
  FFmpeg Bitstream Filters Documentation


    Table of Contents

  *
    1 Description

    <#Description>
  *
    2 Bitstream Filters

    <#Bitstream-Filters>
      o
        2.1 aac_adtstoasc

        <#aac_005fadtstoasc>
      o
        2.2 av1_metadata

        <#av1_005fmetadata>
      o
        2.3 chomp

        <#chomp>
      o
        2.4 dca_core

        <#dca_005fcore>
      o
        2.5 dump_extra

        <#dump_005fextra>
      o
        2.6 dv_error_marker

        <#dv_005ferror_005fmarker>
      o
        2.7 eac3_core

        <#eac3_005fcore>
      o
        2.8 extract_extradata

        <#extract_005fextradata>
      o
        2.9 filter_units

        <#filter_005funits>
      o
        2.10 hapqa_extract

        <#hapqa_005fextract>
      o
        2.11 h264_metadata

        <#h264_005fmetadata>
      o
        2.12 h264_mp4toannexb

        <#h264_005fmp4toannexb>
      o
        2.13 h264_redundant_pps

        <#h264_005fredundant_005fpps>
      o
        2.14 hevc_metadata

        <#hevc_005fmetadata>
      o
        2.15 hevc_mp4toannexb

        <#hevc_005fmp4toannexb>
      o
        2.16 imxdump

        <#imxdump>
      o
        2.17 mjpeg2jpeg

        <#mjpeg2jpeg>
      o
        2.18 mjpegadump

        <#mjpegadump>
      o
        2.19 mov2textsub

        <#mov2textsub-1>
      o
        2.20 mp3decomp

        <#mp3decomp>
      o
        2.21 mpeg2_metadata

        <#mpeg2_005fmetadata>
      o
        2.22 mpeg4_unpack_bframes

        <#mpeg4_005funpack_005fbframes>
      o
        2.23 noise

        <#noise>
          +
            2.23.1 Examples

            <#Examples>
      o
        2.24 null

        <#null>
      o
        2.25 pcm_rechunk

        <#pcm_005frechunk>
      o
        2.26 pgs_frame_merge

        <#pgs_005fframe_005fmerge>
      o
        2.27 prores_metadata

        <#prores_005fmetadata>
      o
        2.28 remove_extra

        <#remove_005fextra>
      o
        2.29 setts

        <#setts>
      o
        2.30 text2movsub

        <#text2movsub-1>
      o
        2.31 trace_headers

        <#trace_005fheaders>
      o
        2.32 truehd_core

        <#truehd_005fcore>
      o
        2.33 vp9_metadata

        <#vp9_005fmetadata>
      o
        2.34 vp9_superframe

        <#vp9_005fsuperframe>
      o
        2.35 vp9_superframe_split

        <#vp9_005fsuperframe_005fsplit>
      o
        2.36 vp9_raw_reorder

        <#vp9_005fraw_005freorder>
  *
    3 See Also

    <#See-Also>
  *
    4 Authors

    <#Authors>

  *
    Description

    <#Description>
  *
    Bitstream Filters

    <#Bitstream-Filters>
  *
    See Also

    <#See-Also>
  *
    Authors

    <#Authors>


    1 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.


    2 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

    <#aac_005fadtstoasc>
  *
    av1_metadata

    <#av1_005fmetadata>
  *
    chomp

    <#chomp>
  *
    dca_core

    <#dca_005fcore>
  *
    dump_extra

    <#dump_005fextra>
  *
    dv_error_marker

    <#dv_005ferror_005fmarker>
  *
    eac3_core

    <#eac3_005fcore>
  *
    extract_extradata

    <#extract_005fextradata>
  *
    filter_units

    <#filter_005funits>
  *
    hapqa_extract

    <#hapqa_005fextract>
  *
    h264_metadata

    <#h264_005fmetadata>
  *
    h264_mp4toannexb

    <#h264_005fmp4toannexb>
  *
    h264_redundant_pps

    <#h264_005fredundant_005fpps>
  *
    hevc_metadata

    <#hevc_005fmetadata>
  *
    hevc_mp4toannexb

    <#hevc_005fmp4toannexb>
  *
    imxdump

    <#imxdump>
  *
    mjpeg2jpeg

    <#mjpeg2jpeg>
  *
    mjpegadump

    <#mjpegadump>
  *
    mov2textsub

    <#mov2textsub-1>
  *
    mp3decomp

    <#mp3decomp>
  *
    mpeg2_metadata

    <#mpeg2_005fmetadata>
  *
    mpeg4_unpack_bframes

    <#mpeg4_005funpack_005fbframes>
  *
    noise

    <#noise>
  *
    null

    <#null>
  *
    pcm_rechunk

    <#pcm_005frechunk>
  *
    pgs_frame_merge

    <#pgs_005fframe_005fmerge>
  *
    prores_metadata

    <#prores_005fmetadata>
  *
    remove_extra

    <#remove_005fextra>
  *
    setts

    <#setts>
  *
    text2movsub

    <#text2movsub-1>
  *
    trace_headers

    <#trace_005fheaders>
  *
    truehd_core

    <#truehd_005fcore>
  *
    vp9_metadata

    <#vp9_005fmetadata>
  *
    vp9_superframe

    <#vp9_005fsuperframe>
  *
    vp9_superframe_split

    <#vp9_005fsuperframe_005fsplit>
  *
    vp9_raw_reorder

    <#vp9_005fraw_005freorder>


      2.1 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.


      2.2 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.


      2.3 chomp

Remove zero padding at the end of a packet.


      2.4 dca_core

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


      2.5 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


      2.6 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


      2.7 eac3_core

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


      2.8 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.


      2.9 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


      2.10 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


      2.11 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.


      2.12 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.


      2.13 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.


      2.14 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.


      2.15 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.


      2.16 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


      2.17 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


      2.18 mjpegadump

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


      2.19 mov2textsub

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

See also the
text2movsub

<#text2movsub> filter.


      2.20 mp3decomp

Decompress non-standard compressed MP3 audio headers.


      2.21 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).


      2.22 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


      2.23 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

    <#Examples>


        2.23.1 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


      2.24 null

This bitstream filter passes the packets through unchanged.


      2.25 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
(ffmpeg-filters)asetnsamples audio filter

<file:///C:/Utils/ffmpeg-6.1.1-essentials_build/doc/ffmpeg-filters.html#asetnsamples>
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 -


      2.26 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|).


      2.27 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


      2.28 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.


      2.29 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.


      2.30 text2movsub

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

See also the
mov2textsub

<#mov2textsub> filter.


      2.31 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.


      2.32 truehd_core

Extract the core from a TrueHD stream, dropping ATMOS data.


      2.33 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’


      2.34 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.


      2.35 vp9_superframe_split

Split VP9 superframes into single frames.


      2.36 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.


    3 See Also

ffmpeg

<file:///C:/Utils/ffmpeg-6.1.1-essentials_build/doc/ffmpeg.html>,
ffplay

<file:///C:/Utils/ffmpeg-6.1.1-essentials_build/doc/ffplay.html>,
ffprobe

<file:///C:/Utils/ffmpeg-6.1.1-essentials_build/doc/ffprobe.html>,
libavcodec

<file:///C:/Utils/ffmpeg-6.1.1-essentials_build/doc/libavcodec.html>


    4 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.

This document was generated using
/makeinfo/

<https://www.gnu.org/software/texinfo/>.

