+Service Documentation
+
+Authors: Charles Yates <charles.yates@pandora.be>
+ Dan Dennedy <dan@dennedy.org>
+Last Revision: 2009-05-08
+
+
+SERVICES
+--------
+
+ Services marked as "(Proprietary)" are not distributed with the LGPL
+ version of mlt.
+
Producers
---------
- ffmpeg
+ avformat
+
+ Description
+
+ ffmpeg libavformat based producer for video and audio.
+
+ Constructor Argument
+
+ 'file' - a filename specification or URL in the form:
+ [{protocol}|{format}]:{resource}[?{format-parameter}[&{format-parameter}...]]
+ For example, video4linux:/dev/video1?width:320&height:240
+ Note: on the bash command line, & must be escaped as '\&'.
+ Also, note the use of ':' instead of '=' for parameters.
+ Use 'ffmpeg -formats' to see a list of supported protocols
+ and formats.
+
+ Details
+
+ Format parameters only appear to be useful with 'video4linux' or
+ 'audio_device' formats. For 'video4linux' the parameters are
+ width, height, frame_rate, frame_rate_base, and standard (ntsc|pal).
+ For 'audio_device' the parameters are channels and sample_rate.
+
+ Initialisation Properties
+
+ int video_index - index of video stream to use (-1 is off)
+ int audio_index - index of audio stream to use (-1 is off)
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ string resource - file location
+ double source_fps - the framerate of the resource
+ double aspect_ratio - sample aspect ratio of the resource
+ - this is determined on every frame read
+
+ Dependencies
+
+ ffmpeg
- Description
+ Known Bugs
- Test case pipe based producer for video and audio.
+ Audio sync discrepancy with some content.
+ Not all libavformat supported formats are seekable.
+ Fails to play beyond first frame of video of sources with PTS not
+ starting at 0 (video4linux).
- Constructor Argument
+ loader
- 'file' - produce a/v from file
- v4l - produce a/v from video4linux and dsp device
+ Description
- Initialisation Properties
+ A friendly giant that likes to rhyme and throw rocks
- string video_type - "file" or "v4l"
- string video_file - file or v4l device
- string video_size - WxH of video to produce (default: "")
- int video_loop - loop video until audio exhausted (default: 0)
- string audio_type - "file" or "dsp"
- string audio_file - file or dsp device
- int audio_rate - audio frequency (default: 48000)
- int audio_channels - audio channels (default: 2)
- int audio_track - audio track to use (default: 0)
- int audio_loop - loop audio until video exhausted (default: 0)
- timecode in - in point
- timecode out - out point
- double fps - output frames per second (default: 25)
- double aspect_ratio - aspect ratio of video
+ Constructor Argument
- Read Only Properties
+ 'file' - a filename specification:
+ [{mlt-service}:]{resource} | {mlt-service}
+ - can also be the name of a producer service that can
+ accept the resource specified post construction.
- string resource - file or "v4l"
- int end_of_clip - holds 1 when input is exhausted
+ Initialisation Properties
- Dependencies
+ int in - in point
+ int out - out point
+ + all producer initialising properties
- ffmpeg executable.
+ Read Only Properties
- Known Bugs
+ string resource - file location
+ + all producer read only properties
- in point setting is broken.
+ Details
- Implementation does not allow fast random access.
+ This producer has two roles:
+ 1. it handles the mappings of all file names to the other
+ producers;
+ 2. it attaches normalising filters (rescale, resize and resample)
+ to the producers (when necessary).
+
+ This producer simplifies many aspects of use. Essentially, it
+ ensures that a consumer will receive images and audio precisely as
+ they request them.
+
+ Dependencies
+
+ all.
+
+ Known Bugs
+
+ None.
+
+
+ colour
+
+ Description
+
+ A simple colour generator.
+
+ Constructor Argument
+
+ colour - A colour value is a hexadecimal representation of RGB plus
+ alpha channel as 0xrrggbbaa.
+ - Also colours can be the words: white, black, red, green,
+ or blue.
+ - The default colour is black.
+
+ Initialisation Properties
+
+ none
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+
libdv
- Description
+ Description
- libdv based decoder for video and audio.
+ libdv based decoder for video and audio.
- Constructor Argument
+ Constructor Argument
- 'file' - produce a/v from file
+ 'file' - produce a/v from file
- Initialisation Properties
+ Initialisation Properties
- timecode in - in point
- timecode out - out point
+ int in - in point
+ int out - out point
- Read Only Properties
+ Read Only Properties
- string resource - file location
- double fps - output frames per second
- double aspect_ratio - aspect ratio of video]
- timecode length - duration of resource (in seconds)
+ string resource - file location
+ double fps - output frames per second
+ int length - duration of resource (in frames)
+
+ Mutable Properties
+
+ string quality - one of "best," "fast" or anything else chooses
+ medium.
- Dependencies
+ Dependencies
- libdv.
+ libdv.
- Known Bugs
+ Known Bugs
- None.
