Contents
Introduction

3

1 CD-audio test
4
1.1 CD’s used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Results all CD’s together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Interesting quirks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.1 Mono encoded as stereo (Dan Browns Angels and Demons) . . . . . . . . 7
1.3.2 Compressibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4 Convergence of the results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2 High-resolution audio
2.1 Nine Inch Nails’ The Slip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Howard Shore’s soundtrack for The Lord of the Rings: The Return of the King .
2.3 Wasted bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13
13
16
18

3 Multichannel audio
20
3.1 Howard Shore’s soundtrack for The Lord of the Rings: The Return of the King . 20
A Motivation for choosing these CDs

23

B Test setup
B.1 Scripting and graphing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2 Codecs and parameters used . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.3 MD5 checksumming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27
27
27
28

C Revision history

30

Bibliography

312Introduction
While testing the efficiency of lossy codecs can be quite cumbersome (as results differ foreach person), comparing lossless codecs is much easier. As the last well documented andcomprehensive test available on the internet has been a few years ago, I thought it would be agood idea to update.
Beside comparing with CD-audio (which is often done to assess codec performance) and spittingout a grand total, this comparison also looks at extremes that occurred during the test andtakes a look at ’high-resolution audio’ and multichannel/surround audio.
While the comparison was made to update the comparison-page on the FLAC website, it aims
to be fair and unbiased. Because of this, you’ll probably won’t find anything that looks like aconclusion: test results are displayed and analysed, but there is no judgement or choice made.
As different people have different demands, there is probably no codec that is ’the best’ foreveryone anyway.
It is important to understand that nothing in this document is set in stone, codecs are still being
tweaked and big surprises are still very well possible, see for example the still recent move ofApple to make ALAC open-source. Besides that, the test material is, while being quite diverse,
currently limited to 43 CDs for the CD-audio test, 2 sources for the high-resolution audio test
and 1 source for the multichannel test. Because of this, the results should be used with care.
Furthermore, this comparison is ”only about numbers”, comparing speed to compression. Other
important stuff, like software/hardware support and development activity are not mentioned
at all. For more information on these features, I would like to recommend the HydrogenAudio
comparison of lossless codecs [5] and the codec comparison on FLAC’s homepage [4].

3Chapter 1
CD-audio test
The most important use of lossless codecs nowadays is compressing CD-audio. Because ofthis, most of this report focuses on CD-audio. First, the performance of all codecs on thewhole corpus will be examined. Next, some CDs will be examined separately to comment on
particular quirks and weak points of certain codecs.

1.1

CD’s used

The CD’s used in this test are listed in table A.1 on page 24, because the list became too long toinclude here. Besides the title of the disc, there is a very general indication of the kind of music
it is, should represent or what special significance it has, in case the performer is unfamiliar toyou. These CD’s should encompass a wide range of music and therefore give balanced results,
with the weak spots of each codec exposed equally. For more information, see appendix A.
Quite some effort was put into choosing and balancing the list of CDs, with a lot of help from[3]. In particular, Tom Beck, developer of the TAK codec, pointed out that mastering canmake a real difference in codec performance, and therefore the test should encompass as muchdifferent ’mastering techniques as possible’.

1.2

Results all CD’s together

The results following are from all the CDs mentioned above averaged. This was done byaveraging the CD results, not those of the individual tracks. This is done because otherwise
CDs with more tracks would influence the results more than CDs with only a few tracks.

4Compression (% of WAV-size)

Encoding CPU speed vs compression
for All tracks
63
62
61
60
59
58
57
56
55
54
53

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

(a) Displayed the usual way

Compression (% of WAV-size)

Encoding CPU-usage vs compression
for All tracks
63
62
61
60
59
58
57
56
55
54
53
0.1%

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

0.2%

0.5%

1%
2%
5%
10%
CPU-usage (% of 1 core)

20%

50%

(b) Displayed as realtime CPU-usage

Figure 1.1: Encoding codec performance of all CD’s averaged

5Compression (% of WAV-size)

Decoding CPU speed vs compression
for All tracks
63
62
61
60
59
58
57
56
55
54
53

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

0

100

200
300
400
500
Decoding speed (times realtime)

600

700

(a) Displayed the usual way

Compression (% of WAV-size)

Decoding CPU-usage vs compression
for All tracks
63
62
61
60
59
58
57
56
55
54
53
0.1%

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

0.2%

0.5%

1%
2%
5%
10%
CPU-usage (% of 1 core)

20%

50%

(b) Displayed as realtime CPU-usage

Figure 1.2: Decoding codec performance of all CD’s averaged

6

1.3

Interesting quirks

While testing different CD’s to obtain a balanced total, the results of the individual CD’s wereplotted as well to look for certain peculiarities, both to report and to assess the validity of thetest. If the results of most CD’s look similar and any strange behaviour is explainable, one
could say the test is more or less valid because it converges. Apart from ALAC –fast, FLAC
setting -0 and -3 and Shorten fluctuating a lot (because of lacking stereo decorrelation), there
was only one case in which non-standard behaviour was observed, which will be discussed next.
Furthermore, some observations will be discussed.

