• Claudio Freire's avatar
    avcodec/aacpsy: Fix AAC Psy PE reduction calculation when multiple iterations are required · 84f4be42
    Claudio Freire authored
    This is a small change, but it does have a big impact on bit allocation.
    
    all the regressions marked in the report have no audible
    difference (I didn't check them all though), but the improvements can
    be heard.
    
    This affects mostly high bit rates. It's related to issue #2686.
    
    In the report, A is the patched version, B is unpatched, all
    comparisons show deltas in the form (A-B), so a positive pSNR delta
    means a better quality in the patched version, and negative a
    regression. Regressions are only considered for pSNR deltas below
    -1db, they're considered serious below -6db.
    
    All measurements were done with tiny_psnr.
    
    The summary of the report inline for quick reading:
    
    Files: 58
    Bitrates: 6
    Tests: 347
    Serious Regressions: 0 (0%)
    Regressions: 10 (2%)
    Improvements: 54 (15%)
    Big improvements: 26 (7%)
    Worst regression - sine_tester.flac - 384k
      - StdDev: 1.68        pSNR: -3.05     maxdiff: -178.00
    Best improvement - 07 - Bound.flac - 384k
      - StdDev: -1700.05    pSNR: 20.64     maxdiff: -29595.00
    Average          - StdDev: -55.67       pSNR: 1.20      maxdiff: -1593.00
    Signed-off-by: 's avatarMichael Niedermayer <michaelni@gmx.at>
    84f4be42
aacpsy.c 36.3 KB