+ DVCPRO is incorrectly identified as 16:9 aspect ratio. You must use
+ libdv from CVS or a post 0.101 release.
- mcdv
+ mcdv (Proprietary)
- Description
+ Description
- Mainconcept based dv decoder for video and audio.
+ MainConcept based dv decoder for video and audio.
- Constructor Argument
+ Constructor Argument
- 'file' - produce a/v from file
+ 'file' - produce a/v from file
- Initialisation Properties
+ Initialisation Properties
- timecode in - in point
- timecode out - out point
+ int in - in point
+ int out - out point
- Read Only Properties
+ Read Only Properties
- string resource - file location
- double fps - output frames per second
- double aspect_ratio - aspect ratio of video
- timecode length - duration of resource (in seconds)
+ string resource - file location
+ double fps - output frames per second
+ int length - duration of resource (in frames)
- Dependencies
+ Dependencies
- mainconcept dv sdk and libdv.
- "dv_sdk" installed parallel to mlt.
+ MainConcept DV or DVCPRO SDK, libdv.
+ "dv_sdk" installed parallel to mlt.
- Known Bugs
+ Known Bugs
- Can be problematic with source NTSC DV files? really? yes - try
- playing pond.dv...
+ None
- mcmpeg
+ mcmpeg (Proprietary)
+
+ Description
+
+ MainConcept based mpeg decoder for video and audio.
+
+ Constructor Argument
- Description
+ 'file' - produce a/v from file
- Mainconcept based mpeg decoder for video and audio.
+ Initialisation Properties
- Constructor Argument
+ int in - in point
+ int out - out point
- 'file' - produce a/v from file
+ Read Only Properties
- Initialisation Properties
+ string resource - file location
+ double fps - output frames per second
+ double aspect_ratio - sample aspect ratio of video
+ int length - duration of resource (in frames)
+
+ Dependencies
- timecode in - in point
- timecode out - out point
+ MainConcept MPEG SDK.
+ "mpeg_sdk_release" installed parallel to mlt.
- Read Only Properties
+ Known Bugs
- string resource - file location
- double fps - output frames per second
- double aspect_ratio - aspect ratio of video
+ None.
- Dependencies
+ noise
- mainconcept mpeg sdk.
- "mpeg_sdk_demo" installed parallel to mlt.
+ Description
- Known Bugs
+ White noise producer
- None.
+ Constructor Argument
+
+ none
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ string resource - file location
+ double fps - output frames per second
+ double aspect_ratio - sample aspect ratio of video
+ int length - duration of resource (in frames)
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
pango
-
- Description
- A title generator that uses the Pango international text layout
- and Freetype2 font renderer.
+ Description
+
+ A title generator that uses the Pango international text layout
+ and Freetype2 font renderer.
+
+ Constructor Argument
+
+ string file - a text file containing Pango markup, see:
+ http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html
+ - requires xml-like encoding special chars from:
+ <, >, & -to- <, >, &
+
+ Details
+
+ Supplying a filename with extension ".txt" causes the loader
+ producer to load with pango. If the filename begins with "+" the
+ pango producer interprets the filename as pango text. This is a
+ shortcut to embed titles in melt commands. For MLT XML, it is
+ recommended that you embed the title text in the property value.
+
+ Pango has builtin scaling. It will rescale the originally rendered
+ title to whatever the consumer requests. Therefore, it will lose
+ its aspect ratio if so requested, and it is up to the consumer to
+ request a proper width and height that maintains the image aspect.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ string markup - a string containing Pango markup see:
+ http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html
+ - requires xml-like encoding special chars from:
+ <, >, & -to- <, >, &
+ string fgcolour - an RGBA colour specification of the text
+ (i.e. 0xrrggbbaa)
+ string bgcolour - an RGBA colour of the background rectangle
+ string align - paragraph alignment: left, centre, right
+ - also, numbers 0, 1 and 2 can be used respectively.
+ int pad - the number of pixels to pad the background rectangle
+ beyond edges of text. default 0.
+ string markup - see constructor argument
+ string text - non-markup string in UTF-8 encoding (can contain
+ markup chars un-encoded)
+ string font - the default typeface to use when not using markup.
+ default "Sans 48". FreeType2 renders at 72 dpi.
+ string encoding - the text encoding type of the input if not UTF-8.
+ - see 'iconv --list' for a list of possible inputs.
+ int weight - the weight of the font (default is 400)
+
+ Read Only Properties
+
+ string resource - the text/markup file or "pango" if no file.
+ int real_width - the original, unscaled width of the rendered title.
+ int real_height - the original, unscaled height of the title.
+ int width - the last requested scaled image width.
+ int height - the last requested scaled image height.
+
+ Dependencies
+
+ libpango-1.0, libpangoft2-1.0, libfreetype, libgdk_pixbuf-2.0,
+ libglib-2.0, libgobject-2.0, libgmodule-2.0, libfontconfig.
