yading@10: .\" Automatically generated by Pod::Man 2.23 (Pod::Simple 3.14)
yading@10: .\"
yading@10: .\" Standard preamble:
yading@10: .\" ========================================================================
yading@10: .de Sp \" Vertical space (when we can't use .PP)
yading@10: .if t .sp .5v
yading@10: .if n .sp
yading@10: ..
yading@10: .de Vb \" Begin verbatim text
yading@10: .ft CW
yading@10: .nf
yading@10: .ne \\$1
yading@10: ..
yading@10: .de Ve \" End verbatim text
yading@10: .ft R
yading@10: .fi
yading@10: ..
yading@10: .\" Set up some character translations and predefined strings.  \*(-- will
yading@10: .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
yading@10: .\" double quote, and \*(R" will give a right double quote.  \*(C+ will
yading@10: .\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
yading@10: .\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
yading@10: .\" nothing in troff, for use with C<>.
yading@10: .tr \(*W-
yading@10: .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
yading@10: .ie n \{\
yading@10: .    ds -- \(*W-
yading@10: .    ds PI pi
yading@10: .    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
yading@10: .    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
yading@10: .    ds L" ""
yading@10: .    ds R" ""
yading@10: .    ds C` ""
yading@10: .    ds C' ""
yading@10: 'br\}
yading@10: .el\{\
yading@10: .    ds -- \|\(em\|
yading@10: .    ds PI \(*p
yading@10: .    ds L" ``
yading@10: .    ds R" ''
yading@10: 'br\}
yading@10: .\"
yading@10: .\" Escape single quotes in literal strings from groff's Unicode transform.
yading@10: .ie \n(.g .ds Aq \(aq
yading@10: .el       .ds Aq '
yading@10: .\"
yading@10: .\" If the F register is turned on, we'll generate index entries on stderr for
yading@10: .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
yading@10: .\" entries marked with X<> in POD.  Of course, you'll have to process the
yading@10: .\" output yourself in some meaningful fashion.
yading@10: .ie \nF \{\
yading@10: .    de IX
yading@10: .    tm Index:\\$1\t\\n%\t"\\$2"
yading@10: ..
yading@10: .    nr % 0
yading@10: .    rr F
yading@10: .\}
yading@10: .el \{\
yading@10: .    de IX
yading@10: ..
yading@10: .\}
yading@10: .\"
yading@10: .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
yading@10: .\" Fear.  Run.  Save yourself.  No user-serviceable parts.
yading@10: .    \" fudge factors for nroff and troff
yading@10: .if n \{\
yading@10: .    ds #H 0
yading@10: .    ds #V .8m
yading@10: .    ds #F .3m
yading@10: .    ds #[ \f1
yading@10: .    ds #] \fP
yading@10: .\}
yading@10: .if t \{\
yading@10: .    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
yading@10: .    ds #V .6m
yading@10: .    ds #F 0
yading@10: .    ds #[ \&
yading@10: .    ds #] \&
yading@10: .\}
yading@10: .    \" simple accents for nroff and troff
yading@10: .if n \{\
yading@10: .    ds ' \&
yading@10: .    ds ` \&
yading@10: .    ds ^ \&
yading@10: .    ds , \&
yading@10: .    ds ~ ~
yading@10: .    ds /
yading@10: .\}
yading@10: .if t \{\
yading@10: .    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
yading@10: .    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
yading@10: .    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
yading@10: .    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
yading@10: .    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
yading@10: .    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
yading@10: .\}
yading@10: .    \" troff and (daisy-wheel) nroff accents
yading@10: .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
yading@10: .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
yading@10: .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
yading@10: .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
yading@10: .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
yading@10: .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
yading@10: .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
yading@10: .ds ae a\h'-(\w'a'u*4/10)'e
yading@10: .ds Ae A\h'-(\w'A'u*4/10)'E
yading@10: .    \" corrections for vroff
yading@10: .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
yading@10: .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
yading@10: .    \" for low resolution devices (crt and lpr)
yading@10: .if \n(.H>23 .if \n(.V>19 \
yading@10: \{\
yading@10: .    ds : e
yading@10: .    ds 8 ss
yading@10: .    ds o a
yading@10: .    ds d- d\h'-1'\(ga
yading@10: .    ds D- D\h'-1'\(hy
yading@10: .    ds th \o'bp'
yading@10: .    ds Th \o'LP'
yading@10: .    ds ae ae
yading@10: .    ds Ae AE
yading@10: .\}
yading@10: .rm #[ #] #H #V #F C
yading@10: .\" ========================================================================
yading@10: .\"
yading@10: .IX Title "FFMPEG-BITSTREAM-FILTERS 1"
yading@10: .TH FFMPEG-BITSTREAM-FILTERS 1 "2013-04-21" " " " "
yading@10: .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
yading@10: .\" way too many mistakes in technical documents.
