Abstract:
Personal blind sound quality comparison of AAC-LC and xHE-AAC.
The targeted bitrate was 96kbps and 128kbps.
Encoders:
The latest versions as of 2020 August were used.
ffmpeg version N-98640-gfa7ad81dab Copyright (c) 2000-2020 the FFmpeg developers built with gcc 9.2.0 (Rev2, Built by MSYS2 project) FFmpeg's native AAC encoder (-c:a aac)
Freeware Advanced Audio Coder FAAC 1.30
FDK-AAC 2.0.1 (-c:a libfdk_aac)
exhale - ecodis extended high-efficiency and low-complexity encoder version 1.0.6 (x64, built on Jul 28 2020)
Settings:
FFmpeg's native AAC encoder, FAAC 1.30, and FDK-AAC 2.0.1 were used as the AAC-LC encoder.
exhale 1.0.6 was used as the xHE-AAC encoder.
ffmpeg98640 -i in.wav -c:a aac -b:a 96k out.mp4
faac-1.30 -b 96 in.wav -o out.mp4 --overwrite
ffmpeg98640 -i in.wav -c:a libfdk_aac -b:a 96k out.mp4
exhaleApp106 3 in.wav out.mp4
ffmpeg98640 -i in.wav -c:a aac -b:a 128k out.mp4
faac-1.30 -b 128 in.wav -o out.mp4 --overwrite
ffmpeg98640 -i in.wav -c:a libfdk_aac -b:a 128k out.mp4
exhaleApp106 5 in.wav out.mp4
Samples:
15 sound samples from Kamedo2's samples.
12 sound samples from IgorC's samples.
Total 27 sound samples.
Hardwares:
Sony PSP-3000 + RP-HT560.
Results:
Conclusions & Observations:
For 128kbps, exhale and fdk-aac were the winner, and the new FAAC 1.30 won the second place. There were no big difference between the FDK-AAC, one of the best AAC encoder, and the xHE-AAC encoder at 128kbps.
For 96kbps, the xHE-AAC encoder exhale won the decisive victory. For the AAC-LC encoders, the FDK-AAC seems to be the best.
The exhale at 96kbps has the comparable fidelity to the FDK-AAC encoder at 128kbps.
Anova analysis:
FRIEDMAN version 1.24 (Jan 17, 2002) http://ff123.net/
Blocked ANOVA analysis
Number of listeners: 27
Critical significance: 0.05
Significance of data: 1.11E-016 (highly significant)
---------------------------------------------------------------
ANOVA Table for Randomized Block Designs Using Ratings
Source of Degrees Sum of Mean
variation of Freedom squares Square F p
Total 215 91.28
Testers (blocks) 26 19.78
Codecs eval'd 7 51.18 7.31 65.51 1.11E-016
Error 182 20.31 0.11
---------------------------------------------------------------
Fisher's protected LSD for ANOVA: 0.179
Means:
exh128 fdk128 exh096 faa128 fdk096 ffm128 faa096 ffm096
4.39 4.27 4.15 3.76 3.49 3.44 3.20 2.97
---------------------------- p-value Matrix ---------------------------
fdk128 exh096 faa128 fdk096 ffm128 faa096 ffm096
exh128 0.208 0.011* 0.000* 0.000* 0.000* 0.000* 0.000*
fdk128 0.194 0.000* 0.000* 0.000* 0.000* 0.000*
exh096 0.000* 0.000* 0.000* 0.000* 0.000*
faa128 0.004* 0.001* 0.000* 0.000*
fdk096 0.597 0.002* 0.000*
ffm128 0.009* 0.000*
faa096 0.012*
-----------------------------------------------------------------------
exh128 is better than exh096, faa128, fdk096, ffm128, faa096, ffm096
fdk128 is better than faa128, fdk096, ffm128, faa096, ffm096
exh096 is better than faa128, fdk096, ffm128, faa096, ffm096
faa128 is better than fdk096, ffm128, faa096, ffm096
fdk096 is better than faa096, ffm096
ffm128 is better than faa096, ffm096
faa096 is better than ffm096
Raw data:
FFmpeg's native FAAC FDK-AAC exhale FFmpeg's native FAAC FDK-AAC exhale
1.700 3.300 3.100 4.100 2.500 3.700 4.400 4.200
3.300 4.200 3.600 4.300 3.800 4.400 4.500 4.500
3.300 3.500 3.900 4.000 3.700 3.800 4.100 4.300
2.800 3.800 3.600 4.400 3.400 4.200 4.500 4.600
2.900 3.600 3.900 4.300 3.200 4.000 4.400 4.500