+
+ Known Bugs
+
+ The foreground and background Pango markup span attributes are not
+ supported.
+ Word wrapping is not supported.
- Constructor Argument
+ pixbuf
- string file - a text file containing Pango markup, see:
- http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html
- - requires xml-like encoding special chars: <, >, & to <, >, &
+ Description
- Initialisation Properties
+ A still graphics to video generator using gdk-pixbuf
- timecode in - in point
- timecode out - out point
+ Constructor Argument
- Mutable Properties
-
- int video_standard - enum mlt_video_standard from mlt_frame.h
- PAL = 0, NTSC = 1
- this determines proper pixel aspect ratio
+ 'file' - The name of a graphics file loadable by
+ a gdk-pixbuf loader. see /usr/lib/gdk-pixbuf/loaders
+ definitely png, jpeg, tiff, pnm, and xpm
+ - If "%" in filename, the filename is used with sprintf
+ generate a filename from a counter for multi-file/flipbook
+ animation. The file sequence ends when numeric
+ discontinuity >100.
+ - If filename contains "/.all.", suffix with an extension to
+ load all pictures with matching extension from a directory.
+ - If filename contains the string "<svg", then pixbuf tries
+ to load the filename as inline SVG XML, which is convenient
+ for melt commands.
+
+ Details
+
+ Pixbuf has builtin scaling. It will rescale the originally rendered
+ title to whatever the consumer requests. Therefore, it will lose
+ its aspect ratio if so requested, and it is up to the consumer to
+ request a proper width and height that maintains the image aspect.
- string markup - a string containing Pango markup see:
- http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html
- - requires xml-like encoding special chars: <, >, & to <, >, &
+ Initialisation Properties
- int fgcolor - an rgba color specification of the text (i.e. 0xrrggbbaa)
- int bgcolor - an rgba color of the background rectangle
- int align - paragraph alignment: 0 = left, 1 = center, 2 = right
- int pad - the number of pixels to pad the background rectangle beyond edges of text
- default 0
- string markup - see constructor argument
- string text - non-markup text (can contain markup chars un-encoded)
- string font - the default typeface to use when not using markup
- default "Sans 48"
- int x - the horizontal position of the title on the frame
- default 0
- int y - the vertical position of the title on the frame
- default 0
- double mix - the overall opacity control of the generated title
- default 1.0
+ int in - in point
+ int out - out point
+ int begin - when using an image sequence, this sets the starting
+ number.
- Read Only Properties
+ Mutable Properties
- string resource - the text/markup file or "pango" if no file
+ int ttl - how long (in frames) to repeat each picture in file
+ sequences. default is 25.
- Dependencies
+ Read Only Properties
- libpango-1.0, libpangoft2-1.0, libfreetype, libgdk_pixbuf-2.0, libglib-2.0,
- libgobject-2.0, libgmodule-2.0, libfontconfig
+ string resource - file location. See Constructor Argument above.
+ int real_width - the original, unscaled width of the rendered title.
+ int real_height - the original, unscaled height of the title.
+ int width - the last requested scaled image width.
+ int height - the last requested scaled image height.
- Known Bugs
+ Dependencies
- no frame-alignment functionality
+ libgdk_pixbuf-2.0, libglib-2.0, libgobject-2.0, libgmodule-2.0
- pixbuf
+ Known Bugs
- Description
+ XXX: in/out settings are incorrectly handled.
- A graphics overlay generator using gdk-pixbuf
+ ppm
+
+ Description
- Constructor Argument
+ Reads a stream of contiguous PPM images.
+
+ Constructor Argument
- 'file' - The name of a graphics file loadable by
- a gdk-pixbuf loader. see /usr/lib/gdk-pixbuf/loaders
- definitely png, jpeg, tiff, pnm, and xpm
- - If "%" in filename, the filename is used with sprintf
- generate a filename from a counter for multi-file/flipbook animation.
- The file sequence ends when numeric discontinuity >100.
- - If filename contains "/.all.", suffix with an extension to load
- all pictures with matching extension from a directory
+ command - a shell command to run something that produces ppm
+ streams on stdout.
+
+ Initialisation Properties
- Initialisation Properties
+ none
+
+ Read Only Properties
- timecode in - in point
- timecode out - out point
+ string resource - the command
+
+ Dependencies
- Mutable Properties
+ none
+
+ Known Bugs
- int video_standard - enum mlt_video_standard from mlt_frame.h
- PAL = 0, NTSC = 1
- this determines proper pixel aspect ratio
- double ttl - how long (seconds) to repeat each picture in file sequences
- int x - the horizontal offset from the left edge of the frame
- int y - the vertical offset from the top edge of the frame
- double mix - the opacity factor to apply to the second frame
- (used in addition to alpha channel).
+ Since it uses pipes, it is not compatible with bluefish.
+ xml
- Read Only Properties
+ Description
- string resource - file location
+ Construct a service network from an XML description.
+ See docs/mlt-xml.txt.
