filters oneliners
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This page contains one-liners illustrating the many possibilities of GPAC filters architecture. For a more detailed information, it is highly recommended that you read:
- the general concepts page
- the gpac application help
To get a better understanding of each command illustrated in this case, it is recommended to:
- run the same command with
-graphspecified to see the filter graph associated - read the help of the different filters in this graph using
gpac -h filter_name
Whenever an option is specified, e.g. dest.mp4:foo, you can get more info and locate the parent filter of this option using gpac -h foo.
The filter session is by default quiet, except for warnings and error reporting. To get information on the session while running, use -r option. To get more runtime information, use the log system.
Given the configurable nature of the filter architecture, most examples given in one context can be reused in another context. For example:
- from the dump examples:
gpac -i source reframer:saps=1 -o dump/$num$.png
- from the encode examples:
gpac -i source ffsws:osize=320x240 enc:c=avc:b=1m -o dst.mp4
This can be recombine as dump key frames to png while rescaling:
gpac -i source reframer:saps=1 ffsws:osize=128x72 -o dump/$num$.png
NOTE The command lines given here are usually using a local file for source or destination URLs, but they can work with remote URLs as well.
Reminder Most filters are never specified at the prompt, they are dynamically loaded during the graph resolution. GPAC filters can use either:
- global options, e.g.
--foo, applying to each instance of any filter defining thefoooption, - local options to a given filter and any filters dynamically loaded, e.g.
:foo. This is called argument inheriting.
NOTE This page is under permanent construction, feel free to contribute !
Check if a source is supported and get quick information on the media streams - see filter, howto
gpac -i source inspect
gpac -info source
Check if a source is supported and get verbose information on the media streams - see filter, howto
gpac -i source inspect:full
Check if a source is supported and get all possible media stream states in the media streams (codec change & co) - see filter, howto
gpac -i source inspect:allp
Dump all packets info of a source from 60 to 80 seconds, listing one stream after the other - see filter
gpac -i source inspect:deep:start=60:dur=20:interleave=false
Dump CTS, DTS, random access and size of packets of a source to a log file - see filter, howto
gpac -i source inspect:deep:fmt="%dts% %dts% %sap% %size%%lf":log=mylogs.txt
Analyze packets of a source - see filter, howto
gpac -i source.264 inspect:deep:analyze=on
Note This is similar to (but more complete than) MP4Box -dnal option
Count all streams in a source - see filter, doc
res = `gpac -i source probe`
Count all AC3 audio streams in a source - see filter, doc
res = `gpac -i source @#CodecID=ac3 probe`
Extract AVC track, potentially transcoding - see filter
gpac -i source -o dst.264
Extract AVC track if any - see filter
gpac -i source @#CodecID=avc -o dst.264
Extract AAC track - see filter
gpac -i source -o dst.aac
Decode audio track to 16 bit pcm - see filter
gpac -i source -o dst.wav
Decode video track to YUV 420 - see filter
gpac -i source -o dst_$Width_$Height$.yuv
Decode video track starting from frame 2s for 1s to YUV 420 - see filter
gpac -i source -o dst_$Width_$Height$.yuv:start=2:dur=1
Dump video track key frames to PNG see filter
gpac -i source reframer:saps=1 -o dump/$num$.png
Extract all tracks - see filter
gpac -i source reframer -o dump_$ID$:dynext
Extract all audio tracks - see doc
gpac -i source reframer @#audio -o dump_$ID$:dynext
Extract all AAC audio tracks - see doc
gpac -i source reframer @#CodecID=aac -o dump_$ID$:dynext
Mux sources to MP4 - see filter
gpac -i source -i source2 -o dst.mp4
Mux sources to MP4 specifying language - see doc
gpac -i source -i source2:#Language=fr -o dst.mp4
