MI JPD API

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REVISION HISTORY

Revision No.	Description	Date
2.00	Initial release	12/17/2020
	Added PROCFS introduction	08/25/2021
	Added maximum decoding resolution introduction	06/28/2022
	Added Opera Decode Flow Chart	06/29/2021
2.01	Added APIs for stepping decoding or refreshing the repeated frame after paused decoding: MI_JPD_PauseChn, MI_JPD_RefreshChn, MI_JPD_ResumeChn,MI_JPD_StepChn	07/15/2022
	Refine Struct, compatible with 32-bit and 64-bit address lengths MI_JPD_StreamBuf_t MI_JPD_DirectInputBuf_t	10/25/2022
	Refine Struct, support set pts params MI_JPD_StreamBuf_t	11/10/2022
	Update procfs debug information	12/01/2022
	Modify the description of the MI_PTR64 u64Reserved variable	01/09/2023
	Modify the description of the MI_SYS_PixelFormat_e ePixelFormat variable	03/13/2023
	Add the description of usage restrictions of realtime mode	03/13/2023
	Added modparam introduction	04/12/2023
2.02	Added iFackel and iBopper information Updated modparam	08/26/2024
2.03	Added jaguar1 information	01/10/2025
2.04	Added support for the maxChnNum parameter configuration in modparam	02/27/2025
2.05	Added mhera information	11/12/2025
2.06	Added support for the maxChnId parameter configuration in modparam	05/25/2026

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1. OVERVIEW

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1.1. Module Overview

JPD module provides the functions of creating decoding channel, controlling decoding, and transmitting coded streams.

There are two main types of input sources of JPD module:

• APP reads stream file and sends data to JPD module;

• APP sends the stream data received by the network directly to JPD module.

  Table 1‑1 Chip decoding specifications

  Chip	Max Channels	Channel Number Range	Protocol	Resolution Range	Max Performance
  Tiramisu	16	[0, 16)	JPEG	max 8192x8192, min 16x8	3840x2160@20fps
  Muffin	16*4	[0, 16)	JPEG	max 8192x8192, min 16x8	3840x2160@20fps
  Mochi	16*2	[0, 16)	JPEG	max 8192x8192, min 16x8	3840x2160@20fps
  Opera	16	[0, 16)	JPEG	max 8192x8192, min 16x8	1920x1080@60fps
  Souffle	64	[0, 64)	JPEG	max 8192x8192, min 16x8	3840x2160@15fps
  iFackel	64	[0, 64)	JPEG	max 8192x8192, min 16x16	1920x1080@60fps
  iBopper	64	[0, 64)	JPEG	max 8192x8192, min 16x16	1920x1080@60fps
  jaguar1	64	[0, 64)	JPEG	max 8192x8192, min 16x16	1920x1080@30fps
  mhera	64*2	[0, 128)	JPEG	max 8192x8192, min 16x16	3840x2160@20fps

Note :

The channel number range describes the range of legal values for the decoding channel number. The total number of channels that a single JPD device can create is constrained by its maximum number of channels.

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1.2. Decode Flow Chart

1.2.1. Tiramisu Decode Flow Chart

Tiramisu only supports 1 device, and device id is 0.

1.2.2. Muffin Decode Flow Chart

Muffin supports 4 devices, and the id are 0, 1, 2, 3.

1.2.3. Mochi Decode Flow Chart

Mochi supports 2 devices, and the id are 0, 1.

1.2.4. Opera Decode Flow Chart

Opera only supports 1 device, and device id is 0.

1.2.5. Souffle Decode Flow Chart

Souffle only supports 1 device, and device id is 0.

1.2.6. iFackel Decode Flow Chart

iFackel only supports 1 device, and device id is 0.

1.2.7. iBopper Decode Flow Chart

iBopper only supports 1 device, and device id is 0.

1.2.8. jaguar1 Decode Flow Chart

jaguar1 only supports 1 device, and device id is 0.

1.2.9. mhera Decode Flow Chart

mhera supports 2 devices, and the id are 0, 1.

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1.3. Keyword Description

• JPG/JPEG

  Joint Photographic Experts Group: the JPEG standard is developed by the organization.

• JPD

  JPG Decoder.

• STR

  Suspend To RAM: It means that after the system is shut down or enters the power saving mode, other hardware except the memory is powered off, achieving the effect of fast restart while being compatible with low power consumption.

• APP

  Application.

---

1.4. modparam

• The JPD supports modifying some parameter configurations through modparam, users can modify it as required. The following table describes the parameters:

  Parameter name	Default	Supported platforms	Customer configuration	Function
  jpd_clock	0	iFackel/iBopper/jaguar1/mhera	Y	JPD hardware clock. If not set or set to 0, the default value will be used internally.
  maxChnNum	16/16/16/64	iFackel/iBopper/jaguar1/mhera	Y	The maximum number of channels that can be created on a single JPD device, with a valid range of [1, N] (where N refers to Table 1‑1 Chip decoding specifications). If left unconfigured or set beyond the valid range, the system will internally use the default value.
  maxChnId	64	mhera	Y	The maximum channel number that can be created on a single JPD channel, with a valid range of [1, N) (where N refers to Table 1‑1 Chip decoding specifications). If left unconfigured or set beyond the valid range, the system will internally use the default value.

• Module parameters can be configured and modified using modparam.json files, which is usually under /config path in the board.

  "E_MI_MODULE_ID_JPD" :
  {
      "maxChnNum" : 16,
      "maxChnId" : 64,
      "jpd_clock" : 0
  }
  

• Module parameters can be configured and modified using echo commands, the process is as follows:

  • Create a json file or copy from /config path, and modify according to the required format. Take parameter jpd_clock as an example: Create a file named jpd_clock.json with:

    "E_MI_MODULE_ID_JPD" :
    {
        "maxChnNum" : 64,
        "maxChnId" : 16,
        "jpd_clock": 384000000
    }
    

  • Import the json configuration using the following commands:

    echo jpd_clock.json > /proc/mi_modules/mi_common/modparam
    

  • Run the application or call the JPD related api.

• Note

  • Module parameters take effect when insmod mi_jpd.ko, after the JPD module is started, the modification command cannot take effect.

  • After the system restarts, module parameters are reset to default values. Users needs to reconfigure module parameters.