- Dependencies
+ Constructor Argument
- libgdk_pixbuf-2.0, libglib-2.0, libgobject-2.0, libgmodule-2.0
+ URL - an XML text file containing MLT XML
+ - Since MLT XML files can be parameterised, the URL syntax is:
+ {file-name}[?{param-name}{'='|':'}{param-value}[&{param-name}{'='|':'}{param-value}...]]
+ A colon is allowed instead of an equal sign to pacify melt,
+ who tokenises anything with an equal sign as a property
+ setting. Also, when running melt from the shell, beware of
+ the '?' and shell filename expansion. You can surround the URL
+ with single quotations to prevent expansion. Finally, the loader
+ will fail to match the filename when you use parameters, so
+ preface the url with 'xml:' to force the loader to load with
+ the xml service.
+
+ Read Only Properties
- Known Bugs
+ string resource - file location
- none
+ Dependencies
- ppm
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
+ libxml2
+
+ Known Bugs
+
+ Non-referenced producers and playlists are not destroyed until the
+ network is destroyed.
+ A referenced producer or playlist must appear before the reference.
+ A filter that occurs before a producer has been defined causes a
+ segfault.
+
+ vorbis
+
+ Description
+
+ OGG Vorbis file reader.
+
+ Constructor Argument
+
+ 'file' - file to use (only .ogg supported at the moment)
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ double fps - this is fixed at 25 for PAL currently
+
+ Dependencies
+
+ libvorbisfile
+ Known Bugs
+
+ Fixed frame size (PAL audio chunks).
+ Doesn't cover ogg files with multiple, differing sections.
Filters
-------
- deinterlace
+ brightness
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
-
- ffmpeg_dub
+ Description
+
+ Shift the luma component using a constant value.
+
+ Constructor Argument
+
+ start - the constant floating point numeric value to apply.
+ - the default is 0.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+ double start - see Constructor Argument above.
+ double end - the ending adjustment value. the filter interpolates
+ between the start and end adjustments over the
+ duration of the effect.
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ Does not go completely to black or white.
+
+
+ channelcopy
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
+ Description
+
+ Copy audio from one channel to another channel.
+
+ Constructor Argument
+
+ to - the 0-indexed channel to copy into, default is 1.
+
+ Mutable Properties
+
+ int to - see above
+ int from - the channel from which to copy, default is 0.
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+
+ deinterlace
+
+ Description
+
+ Deinterlace a frame consisting of two fields using bob, weave,
+ greedy, one-field, and linear blend methods. This code is
+ appropriated from the Xine XV video output plugin.
+
+ Constructor Argument
+
+ method - a string containing the deinterlace method: bob, weave,
+ greedy, onefield, or linearblend. The default is
+ linearblend.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+ string method
+
+ Details
+
+ If the frame properties "progressive" or "consumer_progressive"
+ are non-zero, then the filter is not applied. Also, if applied,
+ this sets the frame property "progressive" to 1.
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ Not a bug, but it only provides fair quality.
+
+
gamma
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
+ Description
+
+ Adjust image luma using a non-linear power-law curve
+
+ Constructor Argument
+
+ gamma - a floating point value. The default is 1.0, or none.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ double gamma - the exponential factor of the power-law curve
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
greyscale
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
-
- resize
-
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
+ Description
-Transitions
------------
+ Convert colour image to greyscale
+
+ Constructor Argument
- composite
-
- Description
+ none
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+ gtkrescale
+
+ Description
+
+ Scale the producer video frame size to match the consumer.
+ This filter is designed for use as a normaliser for the loader producer.
+
+ Constructor Argument
+
+ interpolation - the rescaling method, one of:
+ nearest (lowest quality, fastest),
+ tiles,
+ bilinear (default; good quality, moderate speed),
+ hyper (best quality, slowest).
+
+ Initialisation Properties
- An alpha-channel based compositor for two frames.
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ string interpolation - see constructor argument above
+
+ If a property "consumer_aspect_ratio" exists on the frame, then
+ rescaler normalises the producer's aspect ratio and maximises the
+ size of the frame, but may not produce the consumer's requested
+ dimension. Therefore, this option works best in conjunction with the
+ resize filter. This behavior can be disabled by another service by
+ either removing the property, setting it to zero, or setting
+ frame property "distort" to 1.
+
+ Dependencies
+
+ libgdk_pixbuf-2.0, libglib-2.0, libgobject-2.0, libgmodule-2.0
+
+ Known Bugs
+
+ none
+
+ jackrack
+
+ Description
+
+ Creates Jack ports and runs a JackRack project to process audio
+ through a stack of LADSPA filters.
+
+ Constructor Argument
+
+ src - a JackRack file
+
+ Details
+
+ If you are using a consumer that uses ALSA, then you should start
+ jackd with the dummy driver: jackd -d dummy.
+ I also recommend using a period size of 2048: -p 2048.