Mux sources to fMP4 - see filter
gpac -i source -i source2 -o dst.mp4:frag
Force remultiplexing an MP4 (all syntaxes are equivalent) - see filter
gpac -i source.mp4 reframer -o dst.mp4
gpac -i source.mp4 -o dst.mp4:remux
gpac -i source.mp4 -o dst.mp4:store=inter
gpac -i source.mp4 -o dst.mp4:inter
Mux sources to single program MPEG-2 TS - see filter
gpac -i source -i source2 -o dst.ts
Mux sources to MPEG-2 TS, specifying service ID - see filter
gpac -i source:#ServiceID=1 -i source2:#ServiceID=2 -o dst.ts
Mux sources to MPEG-2 TS with a target mux rate - see filter
gpac -i source:#ServiceID=1 -i source2:#ServiceID=2 -o dst.ts:rate=10m
Mux sources to MKV (for builds with FFMPEG support) - see filter
gpac -i source -o dst.mkv
Remux sources to MP4 forcing bitstream reparsing (all syntaxes are equivalent)
gpac -i source unframer -o dst.mp4
MP4Box -add source:unframer -new dst.mp4
Encode an MP3 to an AAC file at 100 kbps - see filter
gpac -i source.mp3 -o dst.aac:b=100k
Encode an MP3 to AAC in MP4 file at 100 kbps - see filter
gpac -i source.mp3 enc:c=aac:b=100k -o dst.mp4
Transcode to AAC at 100 kbps and AVC at 1m, intra every 2s - see filter
gpac -i source enc:c=aac:b=100k:FID=1 enc:c=avc:b=1m:fintra=2:FID=2 -o dst.mp4:SID=1,2
Rescale video and encode to AVC at 1m, leaving other streams if any unmodified - see filter
gpac -i source ffsws:osize=320x240 enc:c=avc:b=1m -o dst.mp4
Rescale YUV video and encode to AVC at 1m - see filter
gpac -i source.yuv:size=1280x720 ffsws:osize=320x240 enc:c=avc:b=1m -o dst.mp4
Resample audio to 48khz - see filter
gpac -i source resample:sr=48k -o dump.pcm
gpac -i source.pcm:sr=44100:ch=1 resample:sr=48k -o dump.pcm
Setting FFmpeg and x264 options - see filter
gpac -i vid.mp4 enc:c=avc:b=2m:fintra=2:vprofile=baseline:preset=ultrafast:tune=zerolatency::x264-params=no-mbtree:sliced-threads:sync-lookahead=0 -o dst.mp4
Transcode to AVC 1mbps and aac 128k while monitoring video output and filter stats- see filter
gpac -i source enc:c=avc:b=1m enc:c=aac:b=128k -o dst.mp4 vout:vsync=0 -r
Downscale and transcode to AVC 1mbps and aac 128k while monitoring video output - see filter
gpac -i source ffsws:osize=256x144 enc:c=avc:b=1m enc:c=aac:b=128k -o dst.mp4 vout:vsync=0
Use two-pass encoding with FFMPEG (libx264 only for GPAC 2.0, all codecs for higher versions) - see filter
#first pass
gpac -i source enc:c=avc:b=3m:pass1 -o null
#second pass
gpac -i source enc:c=avc:b=3m:pass2 -o dst.mp4
rescale without respecting aspect ratio
gpac -i source1.mp4 ffsws:osize=512x512 vout
rescale respecting aspect ratio and pad color to red
gpac -i source1.mp4 ffsws:osize=512x512:keepar=full:padclr=red vout
rescale without respecting aspect ratio nut set output aspect ratio, output video will be 340x512 (340=510*2/3 )
gpac -i source1.mp4 ffsws:osize=510x512:osr=3/2 vout
Encrypt and dash several sources using a single drm configuration - see filter
gpac -i source1.mp4 -i source2.aac cecrypt:cfile=drm.xml -o live.mpd
Encrypt and dash several sources using one drm configuration per source - see filter
gpac -i source1.mp4:#CryptInfo=drm1.xml -i source2.aac:#CryptInfo=drm1.xml cecrypt -o live.mpd
perform pre-dashing before encryption for key roll at segment boundaries - see filter
gpac -i source.mp4 dasher:gencues cecrypt:cfile=roll_seg.xml -o live.mpd
Grab a compressed stream (e.g. AVC|H264) from stdin, remove all non I-frames and non-video PIDs and output as raw 264 over stdout - see filter howto
gpac -i - @#video reframer:saps=1 -o stdout:ext=264
Grab a raw stream (e.g. YUV420) from stdin and output as raw 264 over stdout - see filter howto
gpac -i stdin:ext=yuv:size=1280x720 -o stdout:ext=264
Grab a TS UDP stream and remux as fragmented mp4 over a named pipe - see filter howto
gpac -i udp://234.0.0.1:1234 -o pipe://mypipe:ext=mp4:mkp:frag
Mux source to real-time M2TS UDP multicast stream - see filter howto
gpac -i source.mp4 -o udp://234.0.0.1:1234/:ext=ts:realtime
See Howtos DASH, DASH Low Latency and dasher filter.
