Provided by: ffmpeg_4.1.4-1build2_amd64 bug

NAME

       ffmpeg-bitstream-filters - FFmpeg bitstream filters

DESCRIPTION

       This document describes the bitstream filters provided by the libavcodec library.

       A bitstream filter operates on the encoded stream data, and performs bitstream level
       modifications without performing decoding.

BITSTREAM FILTERS

       When you configure your FFmpeg build, all the supported bitstream filters are enabled by
       default. You can list all available ones using the configure option "--list-bsfs".

       You can disable all the bitstream filters using the configure option "--disable-bsfs", and
       selectively enable any bitstream filter using the option "--enable-bsf=BSF", or you can
       disable a particular bitstream filter using the option "--disable-bsf=BSF".

       The option "-bsfs" of the ff* tools will display the list of all the supported bitstream
       filters included in your build.

       The ff* tools have a -bsf option applied per stream, taking a comma-separated list of
       filters, whose parameters follow the filter name after a '='.

               ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1:opt2=str2][,filter2] OUTPUT

       Below is a description of the currently available bitstream filters, with their
       parameters, if any.

   aac_adtstoasc
       Convert MPEG-2/4 AAC ADTS to an MPEG-4 Audio Specific Configuration bitstream.

       This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4 ADTS header and removes
       the ADTS header.

       This filter is required for example when copying an AAC stream from a raw ADTS AAC or an
       MPEG-TS container to MP4A-LATM, to an FLV file, or to MOV/MP4 files and related formats
       such as 3GP or M4A. Please note that it is auto-inserted for MP4A-LATM and MOV/MP4 and
       related formats.

   av1_metadata
       Modify metadata embedded in an AV1 stream.

       td  Insert or remove temporal delimiter OBUs in all temporal units of the stream.

           insert
               Insert a TD at the beginning of every TU which does not already have one.

           remove
               Remove the TD from the beginning of every TU which has one.

       color_primaries
       transfer_characteristics
       matrix_coefficients
           Set the color description fields in the stream (see AV1 section 6.4.2).

       color_range
           Set the color range in the stream (see AV1 section 6.4.2; note that this cannot be set
           for streams using BT.709 primaries, sRGB transfer characteristic and identity (RGB)
           matrix coefficients).

           tv  Limited range.

           pc  Full range.

       chroma_sample_position
           Set the chroma sample location in the stream (see AV1 section 6.4.2).  This can only
           be set for 4:2:0 streams.

           vertical
               Left position (matching the default in MPEG-2 and H.264).

           colocated
               Top-left position.

       tick_rate
           Set the tick rate (num_units_in_display_tick / time_scale) in the timing info in the
           sequence header.

       num_ticks_per_picture
           Set the number of ticks in each picture, to indicate that the stream has a fixed
           framerate.  Ignored if tick_rate is not also set.

   chomp
       Remove zero padding at the end of a packet.

   dca_core
       Extract the core from a DCA/DTS stream, dropping extensions such as DTS-HD.

   dump_extra
       Add extradata to the beginning of the filtered packets.

       freq
           The additional argument specifies which packets should be filtered.  It accepts the
           values:

           k
           keyframe
               add extradata to all key packets

           e
           all add extradata to all packets

       If not specified it is assumed e.

       For example the following ffmpeg command forces a global header (thus disabling individual
       packet headers) in the H.264 packets generated by the "libx264" encoder, but corrects them
       by adding the header stored in extradata to the key packets:

               ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts

   eac3_core
       Extract the core from a E-AC-3 stream, dropping extra channels.

   extract_extradata
       Extract the in-band extradata.

       Certain codecs allow the long-term headers (e.g. MPEG-2 sequence headers, or H.264/HEVC
       (VPS/)SPS/PPS) to be transmitted either "in-band" (i.e. as a part of the bitstream
       containing the coded frames) or "out of band" (e.g. on the container level). This latter
       form is called "extradata" in FFmpeg terminology.