- Constructor Argument
+ jackd -ddummy -r48000 -p2048
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ The following can be used without a rack file in order to connect
+ filter_jackrack to a running instance of JackRack:
+ string out_1 - Jack port to connect MLT's output port (JackRack's input)
+ string out_2 - Jack port to connect MLT's output port (JackRack's input)
+ string in_1 - Jack port to connect MLT's input port (JackRack's output)
+ string in_2 - Jack port to connect MLT's input port (JackRack's output)
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
none
+
+ Dependencies
+
+ Jack, LADSPA, glib-2.0, libxml2
+
+ Known Bugs
+
+ Currently, due to timing and synchronisation issues, the audio
+ is distorted with repeated samples and latency clicks.
+ no encapsulated resampling and jack runs at a fixed frequency
+
+ ladspa
+
+ Description
+
+ Runs a JackRack project to process audio through a stack of
+ LADSPA filters without using Jack.
+
+ Constructor Argument
+
+ src - a JackRack file
- Mutable Properties
+ Details
- int x - the horizontal offset from the left edge of the frame
- int y - the vertical offset from the top edge of the frame
- double mix - the opacity factor to apply to the second frame
- (used in addition to alpha channel).
+ Due to audio integrity issues with the jackrack filter, this
+ filter is better for runtime, while jackrack is more suitable
+ for prototyping a rack file using the Jack Rack GUI.
- Read Only Properties
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
none
-
- Dependencies
+
+ Dependencies
+
+ Jack, LADSPA, glib-2.0, libxml2
+ Jack is still required because this coexists with the jackrack
+ filter.
+
+ Known Bugs
+
+ no encapsulated resampling and jack runs at a fixed frequency
+
+ luma
+
+ Description
+
+ Applies a luma transition between the current and next frames.
+ Useful for transitions from a slideshow created using producer
+ pixbuf.
+
+ Constructor Argument
+
+ file - a luma wipe
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+ int period - how long to wait between success iterations of the
+ transition. For best results set this to a multiple
+ of ttl used in pixbuf. The default is 24.
+
+ luma. - all properties beginning with "luma." are passed to the
+ encapsulated luma transition. For example, luma.out controls
+ the duration of the wipe.
+
+ Dependencies
+
+ transition_luma and its dependencies
+
+ Known Bugs
+
+ none
+
+ mcrescale
+
+ Description
+
+ Scale the producer video frame size to match the consumer.
+ This filter is designed for use as a normaliser for the loader producer.
+
+ Constructor Argument
+
+ interpolation - the rescaling method, one of:
+ nearest (lowest quality, fastest),
+ bilinear (default; good quality, moderate speed),
+ hyper (best quality, slowest).
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ string interpolation - see constructor argument above
+
+ If a property "consumer_aspect_ratio" exists on the frame, then
+ rescaler normalises the producer's aspect ratio and maximises the
+ size of the frame, but may not produce the consumer's requested
+ dimension. Therefore, this option works best in conjunction with the
+ resize filter. This behavior can be disabled by another service by
+ either removing the property, setting it to zero, or setting
+ frame property "distort" to 1.
+
+ Dependencies
+
+ the mainconcept rescaling sdk.
+
+ Known Bugs
+
+ none
+
+ mirror
+
+ Description
+
+ Provides various mirror and image reversing effects.
+
+ Constructor Argument
+
+ mirror - horizontal, vertical, diagonal, flip, flop
+
+ Initialisation Properties
+
+ int reverse - being 0 or 1
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+
+ mono
+
+ Description
+
+ Mix all channels of audio into a mono signal and output it as
+ N channels.
+
+ Constructor Argument
+
+ channels - the number of output channels (default 2)
+
+ Initialisation Properties
+
+ none
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+
+ obscure
+
+ Description
- none
-
- Known Bugs
+ Obscuring filter.
+
+ Constructor Argument
- Need to add field-based rendering.
+ none
+
+ Initialisation Properties
+
+ string start - in the format X,Y:WxH[:PWxPY]
+ - PWxPY is the size of the averaging region in pixels.
+ string end - in the format X,Y:WxH[:PWxPY]
+ int in - in point
+ int out - out point
- luma
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+ region
- Description
-
- A generic dissolve and wipe transition processor. It gets its name
- from how it uses a grayscale "map" file. As the luma value varies
- over time, a threshold filter is applied to the map to determine
- what parts of frame A vs. frame B to show. It only reads PGM
- files, but it does handle 16 bit PGM. This performs field-based
- rendering.
-
- Constructor Argument
+ Description
+
+ Apply one or more filters to a region of the video image. The region
+ can be shaped as well using the alpha channel of another producer.
+
+ Constructor Argument
+
+ resource - A file whose alpha channel will "shape" the region.
+ - The string "circle" is a shortcut but it requires pixbuf with
+ the librsvg loader. The circle is automatically stretched
+ to the region to create an ellipse.
+
+ Initialisation Properties
- string file - the luma map file name. If not supplied, a dissolve.