---

2. API REFERENCE

---

This module provides the following APIs:

API Name	Function
MI_JPD_CreateDev	Create device
MI_JPD_DestroyDev	Destroy device
MI_JPD_CreateChn	Create a decoding channel.
MI_JPD_DestroyChn	Destroy a decoding channel.
MI_JPD_GetChnAttr	Get the decoding channel attribute.
MI_JPD_StartChn	Decoding channel starts receiving code stream.
MI_JPD_StopChn	Decoding channel stops receiving code stream.
MI_JPD_GetChnStatus	Get the decoding channel status.
MI_JPD_ResetChn	Reset the decoding channel.
MI_JPD_GetStreamBuf	Get the specified length bitstream buffer from the decoding channel.
MI_JPD_PutStreamBuf	Notify the decoding channel that the stream is put successfully and the decoding channel will start decoding.
MI_JPD_DropStreamBuf	Notify the decoding channel that the stream is dropped, and the decoding channel will release the corresponding code stream buffer obtained through MI_JPD_GetStreamBuf. MI_JPD_DropStreamBuf and MI_JPD_PutStreamBuf are mutually exclusive calls.
MI_JPD_QueryStreamInfo	Query the stream information from the decoding channel.
MI_JPD_DirectBufDecode	The decoding channel decodes directly according to the input and output buffer specified by app.
MI_JPD_PauseChn	Pause channel decoding.
MI_JPD_RefreshChn	Refresh the channel and re-decode the current frame.
MI_JPD_ResumeChn	Resume channel decoding.
MI_JPD_StepChn	Channel single frame decoding.

---

2.1. MI_JPD_CreateDev

• Function

  Create device.

• Syntax

  MI_S32 MI_JPD_CreateDev(MI_JPD_DEV JpdDev, MI_JPD_InitParam_t *pstInitParam);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  pstInitParam	Initialization parameters, which have no actual effect at present, are reserved for future expansion. Please refer to MI_JPD_InitParam_t.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • This function cannot be called, MI_JPD_CreateChn needs to specify a valid device id, and the corresponding device will be created internally.

  • This interface cannot be called repeatedly, it needs to be used in a pair with MI_JPD_DestroyDev, otherwise it returns to fail.

• Related API

  MI_JPD_DestroyDev

---

2.2. MI_JPD_DestroyDev

• Function

  Destroy device.

• Syntax

  MI_S32 MI_JPD_DestroyDev(MI_JPD_DEV JpdDev);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • This function must be called after the device is created, otherwise it returns to fail.

  • If this interface is not called before the app exits, the device will be automatically destroyed internally.

  • This interface cannot be called repeatedly, it needs to be used in a pair with MI_JPD_CreateDev, otherwise it returns to fail.

• Related API

  MI_JPD_CreateDev

---

2.3. MI_JPD_CreateChn

• Function

  Create a decoding channel.

• Syntax

  MI_S32 MI_JPD_CreateChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_ChnCreatConf_t *pstChnCreatConf)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstChnCreatConf	The decoding channel create configuration pointer, please refer to MI_JPD_ChnCreatConf_t.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • The channel ID cannot exceed the maximum channel number range.

  • The user can set the output pixel format through the ePixelFormat parameter when calling MI_JPD_CreateChn.

    Chip	Max Decoding Channels	Output Pixel Format
    Tiramisu	16	YUYV
    Muffin	16	YUYV
    Mochi	16	YUYV
    Opera	16	YUYV
    Souffle	64	YUYV,NV12
    iFackel	16(Default value. The actual value is determined by module parameter maxChnNum if maxChnNum was set)	YUYV,NV12
    iBopper	16(Default value. The actual value is determined by module parameter maxChnNum if maxChnNum was set)	YUYV
    jaguar1	16(Default value. The actual value is determined by module parameter maxChnNum if maxChnNum was set)	YUYV,NV12
    mhera	64(Default value. The actual value is determined by module parameter maxChnNum if maxChnNum was set)	YUYV,NV12

  • The user can set the size of the stream buffer through the u32StreamBufSize parameter when calling MI_JPD_CreateChn. Users can choose a reasonable value setting according to actual needs. According to the empirical value, the buffer size can be referred to as follows.

    Resolution Range	Buffer Size
    [min,720x576]	512KB
    (720x576,1920x1080]	1MB
    (1920x1080,max]	4MB

    Among them, min and max can be found in Chip decoding specifications.

  • When user creates multiple channels in one device and binds the channels with SCL module, the binding mode can only be set to one of E_MI_SYS_BIND_TYPE_FRAME_BASE or E_MI_SYS_BIND_TYPE_REALTIME. The simultaneous use of two modes is not supported.

• Example

  MI_S32 StartJpd(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev = 0;
      MI_JPD_CHN JpdChn = 0;
      MI_JPD_ChnCreatConf_t stChnCreatConf;
  
      memset(&stChnCreatConf, 0x0, sizeof(MI_JPD_ChnCreatConf_t));
      stChnCreatConf.u32StreamBufSize = 0x100000;
      stChnCreatConf.u32MaxPicWidth = 1920;
      stChnCreatConf.u32MaxPicHeight = 1080;
      stChnCreatConf.ePixelFormat = E_MI_SYS_PIXEL_FRAME_YUV422_YUYV;
      s32Ret = MI_JPD_CreateChn(JpdDev, JpdChn, &stChnCreatConf);
      if(MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_CreateChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
      s32Ret = MI_JPD_StartChn(JpdDev, JpdChn);
      if(MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_StartChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      return s32Ret;
  }
  

• Related API

  MI_JPD_DestroyChn

---

2.4. MI_JPD_DestroyChn

• Function

  Destroy a decoding channel.

• Syntax

  MI_S32 MI_JPD_DestroyChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • It is not allowed to destroy the channel before stopping it.

• Example

  MI_S32 StopJpd(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev = 0;
      MI_JPD_CHN JpdChn = 0;
  
      // Destroy send stream thread
  
      s32Ret = MI_JPD_StopChn(JpdDev, JpdChn);
      if(MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_StopChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      s32Ret = MI_JPD_DestroyChn(JpdDev, JpdChn);
      if(MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_DestroyChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      return s32Ret;
  }
  

• Related API

  MI_JPD_CreateChn

---

2.5. MI_JPD_GetChnAttr

• Function

  Get the decoding channel attribute.

• Syntax

  MI_S32 MI_JPD_GetChnAttr(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_ChnAttr_t *pstChnAttr)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstChnAttr	The decoding channel attribute struct pointer. Please refer to MI_JPD_ChnAttr_t.	Output

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

---

2.6. MI_JPD_StartChn

• Function

  The channel starts receiving code stream.

• Syntax

  MI_S32 MI_JPD_StartChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • The channel must be created before starting receiving the code stream.

  • If the module JPD has post-module, it is recommended to bind the module JPD with post-module before starting receiving the code stream.

  • Call MI_JPD_GetStreamBuf/MI_JPD_PutStreamBuf to send stream only after this API has been called first.

  • This API returns success when called repeatedly.

• Example

  Please refer to the example of MI_JPD_CreateChn.

• Related API

  MI_JPD_StopChn

---

2.7. MI_JPD_StopChn

• Function

  The channel stops receiving code stream.