       This bitstream filter detects the in-band headers and makes them available as extradata.

       remove
           When this option is enabled, the long-term headers are removed from the bitstream
           after extraction.

   filter_units
       Remove units with types in or not in a given set from the stream.

       pass_types
           List of unit types or ranges of unit types to pass through while removing all others.
           This is specified as a '|'-separated list of unit type values or ranges of values with
           '-'.

       remove_types
           Identical to pass_types, except the units in the given set removed and all others
           passed through.

       Extradata is unchanged by this transformation, but note that if the stream contains inline
       parameter sets then the output may be unusable if they are removed.

       For example, to remove all non-VCL NAL units from an H.264 stream:

               ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=pass_types=1-5' OUTPUT

       To remove all AUDs, SEI and filler from an H.265 stream:

               ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=35|38-40' OUTPUT

   hapqa_extract
       Extract Rgb or Alpha part of an HAPQA file, without recompression, in order to create an
       HAPQ or an HAPAlphaOnly file.

       texture
           Specifies the texture to keep.

           color
           alpha

       Convert HAPQA to HAPQ

               ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=color -tag:v HapY -metadata:s:v:0 encoder="HAPQ" hapq_file.mov

       Convert HAPQA to HAPAlphaOnly

               ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=alpha -tag:v HapA -metadata:s:v:0 encoder="HAPAlpha Only" hapalphaonly_file.mov

   h264_metadata
       Modify metadata embedded in an H.264 stream.

       aud Insert or remove AUD NAL units in all access units of the stream.

           insert
           remove
       sample_aspect_ratio
           Set the sample aspect ratio of the stream in the VUI parameters.

       video_format
       video_full_range_flag
           Set the video format in the stream (see H.264 section E.2.1 and table E-2).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.264 section E.2.1 and tables E-3, E-4
           and E-5).

       chroma_sample_loc_type
           Set the chroma sample location in the stream (see H.264 section E.2.1 and figure E-1).

       tick_rate
           Set the tick rate (num_units_in_tick / time_scale) in the VUI parameters.  This is the
           smallest time unit representable in the stream, and in many cases represents the field
           rate of the stream (double the frame rate).

       fixed_frame_rate_flag
           Set whether the stream has fixed framerate - typically this indicates that the
           framerate is exactly half the tick rate, but the exact meaning is dependent on
           interlacing and the picture structure (see H.264 section E.2.1 and table E-6).

       crop_left
       crop_right
       crop_top
       crop_bottom
           Set the frame cropping offsets in the SPS.  These values will replace the current ones
           if the stream is already cropped.

           These fields are set in pixels.  Note that some sizes may not be representable if the
           chroma is subsampled or the stream is interlaced (see H.264 section 7.4.2.1.1).

       sei_user_data
           Insert a string as SEI unregistered user data.  The argument must be of the form
           UUID+string, where the UUID is as hex digits possibly separated by hyphens, and the
           string can be anything.

           For example, 086f3693-b7b3-4f2c-9653-21492feee5b8+hello will insert the string
           ``hello'' associated with the given UUID.

       delete_filler
           Deletes both filler NAL units and filler SEI messages.

       level
           Set the level in the SPS.  Refer to H.264 section A.3 and tables A-1 to A-5.

           The argument must be the name of a level (for example, 4.2), a level_idc value (for
           example, 42), or the special name auto indicating that the filter should attempt to
           guess the level from the input stream properties.

   h264_mp4toannexb
       Convert an H.264 bitstream from length prefixed mode to start code prefixed mode (as
       defined in the Annex B of the ITU-T H.264 specification).

       This is required by some streaming formats, typically the MPEG-2 transport stream format
       (muxer "mpegts").

       For example to remux an MP4 file containing an H.264 stream to mpegts format with ffmpeg,
       you can use the command:

               ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts

       Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw H.264
       (muxer "h264") output formats.

   h264_redundant_pps
       This applies a specific fixup to some Blu-ray streams which contain redundant PPSs
       modifying irrelevant parameters of the stream which confuse other transformations which
       require correct extradata.