1.3.1

Mono encoded as stereo (Dan Browns Angels and Demons)

The biggest difference with the all-round test is the audio book. The tested material contains
a lot of silence, is pure mono (encoded as stereo as CDs don’t have a mono-mode) and features
only one voice. The encoding and decoding performance is displayed in figure 1.3.
Encoding CPU speed vs compression
for Dan Brown - Angels and Demons Disc 3
Compression (% of WAV-size)

45

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

40
35
30
25
20
15
0

100

200
300
400
Encoding speed (times realtime)

500

600

Decoding CPU speed vs compression
for Dan Brown - Angels and Demons Disc 3
Compression (% of WAV-size)

45

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

40
35
30
25
20
15
0

200

400
600
800
Decoding speed (times realtime)

1000

1200

Figure 1.3: Codec performance for the audiobook Angels & Demons

7The most obvious features are the behaviour of FLAC, ALAC and the bad performance of
WavPack, Shorten and LA. FLAC’s behaviour is because at modes -0 and -3 (which are thetwo peaks visible) no stereo decorrelation is done. All other modes have some form of stereo
decorrelation, which obviously helps as this is pure mono: it halves the size of the files here.
This is probably also true for refalac’s –fast mode. WavPacks bad performance is a known’bug’. Newer encoders have an option –optimize-mono, but it has to be set manually as it
might break compatibility with older decoders. Shorten has no stereo decorrelation at all andLA seems to suffer from the same bug as WavPack does.
When looking for best compression, OptimFROG has a very small lead. Its –bestnew mode
has the best compression (17.727%) while Monkey’s Audio -c4000 (extra high) compresses only
little less (17.733%). It is strange, but Monkey’s Audio insane mode (which is slower thanthe extra high mode) gets only 18.0%. TAK and FLAC both perform very well considering
their speed. A last remark is that LZMA2 (7-zip’s compression mode), while not displayed in
the graph, does very well considering it is not an audio codec, it scores 30% compression andoutperforms ALAC fast, FLAC -0, -3 and Shorten here.
Encoding CPU speed vs compression
for Angels and Demons monoCompression (% of WAV-size)

41

FLAC 1.3.0
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0-beta
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.19)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

40
39
38
37
36
35
0

100

200

300
400
500
600
700
Encoding speed (times realtime)

800

900

Decoding CPU speed vs compression
for Angels and Demons monoCompression (% of WAV-size)

41

FLAC 1.3.0
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0-beta
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.19)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

40
39
38
37
36
35
0

100

200

300 400 500 600 700
Decoding speed (times realtime)

800

900

1000

Figure 1.4: Codec performance for the audiobook mixed to mono
To find out which part of the performance of the codecs was due to the file being mono and8which was due to the file containing lots of silence and only one voice, I decided to rerun thetest with the files mixed to mono. This mono mixing was done with SoX using ”remix 1” as afilter. So no mixing, I just took the first (left) channel to form the mono-channel.
The results are displayed in figure 1.4 on the preceding page. The results for this test are
more like the overall result, with the performance of LA and WavPack back on par and shorten(which seems to have no stereo decorrelation at all) benefits the most. The strange behaviourof Monkey’s Audio stays, however. The most striking difference between the stereo original
and the mono mix is that FLAC and the lower TAK and WavPack levels have halved theirencoding time: apparently, stereo decorrelation takes a lot of time. In FLAC, stereo correlation
is more or less ’brute-force’, so that fits the picture very well.

1.3.2

Compressibility

While the results of these tests show that codecs perform similar on very different material (inother words, no codec is very good at a certain kind of music while not at others), some kinds ofmusic seem to have more room for ’improvement’. For example, when looking at Yann Tiersen- Le Fabuleux Destin d’Amélie Poulain (see figure 1.5), OptimFROG bestnew preset delivers afile 9.3% smaller than its fast preset. Likewise Monkey’s Audio gets a 8.8% smaller file whencomparing the fast with the insane preset and TAK improves 9.8%. However, when looking at
System of a Down - Mezmerize (see figure 1.6), OptimFROG gets 2.5% extra out, Monkey’s
audio 2.6% and TAK 3.9%.
Encoding CPU speed vs compression
for Yann Tiersen - Le Fabuleux Destin dAmÃ©lie Poulain

Compression (% of WAV-size)

58

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

56
54
52
50
48
46
44

0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

Figure 1.5: Compression versus encoding speed for Le Fabuleux Destin d’Amélie Poulain
So it seems the ’law of diminishing returns’ is different for each CD, but it seems to match
well between different codecs. It is easily seen in the graphs, as the y-axis for the Mezmerize
album run from 67% to 78% of the original file size, a difference of 14%, while for the otherCD this is a difference of 24%. For most CDs the difference wasn’t this large or small (thesewere two carefully selected extremes) but it is related to music genre: metal has usually lessimprovement while quiet, clean music has large improvements.
This difference might be explained by instrumentation. In metal music, the sound is usuallysaturated with overdriven guitars and is usually percussion-heavy. The extensive use of cymbals

9Encoding CPU speed vs compression
for System of a Down - MezmerizeCompression (% of WAV-size)

78

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

76
74
72
70
68
0

50

100
150
200
250
300
Encoding speed (times realtime)

