Judging an a/v sync isn’t easy. Not only are there several different sync goals that a viewer might have, but over the coarse of a 40 minute sync, it becomes difficult to remember which parts were really good and which were lacking. But it would be nice to be able to say with some repeatability and reliability how well a sync works, so to that end I propose the following type of measurement of a sync.

The sync is divided up into 15 second intervals, and each of those intervals is judged according to how well it works. Then there can be numbers (weighted averages) assigned to the entire sync or each song, for example, that indicate how well the sync worked on average. There may be disagreement about how well one of these segments of a sync works, but I don’t think the problem will be nearly as bad as the disagreement that follows from judging entire syncs. In a small amount of time, it is easier to say that a sync contains something interesting or it doesn’t, and if there is honest disagreement, it should be easier to find a common ground. For the Stairway to Oz contest, I used a method like this to do my part of the judging, and it seemed to work well.

But there are levels for appreciating syncs that aren’t suited to this type of analysis. The starting point has to be important to say that the audio and video are synching. If a piece of music goes well with a piece of video in the sense that the music makes a good soundtrack, but it doesn’t really matter where the music starts, then it’s not about the two being synchronized, it’s more about an artistic matching. This type of judging isn’t about artistic matching. This type of judging is designed to judge how well they sync as if the entire sync is made of a bunch of 15 second syncs. So it’s not really about how enjoyable the sync is to watch, unless you love it when stuff goes together and don’t care about much else.

The first full length sync that I’ve judged like this is the famous Dark Side of the Rainbow. After watching it dozens of times, I still couldn’t really say for sure which parts I thought were the strongest, and which were the weakest. It should be noted that this uses the Pre-89 version of the video, which is slightly different (less than a few seconds) than the modern video, which Baker B. brought to my attention: http://breton.home.boone.net/darksideoftherainbow.html I agree with him that this is the best of the variations.

Before listing numbers, I need to say what each number means.

I decided to break it up into essentially two scales, positive and negative, corresponding to synching and not synching in the following manner:

10	means outstanding sync. Startling and perfectly timed
9	means exceptional, but lacking in some small way
8	means exceptional, but lacking in some way
7	means excellent, but not shockingly excellent.
6	means very nice, but not wonderful
5	means that it's good for a sync that's going well
4	means it's got a little something, but nothing yet that you'd want to point out as being cool.
3	means everything's going alright, but it's nothing special
2	means it leaves a little to be desired, but it's OK.
1	means it's hanging in there.
0	means it's falling flat.
-1	means it's a little bad.
-2	means it's getting annoying
-3	means it's solidly not synching
-4	means it's starting to grate
-5	means nobody should be saying that the two go together
-6	means it's really grating
-7	means it's really bad
-8	means horrible
-9	means hated it
-10	means nobody's gonna make you watch that again

The scale should be fine tuned to make it as linear as possible, but this seems like a reasonable start.

Here’s how well the songs score. First we have the title, then the time segments that each song covers, then the average score, then the number of intervals sampled for that song. For simplicity, I rounded each song off to cover an integer number of intervals.

Song Times Score Intervals

Speak to Me/Breathe	0.0 - 4.0	1.31	16
On the Run	4.0 - 7.30	-0.43	14
Time	7.30 - 14.40	2.86	29
The Great Gig in the Sky	14.40 - 19.20	5.53	19
Money	19.20 - 25.55	2.73	26
Us and Them	25.55 - 33.35	3.80	30
Any Colour You Like	33.35 - 37.0	-0.43	14
Brain Damage	37.0 - 40.50	4.44	16
Eclipse	40.50 - 42.55	5.44	9
			2.90

A score near zero means that there is no sync, so an overall score of 2.9 means that, on average, some significant synching going on.

But saying which songs were best on average isn’t the only kind of thing that we would like to know about a sync. Another thing to note is which parts of a sync scored very high. But to do that, we need to look at individual segment scores, which follow.