• Syntax

  MI_S32 MI_JPD_StopChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • If the module JPD has post-module, it is recommended to stop receiving the code stream before unbinding the module JPD with post-module.

  • After calling this API, the return value of MI_JPD_GetStreamBuf/MI_JPD_PutStreamBuf is MI_ERR_JPD_CHN_NOT_START.

  • This API returns MI_ERR_JPD_CHN_NOT_START when called repeatedly.

• Example

  Please refer to the example of MI_JPD_DestroyChn.

• Related API

  MI_JPD_StartChn

---

2.8. MI_JPD_GetChnStatus

• Function

  Get the decoding channel status.

• Syntax

  MI_S32 MI_JPD_GetChnStatus(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_ChnStatus_t *pstChnStatus)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstChnStatus	The decoding channel status struct pointer. Please refer to MI_JPD_ChnStatus_t.	Output

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

---

2.9. MI_JPD_ResetChn

• Function

  Reset the decoding channel.

• Syntax

  MI_S32 MI_JPD_ResetChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

---

2.10. MI_JPD_GetStreamBuf

• Function

  Get the specified length bitstream buffer from the decoding channel.

• Syntax

  MI_S32 MI_JPD_GetStreamBuf(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_U32 u32RequiredLength,
                             MI_JPD_StreamBuf_t *pstRetStreamBuf, MI_S32 s32MilliSecToWait)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  u32RequiredLength	The required length of the stream buffer.	Input
  pstRetStreamBuf	The stream buffer struct pointer returned by module, please refer to MI_JPD_StreamBuf_t.	Output
  s32MilliSecToWait	Request timeout parameter, value range: -1: block; 0: nonblock; Positive: timeout in milliseconds.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • After calling the interface successfully, copy the corresponding JPG coded stream to the address space returned by the interface. If it succeeds, call MI_JPD_PutStreamBuf; if it fails, call MI_JPD_DropStreamBuf.

  • Only frame streaming mode is supported: a JPG bitstream of one complete frame is sent at a time.

• Example

  MI_S32 JpdSendStreamThreadFunc(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev = 0;
      MI_JPD_CHN JpdChn = 0;
      MI_U32 u32RequiredLength = 0;
      MI_S32 s32MilliSec = 0;
      MI_JPD_StreamBuf_t stRetStreamBuf;
  
      do {
          //Check if you need stop sending stream
          if (g_bStop)
          {
              break;
          }
  
          //get one stream from file or ipc, then assign u32RequiredLength to the size of the current stream
  
          memset(&stRetStreamBuf, 0x0, sizeof(MI_JPD_StreamBuf_t));
          s32MilliSec = 30;  //timeout is 30ms
          s32Ret = MI_JPD_GetStreamBuf(JpdDev, JpdChn, u32RequiredLength, &stRetStreamBuf, s32MilliSec);
          if (MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_GetStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
              continue;
          }
  
          if (stRetStreamBuf.u32HeadLength+stRetStreamBuf.u32TailLength < u32RequiredLength)
          {
              //something wrong happen
              printf("MI_JPD_GetStreamBuf return wrong value: HeadLen%u TailLen%u RequiredLength%u\n", stRetStreamBuf.u32HeadLength, stRetStreamBuf.u32TailLength, u32RequiredLength);
              s32Ret = MI_JPD_DropStreamBuf(JpdDev, JpdChn, &stRetStreamBuf);
              if (MI_SUCCESS != s32Ret)
              {
                  printf("MI_JPD_DropStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
                  continue;
              }
          }
          else
          {
              memcpy(stRetStreamBuf.pu8HeadVirtAddr, addr_of_stream, min(stRetStreamBuf.u32HeadLength, u32RequiredLength));
              if (stRetStreamBuf.u32TailLength > 0)
                  memcpy(stRetStreamBuf.pu8TailVirtAddr, addr_of_stream+stRetStreamBuf.u32HeadLength, min(stRetStreamBuf.u32TailLength, u32RequiredLength-stRetStreamBuf.u32HeadLength));
          }
  
          stRetStreamBuf.u32ContentLength = u32RequiredLength;
          s32Ret = MI_JPD_PutStreamBuf(JpdDev, JpdChn, &stRetStreamBuf);
          if (MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_PutStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
              continue;
          }
      }while(!g_bStop);
  
      return MI_SUCCESS;
  }
  

• Related API

  MI_JPD_PutStreamBuf

  MI_JPD_DropStreamBuf

---

2.11. MI_JPD_PutStreamBuf

• Function

  Notify the decoding channel that the stream is sent successfully and the decoding channel will start decoding.

• Syntax

  MI_S32 MI_JPD_PutStreamBuf(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_StreamBuf_t *pstRetStreamBuf)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstRetStreamBuf	The stream buffer pointer gotten by calling MI_JPD_GetStreamBuf, please refer to MI_JPD_StreamBuf_t.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • After calling MI_JPD_GetStreamBuf successfully, copy the corresponding JPG coded stream to the address space returned by MI_JPD_GetStreamBuf. If it succeeds, call this interface; if it fails, call MI_JPD_DropStreamBuf.

• Example

  Please refer to the example of MI_JPD_GetStreamBuf.

• Related API

  MI_JPD_GetStreamBuf

---

2.12. MI_JPD_DropStreamBuf

• Function

  Notify the decoding channel that the stream is dropped, and the decoding channel will release the corresponding code stream buffer obtained through MI_JPD_GetStreamBuf.

• Syntax

  MI_S32 MI_JPD_DropStreamBuf(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_StreamBuf_t *pstRetStreamBuf)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstRetStreamBuf	The stream buffer pointer gotten by calling MI_JPD_GetStreamBuf, please refer to MI_JPD_StreamBuf_t.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • After calling MI_JPD_GetStreamBuf successfully, copy the corresponding JPG coded stream to the address space returned by MI_JPD_GetStreamBuf. If it succeeds, call MI_JPD_PutStreamBuf; if it fails, call this interface.

• Example

  Please refer to the example of MI_JPD_GetStreamBuf.

• Related API

  MI_JPD_GetStreamBuf

---

2.13. MI_JPD_QueryStreamInfo

• Function

  Query the stream information from the decoding channel.

• Syntax

  MI_S32 MI_JPD_QueryStreamInfo(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_DirectInputBuf_t *pstInputBuf, MI_JPD_StreamInfo_t *pstStreamInfo)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstInputBuf	The struct pointer of input buffer, please refer to MI_JPD_DirectInputBuf_t.	Input
  pstStreamInfo	The struct pointer of stream information, please refer to MI_JPD_StreamInfo_t.	Output

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • The u32BufWidth/u32BufHeight refers to the actual width/height of the output buffer, while u32CurPicWidth/u32CurPicHeight refers to the effective width/height of the image.

