[MPlayer-users] Seek and chapter

[Alexander Roalter]

Nico Sabbi wrote:
> Il Friday 09 November 2007 14:52:47 Olivier Rolland ha scritto:
>> On Nov 9, 2007 Nico Sabbi wrote:
>>>>> I find it unlikely that it ever worked that way - at least
>>>>> reliably - anyway now it's not possible (although it's easy
>>>>> to add the relative code). A quick workaround is:
>>>>> $ mplayer -identify|grep -i chapter
>>>>> $ mplayer -ss YOURTIME
>> In the end, this is exactely what I want to achieve. But as long as
>> seeking in a DVD title isn't reliable at all, 
> 
> who said it? seeking in dvd _is_ quite reliable
> because mplayer will use the time map stored in the ifo files
> 
>> I used to find in 
>> which chapter YOURTIME belonged and the starting time of this
>> chapter (CHAPTERTIME). I then only had to seek to CHAPTERTIME -
>> YOURTIME from the begining of the chapter.
> 
> 
> same as above: -ss works equally well when playing dvd:// streams
> (but not the vob files)
> 
>>>> Unfortunately, this does not work reliably with a DVD !
>>> depends on the dvd. How far is the final position offset
>>> from the one you specified?
>> It really depends. It can be any time from the begining to the end
>> of the title.
>>
>> Olivier
> 
> post an example

If I take one arbitrary DVD of mine, I get the following chapter list:

CHAPTERS: CHAPTERS: 
00:00:00,00:03:42,00:06:30,00:12:25,00:13:57,00:17:49,00:24:38,00:29:02,
00:33:08,00:38:27,00:42:07,00:46:42,00:50:24,00:54:15,00:58:33,01:03:33,
01:07:25,01:11:00,01:15:25,01:19:42,01:22:29,01:27:03,01:31:54,01:37:40,
01:44:20,

Interestingly though, playing the DVD, the OSD menu (or the V:xxxx 
console output) starts at 0 seconds, goes all the way up to 3024 seconds 
and then resets to 0 seconds (I reckon it's where the layer break is).

3024 seconds are 00:50:24, which, surprise, surprise, is a chapter break 
(chapter 13).

This means specifiying an offset below chapter 13 works well, but e.g. 
specifying -ss 01:03:29 (chapter 16) won't work, since chapter 16 
displays 789 seconds as video offset (50:24+ 13:09(=789 sec) = 1:03:33 
voilà)

btw: before chapter 17 there's another reset, as jumping to 17 is at 24 
seconds, oh, what the heck, I'll give you the complete list:

chpt 	time		V:
1	00:00:00	0.0
2	00:03:42	223.0
3	00:06:30	390.7
4	00:12:25	745.8
5	00:13:57	837.9
6	00:17:49	1069.6
7	00:24:38	1478.8
8	00:29:02	1742.9
9	00:33:08	1988.9
10	00:38:27	2307.7
11	00:42:07	2527.8
12	00:46:42	2802.6
13 	00:50:24	0.0
14	00:54:15	231.4
15	00:58:33	489.5
16	01:03:33	789.0
17	01:07:25	24.5
18	01:11:00	239.0
19	01:15:25	504.0
20	01:19:42	761.0
21	01:22:29	928.6
22	01:27:03	1201.7
23	01:31:54	1493.2
24	01:37:40	1839.2

The Movie in Question is the German DVD of "The Hitchhiker's Guide to 
the Galaxy", by Buena Vista (Touchstone).

-- 
cheers,
Alex