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I am looking to develop a tool for editing Closed Captions for MP3s. It is mostly in support of YouTube music videos. I've been looking over the Supported Caption File Formats in this YouTube page and the example they show is:

0:01:23.000,0:01:25.000
This text displays for two seconds starting
1 minute and 23 seconds into the video.

0:02:20.250,0:02:23.8
This text displays from 2 minutes and 20.25 seconds after the start
of the video until 2 minutes and 23.8 seconds after the start of the video.

0:03:14.159
This text displays beginning 3 minutes and 14.159 seconds
after the start of the video for an undefined length of time.

It seems clear enough there, with the first line being start,end time, the blank line being a delimiter, and the rest indicating text and line breaks. The last 'time' entry indicates a start time but no explicit end time - it is up to the software to define how to render it (any examples my software makes, will have an explicit start & end time). That is basically what is shown in the SubViewer (http:// en.wikipedia.org/wiki/SubViewer - link broken to reduce 3 links to maximum of 2) example at Wikipedia.

What neither page makes clear is whether the captions could effectively overlap. E.G. a busy meeting, or songs with lead and back-up vocals. An example of the latter is Johnny O'Keefe's - She's My Baby.

The BG vocals start 

1. Bom, bom, bom, BOM..

Continue that with 2 & 3 (when you're on a good 'bom', roll with it..)

Then JO'K cuts in with ..

4a.                Short black hair..
4b. Bom, bom, bom, BOM..

Does the format specify/expect that all captions will be non-overlapping periods of time, like lines 1-3, or does it also support 'interleaved' text as with lines 4 a/b?

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Could come kind soul add the file-formats & (does not exit yet) closed-caption tags to this post for me? If I go to edit it, I get informed it can only have two links (low rep.), and I'd prefer to keep all 3. – Andrew Thompson Mar 2 '12 at 16:44
OK - reduced the 3 links to 2 in order to edit, but users with <150 rep. cannot create new tags. I think 1) closed-caption should be a new tag for this SE site 2) it should be added to this post. If you have the rep. & agree, please edit. – Andrew Thompson Mar 3 '12 at 9:51

migrated from stackoverflow.com Mar 2 '12 at 16:23

1 Answer

up vote 1 down vote accepted
+100

I tried this just a short while ago, and YouTube supports interleaving captions! You can even jumble the captions around in time. So the first caption could be the last one showing up in the video.

Just specify the starting time and the end time on all of the captions and they will show up during the time you specified.

Have a good time captioning! :)

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Do you have a link where I can see your (or any) sample? I'd really like to see how it is rendered 'live'. – Andrew Thompson Mar 2 '12 at 17:23
There I've added some examples. Sorry for the lame video behind.. xD – Friend of Kim Mar 2 '12 at 17:28
The captions are at 1:23 and from 2:10. – Friend of Kim Mar 2 '12 at 17:29
On the second one around 2:10 it will show (call it) Caption 1. Caption 2 will start right after Caption 1. Caption 2 will also stop right before Caption 1 stops. A Caption 3 also starts inside Caption 1. This (Caption 3) however will stop before Caption 1. – Friend of Kim Mar 2 '12 at 17:38
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