• Example

  Please see the example of MI_JPD_DirectBufDecode.

• Related API

  MI_JPD_DirectBufDecode

---

2.14. MI_JPD_DirectBufDecode

• Function

  The decoding channel decodes directly according to the input and output buffer specified by APP.

• Syntax

  MI_S32 MI_JPD_DirectBufDecode(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn, MI_JPD_DirectInputBuf_t *pstInputBuf, MI_JPD_DirectOutputBuf_t *pstOutputBuf)
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input
  pstInputBuf	The struct pointer of input buffer, please refer to MI_JPD_DirectInputBuf_t.	Input
  pstOutputBuf	The struct pointer of output buffer, please refer to MI_JPD_DirectOutputBuf_t.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • If the output buffer size is not clear, APP needs to call MI_JPD_QueryStreamInfo before calling this interface.The output buffer size is calculated by u32BufWidth/u32BufHeight of MI_JPD_StreamInfo_t, while u32CurPicWidth/u32CurPicHeight refers to the actual effective width/height of the image.

  • The output pixel format set by this interface needs to be consistent with the value of the output pixel format set by the MI_JPD_CreateChn interface.

• Example

  MI_S32 directBufDecode(void)
  {
      MI_S32 s32Ret = MI_SUCCESS;
      MI_JPD_DEV JpdDev = 0;
      MI_JPD_CHN JpdChn = 0;
      MI_U8 *pu8Buf = NULL;
      MI_U32 u32LengthCurStream = 0;
      MI_JPD_DirectInputBuf_t stInputBuf;
      MI_JPD_DirectOutputBuf_t stOutputBuf;
      MI_JPD_StreamInfo_t stStreamInfo;
      MI_U32 u32OutputBufSize = 0;
  
      //get one jpg stream from file or ipc, assign its length to u32LengthCurStream
      pu8Buf = malloc(u32LengthCurStream);
      //copy one jpg stream from file or ipc to pu8Buf
  
      memset(&stInputBuf, 0, sizeof(MI_JPD_DirectInputBuf_t));
      memset(&stOutputBuf, 0, sizeof(MI_JPD_DirectOutputBuf_t));
      memset(&stStreamInfo, 0, sizeof(MI_JPD_StreamInfo_t));
  
      stInputBuf.pu8InputJPGRawFrameDataVirtAddr = pu8Buf;
      stInputBuf.phyAddr = 0;
      stInputBuf.u32Length = u32LengthCurStream;
      // get jpeg stream information and use it to configure output buffer
      s32Ret = MI_JPD_QueryStreamInfo(JpdDev, JpdChn, &stInputBuf, &stStreamInfo);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_QueryStreamInfo failed, s32Ret: 0x%x.\n", s32Ret);
          goto RETURN_FREE;
      }
  
      // set output pixel format to YUYV422
      stOutputBuf.ePixelFormat = E_MI_SYS_PIXEL_FRAME_YUV422_YUYV;
      stOutputBuf.u32Width = stStreamInfo.u32BufWidth;
      stOutputBuf.u32Height = stStreamInfo.u32BufHeight;
      stOutputBuf.u32Stride[0] = stOutputBuf.u32Width * 2;
      u32OutputBufSize = stOutputBuf.u32Stride[0] * stOutputBuf.u32Height;
      s32Ret = MI_SYS_MMA_Alloc(NULL, u32OutputBufSize, &stOutputBuf.phyAddr[0]);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_SYS_MMA_Alloc failed, s32Ret: 0x%x.\n", s32Ret);
          goto RETURN_FREE;
      }
  
      // decoding is triggered directly by the specified input and output buffer
      s32Ret = MI_JPD_DirectBufDecode(JpdDev, JpdChn, &stInputBuf, &stOutputBuf);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_DirectBufDecode failed, s32Ret: 0x%x.\n", s32Ret);
          goto RETURN_FREE;
      }
  
  RETURN_FREE:
      free(pu8Buf);
      return s32Ret;
  }
  

• Related API

  MI_JPD_QueryStreamInfo

---

2.15. MI_JPD_PauseChn

• Function

  Pause channel decoding.

• Syntax

  MI_S32 MI_JPD_PauseChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • After calling this interface, the decoder stops decoding; at this time, the upper layer can continue to send streams, but when the stream buffer is full, MI_JPD_GetStreamBuf will return MI_ERR_JPD_BUF_FULL.

  • This interface can be called repeatedly without error.

• Example

  MI_S32 PauseChn(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev  = 0;
      MI_JPD_CHN JpdChn  = 0;
      MI_U32 u32RefreshCnt = 0;
  
      //While decoding...
  
      s32Ret = MI_JPD_PauseChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_PauseChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      //refresh 10 times
      while (u32RefreshCnt < 10)
      {
          s32Ret = MI_JPD_RefreshChn(JpdDev, JpdChn);
          if(MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_RefreshChn failed, s32Ret: 0x%x.\n", s32Ret);
              break;
          }
          u32RefreshCnt ++;
          usleep(100*1000);
      }
  
      s32Ret = MI_JPD_ResumeChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_ResumeChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
      return MI_SUCCESS;
  }
  

• Related API

  MI_JPD_ResumeChn

---

2.16. MI_JPD_RefreshChn

• Function

  Refresh the channel and re-decode the current frame.

• Syntax

  MI_S32 MI_JPD_RefreshChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • When calling this interface, please ensure that MI_JPD_PauseChn has been called to stop decoding, otherwise it will return MI_ERR_JPD_NOT_DISABLE.

  • Every time this interface is called, it will trigger the decoder to re-decode the current frame; it can be called more than once, and the zoom factor can be adjusted with MI_SCL to adapt to different scene requirements.

  • When calling this interface, please ensure that there is still data to be decoded in the video stream buffer, otherwise refresh cannot be completed.

  • When the user calls the interface continuously, if the last refresh or step task is not completed, the interface will return MI_ERR_JPD_BUSY.

• Example

  Please refer to the example of MI_JPD_PauseChn and MI_JPD_StepChn.

  MI_JPD supports digital zoom during pause. Example: Suppose that the output resolution of MI_DISP in preview mode is 1920x1080, and the 4 channels are all 1080P source streams while decoding and previewing, the output resolution of each channel is set to 960x540 for output display. If you pause the decoding and switch channel 2 to full-screen preview, the image of 960x540 will be displayed in full-screen 1920x1080, and the image data will be distorted. By calling MI_JPD_RefreshChn, the 1920x1080 image of the current pause data frame can be displayed without distortion.

  

  The channel relies on the combination of MI_JPD_PauseChn, MI_JPD_RefreshChn, MI_JPD_ResumeChn and MI_JPD_GetStreamBuf, MI_JPD_PutStreamBuf to realize the pause electronic zoom function, so that images with different resolutions can be obtained for the same bitstream data frame. As follows, image 3 needs to be output 4 times repeatedly.