350

400

Figure 1.6: Compression versus encoding speed for Mezmerize
for example, might influence the compressibility, as the sound of a cymbal is usually characterized as ’colored noise’. As is known, codecs perform very bad on noise-like input, becauseof the high entropy. As lossless codecs try to find correlation in the input as much as possible,
one might conclude that this kind of music (with very present noise-like sound like cymbals)
has little input to filter and a lot of residual to store. The codecs can’t find more correlation
as more resources (CPU, RAM etc.) are allocated to compress.
The music from Le Fabuleux Destin d’Amélie Poulain is characterized by simple instrumentation, usually solo or small ensembles. This is more easily compressed (because there is lessnoise-like content) but there are more ’similarities’ to find and filter too, so besides getting
smaller files with all codecs, compression benefits more from deeper searches.
So, when looking at the averaged results, one should take into account that different kindsof music can bring quite different results. While it seems codecs take roughly the same spot
in whatever ranking you might make with different CDs, the improvements between bettercompressing codecs and slower presets might be different on different kinds of music. If you
want to look at this feature in detail, I’d suggest you take a look at the raw results that should
accompany this report.

1.4

Convergence of the results

One of the most important questions regarding any results of this test would be whether the
results are truly ’average’ and whether they represent all different kinds of CD-audio out there.
As pointed out in section 1.3, this is not the case: some codecs perform better than usual atcertain CD’s. However, most results seem fairly similar while being obtained from very different
material.
From comparing results and trying to draw conclusions on the convergence of the results, one
can observe differences regarding the reliability of certain codecs. For example, when one takes
a look at figure 1.3 on page 7, certain codecs (FLAC -3 and Monkeys Audio -insane) generatelarger files while being slower: choosing a higher ’mode’ will not always result in better results.
In figure 1.7 on page 12 the encoding and decoding performance of all codecs are graphed for
10

four very different kinds of music: a capella choral, metal, soul and jazz. While the averagecompression achieved and speed differs, codecs all perform similar for different kinds of music:
LA and OptimFROG take turns in achieving the best compression while both being pretty
slow, FLAC is always the fastest decoding, Shorten performs at FLAC -0 but slower, Monkey’s
Audio ranges from OptimFROGs –best to WavPacks default setting (but being slower then thelatter), TAK is almost always the best performer when trading off compression to encoding
speed etc.
The ’typical’ position of each codec works for very different kinds of music and is never muchbetter or worse when compared to the average of all CD’s, except perhaps FLAC -0 through
FLAC -3 and Shorten.

11

Encoding CPU speed vs compression
for Confido Domino Minsk - Sacred choral music from White Russia

Decoding CPU speed vs compression
for Confido Domino Minsk - Sacred choral music from White Russia
45

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

44
43
42
41

Compression (% of WAV-size)

Compression (% of WAV-size)

45

40
39

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

44
43
42
41
40
39

0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

0

100

200
300
400
500
600
Decoding speed (times realtime)(a) Encoding choral music

Decoding CPU speed vs compression
for Metallica - Death Magnetic

80
78
76
74
72

Compression (% of WAV-size)

Compression (% of WAV-size)

82

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

70
68

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

80
78
76
74
72
70
68

0

50

100
150
200
250
300
Encoding speed (times realtime)

350

400

0

100

(c) Encoding metal

200
300
400
Decoding speed (times realtime)

500

600

(d) Decoding metal

Encoding CPU speed vs compression
for Joss Stone - Mind Body Soul

Decoding CPU speed vs compression
for Joss Stone - Mind Body Soul

70

70

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

68
66
64
62
60

Compression (% of WAV-size)

Compression (% of WAV-size)

800(b) Decoding choral music

Encoding CPU speed vs compression
for Metallica - Death Magnetic
82

58
56

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

68
66
64
62
60
58
56

0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

0

100

(e) Encoding soul

200
300
400
Decoding speed (times realtime)

500

600

(f) Decoding soul

Encoding CPU speed vs compression
for John Coltrane Live at the half note vol 1

Decoding CPU speed vs compression
for John Coltrane Live at the half note vol 1

58

58

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

56
54
52
50
48
46

Compression (% of WAV-size)

Compression (% of WAV-size)

700

44
42

FLAC 1.3.1
TAK 2.3.0
LA 0.4b
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
Shorten 3.6.1
MP4 ALS RM23
WMA Lossless v12.0

56
54
52
50
48
46
44
42

0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

0

(g) Encoding jazz

100

200
300
400
500
Decoding speed (times realtime)

600(h) Decoding jazz

Figure 1.7: Codec performance for various music genres

12

700

Chapter 2
High-resolution audio
While the use for ’high resolution’ (i.e. a high sample rate or high bit depth) is open to
discussion, lossless codecs are used to pack this kind of material, so it should be tested as well.
Two codecs do not participate in this test: both LA and Shorten do not handle these sample
rates/bit depths at all.

2.1

Nine Inch Nails’ The Slip

The Slip was made available free of charge from the website of NIN, releasing both 44kHz/16-bit
FLAC-files as well as 96kHz/24-bit files.
The results are shown in figure 2.1 and 2.2. Nothing spectacular: all codecs perform similar
when compared to the CD-audio, only FLAC seems to perform worse, being much slower thenusual in both encoding and decoding and compressing a little less. Monkey’s Audio -insane (or-c5000) preset misbehaves here, just like with the Dan Brown audiobook test and the next testin this chapter, it is slower and compresses less then -c4000.