3.600 2.800 3.800 4.200 3.700 3.400 4.100 4.400
3.800 4.300 4.600 5.000 4.000 4.500 5.000 4.800
2.800 3.600 3.400 4.200 3.900 4.100 4.400 4.300
3.000 2.600 3.600 4.300 3.400 2.800 3.900 4.600
2.600 2.900 2.600 4.400 3.700 3.900 4.700 4.500
3.000 3.200 3.400 4.100 3.500 3.800 4.200 4.400
2.900 2.900 3.500 4.200 3.200 3.300 3.700 4.400
3.300 3.800 2.800 4.200 3.600 4.100 4.600 4.400
2.400 2.700 2.800 4.100 2.800 3.800 4.400 4.600
2.900 2.600 3.200 4.200 3.400 3.900 4.400 4.600
2.500 2.700 3.900 4.100 3.400 3.500 4.300 4.500
3.400 3.100 2.900 3.500 3.900 3.700 3.500 3.800
2.900 2.900 3.500 3.700 3.200 3.400 3.900 4.100
3.300 3.400 3.500 3.900 3.700 3.800 4.200 4.100
3.100 2.700 3.400 3.800 3.500 3.600 3.900 4.000
1.800 2.400 3.300 4.300 2.100 2.700 4.600 4.500
2.600 2.800 2.900 3.700 3.500 3.400 3.600 4.000
2.400 3.400 2.800 4.100 2.600 3.800 4.300 4.200
3.300 3.400 3.800 4.200 3.500 4.000 4.300 4.500
3.400 2.800 4.100 4.000 3.700 3.600 4.300 4.200
4.300 3.900 4.400 4.700 4.500 4.600 4.800 5.000
2.900 3.100 3.900 4.100 3.500 3.600 4.300 4.400
%samples 10xh_
%samples 11ff_
%samples 12at_
%samples 13by_
%samples 14fe_
%samples 15ma_
%samples 16mb_
%samples 17qu_
%samples 18vr_
%samples 19am_
%samples 20tt_
%samples 21wa_
%samples 22ex_
%samples 23ht_
%samples 24td_
%samples 01 castanets
%samples 02 fatboy_30sec
%samples 03 eig
%samples 04 Bachpsichord
%samples 05 Enola
%samples 06 trumpet
%samples 07 applaud
%samples 08 velvet
%samples 09 Linchpin
%samples 10 spill_the_blood
%samples 11 female_speech
%samples 12 French_Ad
%feature 6 96kbps 96kbps 96kbps 96kbps 128kbps 128kbps 128kbps 128kbps
%feature 7 AAC-LC AAC-LC AAC-LC xHE-AAC AAC-LC AAC-LC AAC-LC xHE-AAC
%feature 10 N-98640-gfa7ad81dab 1.30 2.0.1 1.0.6 N-98640-gfa7ad81dab 1.30 2.0.1 1.0.6
%feature 11 -c:a aac -b:a 96k -b 96 -c:a libfdk_aac -b:a 96k 3 -c:a aac -b:a 128k -b 128 -c:a libfdk_aac -b:a 128k 5
Bitrates:
%bitrate
ffm096 faa096 fdk096 exh096 ffm128 faa128 fdk128 exh128
98887 112366 97944 115669 131300 146159 129968 151578
98089 99166 97972 101497 130156 132743 130006 118268
98317 102915 98310 112582 130406 136782 130331 146921
98880 103008 98044 105946 131505 137363 130070 138027
98760 104367 98258 109011 130850 137397 130286 133642
98371 97415 98299 106918 130380 132568 130251 138900
98162 97374 98197 95103 130263 135925 130207 125482
98902 106935 97994 110720 131438 139649 129992 142797
99341 101023 99033 117131 131681 135181 131148 153120
98335 102025 98054 105617 130566 135417 130069 131421
98400 104228 97892 103077 130585 139330 129885 137104
98586 102282 98154 110226 130663 135832 130192 151458
98641 105235 98209 103057 130729 140772 130259 128035
98472 100875 98031 101595 130587 136719 130079 136095
97446 111618 98275 104741 129510 147383 130266 124974
100070 107761 99731 106715 133441 142437 131521 147149
98875 107698 97963 120819 131554 141888 129977 156670
98749 106207 98595 114971 131020 141940 130594 153683
98237 96608 98050 119109 130353 129754 130103 140047
98314 101868 98008 105957 130699 136644 130033 130707
99036 103395 99159 104689 131379 137940 131131 132266
99131 106791 99530 111672 131710 142118 131535 150644
103807 134514 98879 110170 142352 167044 130892 144596
99408 103523 98667 95729 130416 136598 130691 125506
98099 97316 97923 107519 130184 133041 129971 139827
98743 110765 98272 90216 131200 144657 130265 125079
98804 107369 98633 103539 131261 138269 130605 130585
%album bitrate
96458 99957 97435 99120 127797 133819 129435 128732