esp32s3 pdm rx录音多通道有杂音，不正常。 (IDFGH-12707)

[crl6]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

参考i2s_pdm_rx.c代码，修改gpio为：

#define EXAMPLE_PDM_RX_CLK_IO GPIO_NUM_19 // I2S PDM RX clock io number
#define EXAMPLE_PDM_RX_DIN_IO GPIO_NUM_20 // I2S PDM RX data in io number
#if CONFIG_IDF_TARGET_ESP32S3
#define EXAMPLE_PDM_RX_DIN1_IO GPIO_NUM_11 // I2S PDM RX data line1 in io number
#define EXAMPLE_PDM_RX_DIN2_IO GPIO_NUM_12 // I2S PDM RX data line2 in io number
#define EXAMPLE_PDM_RX_DIN3_IO GPIO_NUM_13 // I2S PDM RX data line3 in io number
#endif

gpio初始化：

#if CONFIG_IDF_TARGET_ESP32S3
// Only ESP32-S3 can support 4-line PDM RX
.dins = {
EXAMPLE_PDM_RX_DIN_IO,
EXAMPLE_PDM_RX_DIN_IO,
EXAMPLE_PDM_RX_DIN_IO,
EXAMPLE_PDM_RX_DIN_IO,
},
#else
.din = EXAMPLE_PDM_RX_DIN_IO,
#endif

通道配置：

#if CONFIG_IDF_TARGET_ESP32S3
// Enable all slots for example
pdm_rx_cfg.slot_cfg.slot_mode = I2S_SLOT_MODE_STEREO;
//pdm_rx_cfg.slot_cfg.slot_mask = I2S_PDM_LINE_SLOT_ALL;
pdm_rx_cfg.slot_cfg.slot_mask |= I2S_PDM_RX_LINE0_SLOT_RIGHT | I2S_PDM_RX_LINE0_SLOT_LEFT;
pdm_rx_cfg.slot_cfg.slot_mask |= I2S_PDM_RX_LINE1_SLOT_RIGHT | I2S_PDM_RX_LINE1_SLOT_LEFT;

//pdm_rx_cfg.slot_cfg.slot_mask |= I2S_PDM_RX_LINE2_SLOT_RIGHT | I2S_PDM_RX_LINE2_SLOT_LEFT;
//pdm_rx_cfg.slot_cfg.slot_mask |= I2S_PDM_RX_LINE3_SLOT_RIGHT | I2S_PDM_RX_LINE3_SLOT_LEFT;

#endif

pdm_rx_cfg.slot_cfg.slot_mask只要使用超过4通道，录音回来就不正常， 失真，杂音。

用的是同一个pmd立体声mic板子。

[crl6]

PDM_RX.PCM 是6通道，16bit，16000hz。录音文件。i2s_channel_read读取回来的数据保存在psram，读取到2194304字节后，再把2194304字节写入到sd卡 PDM_RX.PCM。 可以排出是写sd卡速度问题导致的。