函数 av_packet_side_data_new 

pub unsafe extern "C" fn av_packet_side_data_new(
    psd: *mut *mut AVPacketSideData,
    pnb_sd: *mut c_int,
    type_: AVPacketSideDataType,
    size: usize,
    flags: c_int,
) -> *mut AVPacketSideData

Allocate a new packet side data.

@param sd pointer to an array of side data to which the side data should be added. *sd may be NULL, in which case the array will be initialized. @param nb_sd pointer to an integer containing the number of entries in the array. The integer value will be increased by 1 on success. @param type side data type @param size desired side data size @param flags currently unused. Must be zero

@return pointer to freshly allocated side data on success, or NULL otherwise.