13

Encoding CPU speed vs compression
for Nine Inch Nails - The Slip - 44-16
Compression (% of WAV-size)

69

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

68
67
66
65
64
63
62
61
60
0

50

100
150
200
250
300
Encoding speed (times realtime)

350

400

(a) Sample with 44/16

Encoding CPU speed vs compression
for Nine Inch Nails - The Slip - 96-24
Compression (% of WAV-size)

72

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

71
70
69
68
67
66
65
0

20

40

60
80
100
120
140
Encoding speed (times realtime)

160(b) Sample with 96/24

Figure 2.1: Encoding performance

14

180

Decoding CPU speed vs compression
for Nine Inch Nails - The Slip - 44-16
Compression (% of WAV-size)

69

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

68
67
66
65
64
63
62
61
60
0

50

100

150 200 250 300 350
Decoding speed (times realtime)

400

450

500

(a) Sample with 44/16

Decoding CPU speed vs compression
for Nine Inch Nails - The Slip - 96-24
Compression (% of WAV-size)

72

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

71
70
69
68
67
66
65
0

20

40

60
80
100
120
Decoding speed (times realtime)

140(b) Sample with 96/24

Figure 2.2: Decoding performance

15

160

2.2

Howard Shore’s soundtrack for The Lord of the Rings:
The Return of the KingThe complete recordings of the soundtrack for The Return of the King features an DVD-A
along with the 4 audio CDs. This disc was used in the following test. While I first tried
another DVD-A from the same trilogy, this disc had some features that made it unsuitable forthis comparison, see section 2.3 on the matter. The results are shown in figure 2.3 and 2.4.
The results are very similar to those obtained with NIN’s The Slip in section 2.1. Interesting tonote it that the differences between different codecs and compression modes are even smaller,
similar to the discussion in section 1.3.2, moving to 24-bit adds a lot of incompressible noise to
the input.
Encoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 44-16
Compression (% of WAV-size)

48

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

47
46
45
44
43
42
41
40
39
0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

(a) Sample with 44/16

Compression (% of WAV-size)

Encoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 48-24
62.5
62.0
61.5
61.0
60.5
60.0
59.5
59.0
58.5
58.0
57.5

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

0

50

100
150
200
250
Encoding speed (times realtime)

300(b) Sample with 48/24

Figure 2.3: Encoding performance

16

350

Decoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 44-16
Compression (% of WAV-size)

48

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

47
46
45
44
43
42
41
40
39
0

100

200
300
400
Decoding speed (times realtime)

500

600

(a) Sample with 44/16

Compression (% of WAV-size)

Decoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 48-24
62.5
62.0
61.5
61.0
60.5
60.0
59.5
59.0
58.5
58.0
57.5

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

0

50

100
150
200
250
300
Decoding speed (times realtime)

350(b) Sample with 48/24

Figure 2.4: Decoding performance

17

400

2.3

Wasted bits

When testing the complete recordings of The Lord of the Rings: The Two Towers soundtrack,some rather strange results were obtained, shown in figure 2.5 and 2.6. After looking at theanalyse-files generated by the official FLAC decoder, it became clear that something called’wasted bits’ was responsible for this behaviour.
Encoding CPU speed vs compression
for Lord of the Rings The Two Towers - stereo 44-16
Compression (% of WAV-size)

51

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

50
49
48
47
46
45
44
43
0

50

100

150
200
250
300
350
Encoding speed (times realtime)

400

450

(a) Sample with 44/16

Encoding CPU speed vs compression
for Lord of the Rings The Two Towers - stereo 48-24
Compression (% of WAV-size)

64

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

62
60
58
56
54
52
50
0

50

100
150
200
250
Encoding speed (times realtime)

300

350

(b) Sample with 48/24 (2 wasted bits)

Figure 2.5: Encoding performance
The first thing that stands out when looking at these results is that the results seem to form twogroups: one group (consisting of FLAC, WavPack, TAK and OptimFROG) that does pretty
well on these samples and one group (Monkeys Audio, ALAC, TTA and MP4ALS) that fallshort. This is because the latter group of codecs do not search for so called wasted bits. This
2 wasted bits mean that, while the files are packed in a 24-bit file, the data actually is 22-bit
only and the two least significant bits are always zero. ALS can perform better, but a switch(-l) has to be used on encoding.
Of course one could wonder why this exists, material which is ’only’ 22-bit while it is advertised18

Decoding CPU speed vs compression
for Lord of the Rings The Two Towers - stereo 44-16
Compression (% of WAV-size)

51

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

50
49
48
47
46
45
44
43
0

100

200
300
400
500
Decoding speed (times realtime)

600

700

(a) Sample with 44/16

Decoding CPU speed vs compression
for Lord of the Rings The Two Towers - stereo 48-24
Compression (% of WAV-size)

64

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
Monkey’s Audio 4.12
OptimFROG 4.910b
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

62
60
58
56
54
52
50
0

50

100
150
200
250
300
Decoding speed (times realtime)

350

400

(b) Sample with 48/24 (2 wasted bits)

Figure 2.6: Decoding performanceas being 24-bit. In this case, the material was packed on the DVD-A with a lossless codec whichis called MLP (Meridian Lossless Packaging) which is a proprietary format. (Just as a side note:
It’s compression was 59.3%) MLP is among the codecs that benefits from wasted bits as well,so this way it was possible to fit the audio on one disc, with 8GB of 8.5GB filled, without
these wasted bits the disc would have been too small. It actually is listed as an ’feature’ by its
creators, but is not often seen on commercial discs apparently. For more information, you cansearch for ’LossyWAV’, which is an application that makes use of the wasted bit system.
So, in the rare case you come across a disc which is compressed with MLP and is packed-as24bit-but-actually-isnt-24bit, half of the tested codecs might not be able to handle this very
well.