  Calling sequence of API combination:

  Step 1: Call MI_JPD_GetStreamBuf and MI_JPD_PutStreamBuf to send the video stream data of data frame ‘1’ and ‘2’.

  Step 2: Call MI_JPD_PauseChn to pause the decoder and enter the decoded output repeat image frame mode.

  Step 3: Call MI_JPD_GetStreamBuf and MI_JPD_PutStreamBuf to send the video stream data that needs to repeatedly output image "3" to the decoder.

  Step 4: Repeatedly call MI_JPD_RefreshChn to output image ‘3’, and output 1 frame of image for each call. The number of calls is unlimited. The current example is called 4 times.

  Step 5: Call MI_JPD_ResumeChn to exit the repeated decoding same image frame mode.

  Step 6: Call MI_JPD_GetStreamBuf and MI_JPD_PutStreamBuf to send the video stream data of data frame ‘4’ and ‘5’.

  

  

• Related API

  MI_JPD_PauseChn

  MI_JPD_ResumeChn

---

2.17. MI_JPD_ResumeChn

• Function

  Resume channel decoding.

• Syntax

  MI_S32 MI_JPD_ResumeChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • Before calling this interface, be sure the channel has been created; otherwise, the error code MI_ERR_JPD_CHN_UNEXIST will be returned.

  • Before calling this interface, be sure the channel has been enable; otherwise, the error code MI_ERR_JPD_CHN_NOT_START will be returned.

  • It is allowed to call this interface repeatedly.

  • If the last refresh or step task is not completed when calling this interface, the interface will return MI_ERR_JPD_BUSY.

• Example

  Please refer to the example of MI_JPD_PauseChn and MI_JPD_StepChn.

• Related API

  MI_JPD_PauseChn

---

2.18. MI_JPD_StepChn

• Function

  Channel single frame decoding.

• Syntax

  MI_S32 MI_JPD_StepChn(MI_JPD_DEV JpdDev, MI_JPD_CHN JpdChn);
  

• Parameter

  Parameter Name	Description	Input/Output
  JpdDev	Device number	Input
  JpdChn	The decoding channel number.	Input

• Return Value

  • MI_SUCCESS: Successful.

  • Not MI_SUCCESS: Failed, see ERROR CODE for details.

• Requirement

  • Header: mi_jpd.h, mi_jpd_datatype.h

  • Library: libmi_jpd.a/libmi_jpd.so

• Note

  • Each time this interface is called, it will trigger the decoder to decode the next frame; it can be called multiple times, and the zoom factor can be adjusted with MI_SCL to suit different scene requirements.

  • When calling this interface, the user needs to ensure that there is still data to be decoded in the video stream buffer, otherwise the step cannot be completed.

  • When the user calls the interface multiple times, if the last refresh or step task is not completed, the error code MI_ERR_JPD_BUSY will be returned.

• Example

  Case 1:

  MI_S32 StepChn(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev  = 0;
      MI_JPD_CHN JpdChn  = 0;
      MI_JPD_StreamBuf_t stRetStreamBuf;
  
      //While decoding...
  
      s32Ret = MI_JPD_PauseChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_PauseChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      memset(&stRetStreamBuf, 0x0, sizeof(MI_JPD_StreamBuf_t));
      u32RequiredLength = u32FrameLen;
      s32TimeOutMs = 0;
      /// It can be replaced by another independent thread when calling MI_JPD_GetStreamBuf and MI_JPD_PutStreamBuf
  
      s32Ret = MI_JPD_GetStreamBuf(JpdDev, JpdChn, u32RequiredLength, &stRetStreamBuf, s32TimeOutMs);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_GetStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      //Copy data from user buffer to stream buffer
  
      s32Ret = MI_JPD_PutStreamBuf(JpdDev, JpdChn, &stRetStreamBuf);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_PutStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      s32Ret = MI_JPD_StepChn(JpdDev, JpdChn);
      if(MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_StepChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
      usleep(20*1000);
  
      s32Ret = MI_JPD_ResumeChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_ResumeChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
      return MI_SUCCESS;
  }
  

  Case 2:

  MI_S32 refresh_and_step_chn(void)
  {
      MI_S32 s32Ret = MI_ERR_JPD_FAILED;
      MI_JPD_DEV JpdDev  = 0;
      MI_JPD_CHN JpdChn  = 0;
      MI_U32 u32LoopCnt = 0;
      MI_JPD_StreamBuf_t stRetStreamBuf;
  
      //While decoding...
  
      s32Ret = MI_JPD_PauseChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_PauseChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      memset(&stRetStreamBuf, 0x0, sizeof(MI_JPD_StreamBuf_t));
      u32RequiredLength = u32FrameLen;
      s32TimeOutMs = 0;
      /// It can be replaced by another independent thread when calling MI_JPD_GetStreamBuf and MI_JPD_PutStreamBuf
  
      s32Ret = MI_JPD_GetStreamBuf(JpdDev, JpdChn, u32RequiredLength, &stRetStreamBuf, s32TimeOutMs);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_GetStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      //copy data from user buffer to stream buffer here …
  
      s32Ret = MI_JPD_PutStreamBuf(JpdDev, JpdChn, &stRetStreamBuf);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_PutStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
  
      /*Loop 10 times*/
      While(u32LoopCnt < 10)
      {
          s32Ret = MI_JPD_RefreshChn(JpdDev, JpdChn);
          if(MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_RefreshChn failed, s32Ret: 0x%x.\n", s32Ret);
              return s32Ret;
          }
          usleep(20*1000);
  
          memset(&stRetStreamBuf, 0x0, sizeof(MI_JPD_StreamBuf_t));
          u32RequiredLength = u32FrameLen;
          s32TimeOutMs = 0;
          /// It can be replaced by another independent thread calling MI_JPD_GetStreamBuf ///and MI_JPD_PutStreamBuf
  
          s32Ret = MI_JPD_GetStreamBuf(JpdDev, JpdChn, u32RequiredLength, &stRetStreamBuf, s32TimeOutMs);
          if (MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_GetStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
              return s32Ret;
          }
  
          //Copy data from user buffer to stream buffer
  
          s32Ret = MI_JPD_PutStreamBuf(JpdDev, JpdChn, &stRetStreamBuf);
          if (MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_PutStreamBuf failed, s32Ret: 0x%x.\n", s32Ret);
              return s32Ret;
          }
  
          s32Ret = MI_JPD_StepChn(JpdDev, JpdChn);
          if(MI_SUCCESS != s32Ret)
          {
              printf("MI_JPD_StepChn failed, s32Ret: 0x%x.\n", s32Ret);
              return s32Ret;
          }
          usleep(20*1000);
          u32LoopCnt ++;
      }
  
      s32Ret = MI_JPD_ResumeChn(JpdDev, JpdChn);
      if (MI_SUCCESS != s32Ret)
      {
          printf("MI_JPD_ResumeChn failed, s32Ret: 0x%x.\n", s32Ret);
          return s32Ret;
      }
      return MI_SUCCESS;
  }
  