Generating a live profile, static MPD
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd
Generating a onDemand profile, static MPD from a source
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd:profile=onDemand
Generating a HLS with one file per segment
gpac -i source.mp4 -i source2.mp4 -o dash/live.m3u8
Generating a HLS with single file from a source
gpac -i source.mp4 -i source2.mp4 -o dash/live.m3u8:sfile
Generating a HLS and MPD with one file per segment
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd:dual
Generating a HLS with single file and MPD from a source
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd:dual:profile=onDemand
Generating a live profile, dynamic offering
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd:dmode=dynamic
Generating a live profile, dynamic offering with time regulation at each segment
gpac -i source.mp4 -i source2.mp4 -o dash/live.mpd:dmode=dynamic:sreg
Generating a live profile, low-latency, dynamic offering with time regulation at each frame
gpac -i source.mp4 -i source2.mp4 reframer:rt=on -o dash/live.mpd:dmode=dynamic:segdur=1:cdur=0.1
Generating a live profile, low-latency, dynamic offering with time regulation at each frame and offering it as HTTP, with 1h timeshift
gpac -i source.mp4 -i source2.mp4 reframer:rt=on -o http://127.0.0.1:8080/live.mpd:gpac:dmode=dynamic:segdur=1:cdur=0.1:rdirs=/tmp:tsb=3600
Looping two sources to simulate a live over http
gpac --floop=-1 flist:srcs=source.mp4 flist:srcs=source2.mp4 reframer:rt=on -o http://127.0.0.1:8080/live.mpd:gpac:dmode=dynamic:segdur=1:cdur=0.1:rdirs=/tmp:tsb=3600
Live UTC counter single resolution over HTTP in low latency
gpac avgen enc:c=aac:b=100k:FID=1 enc:c=avc:b=2m:fintra=1:FID=2 -o http://127.0.0.1:8080/live.mpd:gpac:SID=1,2:dmode=dynamic:segdur=1:cdur=0.1:rdirs=/tmp
Live UTC counter 2 resolutions over HTTP in low latency
gpac avgen:sizes=1280x720,1920x1080:rates=2M,5M enc:c=aac:b=100k:FID=1 enc:c=avc:fintra=1:FID=2 -o http://127.0.0.1:8080/live.mpd:gpac:SID=1,2:dmode=dynamic:segdur=1:cdur=0.1:rdirs=/tmp
Generate trick mode from source1 and use both source1 A+V, source2 V and trick mode in dash:
gpac -i source1.mp4 @#video reframer:saps=1 -i source2.mp4 @#video @1 @@ -o dash/live.mpd
Insert custom DASH tags in manifest:
gpac -i source:#RDesc=<rep_desc>bar</rep_desc>:#ASCDesc=<as_desc>bar</as_desc>:#PDesc=<p_desc>bar</p_desc> -o manifest.mpd
Insert custom HLS tags in manifest (global tags use hlsx option and per-PID tags use HLSMExt property) and variant playlists (HLSVExt PID property):
gpac -i source::#HLSMExt=vfoo,vbar=video::#HLSVExt=#fooVideo,#bar1=optVideo -i source2::#HLSMExt=afoo,abar=audio-en::#HLSVExt=#fooAudio,#bar1=optAudio -o manifest.m3u8::hlsx=#SomeExt,#SomeOtherExt=true
Note: If the source is an MP4 file, it is much simpler/faster to perform these operations using MP4Box
Add 200 ms delay to audio (audio later than other streams) - see filter
gpac -i source restamp:delay_a=2/10 -o dst
Add -1s delay to audio (audio earlier than other streams) - see filter
gpac -i source restamp:delay_a=-1 -o dst
Speedup all tracks except audio by 10% (speed 1.1) - see filter
gpac -i source restamp:fps=-11/10 -o dst
Change video FPS to 29.97 with frame cloning - see filter
gpac -i source restamp:fps=30000/1001:rawv=force -o dst
Extract from 1min to 2min30s - see filter
gpac -i source reframer:xs=T00:01:00:xe=T00:02:30 -o dst
Extract from 1min to 2min30s after decoding (sample-accurate audio) - see filter
gpac -i source reframer:raw=av::xs=T00:01:00:xe=T00:02:30 -o dst
Extract from 1min to 2min30s and 5min20s to 6min - see filter
gpac -i source reframer:xs=T00:01:00,T00:05:20:xe=T00:02:30,T00:06:00 -o dst
Extract from 5min20s to end - see filter
gpac -i source reframer:xs=T00:05:20 -o dst
Extract from 1min to 2min30s and 5min20s to end - see filter
gpac -i source reframer:xs=T00:01:00,T00:05:20:xe=T00:02:30 -o dst
Loop file forever playback - see filter
gpac flist:srcs=source.mp4:floop=-1 aout vout
Read all PNGs from a directory, sorting by creation date - see filter
gpac flist:srcs=src/*.png:fsort=date vout
Resize a set of videos with aspect ratio respected - see filter
gpac flist:srcs=1.mp4,2.mp4,3.mp4 ffsws:osize=1280x720:keepar=full c=avc -o dst.mp4
Concatenate all MP4 from directory dir:
gpac flist:srcs=*.mp4 vout
#same as above but through a playlist
ls *.mp4 > pl.m3u
gpac -i pl.m3u vout
Basic playback - see howto
gpac -play source
Video only playback - see howto
gpac -i source vout
Video only playback, no sync - see howto
gpac -i source vout:sync=0
Audio only playback - see howto
gpac -i source aout
Single-threaded GUI playback - see howto
gpac compositor:player=gui:src=source
gpac -threads=0 -gui source
Single-threaded compositor playback (available as alias -mp4c) - see howto
gpac compositor:player=base:src=source
gpac -threads=0 -mp4c source
NOTE The -mp4c and -gui aliases will by default set -threads=2.
