Video encoding method, video decoding method, and apparatus

A video decoding method, comprising:

• receiving a first standard dynamic range (SDR) bitstream, wherein the first SDR bitstream comprises preset data, and the preset data is obtained by encoding a correspondence and a target residual value;
• mapping reconstructed data of the first SDR bitstream to second high dynamic range (HDR) data based on the correspondence;
• and
• determining first HDR data based on the target residual value and the second HDR data;
• wherein the preset data further comprises a residual mapping manner and a clamping manner, wherein the residual mapping manner and the clamping manner indicates how the target residual value is determined.

A video encoding apparatus, comprising:

• a processor;
• and
• a nonvolatile memory coupled to the processor, wherein the processor invokes program code stored in the memory to:
• obtain source data, wherein the source data comprises first high dynamic range (HDR) data and a first standard dynamic range (SDR) bitstream for same video data;
• map reconstructed data of the first SDR bitstream to second HDR data based on a correspondence between the reconstructed data of the first SDR bitstream and the first HDR data;
• determine a target residual value between the second HDR data and the first HDR data, wherein a bit width of the target residual value is less than or equal to a first bit width, and the first bit width is a data bit width for encoding a first SDR video into the first SDR bitstream;
• encode the correspondence and the target residual value, to determine preset data;
• and
• transmit the first SDR bitstream to which the preset data is added;
• wherein the preset data further comprises a residual mapping manner and a clamping manner, wherein the residual mapping manner and the clamping manner indicates how the target residual value is determined.

A video decoding apparatus, comprising:

• a processor;
• and
• a nonvolatile memory coupled to the processor, wherein the processor invokes program code stored in the memory to:
• receive a first standard dynamic range (SDR) bitstream, wherein the first SDR bitstream comprises preset data, and the preset data is obtained by encoding a correspondence and a target residual value;
• map reconstructed data of the first SDR bitstream to second high dynamic range (HDR) data based on the correspondence;
• and
• determine first HDR data based on the target residual value and the second HDR data;
• wherein the preset data further comprises a residual mapping manner and a clamping manner, wherein the residual mapping manner and the clamping manner indicates how the target residual value is determined.