_DEVICE_OUT_SPEAKER;
+            } else if (val & AUDIO_DEVICE_OUT_AUX_LINE) {
+                ALOGD("%s: capture ec ref from line out", __func__);
+                ffvmod.ec_ref_dev = AUDIO_DEVICE_OUT_AUX_LINE;
+            } else {
+                ALOGE("%s: Invalid ec ref out device", __func__);
+            }
+        }
+
+        ret = str_parms_get_int(parms, AUDIO_PARAMETER_FFV_CHANNEL_INDEX, &val);
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_FFV_CHANNEL_INDEX);
+            ALOGD("%s: set target chan index %d", __func__, val);
+            ffvmod.target_ch_idx = val;
+        }
+    }
+}