mirror of
https://github.com/librempeg/librempeg
synced 2024-11-22 18:49:58 +00:00
b339dccbba
Based on a patch by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>. http://lists.ffmpeg.org/pipermail/ffmpeg-devel/2012-December/136677.html The original patch was rebased by Tudor SUCIU <tudor.suciu@gmail.com>. Lots of additional features and fixes are made by me. Fixes ticket #2086. Changes since last version: - change default page to all pages Signed-off-by: Marton Balint <cus@passwd.hu> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
203 lines
6.3 KiB
Plaintext
203 lines
6.3 KiB
Plaintext
@chapter Decoders
|
|
@c man begin DECODERS
|
|
|
|
Decoders are configured elements in FFmpeg which allow the decoding of
|
|
multimedia streams.
|
|
|
|
When you configure your FFmpeg build, all the supported native decoders
|
|
are enabled by default. Decoders requiring an external library must be enabled
|
|
manually via the corresponding @code{--enable-lib} option. You can list all
|
|
available decoders using the configure option @code{--list-decoders}.
|
|
|
|
You can disable all the decoders with the configure option
|
|
@code{--disable-decoders} and selectively enable / disable single decoders
|
|
with the options @code{--enable-decoder=@var{DECODER}} /
|
|
@code{--disable-decoder=@var{DECODER}}.
|
|
|
|
The option @code{-codecs} of the ff* tools will display the list of
|
|
enabled decoders.
|
|
|
|
@c man end DECODERS
|
|
|
|
@chapter Video Decoders
|
|
@c man begin VIDEO DECODERS
|
|
|
|
A description of some of the currently available video decoders
|
|
follows.
|
|
|
|
@section rawvideo
|
|
|
|
Raw video decoder.
|
|
|
|
This decoder decodes rawvideo streams.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item top @var{top_field_first}
|
|
Specify the assumed field type of the input video.
|
|
@table @option
|
|
@item -1
|
|
the video is assumed to be progressive (default)
|
|
@item 0
|
|
bottom-field-first is assumed
|
|
@item 1
|
|
top-field-first is assumed
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@c man end VIDEO DECODERS
|
|
|
|
@chapter Audio Decoders
|
|
@c man begin AUDIO DECODERS
|
|
|
|
@section ffwavesynth
|
|
|
|
Internal wave synthetizer.
|
|
|
|
This decoder generates wave patterns according to predefined sequences. Its
|
|
use is purely internal and the format of the data it accepts is not publicly
|
|
documented.
|
|
|
|
@section libcelt
|
|
|
|
libcelt decoder wrapper.
|
|
|
|
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
|
|
Requires the presence of the libcelt headers and library during configuration.
|
|
You need to explicitly configure the build with @code{--enable-libcelt}.
|
|
|
|
@section libgsm
|
|
|
|
libgsm decoder wrapper.
|
|
|
|
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
|
|
the presence of the libgsm headers and library during configuration. You need
|
|
to explicitly configure the build with @code{--enable-libgsm}.
|
|
|
|
This decoder supports both the ordinary GSM and the Microsoft variant.
|
|
|
|
@section libilbc
|
|
|
|
libilbc decoder wrapper.
|
|
|
|
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
|
|
audio codec. Requires the presence of the libilbc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libilbc}.
|
|
|
|
@subsection Options
|
|
|
|
The following option is supported by the libilbc wrapper.
|
|
|
|
@table @option
|
|
@item enhance
|
|
|
|
Enable the enhancement of the decoded audio when set to 1. The default
|
|
value is 0 (disabled).
|
|
|
|
@end table
|
|
|
|
@section libopencore-amrnb
|
|
|
|
libopencore-amrnb decoder wrapper.
|
|
|
|
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
|
|
Narrowband audio codec. Using it requires the presence of the
|
|
libopencore-amrnb headers and library during configuration. You need to
|
|
explicitly configure the build with @code{--enable-libopencore-amrnb}.
|
|
|
|
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
|
|
without this library.
|
|
|
|
@section libopencore-amrwb
|
|
|
|
libopencore-amrwb decoder wrapper.
|
|
|
|
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
|
|
Wideband audio codec. Using it requires the presence of the
|
|
libopencore-amrwb headers and library during configuration. You need to
|
|
explicitly configure the build with @code{--enable-libopencore-amrwb}.
|
|
|
|
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
|
|
without this library.
|
|
|
|
@section libopus
|
|
|
|
libopus decoder wrapper.
|
|
|
|
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
|
|
Requires the presence of the libopus headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libopus}.
|
|
|
|
@c man end AUDIO DECODERS
|
|
|
|
@chapter Subtitles Decoders
|
|
@c man begin SUBTILES DECODERS
|
|
|
|
@section dvdsub
|
|
|
|
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
|
|
also be found in VobSub file pairs and in some Matroska files.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item palette
|
|
Specify the global palette used by the bitmaps. When stored in VobSub, the
|
|
palette is normally specified in the index file; in Matroska, the palette is
|
|
stored in the codec extra-data in the same format as in VobSub. In DVDs, the
|
|
palette is stored in the IFO file, and therefore not available when reading
|
|
from dumped VOB files.
|
|
|
|
The format for this option is a string containing 16 24-bits hexadecimal
|
|
numbers (without 0x prefix) separated by comas, for example @code{0d00ee,
|
|
ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
|
|
7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
|
|
@end table
|
|
|
|
@section libzvbi-teletext
|
|
|
|
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
|
|
subtitles. Requires the presence of the libzvbi headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libzvbi}.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item txt_page
|
|
List of teletext page numbers to decode. You may use the special * string to
|
|
match all pages. Pages that do not match the specified list are dropped.
|
|
Default value is *.
|
|
@item txt_chop_top
|
|
Discards the top teletext line. Default value is 1.
|
|
@item txt_format
|
|
Specifies the format of the decoded subtitles. The teletext decoder is capable
|
|
of decoding the teletext pages to bitmaps or to simple text, you should use
|
|
"bitmap" for teletext pages, because certain graphics and colors cannot be
|
|
expressed in simple text. You might use "text" for teletext based subtitles if
|
|
your application can handle simple text based subtitles. Default value is
|
|
bitmap.
|
|
@item txt_left
|
|
X offset of generated bitmaps, default is 0.
|
|
@item txt_top
|
|
Y offset of generated bitmaps, default is 0.
|
|
@item txt_chop_spaces
|
|
Chops leading and trailing spaces and removes empty lines from the generated
|
|
text. This option is useful for teletext based subtitles where empty spaces may
|
|
be present at the start or at the end of the lines or empty lines may be
|
|
present between the subtitle lines because of double-sized teletext charactes.
|
|
Default value is 1.
|
|
@item txt_duration
|
|
Sets the display duration of the decoded teletext pages or subtitles in
|
|
miliseconds. Default value is 30000 which is 30 seconds.
|
|
@item txt_transparent
|
|
Force transparent background of the generated teletext bitmaps. Default value
|
|
is 0 which means an opaque (black) background.
|
|
@end table
|
|
|
|
@c man end SUBTILES DECODERS
|