• Related API

  MI_JPD_PauseChn

  MI_JPD_ResumeChn

---

3. DATA TYPE

---

The JPD related data types and data structures are defined as follows:

Data Structure	Description
MI_JPD_DEV	Define JPD device ID type
MI_JPD_CHN	Define JPD channel ID type
MI_JPD_ErrCode_e	Define error code enumeration.
MI_JPD_InitParam_t	Define device initialization parameter structure.
MI_JPD_ChnCreatConf_t	Define channel create configuration structure.
MI_JPD_ChnAttr_t	Define channel attribute structure.
MI_JPD_ChnStatus_t	Define channel status structure.
MI_JPD_StreamBuf_t	Define stream buffer structure.
MI_JPD_StreamInfo_t	Define stream information structure.
MI_JPD_DirectInputBuf_t	Define input buffer structure.
MI_JPD_DirectOutputBuf_t	Define output buffer structure.

---

3.1. MI_JPD_DEV

• Description

  Define JPD device ID type .

• Syntax

  typedef MI_S32 MI_JPD_DEV;
  

---

3.2. MI_JPD_CHN

• Description

  Define JPD channel ID type.

• Syntax

  typedef MI_S32 MI_JPD_CHN;
  

---

3.3. MI_JPD_ErrCode_e

• Description

  Define error code enumeration.

• Syntax

  typedef enum
  {
      E_MI_JPD_ERR_CODE_UNKNOW = 0x0,
      E_MI_JPD_ERR_CODE_ILLEGAL_ACCESS,
      E_MI_JPD_ERR_CODE_DEC_TIMEOUT,
      E_MI_JPD_ERR_CODE_OUT_OF_MEMORY,
      E_MI_JPD_ERR_CODE_MAX
  } MI_JPD_ErrCode_e;
  

• Member

  Member	Description
  E_MI_JPD_ERR_CODE_UNKNOW	Unknown error.
  E_MI_JPD_ERR_CODE_ILLEGAL_ACCESS	Illegal access, e.g. uninitialized or faulty hardware.
  E_MI_JPD_ERR_CODE_DEC_TIMEOUT	Decode timeout.
  E_MI_JPD_ERR_CODE_OUT_OF_MEMORY	Out of memory.

---

3.4. MI_JPD_InitParam_t

• Description

  Define device initialization parameter structure.

• Syntax

  typedef struct MI_JPD_InitParam_s
  {
      MI_U32 u32Reserved;
  } MI_JPD_InitParam_t;
  

• Member

  Member	Description
  u32Reserved	Not used, reserved for future expansion.

• Related Data Type and Interface

  MI_JPD_CreateDev

---

3.5. MI_JPD_ChnCreatConf_t

• Description

  Define channel create configuration structure.

• Syntax

  typedef struct MI_JPD_ChnCreatConf_s
  {
      MI_U32 u32StreamBufSize;
      MI_SYS_PixelFormat_e ePixelFormat;
      MI_U32 u32MaxPicWidth;
      MI_U32 u32MaxPicHeight;
  } MI_JPD_ChnCreatConf_t;
  

• Member

  Member	Description
  u32StreamBufSize	The total size of stream buffer.
  ePixelFormat	The pixel format of output Image, Please refer to the description of MI_JPD_CreateChn.
  u32MaxPicWidth	The maximum width of decoded picture.
  u32MaxPicHeight	The maximum height of decoded picture.

• Related Data Type and Interface

  MI_JPD_CreateChn

---

3.6. MI_JPD_ChnAttr_t

• Description

  Define channel attribute structure.

• Syntax

  typedef struct MI_JPD_ChnAttr_s
  {
      MI_U32 u32StreamBufSize;
      MI_JPD_StreamInfo_t stStreamInfo;
  } MI_JPD_ChnAttr_t;
  

• Member

  Member	Description
  u32StreamBufSize	The total size of stream buffer.
  stStreamInfo	Stream information, please refer to MI_JPD_StreamInfo_t description.

• Related Data Type and Interface

  MI_JPD_GetChnAttr

---

3.7. MI_JPD_ChnStatus_t

• Description

  Define channel status structure.

• Syntax

  typedef struct MI_JPD_ChnStatus_s
  {
      MI_U32 u32LeftStreamBytes;
      MI_U32 u32LeftStreamFrames;
      MI_U32 u32LeftPics;
      MI_U32 u32RecvStreamFrames;
      MI_U32 u32DecodeStreamFrames;
      MI_BOOL bChnStart;
      MI_JPD_ErrCode_e eErrCode;
  } MI_JPD_ChnStatus_t;
  

• Member

  Member	Description
  u32LeftStreamBytes	The number of bytes to be decoded in the stream buffer.
  u32LeftStreamFrames	The number of frames to be decoded in the stream buffer.
  u32LeftPics	The number of decode pictures in the picture buffer.
  u32RecvStreamFrames	The total number of received frames.
  u32DecodeStreamFrames	The total number of decoded frames.
  bChnStart	Whether the decoding channel has started receiving bitstream.
  eErrCode	Error code.

• Related Data Type and Interface

  MI_JPD_GetChnStatus

---

3.8. MI_JPD_StreamBuf_t

• Description

  Define stream buffer structure.

• Syntax

  typedef struct MI_JPD_StreamBuf_s
  {
      union
      {
          MI_U8*   pu8HeadVirtAddr; // ring buffer first part user mode VA
          MI_PTR64 u64Reserved;
      };
      MI_PHY u64HeadPhyAddr; // ring buffer first part PA
      MI_U32 u32HeadLength;  // ring buffer first part Length
      union
      {
          MI_U8*   pu8TailVirtAddr; // ring buffer 2nd part user mode VA
          MI_PTR64 u64Reserved2;
      };
      MI_PHY u64TailPhyAddr;   //ring buffer 2nd part PA
      MI_U32 u32TailLength;    //ring buffer 2nd part length
      MI_U32 u32ContentLength; //current used content length
      MI_U64 u64Pts;
  }MI_JPD_StreamBuf_t;
  

• Member

  Member	Description
  pu8HeadVirtAddr	The first part virtual address of bitstream buffer.
  u64Reserved	Reserved, compatible with 32-bit and 64-bit address lengths.(unavailable)
  u64HeadPhyAddr	The first part physical address of bitstream buffer.
  u32HeadLength	The first part length of bitstream buffer.
  pu8TailVirtAddr	The second part virtual address of bitstream buffer.(unavailable)
  u64Reserved2	Reserved, compatible with 32-bit and 64-bit address lengths.(unavailable)
  u64TailPhyAddr	The second part physical address of bitstream buffer.(unavailable)
  u32TailLength	The second part length of bitstream buffer.(unavailable)
  u32ContentLength	Actual effective data length of bitstream buffer.
  u64Pts	Video stream packet timestamp, unit is microsecond.