yading@10: .if n .ad l
yading@10: .nh
yading@10: .SH "NAME"
yading@10: ffmpeg\-bitstream\-filters \- FFmpeg bitstream filters
yading@10: .SH "DESCRIPTION"
yading@10: .IX Header "DESCRIPTION"
yading@10: This document describes the bitstream filters provided by the
yading@10: libavcodec library.
yading@10: .PP
yading@10: A bitstream filter operates on the encoded stream data, and performs
yading@10: bitstream level modifications without performing decoding.
yading@10: .SH "BITSTREAM FILTERS"
yading@10: .IX Header "BITSTREAM FILTERS"
yading@10: When you configure your FFmpeg build, all the supported bitstream
yading@10: filters are enabled by default. You can list all available ones using
yading@10: the configure option \f(CW\*(C`\-\-list\-bsfs\*(C'\fR.
yading@10: .PP
yading@10: You can disable all the bitstream filters using the configure option
yading@10: \&\f(CW\*(C`\-\-disable\-bsfs\*(C'\fR, and selectively enable any bitstream filter using
yading@10: the option \f(CW\*(C`\-\-enable\-bsf=BSF\*(C'\fR, or you can disable a particular
yading@10: bitstream filter using the option \f(CW\*(C`\-\-disable\-bsf=BSF\*(C'\fR.
yading@10: .PP
yading@10: The option \f(CW\*(C`\-bsfs\*(C'\fR of the ff* tools will display the list of
yading@10: all the supported bitstream filters included in your build.
yading@10: .PP
yading@10: Below is a description of the currently available bitstream filters.
yading@10: .SS "aac_adtstoasc"
yading@10: .IX Subsection "aac_adtstoasc"
yading@10: .SS "chomp"
yading@10: .IX Subsection "chomp"
yading@10: .SS "dump_extradata"
yading@10: .IX Subsection "dump_extradata"
yading@10: .SS "h264_mp4toannexb"
yading@10: .IX Subsection "h264_mp4toannexb"
yading@10: Convert an H.264 bitstream from length prefixed mode to start code
yading@10: prefixed mode (as defined in the Annex B of the ITU-T H.264
yading@10: specification).
yading@10: .PP
yading@10: This is required by some streaming formats, typically the \s-1MPEG\-2\s0
yading@10: transport stream format (\*(L"mpegts\*(R").
yading@10: .PP
yading@10: For example to remux an \s-1MP4\s0 file containing an H.264 stream to mpegts
yading@10: format with \fBffmpeg\fR, you can use the command:
yading@10: .PP
yading@10: .Vb 1
yading@10: \&        ffmpeg \-i INPUT.mp4 \-codec copy \-bsf:v h264_mp4toannexb OUTPUT.ts
yading@10: .Ve
yading@10: .SS "imx_dump_header"
yading@10: .IX Subsection "imx_dump_header"
yading@10: .SS "mjpeg2jpeg"
yading@10: .IX Subsection "mjpeg2jpeg"
yading@10: Convert \s-1MJPEG/AVI1\s0 packets to full \s-1JPEG/JFIF\s0 packets.
