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