• Note

  • The decoding channel stream buffer diagram may have the following situations:

    a)

    

    Stream buffer is free. If the length of Free1 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr of stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength.

    b)

    

    The first part of the stream buffer stores a jpeg coded stream that was previously sent in but has not yet been decoded. If the length of Free1 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr_free1 of stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength.

    c)

    

    The middle part of the stream buffer stores a jpeg coded stream that was previously sent in but has not yet been decoded, with both sides free. If the length of Free1 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr_free1 of stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength.

    d)

    

    The last part of the stream buffer stores a jpeg coded stream that was previously sent in but has not yet been decoded. If the length of Free1 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr of stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength.

    e)

    

    Only the middle part of the stream buffer is free. If the length of Free1 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr_free1 of stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength.

  • The decoding channel stream buffer diagram may have the following situations:

    

    The middle part of the stream buffer stores a jpeg coded stream that was previously sent in but has not yet been decoded, the length of Free1 does not meet the expected length u32RequiredLength, there is still a free buffer at the first part of the stream buffer. If the length of Free2 meets the expected length u32RequiredLength, the decoding channel will assign the start_addr of the stream buffer to pu8HeadVirtAddr, and assign u32RequiredLength to u32HeadLength. Otherwise, since the current length of the free buffer is less than the expected length from APP, APP fails to obtain the stream buffer of the expected length.

  • u32ContentLength means actual effective data length of bitstream. If the actual coded stream length transmitted by app is less than the expected length u32RequiredLength of MI_JPD_GetStreamBuf, APP needs to assign the actual length to u32ContentLength, then call MI_JPD_PutStreamBuf.

• Related Data Type and Interface

  MI_JPD_GetStreamBuf

  MI_JPD_PutStreamBuf

  MI_JPD_DropStreamBuf

---

3.9. MI_JPD_StreamInfo_t

• Description

  Define stream information structure.

• Syntax

  typedef struct MI_JPD_StreamInfo_s
  {
      MI_U32 u32CurPicWidth;
      MI_U32 u32CurPicHeight;
      MI_SYS_PixelFormat_e ePixelFormat;
      MI_U32 u32BufWidth;
      MI_U32 u32BufHeight;
  } MI_JPD_StreamInfo_t;
  

• Member

  Member	Description
  u32CurPicWidth	The current effective width of decoded picture.
  u32CurPicHeight	The current effective height of decoded picture.
  ePixelFormat	Input pixel format, with support the code stream encoded by YUV444,YUV440,YUV422,YUV420,YUV411 and YUV400. Please refer to MI_SYS_PixelFormat_e description.
  u32BufWidth	The actual width of the output buffer.
  u32BufHeight	The actual height of the output buffer.

• Note

  • If the output buffer size is not clear, APP needs to call this interface before calling MI_JPD_DirectBufDecode. The output buffer size is calculated by u32BufWidth/u32BufHeight, while u32CurPicWidth/u32CurPicHeight refers to the actual effective width/height of the image.

  • Currently, the query ePixelFormat is not supported.

• Related Data Type and Interface

  MI_JPD_ChnAttr_t

  MI_JPD_QueryStreamInfo

---

3.10. MI_JPD_DirectInputBuf_t

• Description

  Define input buffer structure.

• Syntax

  typedef struct MI_JPD_DirectInputBuf_s
  {
      union
      {
          MI_U8*   pu8InputJPGRawFrameDataVirtAddr;
          MI_PTR64 u64Reserved;
      };
      MI_PHY phyAddr;
      MI_U32 u32Length;
  }MI_JPD_DirectInputBuf_t;
  

• Member

  Member	Description
  pu8InputJPGRawFrameDataVirtAddr	The virtual address that stores JPG bitstream data.
  u64Reserved	Reserved, compatible with 32-bit and 64-bit address lengths.(unavailable)
  phyAddr	Optional, the physical address that stores JPG bitstream data, default value is 0.
  u32Length	The length of JPG bitstream data.

• Note

  • The input buffer cannot be gotten from MI_JPD_GetStreamBuf, but through the system application.

  • If the coded stream is always sent and decoded in this way, the parameter u32StreamBufSize of MI_JPD_CreateChn can be set to 0, to spare the decoding channel the effort of allocating the stream buffer.

  • The purpose of synchronous decoding is achieved through the MI_JPD_DirectBufDecode interface. Pass MI_JPD_GetStreamBuf/ MI_JPD_PutStreamBuf for asynchronous decoding process.

• Related Data Type and Interface

  MI_JPD_QueryStreamInfo

  MI_JPD_DirectBufDecode

3.11. MI_JPD_DirectOutputBuf_t

• Description

  Define output buffer structure.

• Syntax

  typedef struct MI_JPD_DirectOutputBuf_s
  {
      MI_SYS_PixelFormat_e ePixelFormat;
      MI_U32 u32Width;
      MI_U32 u32Height;
      MI_U32 u32Stride[2];
      MI_PHY phyAddr[2];
  }MI_JPD_DirectOutputBuf_t;
  

• Member

  Member	Description
  ePixelFormat	Output pixel format, please refer to the description of MI_JPD_CreateChn.
  u32Width	The actual width of output buffer.
  u32Height	The actual height of output buffer.
  u32Stride	u32Stride[0]: the stride of Y data; u32Stride[1]: the stride of UV data.
  phyAddr	phyAddr[0]: the start physical address of Y data; phyAddr[1]: the start physical address of UV data.

• Note

  • Output pixel format, Please refer to the description of MI_JPD_CreateChn.