19

Chapter 3
Multichannel audio
While surround sound is usually paired with a movie and not often sold ’just audio’, it might
become an interesting topic in the future. Since the introduction of stereo sound, people havebeen talking about ’more than 2 channels’, and while sales of surround-sound music never really
took of it has some really interesting advantages over stereo.
Because it never really took of, codecs usually focus on mono and stereo sound. For example,
FLAC has a few tricks to use the similarity of stereo channels to get some more compression,
but there is no such decorrelation for multichannel audio. Other codecs, like Monkey’s Audio,
OptimFROG and shorten have no support for multichannel audio at all.

3.1

Howard Shore’s soundtrack for The Lord of the Rings:
The Return of the KingThe complete recordings of The Lord of the Rings (The Two Towers) soundtrack feature theusual 44.1kHz/16-bit stereo sound on CD, but also pack an Audio-DVD with the same musicin 48kHz/24-bit stereo sound and 48kHz/24-bit surround sound. As this and the same package
for the Two Towers discussed in section 2.3 are the only 2 sources of lossless multichannel audio
I have, this is the only material used for comparison. Only the first 8 tracks are tested becauseof size constraints on the ramdisk.
The results for these tests are shown in 3.1 and 3.2. It seems that, like the comparison between
16-bit and 24-bit audio, the number of channels does not seem to matter much. The only
strange thing is that TTA performs pretty bad compared to its usual performance. This isstrange because being able to encode multichannel-audio (up to 65536 channels) is one of its
selling points on the TTA-website. FLAC is performing better then usual, but the difference isonly small so mastering (or the way of down-mixing to stereo) could be a reason for this, thisis no reason to believe that FLAC performs better then usual on all multichannel material.

20

Encoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 48-24
Compression (% of WAV-size)

62.5

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

62.0
61.5
61.0
60.5
60.0
59.5
59.0
58.5
58.0
0

50

100
150
200
250
Encoding speed (times realtime)

300

350

(a) Sample with 48/24 stereo

Encoding CPU speed vs compression
for Lord of the Rings The Return of the King - surround 48-24
Compression (% of WAV-size)

57

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

56
55
54
53
52
51
50
0

20

40
60
80
Encoding speed (times realtime)

100(b) Sample with 48/24 surroundFigure 3.1: Encoding performance

21

120

Decoding CPU speed vs compression
for Lord of the Rings The Return of the King - stereo 48-24
Compression (% of WAV-size)

62.5

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

62.0
61.5
61.0
60.5
60.0
59.5
59.0
58.5
58.0
50

100

150
200
250
300
Decoding speed (times realtime)

350

400

(a) Sample with 48/24 stereo

Decoding CPU speed vs compression
for Lord of the Rings The Return of the King - surround 48-24
Compression (% of WAV-size)

57

FLAC 1.3.1
TAK 2.3.0
TTA 3.4.1
WavPack 4.70.0
ALAC (refalac 1.44)
MP4 ALS RM23
WMA Lossless v12.0

56
55
54
53
52
51
50
20

40

60

80
100
120
140
Decoding speed (times realtime)

160(b) Sample with 48/24 surroundFigure 3.2: Decoding performance

22

180

Appendix A
Motivation for choosing these CDs
The validity of this test is for a large part dependent on the audio material used. It was chosen
to pick full CDs instead of single tracks because single tracks might exhibit a single strong’characteristic’ which could influence the test. We want to capture the influence of a certain
genre, not that of a peculiarity of a track. However, we might still capture the ’sound’ ofa certain album (for example the way it was mixed or mastered), but this is not reasonably
avoided, as one would have to test an awful lot of CDs.
See table A.1 for the CDs and some data describing their contents. For more information on
the DR measurement, see www.pleasurizemusic.com
Each CD in this list is there for a reason. First of all, for every main genre I could find (withsome help of wikipedia [2] and the list of genres for which Grammy-awards are awarded [1]) I
tried to add a CD or two. The only genre that is missing that is on the list of Grammy awards
is gospel, but this might be added in the future. Besides, one could argue gospel is close tosoul music and there is already some ’religious’ music in the test. At least one can conclude
that drawing a line and getting the list right is not easy.
Not every genre has the same amount of CDs tested, and this is not easily explained: one could
argue that certain music genres feature much more diverse kinds of subgenres or that certain(distinct) genres sound much alike technically, and the division is mainly on lyrics. While thisall holds true, I would say there is no inherently better way to ’balance’ a test, there’s noaccounting for tastes. Even the very classification of music in genres has spawned numerous
discussion.
I did my best to balance the CDs between different genres and give every genre as much credit
as it deserves. If you think there’s something wrong and the list could be balanced better,
please post suggestions at the thread mentioned in the bibliography at [3].
For rock, ”30 Seconds to Mars - This is War” and ”Rush - Grace under Pressure”
were added. The first is more recent and has seen moderate dynamic range compression, while
the second is (despite it being a later remaster) from the ’80s and has a lot more dynamic
range. They are musically quite different ’spots’ of the rock-genre as well. Considering rock,”Jeff Waynes Musical Version of the War of The Worlds” might be regarded as rockas well, but this features far more electronic influences and is half audiobook, half music, so itfits no general category at all.
Confido Domino Minsk’s Sacred choral music from White Russia is half orchestralplus choir and half a capella choir. It features, as it’s name would suggest, mainly religious
music and tests the various codecs on their handling of voice-only content.
23

