From 200cb3393dbdbb14847cb9b6a96a6f823ae93f50 Mon Sep 17 00:00:00 2001
From: Yu YongZhen <yuyz@rock-chips.com>
Date: Fri, 11 May 2018 14:45:40 +0800
Subject: [PATCH] add dcbfilter 16bit process
---
src/pcm/pcm.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 167 insertions(+), 1 deletion(-)
diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c
index fc7bd52..9c90afb 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -664,6 +664,167 @@ playback devices.
P_STATE(PAUSED) | \
P_STATE(DRAINING))
+//#define DCB_FILTER_16BIT
+#ifdef DCB_FILTER_16BIT
+
+#define A1 32511 // (1-2^(-7)) Q32:1.31 // 32752=>0.99951171875
+
+#define TO_16BIT_SHIFT 15
+#define MAX_Uint_PCMBIT_SIZE 4294967296
+#define MAX_UNSIGN_PCMBIT_SIZE 65536
+#define MAX_SIGN_POS_PCMBIT_SIZE 32768
+#define MAX_SIGN_NEG_PCMBIT_SIZE -32768
+
+/* static variables for previous values */
+/* left 1 */
+static int16_t x_prev_l1=0;
+static int16_t y_prev_l1=0;
+/* right 1 */
+static int16_t x_prev_r1=0;
+static int16_t y_prev_r1=0;
+/* left 2 */
+static int16_t x_prev_l2=0;
+static int16_t y_prev_l2=0;
+/* right 1 */
+static int16_t x_prev_r2=0;
+static int16_t y_prev_r2=0;
+/* left 1 */
+static int16_t x_prev_l3=0;
+static int16_t y_prev_l3=0;
+/* right 1 */
+static int16_t x_prev_r3=0;
+static int16_t y_prev_r3=0;
+
+void dc_filter_left1(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_l1;
+ a1_y_prev = A1*y_prev_l1/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_l1 = sampleIn;
+ y_prev_l1 = sampleOut;
+
+ *pcmIn = sampleOut;
+}
+void dc_filter_right1(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_r1;
+ a1_y_prev = A1*y_prev_r1/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_r1 = sampleIn;
+ y_prev_r1 = sampleOut;
+
+ *pcmIn = sampleOut;
+}
+void dc_filter_left2(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_l2;
+ a1_y_prev = A1*y_prev_l2/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_l2 = sampleIn;
+ y_prev_l2 = sampleOut;
+
+ *pcmIn = sampleOut;
+}
+
+void dc_filter_right2(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_r2;
+ a1_y_prev = A1*y_prev_r2/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_r2 = sampleIn;
+ y_prev_r2 = sampleOut;
+
+ *pcmIn = sampleOut;
+}
+void dc_filter_left3(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_l3;
+ a1_y_prev = A1*y_prev_l3/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_l3 = sampleIn;
+ y_prev_l3 = (int16_t)sampleOut;
+
+ *pcmIn = sampleOut;
+}
+
+void dc_filter_right3(int16_t *pcmIn)
+{
+ int16_t sampleIn, delta_x, sampleOut;
+ int16_t a1_y_prev;
+
+ sampleIn = *pcmIn;
+ delta_x = sampleIn-x_prev_r3;
+ a1_y_prev = A1*y_prev_r3/MAX_SIGN_POS_PCMBIT_SIZE;
+ sampleOut = delta_x+a1_y_prev;
+
+ x_prev_r3 = sampleIn;
+ y_prev_r3 = (int16_t)sampleOut;
+
+ *pcmIn = sampleOut;
+}
+
+void DCBDoing(void* pIn, int length, int channels)
+{
+ int i = 0;
+ int16_t * pInBuf = (int16_t *)pIn;
+
+ //printf("vicent-DCB_Doing---------------length = %d\n",length);
+
+ for(i = 0; i < length; i ++ ) {
+
+ int curChannel = i % channels;
+
+ switch(curChannel){
+ case 0:
+ dc_filter_left1(pInBuf);
+ break;
+ case 1:
+ dc_filter_right1(pInBuf);
+ break;
+ case 2:
+ dc_filter_left2(pInBuf);
+ break;
+ case 3:
+ dc_filter_right2(pInBuf);
+ break;
+ case 4:
+ dc_filter_left3(pInBuf);
+ break;
+ case 5:
+ dc_filter_right3(pInBuf);
+ break;
+ default:
+ break;
+ }
+ pInBuf++;
+ }
+}
+#endif
/* check whether the PCM is in the unexpected state */
static int bad_pcm_state(snd_pcm_t *pcm, unsigned int supported_states)
{
@@ -1509,7 +1670,12 @@ snd_pcm_sframes_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_uframes_t
}
if (bad_pcm_state(pcm, P_STATE_RUNNABLE))
return -EBADFD;
- return _snd_pcm_readi(pcm, buffer, size);
+
+ snd_pcm_sframes_t tmp = _snd_pcm_readi(pcm, buffer, size);
+#ifdef DCB_FILTER_16BIT
+ DCBDoing((void*)buffer, tmp * pcm->frame_bits / 8 / sizeof(int16_t), pcm->channels);
+#endif
+ return tmp;
}
/**
--
2.7.4