• Related Data Type and Interface

  MI_JPD_DirectBufDecode

---

4. ERROR CODE

---

The error code is shown in the following table:

Error Code	Macro Definition	Description
0xA0202001	MI_ERR_JPD_INVALID_DEVID	Invalid Device ID.
0xA0202002	MI_ERR_JPD_INVALID_CHNID	Invalid Channel ID.
0xA0202003	MI_ERR_JPD_ILLEGAL_PARAM	Illegal parameter or inputted parameter exceeding channel decoding capability.
0xA0202004	MI_ERR_JPD_CHN_EXIST	Channel to be created already exists.
0xA0202005	MI_ERR_JPD_CHN_UNEXIST	Channel does not exist.
0xA0202006	MI_ERR_JPD_NULL_PTR	Null pointer.
0xA0202007	MI_ERR_JPD_NOT_CONFIG	Not configured before use.
0xA0202008	MI_ERR_JPD_NOT_SUPPORT	This operation or function is not supported.
0xA0202009	MI_ERR_JPD_NOT_PERM	Illegal operation
0xA020200C	MI_ERR_JPD_NOMEM	Memory allocation fails, such as insufficient memory
0xA020200D	MI_ERR_JPD_NOBUF	Buffer allocation fails, like the requested data buffer is too large
0xA020200E	MI_ERR_JPD_BUF_EMPTY	No data in buffer.
0xA020200F	MI_ERR_JPD_BUF_FULL	Buffer full.
0xA0202010	MI_ERR_JPD_SYS_NOTREADY	The system is not initialized or the dependent modules are not loaded.
0xA0202011	MI_ERR_JPD_BADADDR	Address error.
0xA0202012	MI_ERR_JPD_BUSY	System busy.
0xA0202013	MI_ERR_JPD_CHN_NOT_START	Channel not started or already stopped.
0xA0202014	MI_ERR_JPD_CHN_NOT_STOP	Channel cannot be closed before code stream reception is stopped.
0xA0202015	MI_ERR_JPD_NOT_INIT	Device is not initialized.
0xA0202016	MI_ERR_JPD_INITED	Device to be initialized is already initialized.
0xA0202017	MI_ERR_JPD_NOT_ENABLE	The channel is not enabled.
0xA0202018	MI_ERR_JPD_NOT_DISABLE	The channel is not disabled.
0xA020201C	MI_ERR_JPD_CHN_NO_CONTENT	Channel has no data.
0xA020201F	MI_ERR_JPD_FAILED	Failed.

---

5. PROCFS INTRODUCTION

---

5.1. cat

• Debug info

  #cat /proc/mi_modules/mi_jpd/mi_jpdN
  

  N represents different devices, and the values of N for different chips are as follows:

  Chip	N
  Tiramisu	0
  Muffin	0~3
  Mochi	0~1
  Opera	0
  Souffle	0
  iFackel	0
  iBopper	0
  jaguar1	0
  mhera	0~1

  Cat jpd device 0:

  # cat /proc/mi_modules/mi_jpd/mi_jpd0
  

  

• Debug info analysis

  The printing is divided into two parts, separated by Private JpdN Info. The upper half is common information, and the lower half is jpd module information. It mainly records the usage and configuration attributes of the decoding channel, which can be used to check the attribute configuration and the working status of the current channel to facilitate debugging.

• Parameter Description

  Parameter		Description
  DEV Info	DevID	Hardware device id
  	WorkingTaskCnt	The number of tasks being processed by the device
  CHN Info	ChnID	Channel ID
  	Start	Enable state: 0: Disable 1: Enable
  	DecState	Decoding state: 0: Parse header 1: Decoding 2: End of decoding
  	Width	Current decoding image width
  	Height	Current decoding image height
  	BufW	The output buffer width that needs to be allocated for the current decoding image
  	BufH	The output buffer height that needs to be allocated for the current decoding image
  	StreamBufSize	Code stream input buffer pool size, unit: byte
  	MinAllocSize	Allow the input buffer min size to be allocated successfully
  	WorkingTaskCnt	The number of tasks being processed by the channel
  	IsrDoneCnt	Isr count of done type
  	IsrOtherCnt	Isr count of other type
  	Poll	Time to run OnPollingAsyncOutputTaskConfig, unit: ms
  	Enque	Time to run EnqueueAsyncOutputTask, unit: ms
  	Isr	Time to run isr, unit: ms
  	Check	Time to run CheckOutputTaskStatus, unit: ms
  	Dequeue	Time to run DequeueOutputTask, unit: ms
  	P->E	Time from Poll to Enque, unit: ms
  	E->I	Time from Enque to Isr, unit: ms
  	I->C	Time from Isr to Check, unit: ms
  	C->D	Time from Check to Dequeue, unit: ms
  	P->D	Time from Poll to Dequeue, unit: ms
  	SmoothDecodeTime	Average decode time, unit: ms
  CHN INPUT Info	ChnID	Channel ID
  	SendCnt	The count of stream sent by App
  	LeftCnt	The count of stream left by Input buffer pool
  	SendStreamSize	Total size of stream sent by App
  	LeftStreamBytes	Total size of stream left by Input buffer pool
  	EnqueueCnt	The total number of successful executions of EnqueueAsyncOutputTask
  	DirectCnt	The number of times that MI_JPD_DirectBufDecode is called to trigger decoding
  	DropCnt	The total number of failed executions of EnqueueAsyncOutputTask
  	RewindCnt	The total number of executions of EnqueueAsyncOutputTask rewind
  	ifps	Frame rate of App input stream
  	MinIntvl	The minimum interval of APP input stream, unit: ms
  	MaxIntvl	The maximum interval of APP input stream, unit: ms
  	SumIntvl	The accumulation interval of APP input stream, unit: ms
  	AvgIntvl	The average interval of APP input stream, unit: ms
  	Diff	The current interval of the APP input stream, unit: ms
  CHN OUTPUT Info	ChnID	Channel ID
  	DecCnt	The total number of successful decoding
  	DirectCnt	The total number of successful decoding calls MI_JPD_DirectBufDecode
  	DropCnt	The total number of failed decoding
  	ofps	Output frame rate
  	MinIntvl	The minimum interval of APP output stream, unit: ms
  	MaxIntvl	The maximum interval of APP output stream, unit: ms
  	SumIntvl	The accumulation interval of APP output stream, unit: ms
  	AvgIntvl	The average interval of APP output stream, unit: ms
  	Diff	The current interval of the APP output stream, unit: ms

---

5.2. echo

Function	Dump the bitstream buffer of the specified channel to the specified path
Command	echo dumpsb [chn] [bEnable] [path] > /proc/mi_modules/mi_jpd/mi_jpd[dev]
Parameter Description	[chn]: Channel ID
	[bEnable]: 1: enable dump; 0: disable dump
	[path]: Path to save the file
	[dev]: Device ID
Example	echo dumpsb 3 1 /mnt > /proc/mi_modules/mi_jpd/mi_jpd0 Dump bitstream buffer of channel 3 to /mnt

Function	Dump the decoded output data frame of the specified channel to the specified path
Command	echo dumpfb [chn] [bEnable] [path] > /proc/mi_modules/mi_jpd/mi_jpd[dev]
Parameter Description	[chn]: Channel ID
	[bEnable]: 1: enable dump; 0: disable dump
	[path]: Path to save the file
Example	echo dumpfb 3 1 /mnt > /proc/mi_modules/mi_jpd/mi_jpd0 //Dump output data frame of channel 3 to /mnt