Album
30 Seconds to Mars - This Is War
Abba - Gold: Greatest Hits (1992)
Albert King - Years Gone By
Alicia Keys - The Diary of Alicia Keys
Alison Krauss Union Station - New Favorite
Armik - Rain Dance
Café del Mar - Volumen nueve
Coldplay - Parachutes
Confido Domino Minsk - Sacred choral music from White Russia
Daft Punk - Alive 2007
Dan Brown - Angels and Demons
Enya - Amarantine
Fanfare Ciocarlia - Baro Biao: World Wide Wedding
Gilberto Santa Rosa - Esencia
Giuseppe Verdi - Messa da Requiem (Berliner Philharmoniker
feat. conductor Claudio Abbado)
Howard Shore - The Hobbit: An Unexpected Journey
Iron Maiden - Brave New WorldJames Brown - Love, Power, Peace (Live at the Olympia,
Paris, 1971)
John Coltrane - Live at the half note, vol. 1
Joss Stone - Mind, Body & Soul
J.S. Bach - Magnificat
Koninklijke Militaire Kapel - [no name]
Kraftwerk - Autobahn
Lana del Rey - Born to Die
Lil Wayne - Tha Carter III
Martin O’Donnell & Michael Salvatori - Halo: Reach
Metallica - Death Magnetic
Michael Bublé - meets madison square garden
Mike Oldfield - Tubular Bells (2000 remaster)’N Sync - Home for Christmas
Nicholas Hooper - Harry Potter and the Order of the Phoenix
Peter Tosh - Equal Rights (2011 legacy edition)
Rosenberg Trio - Djangologists
Rush - Grace under Pressure (1997 remaster)
System of a Down - Mezmerize
Szakcsi - Virágom, virágom
Tiësto - In Search of Sunrise 7: Asia
The Lumineers - The Lumineers
Various - Jeff Waynes Musical Version of The War of theWorldsVarious - Latin Village, CD 1: Salsa
Waylon Jennings - Honky Tonk Heroes
Xzibit - At the Speed of Life
Yann Tiersen - Le Fabuleux Destin d’Amélie Poulain

Table A.1: CD data

24

Genre
rock
pop
blues
R&B, soulcountry, bluegrass
flamenco/jazzchill-out
popchoral, religious

Remarks
-

DR
6
13
14
8
10
15
8
8
12

electronic
audiobooknew ageworld music, brasssalsa
orchestral, romantic
orchestral, OST
metal
funk

live
-

5
16
8
12
9
12

live

10
7
12

jazz
soul
orchestral, baroquemilitary brass
electronic
pop
hip hopambient-ish, OST
metal
pop, jazznot classifiablepopsoundtrack
reggae
jazz
rock
metal
world music
dance
folk
radio
drama-ish,rock, orchestral
salsa
country
hip hopminimalism

livevinyl rip
live
-

11
7
13
11
13
5
7
11
3
8
11
8
12
10
7
10
5
10
8
10
11

compilation 8
12
10
11

For electronic music, 3 CDs were used: ”Daft Punk - Alive 2007”, ”Kraftwerk - Autobahn” and ”Tiësto - In Search of Sunrise 7: Asia”. The first is because Daft Punk has
been an popular electronic artist for quite some time and this album is quite recent. Kraftwerk’s
Autobahn was added to counter any recent mastering issues and is as well well known. Tiësto
was added because it was the only dance music I have in my collection and seems to fit in thistest well: it is quite different from the other two CDs in this category. Daft Punk’s CD is alive album.
Dan Browns book Angels and Demons as read by Richard Poe was added to add purespeech to the test as well.
Enya - Amarantine represents New Age music in this test.
Considering world music Fanfare Ciocarlia - Baro Biao: World Wide Wedding andSzakcsi - Virágom, virágom were added. While they are both European (Romanian andHungarian to be precise), they are very different and seem to feature two extremes of what one
would call world music. Fanfare Ciocarlia can be typed as gypsy music as well and is mainly
brass. Szakcsi is very different and features both very serene and stimulating folk music, itconsists of variations on children’s songs and features no brass instruments at all.
To add some latin (which one could call ’world music’ as well of course), two CDs featuringsalsa music were added: Gilberto Santa Rosa - Escencia and a compilation-CD. The firstsounds more like traditional salsa, while the second features more elements of current popular
music.
Classical music is represented by Guiseppe Verdi’s Requiem and Bach’s Magnificat. The
first is from the romantic movement and, as is very Verdi, sounds more like an opera than arequiem. Bach was an baroque composer. Both cultural movements are more or less opposing
considering size: baroque features a small orchestra and a small choir, while romantic music
features large orchestra’s and very large choirs. In this respect, these two recordings spandifferent kinds of orchestral music.
Howard Shore’s soundtrack for The Hobbit: An Unexpected Journey and Nicholas
Hooper - Harry Potter and the Order of the Phoenix are orchestral as well, but The
Hobbit only features choir in a few tracks and is less brass-heavy than the previous two. The
music by Nicholas Hooper uses the orchestra in a much less ’classical’ way, with lots of smallchamber-music like settings, using extensive panpotting and close-miking and featuring nonorchestral instruments. Furthermore, these were composed in 2011 and 2007 respectively, sothey are still relatively fresh.
To add metal to the test Iron Maiden - Brave New World, System of a Down - Mezmerize and Metallica - Death Magnetic were added. System of a Down is quite chaotic and fast,
while Iron Maiden is more steady and brutal. Death Magnetic has been extensively critized for
its extremely high dynamic range compression, which explains the very low DR-number of 3.
John Coltrane - Live at the half note vol.1 and The Rosenberg Trio - Djangologists
were added to represent jazz. Coltrane’s CD represents live recorded music as well.
Joss Stone - Mind, Body & Soul and Alicia Keys - The Diary of Alicia Keys add
soul/R&B to the test.
The vinyl rip of the Koninklijke Militaire Kapel adds some military wind music to thetest.
Lana del Rey’s Born to Die, Michael Bublé’s live album, Coldplay - Parachutes,’N Sync - Home for Christmas and ABBA - Gold: Greatest Hits add some pop music25