Create thumbnails based on key frames in source, with at least 30 seconds between frames and dynamic thumbnail height
gpac -i src reframer:saps=1 thumbs:snap=30 -o dump_$num$.png
Create thumbnails based on key frames in source, with at least 30 seconds between frames in a 6x6 layout with 5x downscale and json generation
gpac -i src reframer:saps=1 thumbs:snap=30:grid=6x6:list=thumbs.json:scale=5 -o dump_$num$.png
Create thumbnails of scene cuts based on key frames in source
gpac -i src reframer:saps=1 thumbs:snap=0:mae=15 -o dump_$num$.png
Use thumbnailer to overlay frame time over video
gpac -i src thumbs:grid=1x1:txt='$time$' vout
Decode source disabling hardware decoders:
gpac -blacklist=vtbdec,nvdec source vout
Decode source MP4 enabling only the minimum filters:
gpac -blacklist=-fin,mp4dmx,ffdec,vout source.mp4 vout
Set gpac as RTMP output server
gpac -i src.mp4 -o rtmp://127.0.0.1:8888/live:gpac:ffmt=flv:rtmp_listen=1
Read from RTMP server
gpac -i rtmp://127.0.0.1:8888/live vout aout
Set gpac as RTMP input server, and use another instance to push
gpac -i rtmp://127.0.0.1:8888/live:gpac:rtmp_listen=1 vout aout
gpac -i src.mp4 -o rtmp://127.0.0.1:8888/live:gpac:ffmt=flv
Read audio and video from device
gpac -i av:// vout aout
Read video from device
gpac -i video:// vout
Read audio from device
gpac -i audio:// aout
read from screen on OSX
gpac -i video://:fmt=avfoundation:dev=screen0 vout
read from screen on Linux
gpac -i video://:fmt=x11grab:dev=:0.0 vout
Read audio after filter from libavfilter (compressor here)
gpac -i audio.mp4 ffavf:afmt=s16:sr=44100::f=acompressor aout
Read video after filter from libavfilter (negate here)
gpac -i video.mp4 ffavf::f=negate vout
Use audio to video filter from libavfilter (showspectrum here)
gpac -i audio.mp4 ffavf:pfmt=yuv::f=showspectrum=size=320x320 aout vout
Use 2 video to video filter from libavfilter (overlay here)
gpac -i video1.mp4:#ffid=a -i video2.mp4:#ffid=b ffavf:pfmt=yuv::f=[a][b]overlay=main_w-overlay_w-10:main_h-overlay_h-10 vout
Compute PSNR
gpac -i video.mp4:#ffid=dist -i ref.mp4:#ffid=ref ffavf::'f=[dist][ref]psnr=f=psnr.log' -o null
Compute SSIM
gpac -i video.mp4:#ffid=dist -i ref.mp4:#ffid=ref ffavf::'f=[dist][ref]ssim=f=ssim.log' -o null
Compute PSNR and SSIM
gpac -i video.mp4:#ffid=dist -i ref.mp4:#ffid=ref \
@@ @@1 ffavf::'f=[dist][ref]psnr=f=psnr2.log' @ -o null \
@@ @@1 ffavf::f='[dist][ref]ssim=f=ssim2.log' @ -o null
SRT session from local file (requires FFMPEG with SRT support)
#player listening for SRT handshake
gpac -play srt://127.0.0.1:1234:gpac:mode=listener
#streamer with real-time regulation
gpac -i video.mp4 reframer:rt=on -o srt://127.0.0.1:1234:gpac:ffmt=mpegts
SRT session from avgen filter (requires FFMPEG with SRT support)
#player listening for SRT handshake
gpac -play srt://127.0.0.1:1234:gpac:mode=listener
#streamer with real-time regulation
gpac avgen reframer:rt=on c=avc c=aac -o srt://127.0.0.1:1234:gpac:ffmt=mpegts
All examples give the content of the JSON playlist (named mix.json here) - see filter, howto
The result can be viewed using gpac avmix:pl=mix.json vout (live mode) or gpac avmix:live=0:pl=mix.json vout (offline mode).