-
- Mutable Properties
+ int in - in point
+ int out - out point
+ plus and region transition properties
+
+ Read Only Properties
+
+ see the region transition
+
+ Dependencies
+
+ transition_region
+
+ Known Bugs
+
+ "circle" is unpredictable in the absence of the librsvg pixbuf loader.
+
- string filename - same as above
- double softness - only when using a luma map, how soft to make the
- edges between A and B. 0.0 = no softness. 1.0 =
- too soft.
-
- Read Only Properties
+ resample
- none
-
- Dependencies
+ Description
- none
-
- Known Bugs
+ Adjust an audio stream's sampling rate, and duplicate channels if
+ producer provides less than consumer requested.
+
+ This filter is automatically invoked by the loader producer for the
+ sake of normalisation over inputs and with the consumer.
- The luma map must be the same size as the B frame.
+ Constructor Argument
-Consumers
----------
+ frequency - a numeric value for the new sample rate
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ int frequency - the target sample rate
+
+ Dependencies
+
+ libresample
+
+ Known Bugs
+
+ Assumes 2 channels during libsamplerate initialisation. Untested
+ with >2 channels.
+
+ rescale
+
+ Description
+
+ Scale the producer video frame size to match the consumer.
+ This filter is designed for use as a normaliser for the loader producer.
+
+ Constructor Argument
+
+ None.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ If a property "consumer_aspect_ratio" exists on the frame, then
+ rescaler normalises the producer's aspect ratio and maximises the
+ size of the frame, but may not produce the consumer's requested
+ dimension. Therefore, this option works best in conjunction with the
+ resize filter. This behavior can be disabled by another service by
+ either removing the property, setting it to zero, or setting
+ frame property "distort" to 1.
+
+ Dependencies
- bluefish
+ none
+
+ Known Bugs
+
+ none but... it only implements a nearest neighbour scaling - it is
+ used as the base class for the gtkrescale and mcrescale filters.
+
+ resize
- Description
+ Description
- BlueFish444 audio and video output module.
-
- Constructor Argument
+ Image scaling and padding and field order adjustment.
+
+ Details
+
+ Normally resize is used to pad the producer's
+ output to what the consumer has requested after an upstream rescale
+ filter first scales the image to maximise usage of the image area.
+ This filter also adjusts the field order to lower field first
+ if the frame property "top_field_first" has been set to 1.
+ Therefore, when done, it sets the top_field_first to 0.
+ This filter is automatically invoked by the loader as part of image
+ sample aspect ratio normalisation.
+
+ Constructor Argument
- int video_standard - 0 = PAL, 1 = NTSC
-
- Initialisation Properties
+ scale - "affine" to use affine transform scaling, otherwise
+ center and pad.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
- int video_standard - see above
-
- Read Only Properties
+ Read Only Properties
- none
-
- Dependencies
+ none
+
+ Dependencies
- BlueVelvet SDK installed parallel to mlt in "bluefish."
-
- Known Bugs
+ none
+
+ Known Bugs
- If mlt crashes, you must reload the BlueDriver kernel module
- due to unreleased DMA buffers.
- Needs an argument or property for multi-card address.
-
- ffmpeg
+ Assumes lower field first output.
+
+ volume
+
+ Description
+
+ Adjust an audio stream's volume level
+ - based on the 'normalize' utility
+
+ Constructor Argument
+
+ gain - a string containing one of:
+ - a floating point value of the gain adjustment
+ - a numeric value with the suffix "dB" to adjust in terms of decibels
+ - "normalise" to normalise the volume to the target amplitude -12dBFS
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+ int window - the number of video frames over which to smooth normalisation.
+ defaults to 75.
+
+ Mutable Properties
+
+ string gain - same as constructor argument above
+
+ string normalise - normalise the volume to the amplitude:
+ - a numeric value with the suffix "dB" to set amplitude in decibels
+ - a floating point value of the relative volume
+ - an unspecified value uses the default -12dBFS
+
+ string limiter - limit all samples above:
+ - a numeric value with the suffix "dB"
+ - a floating point value ( dB = 20 * log10(x) )
+ - an unspecified value uses the default -6dBFS
+
+ double max_gain - a floating point or decibel value of the maximum gain that
+ can be applied during normalisation.
+ - an unspecified value uses the default 20dB
+
+ string end - a gain value just like the gain property above.
+ This causes the gain to be interpolated from 'gain' to 'end'
+ over the duration.
+
+ int window - the size of the normalising smoothing buffer in video frame units.
+ - the smoothing buffer prevents erratic gain changes.
+ - the default value is 75 video frames.
+
+ gain can be applied as a factor to the normalise amplitude!
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ none
+
+ watermark
+
+ Description
+
+ Add a watermark to the frames.
