FFMPEG-BITSTREAM-FILTERS(1) FFMPEG-BITSTREAM-FILTERS(1)
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 (time_scale / num_units_in_display_tick) 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.
delete_padding
Deletes Padding OBUs.
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 except when said
packets already exactly begin with the extradata that is intended to be
added.
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 k.
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
dv_error_marker
Blocks in DV which are marked as damaged are replaced by blocks of the
specified color.
color
The color to replace damaged blocks by
sta A 16 bit mask which specifies which of the 16 possible error status
values are to be replaced by colored blocks. 0xFFFE is the default
which replaces all non 0 error status values.
ok No error, no concealment
err Error, No concealment
res Reserved
notok
Error or concealment
notres
Not reserved
Aa, Ba, Ca, Ab, Bb, Cb, A, B, C, a, b, erri, erru
The specific error status code
see page 44-46 or section 5.5 of
<http://web.archive.org/web/20060927044735/http://www.smpte.org/smpte_store/standards/pdf/s314m.pdf>
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.
pass
insert
remove
Default is pass.
sample_aspect_ratio
Set the sample aspect ratio of the stream in the VUI parameters.
See H.264 table E-1.
overscan_appropriate_flag
Set whether the stream is suitable for display using overscan or
not (see H.264 section E.2.1).
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 (time_scale / num_units_in_tick) 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).
zero_new_constraint_set_flags
Zero constraint_set4_flag and constraint_set5_flag in the SPS.
These bits were reserved in a previous version of the H.264 spec,
and thus some hardware decoders require these to be zero. The
result of zeroing this is still a valid bitstream.
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.
display_orientation
Insert, extract or remove Display orientation SEI messages. See
H.264 section D.1.27 and D.2.27 for syntax and semantics.
pass
insert
remove
extract
Default is pass.
Insert mode works in conjunction with "rotate" and "flip" options.
Any pre-existing Display orientation messages will be removed in
insert or remove mode. Extract mode attaches the display matrix to
the packet as side data.
rotate
Set rotation in display orientation SEI (anticlockwise angle in
degrees). Range is -360 to +360. Default is NaN.
flip
Set flip in display orientation SEI.
horizontal
vertical
Default is unset.
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 (time_scale /
num_units_in_tick). 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).
level
Set the level in the VPS and SPS. See H.265 section A.4 and tables
A.6 and A.7.
The argument must be the name of a level (for example, 5.1), a
general_level_idc value (for example, 153 for level 5.1), or the
special name auto indicating that the filter should attempt to
guess the level from the input stream properties.
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
Accepts an expression whose evaluation per-packet determines how
often bytes in that packet will be modified. A value below 0 will
result in a variable frequency. Default is 0 which results in no
modification. However, if neither amount nor drop is specified,
amount will be set to -1. See below for accepted variables.
drop
Accepts an expression evaluated per-packet whose value determines
whether that packet is dropped. Evaluation to a positive value
results in the packet being dropped. Evaluation to a negative value
results in a variable chance of it being dropped, roughly inverse
in proportion to the magnitude of the value. Default is 0 which
results in no drops. See below for accepted variables.
dropamount
Accepts a non-negative integer, which assigns a variable chance of
it being dropped, roughly inverse in proportion to the value.
Default is 0 which results in no drops. This option is kept for
backwards compatibility and is equivalent to setting drop to a
negative value with the same magnitude i.e. "dropamount=4" is the
same as "drop=-4". Ignored if drop is also specified.
Both "amount" and "drop" accept expressions containing the following
variables:
n The index of the packet, starting from zero.
tb The timebase for packet timestamps.
pts Packet presentation timestamp.
dts Packet decoding timestamp.
nopts
Constant representing AV_NOPTS_VALUE.
startpts
First non-AV_NOPTS_VALUE PTS seen in the stream.
startdts
First non-AV_NOPTS_VALUE DTS seen in the stream.
duration
d Packet duration, in timebase units.
pos Packet position in input; may be -1 when unknown or not set.
size
Packet size, in bytes.
key Whether packet is marked as a keyframe.
state
A pseudo random integer, primarily derived from the content of
packet payload.