to the test. Picking pop music was hard, as quite a lot of pop music can be classified as rockas well, or poprock for that matter. Lana del Rey’s CD is more downtempo, Bublé is morejazz-like, Coldplay is more rock (pop rock probably), ’N Sync is a classical example of a pop
boyband and ABBA adds earlier pop music. The spread of DR reflects that these 5 span quite
different masterings: the album Lana Del Rey has seen quite some dynamic range compression
while the ABBA CD might be considered a pre-loudness war release.
Lil Wayne - Tha Carter III and Xzibit - At the speed of life were added two represent
hip hop.
Martin O’ Donnell & Michael Salvatori’s soundtrack for Halo: Reach is mainly
ambient music, and was added to represent it
Mike Oldfield - Tubular Bells was added to add some older popular music as well, while itis not really possible to name a genre this would fit to.
As classic guitar is featured as a solo instrument in quite a lot of music, Armik - Rain Dance
was added, which is flamenco music. It has a nice high DR too, the highest of all music samples
tested.
For funk, a live album by James Brown, James Brown - Love, Power, Peace (Live at the
Olympia, Paris, 1971) was added. This was recorded in 1971 but it was not released until
1992, on CD.
For some blues, Albert King - Years Gone By was added.
Café del Mar - Volumen nueve features chill-out music.
For reggae, Peter Tosh - Equal Rights was added. The 2011 remaster (legacy edition) wasused, but only the 8 tracks that were originally featured on the first release.
For folk music, The Lumineers - The Lumineers was added. Note that, while this CD isquite recent, its mastering was done with little dynamic range compression.
Waylon Jennings - Honky Tonk Heroes and Alison Krauss & Union Station - New
Favorite to account for country music.
Finally, Yann Tiersen’s soundtrack for Amélie features music with different (but always
few) instruments, and is usually regarded minimalism music. It was added to check performanceon the ’less popular’ instruments featured.

26

Appendix B
Test setup
In earlier versions of this comparison, some codecs were tested through wine and some were
run natively. While wine has a minimal overhead, this wasn’t really fair. Now all tests are run
on a Windows computer, just to make absolutely sure any overhead is equally spread among
all codecs. Between the second and third revision, I was able to find the tools necessary to get
the same consistent measurements, like a CPU-cycle based timer and a RAMdisk. Because of
these tools, the test results are reliable, reproducible and easy to automate.
The machine used is a system built from off-the-shelf components, using a AMD A4-3400
CPU+GPU and 4GB of RAM. Dynamic frequency scaling was disabled for this test (the CPU
was fixed to its 2.7GHz limit) and one core was disabled, so only one core is available to thecodecs. Timing was done with ’timer32.exe’ from the 7-zip benchmark suite, both real time and
cpu time where measured but only cpu time has been used in the following analyses. Before
the test starts, the WAVE files are copied to a ramdisk to bypass the hard drive entirely.

B.1

Scripting and graphing

The scripting was done in PHP (because I’m familiar with it, not because it’s a good choicefor this use) and was basically executing encoding and decoding commands within the timeer
command and sanitizing this data before it went into the cvs-file. It made sure every encoder
would have a fresh copy of the files (in case one encoder would mangle them) in the ramdisk
and measured the size of the WAV-files and compressed files to extract a compression ratio.
These cvs-data was ordered by hand and fed into a graph generator, GLE. This resulted infour graphs: two with the familiar ’encoding or decoding speed’ versus compression and two
which displayed more or less the inverse of the speed versus the compression. The latter two
graphs were added because the linear scale used doesn’t display the really slow codecs well.
This inverse of speed happens to be CPU-usage, which is a value that is probably easy to relate
for most readers.

