hi_mpi_venc_create_chn

The Atlas 200/300/500 Inference Product does not support this API.

The Atlas Training Series Product does not support this API.

Creates an encoding channel.

The channel ID of a single device must not be greater than the maximum channel ID.
An encoding channel has the encoder attributes, RC attributes, and group of pictures (GOP) attributes.
In the encoder attributes, the stream buffer depth, stream fetching mode, and encoding profile must be set according to Table 1.
The recommended encoding sizes are 3840 x 2160 (4K), 1920 x 1080 (1080p), and 1280 x 720 (720p).
For H.264/H.265 encoding, a frame buffer consists of YHeaderSize, CHeaderSize, YSize, CSize, PmeSize, PmeInfoSize, and TmvSize. The encoder calculates the buffer allocation based on the maximum width and height by default. When configuring the channel width and height, ensure that each frame buffer calculated based on the channel width and height is within that calculated based on the maximum channel width and height.
The input/output frame rate (src_frame_rate/dst_frame_rate) in the attributes of the bit rate controller is used to allocate the bit rate (bit_rate) during encoding, but not the final display frame rate of the player. For details about how to set the display frame rate, see hi_mpi_venc_set_h264_vui or hi_mpi_venc_set_h265_vui.
You are advised to set the control frame rate to be the same as the display frame rate. Otherwise, the bit rate during playback may be different from the encoding bit rate set by the user, and the playback bit rate will vary with the configured display frame rate.

hi_s32 hi_mpi_venc_create_chn(hi_venc_chn chn, const hi_venc_chn_attr *attr)

Parameter	Input/Output	Description
chn	Input	Encoding channel ID.
attr	Input	Pointer to the encoding channel attributes.

**Table 1** Restrictions on encoder attributes
Encode Protocol	Encode Mode	Stream Buffer Allocation	Stream Fetching Mode	Encode Profile
H.264	Frame	When mini_buf_mode = 0: Buffer allocation ≥ max_pic_width x max_pic_height x 3/4 When mini_buf_mode = 1: Buffer allocation ≥ 32 x 1024 bytes	Frame/Slice	Baseline Main Profile High Profile
JPEG	Frame	When mini_buf_mode = 0: Minimum buffer allocation for the YUV420 format = Source image width 16-aligned x Source image height 16-aligned x 3/2. Minimum buffer allocation for the YUV422 Packed format = Source image width 16-aligned x Source image height 16-aligned x 2 When mini_buf_mode = 1: Buffer allocation ≥ 32 x 1024 bytes	Frame/Ecs	Baseline
H.265	Frame	When mini_buf_mode = 0: Buffer allocation ≥ max_pic_width x max_pic_height x 3/4 When mini_buf_mode = 1: Buffer allocation ≥ 32 x 1024 bytes	Frame/Slice	Main profile Main 10 Profile (not supported currently)
H.265	Frame	When mini_buf_mode = 0: Buffer allocation ≥ max_pic_width x max_pic_height x (3/4) x (5/4) When mini_buf_mode = 1: Buffer allocation ≥ 32 x 1024 bytes	Frame/Slice	Main 10 profile (not supported currently)

Parent topic: VENC/JPEGE