+
+ Constructor Argument
+
+ resource - the producer to use (ie: a .png)
+
+ Initialisation Properties
+
+ string resource - the producer to use
+ string factory - producer required for the resource (default: 'loader')
+ string geometry - composite geometry
+ string distort - control scaling
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ none
+
+ Dependencies
+
+ mlt core modules and optionally, loader
+
+ Known Bugs
+
+ none
+
+Transitions
+-----------
+
+ composite
+
+ Description
+
+ A key-framable alpha-channel compositor for two frames.
+
+ Details
+
+ Performs dissolves and luma wipes in addition to alpha compositing.
+
+ By default, the aspect ratio of the B frame is respected and the
+ size portion of the geometry specification simply defines a
+ bounding rectangle.
+
+ This performs field-based rendering unless the A frame property
+ "progressive" or "consumer_progressive" or the transition property
+ "progressive" is set to 1.
+
+ Constructor Argument
+
+ none[*]
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+ string factory - The name of a factory service used as a non-PGM
+ producer loader. The default is 'loader'.
- Description
- Constructor Argument
- Initialisation Properties
- Read Only Properties
- Dependencies
- Known Bugs
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+
+ string geometry - key frame specification
+ - this is a ; delimited form of the deprecated start,
+ key[n], end properties
+ int progressive - set to 1 to disable field-based rendering.
+ string distort - when set, causes the B frame image to fill the WxH
+ completely with no regard to B's aspect ratio.
+ string halign - when not distorting, set the horizontal alignment
+ of B within the geometry rectangle.
+ - one of: left (0), centre (1), or right (2).
+ - the default is left.
+ string valign - when not distorting, set the vertical alignment of
+ B within the geometry rectangle.
+ - one of: top (0), middle (1), or bottom (2).
+ - the default is top.
+ string luma - the luma map file name. If not supplied, a dissolve.
+ double softness - only when using a luma map, how soft to make the
+ edges between A and B. 0.0 = no softness. 1.0 =
+ too soft.
+ Any property starting with "luma." is passed to the non-PGM luma
+ producer.
+
+ Deprecated Properties
+
+ string start - a geometry specification as X,Y:WxH[!][:mix]
+ - X, Y, W, H are assumed to pixel units unless they
+ have the suffix '%'
+ - '!' is a shortcut to specify distort, see below.
+ - mix is always a 2 digit percentage, defaults to 100.
+ - default is "85%,5%:10%x10%"
+ string end - the ending size and position.
+ string key[F] - X,Y:WxH[:mix] - set a key frame for geometry between
+ the in and out. F is a frame number and can be
+ negative to make it relative to the out point.
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ Assumes lower field first during field rendering.
- sdl
- Description
+ luma
+
+ Description
- Simple DirectMedia Layer audio and video output module.
-
- Constructor Argument
+ A generic dissolve and wipe transition processor.
- string video_standard - "PAL" (default), "NTSC", or "WxH"
-
- Mutable Properties
+ Details
- double volume - audio level factor
- int video_off - if 1, disable video output
- int audio_off - if 1, disable audio output
- int scale_overlay - if 1, resample video from source pixel aspect
- ratio to square pixels.
-
- Read Only Properties
+ luma gets its name
+ from how it uses a grayscale "map" file. As the luma value varies
+ over time, a threshold filter is applied to the map to determine
+ what parts of frame A vs. frame B to show. It reads PGM files
+ up to 16 bits! Alternatively, it can use the first frame from any
+ producer that outputs yuv, but it will be limited to the luma
+ gamut of 220 values.
+ This performs field-based rendering unless the A frame property
+ "progressive" or "consumer_progressive" or the transition property
+ "progressive" is set to 1.
+
+ Constructor Argument
- none
-
- Dependencies
+ string resource - the luma map file name - either PGM or any other
+ producable video.
+ - If not supplied, a dissolve.
- libSDL-1.2, libasound, libaudio, libXt, libX11, libXext, libSM, libICE
-
- Known Bugs
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+ string factory - The name of a factory service used as a non-PGM
+ producer loader. The default is 'loader'.
+
+ Mutable Properties
+
+ string resource - same as above
+ double softness - only when using a luma map, how soft to make the
+ edges between A and B. 0.0 = no softness. 1.0 =
+ too soft.
+ int reverse - reverse the direction of the transition.
+ Any property starting with "producer." is passed to the non-PGM luma
+ producer.
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ Assumes lower field first output.
+
+ mix
- ?
+ Description
+
+ An two stream audio mixer.
+
+ Constructor Argument
+
+ start - see below
+
+ Initalisation Properties
+
+ int in - in point
+ int out - out point
+
+ Mutable Properties
+
+ double start - the mix level to apply to the second frame.
+ - any negative value causes an automatic crossfade from 0 to 1.
+ double end - the ending value of the mix level. mix level will be interpolated
+ from start to end over the in-out range.
+ int reverse - set to 1 to reverse the direction of the mix.
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ none
+
+ Known Bugs
+
+ Samples from the longer of the two frames are discarded.
