Compressed data structure and apparatus and method related thereto
Compressed waveform data structure is proposed which is suited for segmentation of a plurality of samples of compressed waveform data into a plurality of frames and subsequent storage of each of the frames. The number of bits per sample of the compressed waveform data is variable between the frames, but uniform, i.e. the same among all of the samples, within each of the frames. Each of the frames has a same data storage size. Each of the frames includes, in a predetermined layout, an auxiliary information area for storing auxiliary information that includes compression-related information to be used for decompressing the compressed waveform data, and a data area for storing a plurality of samples of the compressed waveform data of the frame with each of the samples comprising a same number of bits.
1. A waveform storage processing apparatus comprising:
a storage section having a storage area specified with a plurality of addresses each having a data width of n bits;
a segmentation section that segments input waveform data into a plurality of frames;
a compression section that, for each of the frames, performs a compression process on the waveform data to thereby generate compressed waveform data of m divided by bits;
an auxiliary information generation section that, for each of the frames, generates auxiliary information including compression information indicative of a form of the compression process performed on the frame;
a to-be-written data formation section that, for each of the frames, forms a predetermined number j of to-be-written data of n bits on the basis of data of m bits formed by retrieving samples of the compressed waveform data, k samples at a time, and data of n−m bits from of the auxiliary information of a next frame; and
a writing section that sequentially writes the j to-be-written data, formed for each of the frames, to the storage area specified with the predetermined number j of successive addresses of said storage section.
2. A waveform storage processing apparatus as claimed in claim 1 wherein the n−m bits data of the n bit data of one frame stored at the j successive addresses in said storage section comprises an auxiliary information area of the next frame for storing the auxiliary information and the m bit data of the n bit of one frame stored at the j successive addresses in said storage section comprises a data area of the frame for storing the compressed waveform data.
3. A waveform storage processing apparatus as claimed in claim 1 wherein the bit-number m divided by k of the compressed waveform is variable between the frames and a particular number i*k of samples of the waveform data, corresponding to the bit-number m divided by k for one frame, are segmented into the frame by said segmentation section.