Ultrafast 2x lossy audio/image compression algorithm?

I'm looking for an audio or image compression algorithm that can compress a torrent of 16-bit samples

• by a fairly predictable amount (2-3x)
• at very high speed (say, 60 cycles per sample at most: >100MB/s)
• with lossiness being acceptable but, of course, undesirable

My data has characteristics of images and audio (2-dimensional, correlated in both dimensions and audiolike in one dimension) so algorithms for audio or images might both be appropriate.

An obvious thing to try would be this one-dimensional algorithm:

• break up the data into segments of 64 samples
• measure the range of values among those samples (as an example, the samples might be between 3101 and 9779 in one segment, a difference of 6678)
• use 2 to 4 additional bytes to encode the range
• linearly downsample each 16-bit sample to 8 bits in that segment.

For example, I could store 3101 in 16 bits, and store a scaling factor ceil(6678/256) = 27 in 8 bits, then convert each 16-bit sample to 8-bit as s8 = (s16 - base) / scale where base = 3101 + 27>>1, scale = 27, with the obvious decompression "algorithm" of s16 = s8 * 27 + 3101.) Compression ratio: 128/67 = 1.91.

I've played with some ideas to avoid the division operation, but hasn't someone by now invented a superfast algorithm that could preserve fidelity better than this one?

Note: this page says that FLAC compresses at 22 million samples per second (44MB/s) at -q6 which is pretty darn good (assuming its implementation is still single-threaded), if not quite enough for my application. Another page says FLAC has similar performance (40MB/s on a 3.4GHz i3-3240, -q5) as 3 other codecs, depending on quality level.

The QOA format is the only thing I've found that provides predictable compression: lossy, 3.2 bits per sample ― 5x compression.

QOI by the same author is lossless but is not meant for 16-bit samples, and could increase data size by up to 25% if the data is incompressible. But I find the format inspiring ― one could potentially design something that incorporates elements of QOA and QOI to tailor a compression algorithm for one's use case.