+
+
+ region
+
+ Description
+
+ Apply zero or more filters to B frame as it is composited onto
+ a region of the A frame. The "shape" of the region can be defined
+ by the alpha channel of a third producer.
+
+ Constructor Argument
+
+ resource - a shape producer
+
+ Initialisation Properties
+
+ string resource - nothing is rectangle, "circle" is a pixbuf-
+ generated SVG circle, anything else is loaded by the factory.
+ string factory - the service that creates the shape producer.
+ - the default is 'loader'.
+ string filter[N] - one or more filters to apply. All filter
+ properties are passed using the same filter "key"
+ Any property starting with "composite." is passed to the
+ encapsulated composite transition.
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ transition_composite
+
+ Known Bugs
+
+ none
+
+
+Consumers
+---------
+
+ avformat
+
+ Description
+
+ Multiformat transcoding consumer.
+
+ Constructor Argument
+
+ string target - the filename to write to, e.g. test.mpeg.
+
+ Initialisation Properties
+
+ int buffer - the number of frames to buffer, minimum 1, default 25.
+ string rescale - a rescale method, see the Filters/rescale.
+ int progressive - indicates whether to use progressive or field-
+ based rendering, default 0 (off).
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ libavformat
+
+ Known Bugs
+
+ Plenty.
+
+ bluefish (Proprietary)
+
+ Description
+
+ BlueFish444 audio and video output module.
+
+ Constructor Argument
+
+ card - a numeric card id starting at 1, default is 1.
+
+ Initialisation Properties
+
+ string standard - "PAL" (default) or "NTSC"
+ - default is based upon MLT_NORMALISATION
+ environment variable, which defaults to PAL.
+ int frames - the number of DMA video frames. default is 8.
+ minimum is 2. maximum on my system is 11.
+ int buffer - the number of frames to buffer within MLT, minimum 1,
+ default 25.
+ string rescale - a rescale method, see the Filters/rescale.
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ BlueVelvet SDK installed parallel to mlt in "bluefish."
+
+ Known Bugs
+
+ Does not work with any service that uses pipes!
+
+ If mlt crashes, you might need to reload the BlueDriver kernel
+ module due to unreleased DMA buffers.
+
+ Only supports 2 channel audio at the moment.
+
+ libdv
+
+ Description
+
+ libdv dv producer.
+
+ Constructor Argument
+
+ string target - the filename to write to, e.g. /dev/dv1394.
+
+ Initialisation Properties
+
+ int buffer - the number of frames to buffer, minimum 1, default 25.
+ string rescale - a rescale method, see the Filters/rescale.
+
+ Mutable Properties
+
+ int progressive - indicates whether to use progressive or field-
+ based rendering, default 0 (off).
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ libdv
+
+ Known Bugs
+
+ none
+
+ mcmpeg
+
+ Description
+
+ Mainconcept MPEG encoder.
+
+ Constructor Argument
+
+ string target - the filename to write to.
+
+ Initialisation Properties
+
+ int buffer - the number of frames to buffer, minimum 1, default 25.
+ string rescale - a rescale method, see the Filters/rescale.
+ string format - vcd [default], svcd or dvd provide base settings
+ int motion_search_type - 0 to 16 - reduces quality/cpu usage
+ int gop - group of picture size (default: format dependent)
+
+ Mutable Properties
+
+ int progressive - indicates whether to use progressive or field-
+ based rendering, default 0 (off).
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ Mainconcept MPEG SDK
+
+ Known Bugs
+
+ none
+
+ sdl
+ Description
+
+ Simple DirectMedia Layer audio and video output module.
+
+ Constructor Argument
+
+ string video_standard - "PAL" (default), "NTSC", or "WxH"
+
+ Initialisation Properties
+
+ int buffer - the number of frames to buffer, minimum 1, default 25.
+ string rescale - a rescale method, see the Filters/rescale.
+ - Hint: "none" works very good with SDL output.
+
+ Mutable Properties
+
+ double volume - audio level factor
+ int video_off - if 1, disable video output
+ int audio_off - if 1, disable audio output
+ int resize - TODO
+ int progressive - indicates whether to use progressive or field-
+ based rendering, default 0 (off).
+ int audio_buffer - size of the sdl audio buffer (default: 1024)
+
+ Read Only Properties
+
+ none
+
+ Dependencies
+
+ libSDL-1.2, libasound, libaudio, libXt, libX11, libXext, libSM, libICE
+
+ Known Bugs
+
+ none
+
+ xml
+
+ Description
+
+ Serialise the service network to XML.
+ See docs/mlt-xml.txt for more information.
+
+ Constructor Argument
+
+ resource - the name of a file in which to store the XML.
+ - stdout is default.
+
+ Initialisation Properties
+
+ string resource - same as above.
+
+ Dependencies
+
+ libxml2
+
+ Known Bugs
+
+ Untested arbitrary nesting of multitracks and playlists.
+ Property "id" is generated as service type followed by number if
+ no property named "id" exists, but it fails to guarantee uniqueness.