Failed to Create a VENC Channel

Symptom

The return value of hi_mpi_venc_create_chn is not 0, indicating that the channel fails to be created.

Possible Cause

The possible causes of the channel creation failure are as follows:

• The input VENC channel ID is out of the valid range [0, 255], which allows only a maximum of 256 channels.
• The input channel attribute parameter is not within the valid range or the parameter is not supported.
• An existing channel is being created. For example, channel 0 is created again before it is destroyed.

Solution

Rectify the fault as follows:

• Check the error code returned when hi_mpi_venc_create_chn fails to be called.
• If the error code is 0xa0088002, the input channel ID exceeds the valid range. In this case, you need to change the channel ID to a value within the range of [0, 255].
• If the error code is 0xa0088003 or 0xa0088008, the input channel attribute parameter is not within the specified range or the parameter is set to a value that is not supported currently.

  You can further check the kernel log to determine which parameter is incorrect. As shown in the following information, the input resolution is incorrect.

  [Venc]:venc_drv_check_resolution [Line]:342 max picture width (0) err! should in [128,4096]!

  Common causes:

  1. The input parameter structures are not initialized using memset. As a result, some parameters use random values if they are not set.
  2. The header file does not match the API. As a result, the input enumeration type does not meet the expectation.
  3. For details about the supported range of each parameter, see the media data processing API description in the Application Development (C&C++).
• If the error code is 0xa0088004, an existing channel is being created. For example, channel 0 is created again before it is destroyed.

  [Venc]:venc_create_chn [Line]:2449 device:0 chnl:0 had been created! 

  In this case, check the code logics: (1) Check whether a channel is destroyed after being created. (2) Whether the same channel ID is used repeatedly to create channels.