       A new single global PPS is created, and all of the redundant PPSs within the stream are
       removed.

   hevc_metadata
       Modify metadata embedded in an HEVC stream.

       aud Insert or remove AUD NAL units in all access units of the stream.

           insert
           remove
       sample_aspect_ratio
           Set the sample aspect ratio in the stream in the VUI parameters.

       video_format
       video_full_range_flag
           Set the video format in the stream (see H.265 section E.3.1 and table E.2).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.265 section E.3.1 and tables E.3, E.4
           and E.5).

       chroma_sample_loc_type
           Set the chroma sample location in the stream (see H.265 section E.3.1 and figure E.1).

       tick_rate
           Set the tick rate in the VPS and VUI parameters (num_units_in_tick / time_scale).
           Combined with num_ticks_poc_diff_one, this can set a constant framerate in the stream.
           Note that it is likely to be overridden by container parameters when the stream is in
           a container.

       num_ticks_poc_diff_one
           Set poc_proportional_to_timing_flag in VPS and VUI and use this value to set
           num_ticks_poc_diff_one_minus1 (see H.265 sections 7.4.3.1 and E.3.1).  Ignored if
           tick_rate is not also set.

       crop_left
       crop_right
       crop_top
       crop_bottom
           Set the conformance window cropping offsets in the SPS.  These values will replace the
           current ones if the stream is already cropped.

           These fields are set in pixels.  Note that some sizes may not be representable if the
           chroma is subsampled (H.265 section 7.4.3.2.1).

   hevc_mp4toannexb
       Convert an HEVC/H.265 bitstream from length prefixed mode to start code prefixed mode (as
       defined in the Annex B of the ITU-T H.265 specification).

       This is required by some streaming formats, typically the MPEG-2 transport stream format
       (muxer "mpegts").

       For example to remux an MP4 file containing an HEVC stream to mpegts format with ffmpeg,
       you can use the command:

               ffmpeg -i INPUT.mp4 -codec copy -bsf:v hevc_mp4toannexb OUTPUT.ts

       Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw
       HEVC/H.265 (muxer "h265" or "hevc") output formats.

   imxdump
       Modifies the bitstream to fit in MOV and to be usable by the Final Cut Pro decoder. This
       filter only applies to the mpeg2video codec, and is likely not needed for Final Cut Pro 7
       and newer with the appropriate -tag:v.

       For example, to remux 30 MB/sec NTSC IMX to MOV:

               ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov

   mjpeg2jpeg
       Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.

       MJPEG is a video codec wherein each video frame is essentially a JPEG image. The
       individual frames can be extracted without loss, e.g. by

               ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg

       Unfortunately, these chunks are incomplete JPEG images, because they lack the DHT segment
       required for decoding. Quoting from
       <http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml>:

       Avery Lee, writing in the rec.video.desktop newsgroup in 2001, commented that "MJPEG, or
       at least the MJPEG in AVIs having the MJPG fourcc, is restricted JPEG with a fixed -- and
       *omitted* -- Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2, and it
       must use basic Huffman encoding, not arithmetic or progressive. . . . You can indeed
       extract the MJPEG frames and decode them with a regular JPEG decoder, but you have to
       prepend the DHT segment to them, or else the decoder won't have any idea how to decompress
       the data. The exact table necessary is given in the OpenDML spec."

       This bitstream filter patches the header of frames extracted from an MJPEG stream
       (carrying the AVI1 header ID and lacking a DHT segment) to produce fully qualified JPEG
       images.

               ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
               exiftran -i -9 frame*.jpg
               ffmpeg -i frame_%d.jpg -c:v copy rotated.avi

   mjpegadump
       Add an MJPEG A header to the bitstream, to enable decoding by Quicktime.

   mov2textsub
       Extract a representable text file from MOV subtitles, stripping the metadata header from
       each subtitle packet.

       See also the text2movsub filter.

   mp3decomp
       Decompress non-standard compressed MP3 audio headers.

   mpeg2_metadata
       Modify metadata embedded in an MPEG-2 stream.

       display_aspect_ratio
           Set the display aspect ratio in the stream.

