venc_compact_jpeg_tables

Product	Supported
Ascend 950PR/Ascend 950DT	√
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas training products	x
Atlas inference products	√
Atlas 200I/500 A2 inference products	√

Sets whether to compress Huffman and QT tables.

C Prototype

hi_s32 hi_mpi_venc_compact_jpeg_tables(hi_venc_chn chn, hi_u32 table_type, hi_bool enable)

Python Function

ret = acl.himpi.venc_compact_jpeg_tables(chn, table_type, enable)

Parameter	Description
chn	Int, encoding channel ID. Ascend 950PR/Ascend 950DT: The value range of this parameter is [0, 256). The maximum number of channels is 256 for the JPEGD function. Atlas inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256. Atlas A2 training products/Atlas A2 inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256. Among them, a maximum of 256 JPEGD decoding channels and 32 VDEC decoding channels are supported. Atlas 200I/500 A2 inference products: The value range of this parameter is [0, 128). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 128. Atlas A3 training products/Atlas A3 inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256. Among them, a maximum of 256 JPEGD decoding channels and 32 VDEC decoding channels are supported.
table_type	int, compression type. It can only be set to 0, indicating that both the Huffman table data and QT quantization table data are compressed.
enable	Int, whether to compress a file. Value 0 indicates no, and value 1 indicates yes.

Parameter

Description

chn

Int, encoding channel ID.

Ascend 950PR/Ascend 950DT: The value range of this parameter is [0, 256). The maximum number of channels is 256 for the JPEGD function.
Atlas inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256.
Atlas A2 training products/Atlas A2 inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256. Among them, a maximum of 256 JPEGD decoding channels and 32 VDEC decoding channels are supported.
Atlas 200I/500 A2 inference products: The value range of this parameter is [0, 128). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 128.
Atlas A3 training products/Atlas A3 inference products: The value range of this parameter is [0, 256). The JPEGD and VDEC functions share the same channels, and the maximum number of channels is 256. Among them, a maximum of 256 JPEGD decoding channels and 32 VDEC decoding channels are supported.

table_type

int, compression type. It can only be set to 0, indicating that both the Huffman table data and QT quantization table data are compressed.

enable

Int, whether to compress a file. Value 0 indicates no, and value 1 indicates yes.

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

This API must be called after an encoding channel is created and before the channel is destroyed.

After this API is called, compression is supported only when the Huffman or QT table has the same Y, Cb, and Cr components.

Parent topic: VENC/JPEGE APIs