Documentation:Modules/dvbsub
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Module: dvbsub | |
---|---|
Type | Subtitles |
First VLC version | 0.8.0 |
Last VLC version | - |
Operating system(s) | all |
Description | DVB subtitles decoder/encoder |
Shortcut(s) | - |
There are notes in the source code:
/*****************************************************************************
* Preamble
*
* FIXME:
* DVB subtitles coded as strings of characters are not handled correctly.
* The character codes in the string should actually be indexes referring to a
* character table identified in the subtitle descriptor.
*
* The spec is quite vague in this area, but what is meant is perhaps that it
* refers to the character index in the codepage belonging to the language
* specified in the subtitle descriptor. Potentially it's designed for widechar
* (but not for UTF-*) codepages.
*****************************************************************************/
and
/*****************************************************************************
* Notes on DDS (Display Definition Segment)
* -----------------------------------------
* DDS (Display Definition Segment) tells the decoder how the subtitle image
* relates to the video image.
* For SD, the subtitle image is always considered to be for display at
* 720x576 (although it's assumed that for NTSC, this is 720x480, this
* is not documented well) Also, for SD, the subtitle image is drawn 'on
* the glass' (i.e. after video scaling, letterbox, etc.)
* For 'HD' (subs marked type 0x14/0x24 in PSI), a DDS must be present,
* and the subs area is drawn onto the video area (scales if necessary).
* The DDS tells the decoder what resolution the subtitle images were
* intended for, and hence how to scale the subtitle images for a
* particular video size
* i.e. if HD video is presented as letterbox, the subs will be in the
* same place on the video as if the video was presented on an HD set
* indeed, if the HD video was pillarboxed by the decoder, the subs may
* be cut off as well as the video. The intent here is that the subs can
* be placed accurately on the video - something which was missed in the
* original spec.
*
* A DDS may also specify a window - this is where the subs images are moved so that the (0,0)
* origin of decode is offset.
********************************************************************************************/
Contents
Options
- dvbsub-position <integer> { 0, 1, 2, 4, 8, 5, 6, 9, 10 } : Subpicture position(key)
- dvbsub-x <integer> : X coordinate of the rendered subtitle default value: -1
- dvbsub-y <integer> : Y coordinate of the rendered subtitle default value: -1
Encoder
- sout-dvbsub-x <integer> : X coordinate of the encoded subtitle default value: -1
- sout-dvbsub-y <integer> : Y coordinate of the encoded subtitle default value: -1
Appendix
Integer | Alignment | Comment |
---|---|---|
0 | Center | |
1 | Left | |
2 | Right | |
4 | Top | |
8 | Bottom | |
5 | Top-Left | 4 + 1 |
6 | Top-Right | 4 + 2 |
9 | Bottom-Left | 8 + 1 |
10 | Bottom-Right | 8 + 2 |
3 | n/a | contradictory |
7 | n/a | contradictory |
Source code
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