B.2

Codecs and parameters used

Every known lossless codec that could be easily used with scripts on Windows has been tested.
The most notable exception is Real Audio Lossless, as a command line encoders for this format
seems to be unavailable. Considering the parameters, the ones recommended by the developer27

Codec
FLAC
TAK
LA
TTA
WavPack
Monkeys Audio
OptimFROG
ALAC
Shorten
MP4ALSParameters used
-0, -1, -2, -3, -4, -5, -6, -7, -8-p0, -p0e, -p0m, -p1, -p1e, -p1m, -p2, -p2e, -p2m, -p3, -p3e, -p3m,-p4, -p4e, -p4m[-], -high, -high -noseek[-]-f, [-], -h -x, -hh -x-c1000, -c2000, -c3000, -c4000, -c5000–mode fast, –mode normal, –mode high, –mode best, –mode bestnew
[-]
[-]
[-]
Table B.1: Parameters used for each codec(or the command-line help of the encoders) were used, with some exceptions, see table B.1. For
example, not all available compression modes of OptimFROG were used, because there are a
lot and the codec is pretty slow. Also, after some preliminary tests, it was chosen to drop ALS’s-7 mode and OptimFROGs maximumcompression. ALS -7 was simply too slow with little oreven negative gain and OptimFROGs –maximumcompression is not advised for daily use, only
for benchmark purposes. While this is a benchmark, daily use is the focus of this report.
The encoding of ALS -7 and OptimFROG maximumcompression both took 2.5 times the playing length of the files, which for such a comprehensive test is far to long: together they usedhalf of the running time of the test, while they offer no real benefit. On certain CDs, ALS -7
actually performaned worse than ALS without parameters, but this usually wasn’t the case.
This is strange, as the comparison I did in may 2009 (with an earlier version of ALS) did show
fairly large gains, but with this version it seems those gains were lost.

B.3

MD5 checksumming

Checksumming is a safety feature of a few lossless codecs. I tested its impact on encoding
and decoding performance1 , because FLAC has checksumming enabled by default while othercodecs (like TAK) have it disabled by default. The results are shown in B.1 on the next page.
It is clearly visible that especially the fast presets suffer a lot from checksumming, up to 25
percent. To make this a fair comparison between the codecs and because checksumming is
usually not implemented in playback hardware, FLACs checksumming was disabled.

1

These tests were made in the first revision of this comparison and will not be updated, because their use
is only to explain why certain choices were made. Because these tests where done on a different machine witha different configuration, the results can’t be compared directly to other results. For more information on theused equipment, see revision 1 or 2 of this test

28

Compression (% of WAV-size)

Encoding speed vs compression (short set of samples)
61
60
59
58
57
56
55
54
53
52
51

FLAC 1.3.0
FLAC 1.3.0, checksum disabled
TAK 2.2.0, checksum enabled
TAK 2.2.0

0

50

100
150
200
250
Encoding speed (times realtime)

300

350

Compression (% of WAV-size)

Decoding speed vs compression (short set of samples)
61
60
59
58
57
56
55
54
53
52
51
200

FLAC 1.3.0
FLAC 1.3.0, checksum disabled
TAK 2.2.0, checksum enabled
TAK 2.2.0

250

300
350
400
450
Decoding speed (times realtime)

500

550

Figure B.1: Performance of TAK and FLAC with and without checksumming

29

Appendix C
Revision history• Revision 1 - January 7, 2013 - Initial version• Revision 2 - March 19, 2013 - Improved graph readability and optimized for screenreading• Revision 3 - August 10, 2013 - Added Metallica’s Death Magnetic, Coldplay’s Parachutes,
Armik’s Rain Dance, the self-titled album of The Lumineers, Peter Tosh’s Equal Rights,
Alicia Keys’ The Diary of Alicia Keys, ’N Sync’s Home for Christmas, James Brown’s
Love, Power, Peace, ABBA - Gold: Greatest Hits, Waylon Jennings - Honky Tonk Heroes,
Alison Krauss & Union Station - New Favorite, Café del Mar - Volumen nueve andNicholas Hooper - Harry Potter and the Order of the Phoenix.
Testing was moved to a different computer running Windows. Newer versions of FLAC,
TAK, WavPack and Monkey’s Audio. Because of the move to use Windows, a newer(windows-only) release of OptimFROG is tested as well and WMA Lossless is featured in
all tests. Real Audio has been dropped because it has no command line encoder/decoder.
FLAC’s encoding and decoding is now with the undocumented –no-md5-sum, see section
B.3 for more information.
• Revision 4 - January 6, 2015 - Updated to FLAC 1.3.1, WavPack 4.70 and refalac 1.44.
Moved test setup chapter to appendices. Changed to logarithmic plotting for the CPUusage graphs.

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Bibliography[1] ListofGrammyAward
List of Grammy Award categories

categories,

http://en.wikipedia.org/wiki/[2] List of music genres and styles, http://en.wikipedia.org/wiki/Music genre[3] Once more:Time for a new lossless codec comparision?, More comprehensive,
more detail,(a thread I started to ask for advice),
http://www.hydrogenaudio.org/forums/index.php?showtopic=94685[4] FLAC - comparison, http://xiph.org/flac/comparison.html[5] Losslesscomparison
HydrogenAudio
http://wiki.hydrogenaudio.org/index.php?title=Lossless comparison

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Knowledgebase,