Segment		Overall (from -10 to +10)
1	0.0 - 0.15	-1	Speak to Me/Breath
2	0.15 - 0.30	-1
3	0.30 - 0.45	-1
4	0.45 - 1.0	-1
5	1.0 - 1.15	-1
6	1.15 - 1.30	2
7	1.30 - 1.45	1
8	1.45 - 2.0	1
9	2.0 - 2.15	1
10	2.15 - 2.30	3
11	2.30 - 2.45	3
12	2.45 - 3.0	3
13	3.0 - 3.15	1
14	3.15 - 3.30	3
15	3.30 - 3.45	4
16	3.45 - 4.0	4	Speak to Me/Breath
17	4.0 - 4.15	7	On The Run
18	4.15 - 4.30	3
19	4.30 - 4.45	4
20	4.45 - 5.0	2
21	5.0 - 5.15	2
22	5.15 - 5.30	2
23	5.30 - 5.45	-3
24	5.45 - 6.0	-2
25	6.0 - 6.15	-3
26	6.15 - 6.30	-3
27	6.30 - 6.45	-3
28	6.45 - 7.0	-3
29	7.0 - 7.15	-5
30	7.15 - 7.30	-4	On The Run
31	7.30 - 7.45	-4	Time
32	7.45 - 8.0	-3
33	8.0 - 8.15	10
34	8.15 - 8.30	5
35	8.30 - 8.45	3
36	8.45 - 9.0	4
37	9.0 - 9.15	3
38	9.15 - 9.30	3
39	9.30 - 9.45	2
40	9.45 - 10.0	2
41	10.0 - 10.15	2
42	10.15 - 10.30	4
43	10.30 - 10.45	2
44	10.45 - 11.0	1
45	11.0 - 11.15	5
46	11.15 - 11.30	4
47	11.30 - 11.45	2
48	11.45 - 12.0	3
49	12.0 - 12.15	2
50	12.15 - 12.30	2
51	12.30 - 12.45	3
52	12.45 - 13.0	5
53	13.0 - 13.15	2
54	13.15 - 13.30	4
55	13.30 - 13.45	4
56	13.45 - 14.0	3
57	14.0 - 14.15	2
58	14.15 - 14.30	3
59	14.30 - 14.45	5	Time
60	14.45 - 15.0	4	The Great Gig in the Sky
61	15.0 - 15.15	6
62	15.15 - 15.30	4
63	15.30 - 15.45	3
64	15.45 - 16.0	7
65	16.0 - 16.15	6
66	16.15 - 16.30	6
67	16.30 - 16.45	5
68	16.45 - 17.0	7
69	17.0 - 17.15	7
70	17.15 - 17.30	5
71	17.30 - 17.45	6
72	17.45 - 18.0	4
73	18.0 - 18.15	6
74	18.15 - 18.30	4
75	18.30 - 18.45	5
76	18.45 - 19.0	6
77	19.0 - 19.15	6
78	19.15 - 19.30	8	The Great Gig in the Sky
79	19.30 - 19.45	7	Money
80	19.45 - 20.0	5
81	20.0 - 20.15	3
82	20.15 - 20.30	-3
83	20.30 - 20.45	-7
84	20.45 - 21.0	-2
85	21.0 - 21.15	0
86	21.15 - 21.30	4
87	21.30 - 21.45	2
88	21.45 - 22.0	3
89	22.0 - 22.15	1
90	22.15 - 22.30	4
91	22.30 - 22.45	2
92	22.45 - 23.0	2
93	23.0 - 23.15	3
94	23.15 - 23.30	5
95	23.30 - 23.45	3
96	23.45 - 24.0	4
97	24.0 - 24.15	5
98	24.15 - 24.30	2
99	24.30 - 24.45	2
100	24.45 - 25.0	4
101	25.0 - 25.15	7
102	25.15 - 25.30	7
103	25.30 - 25.45	4
104	25.45 - 26.0	4	Money
105	26.0 - 26.15	0	Us and Them
106	26.15 - 26.30	0
107	26.30 - 26.45	2
108	26.45 - 27.0	2
109	27.0 - 27.15	0
110	27.15 - 27.30	1
111	27.30 - 27.45	3
112	27.45 - 28.0	4
113	28.0 - 28.15	4
114	28.15 - 28.30	5
115	28.30 - 28.45	2
116	28.45 - 29.0	10
117	29.0 - 29.15	9
118	29.15 - 29.30	6
119	29.30 - 29.45	4
120	29.45 - 30.0	6
121	30.0 - 30.15	8
122	30.15 - 30.30	7
123	30.30 - 30.45	3
124	30.45 - 31.0	3
125	31.0 - 31.15	7
126	31.15 - 31.30	2
127	31.30 - 31.45	2
128	31.45 - 32.0	2
129	32.0 - 32.15	3
130	32.15 - 32.30	5
131	32.30 - 32.45	3
132	32.45 - 33.0	5
133	33.0 - 33.15	2
134	33.15 - 33.30	4	Us and Them
135	33.30 - 33.45	4	Any Colour You Like
136	33.45 - 34.0	4
137	34.0 - 34.15	1
138	34.15 - 34.30	-1
139	34.30 - 34.45	-2
140	34.45 - 35.0	-3
141	35.0 - 35.15	0
142	35.15 - 35.30	-2
143	35.30 - 35.45	-3
144	35.45 - 36.0	3
145	36.0 - 36.15	-2
146	36.15 - 36.30	0
147	36.30 - 36.45	-2
148	36.45 - 37.0	-3	Any Colour You Like
149	37.0 - 37.15	1	Brain Damage
150	37.15 - 37.30	1
151	37.30 - 37.45	6
152	37.45 - 38.0	7
153	38.0 - 38.15	4
154	38.15 - 38.30	5
155	38.30 - 38.45	7
156	38.45 - 39.0	6
157	39.0 - 39.15	3
158	39.15 - 39.30	2
159	39.30 - 39.45	5
160	39.45 - 40.0	7
161	40.0 - 40.15	6
162	40.15 - 40.30	5
163	40.30 - 40.45	4
164	40.45 - 41.0	2	Brain Damage
165	41.0 - 41.15	3	Eclipse
166	41.15 - 41.30	4
167	41.30 - 41.45	7
168	41.45 - 42.0	7
169	42.0 - 42.15	7
170	42.15 - 42.30	7
171	42.30 - 42.45	9
172	42.45 - 43.0	3
173	43.0 - 43.15	2	Eclipse

So that’s a start. If anyone would like to debate the scores for individual sections, or discuss any of this, please write me at mike@mikecasey.org