venc_set_cu_pred

Applicability

Product	Supported (√/x)
Atlas A3 training products/Atlas A3 inference products	x
Atlas A2 training products/Atlas A2 inference products	x
Atlas training products	x
Atlas inference products	√
Atlas 200I/500 A2 inference products	√

Function Usage

Adjusts the tendency of selecting the CU/MB mode of a channel and supports the tendency adjustment of the inter/intra-frame prediction and encoding block size.

In the encoding protocol, pixel blocks are used as basic processing units, such as the coding units (CUs) in H.265 and macroblocks (MBs) in H.264. The CU mode in this API refers to the selection of pixel blocks of different sizes in inter/intra-frame prediction mode.

Prototype

C Prototype

hi_s32 hi_mpi_venc_set_cu_pred(hi_venc_chn chn, const hi_venc_cu_prediction *cu_pred)

Python Function

ret = acl.himpi.venc_set_cu_pred(chn, cu_pred)

Parameter Description

Parameter	Description
chn	Int, encoding channel ID. Atlas inference products: The value range of the encoding channel ID is [0, 256). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 256. Atlas 200I/500 A2 inference products: The value range of the encoding channel ID is [0, 128). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 128.
cu_pred	Dict, dictionary of the tendency to use the CU mode. For details, see hi_venc_cu_prediction. The dictionary contains the following parameters: pred_mode: Sets the tendency configuration mode. The auto and manual modes are supported. In auto mode, the driver internally performs the tendency configuration. In manual mode, you can define the tendency configuration based on the actual scenario. intra32_cost/intra16_cost/intra8_cost/intra4_cost/inter64_cost/inter32_cost/inter16_cost/inter8_cost: sets each of their tendency values based on each mode. The default value of each parameter is 8, that is, no tendency is configured. The larger the value, the weaker the tendency to use the mode.

Parameter

Description

chn

Int, encoding channel ID.

Atlas inference products: The value range of the encoding channel ID is [0, 256). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 256.
Atlas 200I/500 A2 inference products: The value range of the encoding channel ID is [0, 128). The JPEGE and VENC functions share the same channels, and the maximum number of channels is 128.

cu_pred

Dict, dictionary of the tendency to use the CU mode. For details, see hi_venc_cu_prediction.

The dictionary contains the following parameters:

pred_mode: Sets the tendency configuration mode. The auto and manual modes are supported. In auto mode, the driver internally performs the tendency configuration. In manual mode, you can define the tendency configuration based on the actual scenario.
intra32_cost/intra16_cost/intra8_cost/intra4_cost/inter64_cost/inter32_cost/inter16_cost/inter8_cost: sets each of their tendency values based on each mode. The default value of each parameter is 8, that is, no tendency is configured. The larger the value, the weaker the tendency to use the mode.

Return Value Description

Return Value	Description
ret	Int, error code. 0: success. Other values: failures. For details, see VENC/JPEGE Return Codes.

Restrictions

Only H.264/H.265 encoding channels support this API.
It is recommended that this API be called after a channel is created and before encoding is started, to reduce the number of the API calls during encoding. If this API is called during encoding, the configuration takes effect when the next frame is encoded.
Before calling this API, you are advised to call acl.himpi.venc_get_cu_pred to obtain the tendency configuration of the CU mode.

Note that specific modes are disabled in some scenarios. For example, when the maximum MB size is 16 x 16 in H.264, inter16_cost is included in the baseline and main profile, or inter8_cost is included in the high profile, they do not take effect, even if you have set the tendency parameter.

Parent topic: VENC/JPEGE APIs