Insert text over video:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source.mp4"}] } ] },
{"sources": ["seq1"]},
{"x": 0, "y": -45, "width": 100, "height": 10, "text": ["Some nice text !"], "size": 60, "fill": "black", "line_width": -2, "line_color": "white"}
]
Insert last two lines of text.txt over video:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source.mp4"}] } ] },
{"sources": ["seq1"]},
{"x": 0, "y": -40, "width": 100, "height": 10, "text": ["text.txt", 2], "size": 60, "fill": "black", "line_width": -2, "line_color": "white"}
]
Mix two videos with blending:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1", "seq2"], "mix": { "type": "mix"}, "mix_ratio": 0.5 }
]
Side by side videos:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source1.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1"], "x": -25, "y": 0, "width": 50, "height": 100, "volume":0},
{"sources": ["seq2"], "x": 25, "y": 0, "width": 50, "height": 100, "volume":0}
]
Picture in picture video with alpha (source2 can be a video or an image) :
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source1.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1"]},
{"sources": ["seq2"], "x": 35, "y": 35, "width": 20, "height": 20, "alpha":0.5}
]
Picture in picture video with shape and alpha:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source1.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1"]},
{"sources": ["seq2"], "x": 35, "y": 35, "width": 20, "height": 20, "alpha":0.5, "shape": "ellipse", "line_width":2, "line_color":"cyan"}
]
Picture in picture video with alpha and rotation along Y axis (perspective texture mapping):
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source1.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1"]},
{"sources": ["seq2"], "x": 35, "y": 35, "width": 20, "height": 20, "alpha":0.5, "rotation": "-30", "axis":[0,1,0]}
]
Moving picture in picture video with animated alpha:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source1.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{"sources": ["seq1"]},
{"id": "pip" "sources": ["seq2"], "x": 35, "y": 35, "width": 20, "height": 20, "alpha":0.5},
{"start": 0, "loop": true, "dur": 8, "keys": [0, 0.25, 0.5, 0.75, 1], "anims": [
{"values": [35, -35, -35, 35, 35], "targets": ["pip@x"]},
{"values": [35, 35, -35, -35, 35], "targets": ["pip@y"]},
{"values": [1, 0, 1, 0, 1], "targets": ["logo@alpha"]}
]
}
]
Mix two videos with animated slide effect:
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source.mp4"}] } ] },
{ "id": "seq2", "seq": [ { "src": [{"in": "source2.mp4"}] } ] },
{ "id": "scene", "sources": ["seq1", "seq2"], "mix": { "type": "swipe"}, "mix_ratio": 0.5 },
{"start": 0, "loop": true, "dur": 4, "keys": [0, 0.5, 1], "anims": [
{"values": [1, 0, 1], "targets": ["scene@mix_ratio"]}
]
}
]
Fractal-like animated video reuse
[
{ "id": "seq1", "seq": [ { "src": [{"in": "source.mp4"}] } ] },
{ "id": "gr1", "scenes": [
{"sources": ["seq1"]},
{"id":"use", "use": "gr1", "rotation": 10, "hscale": 0.9, "vscale": 0.9, "use_depth": 10}
]
},
{ "start": 0, "loop": true, "dur": 2, "keys": [0, 0.5, 1], "anims": [
{"values": [0, 20, 0], "targets": ["use@use_depth"]}
]
}
]
Various Topic
- File Inspection
- Using RAW formats
- Encoding
- Using data pipes
- Using sockets
- MP4Box vs gpac
- MP4Box and filters
- Custom ISOBMFF files
- Simulating Real-Time sources
- Working with Network Captures
- Playlists/Splicing/Ad Insertion
- ROUTE & ATSC3.0 services
- Logging in GPAC
- GPAC and Python
- GPAC and NodeJS
- In-place Editing
- Audio-Video Mixer
- Dynamic Rate Control
Categories