           The following fixed values are supported:

           4/3
           16/9
           221/100

           Any other value will result in square pixels being signalled instead (see H.262
           section 6.3.3 and table 6-3).

       frame_rate
           Set the frame rate in the stream.  This is constructed from a table of known values
           combined with a small multiplier and divisor - if the supplied value is not exactly
           representable, the nearest representable value will be used instead (see H.262 section
           6.3.3 and table 6-4).

       video_format
           Set the video format in the stream (see H.262 section 6.3.6 and table 6-6).

       colour_primaries
       transfer_characteristics
       matrix_coefficients
           Set the colour description in the stream (see H.262 section 6.3.6 and tables 6-7, 6-8
           and 6-9).

   mpeg4_unpack_bframes
       Unpack DivX-style packed B-frames.

       DivX-style packed B-frames are not valid MPEG-4 and were only a workaround for the broken
       Video for Windows subsystem.  They use more space, can cause minor AV sync issues, require
       more CPU power to decode (unless the player has some decoded picture queue to compensate
       the 2,0,2,0 frame per packet style) and cause trouble if copied into a standard container
       like mp4 or mpeg-ps/ts, because MPEG-4 decoders may not be able to decode them, since they
       are not valid MPEG-4.

       For example to fix an AVI file containing an MPEG-4 stream with DivX-style packed B-frames
       using ffmpeg, you can use the command:

               ffmpeg -i INPUT.avi -codec copy -bsf:v mpeg4_unpack_bframes OUTPUT.avi

   noise
       Damages the contents of packets or simply drops them without damaging the container. Can
       be used for fuzzing or testing error resilience/concealment.

       Parameters:

       amount
           A numeral string, whose value is related to how often output bytes will be modified.
           Therefore, values below or equal to 0 are forbidden, and the lower the more frequent
           bytes will be modified, with 1 meaning every byte is modified.

       dropamount
           A numeral string, whose value is related to how often packets will be dropped.
           Therefore, values below or equal to 0 are forbidden, and the lower the more frequent
           packets will be dropped, with 1 meaning every packet is dropped.

       The following example applies the modification to every byte but does not drop any
       packets.

               ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv

   null
       This bitstream filter passes the packets through unchanged.

   remove_extra
       Remove extradata from packets.

       It accepts the following parameter:

       freq
           Set which frame types to remove extradata from.

           k   Remove extradata from non-keyframes only.

           keyframe
               Remove extradata from keyframes only.

           e, all
               Remove extradata from all frames.

   text2movsub
       Convert text subtitles to MOV subtitles (as used by the "mov_text" codec) with metadata
       headers.

       See also the mov2textsub filter.

   trace_headers
       Log trace output containing all syntax elements in the coded stream headers (everything
       above the level of individual coded blocks).  This can be useful for debugging low-level
       stream issues.

       Supports H.264, H.265, MPEG-2 and VP9.

   vp9_metadata
       Modify metadata embedded in a VP9 stream.

       color_space
           Set the color space value in the frame header.

           unknown
           bt601
           bt709
           smpte170
           smpte240
           bt2020
           rgb
       color_range
           Set the color range value in the frame header.  Note that this cannot be set in RGB
           streams.

           tv
           pc

   vp9_superframe
       Merge VP9 invisible (alt-ref) frames back into VP9 superframes. This fixes merging of
       split/segmented VP9 streams where the alt-ref frame was split from its visible
       counterpart.

   vp9_superframe_split
       Split VP9 superframes into single frames.

   vp9_raw_reorder
       Given a VP9 stream with correct timestamps but possibly out of order, insert additional
       show-existing-frame packets to correct the ordering.

SEE ALSO

       ffmpeg(1), ffplay(1), ffprobe(1), libavcodec(3)

AUTHORS

       The FFmpeg developers.

       For details about the authorship, see the Git history of the project
       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in the FFmpeg source
       directory, or browsing the online repository at <http://source.ffmpeg.org>.

       Maintainers for the specific components are listed in the file MAINTAINERS in the source
       code tree.

                                                                      FFMPEG-BITSTREAM-FILTERS(1)