yading@10: .PP
yading@10: \&\s-1MJPEG\s0 is a video codec wherein each video frame is essentially a
yading@10: \&\s-1JPEG\s0 image. The individual frames can be extracted without loss,
yading@10: e.g. by
yading@10: .PP
yading@10: .Vb 1
yading@10: \&        ffmpeg \-i ../some_mjpeg.avi \-c:v copy frames_%d.jpg
yading@10: .Ve
yading@10: .PP
yading@10: Unfortunately, these chunks are incomplete \s-1JPEG\s0 images, because
yading@10: they lack the \s-1DHT\s0 segment required for decoding. Quoting from
yading@10: <\fBhttp://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml\fR>:
yading@10: .PP
yading@10: Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
yading@10: commented that \*(L"\s-1MJPEG\s0, or at least the \s-1MJPEG\s0 in AVIs having the
yading@10: \&\s-1MJPG\s0 fourcc, is restricted \s-1JPEG\s0 with a fixed \*(-- and *omitted* \*(--
yading@10: Huffman table. The \s-1JPEG\s0 must be YCbCr colorspace, it must be 4:2:2,
yading@10: and it must use basic Huffman encoding, not arithmetic or
yading@10: progressive. . . . You can indeed extract the \s-1MJPEG\s0 frames and
yading@10: decode them with a regular \s-1JPEG\s0 decoder, but you have to prepend
yading@10: the \s-1DHT\s0 segment to them, or else the decoder won't have any idea
yading@10: how to decompress the data. The exact table necessary is given in
yading@10: the OpenDML spec.\*(R"
yading@10: .PP
yading@10: This bitstream filter patches the header of frames extracted from an \s-1MJPEG\s0
yading@10: stream (carrying the \s-1AVI1\s0 header \s-1ID\s0 and lacking a \s-1DHT\s0 segment) to
yading@10: produce fully qualified \s-1JPEG\s0 images.
yading@10: .PP
yading@10: .Vb 3
yading@10: \&        ffmpeg \-i mjpeg\-movie.avi \-c:v copy \-bsf:v mjpeg2jpeg frame_%d.jpg
yading@10: \&        exiftran \-i \-9 frame*.jpg
yading@10: \&        ffmpeg \-i frame_%d.jpg \-c:v copy rotated.avi
yading@10: .Ve
yading@10: .SS "mjpega_dump_header"
yading@10: .IX Subsection "mjpega_dump_header"
yading@10: .SS "movsub"
yading@10: .IX Subsection "movsub"
yading@10: .SS "mp3_header_compress"
yading@10: .IX Subsection "mp3_header_compress"
yading@10: .SS "mp3_header_decompress"
yading@10: .IX Subsection "mp3_header_decompress"
yading@10: .SS "noise"
yading@10: .IX Subsection "noise"
yading@10: .SS "remove_extradata"
yading@10: .IX Subsection "remove_extradata"
yading@10: .SH "SEE ALSO"
yading@10: .IX Header "SEE ALSO"
yading@10: \&\fIffmpeg\fR\|(1), \fIffplay\fR\|(1), \fIffprobe\fR\|(1), \fIffserver\fR\|(1), \fIlibavcodec\fR\|(3)
yading@10: .SH "AUTHORS"
yading@10: .IX Header "AUTHORS"
yading@10: The FFmpeg developers.
yading@10: .PP
yading@10: For details about the authorship, see the Git history of the project
yading@10: (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
yading@10: \&\fBgit log\fR in the FFmpeg source directory, or browsing the
yading@10: online repository at <\fBhttp://source.ffmpeg.org\fR>.
yading@10: .PP
yading@10: Maintainers for the specific components are listed in the file
yading@10: \&\fI\s-1MAINTAINERS\s0\fR in the source code tree.