Examples
Apply modification to every byte but don't drop any packets.
ffmpeg -i INPUT -c copy -bsf noise=1 output.mkv
Drop every video packet not marked as a keyframe after timestamp 30s
but do not modify any of the remaining packets.
ffmpeg -i INPUT -c copy -bsf:v noise=drop='gt(t\,30)*not(key)' output.mkv
Drop one second of audio every 10 seconds and add some random noise to
the rest.
ffmpeg -i INPUT -c copy -bsf:a noise=amount=-1:drop='between(mod(t\,10)\,9\,10)' output.mkv
null
This bitstream filter passes the packets through unchanged.
pcm_rechunk
Repacketize PCM audio to a fixed number of samples per packet or a
fixed packet rate per second. This is similar to the asetnsamples audio
filter but works on audio packets instead of audio frames.
nb_out_samples, n
Set the number of samples per each output audio packet. The number
is intended as the number of samples per each channel. Default
value is 1024.
pad, p
If set to 1, the filter will pad the last audio packet with
silence, so that it will contain the same number of samples (or
roughly the same number of samples, see frame_rate) as the previous
ones. Default value is 1.
frame_rate, r
This option makes the filter output a fixed number of packets per
second instead of a fixed number of samples per packet. If the
audio sample rate is not divisible by the frame rate then the
number of samples will not be constant but will vary slightly so
that each packet will start as close to the frame boundary as
possible. Using this option has precedence over nb_out_samples.
You can generate the well known 1602-1601-1602-1601-1602 pattern of
48kHz audio for NTSC frame rate using the frame_rate option.
ffmpeg -f lavfi -i sine=r=48000:d=1 -c pcm_s16le -bsf pcm_rechunk=r=30000/1001 -f framecrc -
pgs_frame_merge
Merge a sequence of PGS Subtitle segments ending with an "end of
display set" segment into a single packet.
This is required by some containers that support PGS subtitles (muxer
"matroska").
prores_metadata
Modify color property metadata embedded in prores stream.
color_primaries
Set the color primaries. Available values are:
auto
Keep the same color primaries property (default).
unknown
bt709
bt470bg
BT601 625
smpte170m
BT601 525
bt2020
smpte431
DCI P3
smpte432
P3 D65
transfer_characteristics
Set the color transfer. Available values are:
auto
Keep the same transfer characteristics property (default).
unknown
bt709
BT 601, BT 709, BT 2020
smpte2084
SMPTE ST 2084
arib-std-b67
ARIB STD-B67
matrix_coefficients
Set the matrix coefficient. Available values are:
auto
Keep the same colorspace property (default).
unknown
bt709
smpte170m
BT 601
bt2020nc
Set Rec709 colorspace for each frame of the file
ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt709:color_trc=bt709:colorspace=bt709 output.mov
Set Hybrid Log-Gamma parameters for each frame of the file
ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt2020:color_trc=arib-std-b67:colorspace=bt2020nc output.mov
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.
setts
Set PTS and DTS in packets.
It accepts the following parameters:
ts
pts
dts Set expressions for PTS, DTS or both.
duration
Set expression for duration.
time_base
Set output time base.
The expressions are evaluated through the eval API and can contain the
following constants:
N The count of the input packet. Starting from 0.
TS The demux timestamp in input in case of "ts" or "dts" option or
presentation timestamp in case of "pts" option.
POS The original position in the file of the packet, or undefined if
undefined for the current packet
DTS The demux timestamp in input.
PTS The presentation timestamp in input.
DURATION
The duration in input.
STARTDTS
The DTS of the first packet.
STARTPTS
The PTS of the first packet.
PREV_INDTS
The previous input DTS.
PREV_INPTS
The previous input PTS.
PREV_INDURATION
The previous input duration.
PREV_OUTDTS
The previous output DTS.
PREV_OUTPTS
The previous output PTS.
PREV_OUTDURATION
The previous output duration.
NEXT_DTS
The next input DTS.
NEXT_PTS
The next input PTS.
NEXT_DURATION
The next input duration.
TB The timebase of stream packet belongs.
TB_OUT
The output timebase.
SR The sample rate of stream packet belongs.
NOPTS
The AV_NOPTS_VALUE constant.
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 AV1, H.264, H.265, (M)JPEG, MPEG-2 and VP9, but depending on
the build only a subset of these may be available.
truehd_core
Extract the core from a TrueHD stream, dropping ATMOS data.
vp9_metadata
Modify metadata embedded in a VP9 stream.
color_space
Set the color space value in the frame header. Note that any frame
set to RGB will be implicitly set to PC range and that RGB is
incompatible with profiles 0 and 2.
unknown
bt601
bt709
smpte170
smpte240
bt2020
rgb
color_range
Set the color range value in the frame header. Note that any value
imposed by the color space will take precedence over this value.
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
(https://git.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
the FFmpeg source directory, or browsing the online repository at
<https://git.ffmpeg.org/ffmpeg>.
Maintainers for the specific components are listed in the file
MAINTAINERS in the source code tree.
FFMPEG-BITSTREAM-FILTERS(1)
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