I have added an enhancement to WavPack to significantly improve its performance with lossyWAV files.
At this point I don't think there's any reason to have any special block size considerations with respect to WavPack...
I had a quick test session on the matter.
Comparison with an older WavPack version (SetF, some LossyWAV 0.3.18 settings):
------- ----------------- ----------------- -----------------
| | WV 4.42a2 -hhx4 | WV 4.41.0 -hhx4 | 42a2 vs. 41 |
| ----- ----- ----- ----- ----- ----- ----- ----- -----
| | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 |
------- ----- ----- ----- ----- ----- ----- ----- ----- -----
| 512 | 407 | 401 | 399 | 453 | 444 | 442 | -46 | -43 | -43 |
| 1024 | 417 | 412 | 410 | 438 | 434 | 432 | -21 | -22 | -22 |
| 2048 | 437 | 430 | 428 | 446 | 439 | 438 | - 9 | - 9 | -10 |
| 4096 | 462 | 455 | 453 | 467 | 460 | 458 | - 5 | - 5 | - 5 |
------- ----- ----- ----- ----- ----- ----- ----- ----- -----
Comparison with FLAC (SetF, some LossyWAV 0.3.18 settings):
------- ----------------- ----------------- -----------------
| | WV 4.42a2 -hhx4 | FLAC 1.2.1 -8 | WV vs. FLAC |
| ----- ----- ----- ----- ----- ----- ----- ----- -----
| | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 |
------- ----- ----- ----- ----- ----- ----- ----- ----- -----
| 512 | 407 | 401 | 399 | 405 | 395 | 394 | + 2 | + 6 | + 5 |
| 1024 | 417 | 412 | 410 | 419 | 415 | 415 | - 2 | - 3 | - 5 |
| 2048 | 437 | 430 | 428 | 443 | 436 | 435 | - 6 | - 6 | - 7 |
| 4096 | 462 | 455 | 453 | 474 | 467 | 466 | -14 | -12 | -13 |
------- ----- ----- ----- ----- ----- ----- ----- ----- -----
Effect of using a WavPack frame size which is multiple than LossyWAV frame size, to clarify whether that may possibly improve performances (mostly when codec is not well optimized for smaller frame sizes). It seems that is not this case.
------------------- ----- ----- -----
| | 1 | 2 | 3 |
------------------- ----- ----- -----
| LW0512-WV0512 | 407 | 401 | 399 |
| LW0512-WV1024 | 418 | 411 | 409 |
| LW0512-WV2048 | 440 | 433 | 431 |
| LW0512-WV4096 | 477 | 470 | 468 |
------------------- ----- ----- -----
I would confirm that WavPack seems now safe to be used with both 1024 and 512 frame size LossyWAV files. As for compression ratio on LossyWAV files, WavPack may now be considered more or less on par with FLAC.
Gap closed, a new nice feature for WavPack, once again thanks to David for his impressive work.