Service Documentation
-Copyright (C) 2004 Ushodaya Enterprises Limited
Authors: Charles Yates <charles.yates@pandora.be>
Dan Dennedy <dan@dennedy.org>
-Last Revision: 2004-11-07
+Last Revision: 2009-05-08
SERVICES
--------
- Services marked as "(Proprietary)" are not distributed with the GPL version
- of mlt.
+ Services marked as "(Proprietary)" are not distributed with the LGPL
+ version of mlt.
Producers
---------
Read Only Properties
string resource - file location
- double fps - this is fixed at 25 for PAL currently
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 must be configured as --enable-shared and installed prior
- to compilation of mlt.
+ ffmpeg
Known Bugs
Audio sync discrepancy with some content.
Not all libavformat supported formats are seekable.
- Ogg Vorbis is currently broken.
- MPEG seeking is inaccurate - doesn't seek to i-frames so you may
- get junk for a few frames.
- RAW DV seeking not supported.
Fails to play beyond first frame of video of sources with PTS not
starting at 0 (video4linux).
- fezzik
+ loader
Description
Details
- Supplying a filename with extension ".txt" causes the Fezzik
+ 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 inigo commands. For westley, it is
+ 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
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
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 inigo commands.
+ for melt commands.
Details
int in - in point
int out - out point
+ int begin - when using an image sequence, this sets the starting
+ number.
Mutable Properties
Since it uses pipes, it is not compatible with bluefish.
- westley
+ xml
Description
Construct a service network from an XML description.
- See docs/westley.txt.
+ See docs/mlt-xml.txt.
Constructor Argument
- URL - an XML text file containing westley XML (schema/DTD pending)
- - Since westley files can be parameterised, the URL syntax is:
+ 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 inigo,
+ 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 inigo from the shell, beware of
+ 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, fezzik
+ with single quotations to prevent expansion. Finally, the loader
will fail to match the filename when you use parameters, so
- preface the url with 'westley:' to force fezzik to load with
- the westley service.
+ preface the url with 'xml:' to force the loader to load with
+ the xml service.
Read Only Properties
Description
Scale the producer video frame size to match the consumer.
- This filter is designed for use as a Fezzik normaliser.
+ This filter is designed for use as a normaliser for the loader producer.
Constructor Argument
Details
If you are using a consumer that uses ALSA, then you should start
- jacks with the dummy driver: jackd -d dummy.
+ jackd with the dummy driver: jackd -d dummy.
I also recommend using a period size of 2048: -p 2048.
jackd -ddummy -r48000 -p2048
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
+
+ Details
+
+ 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.
+
+ Initialisation Properties
+
+ int in - in point
+ int out - out point
+
+ Read Only Properties
+
+ none
+
+ Mutable Properties
+
+ none
+
+ 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
Description
Scale the producer video frame size to match the consumer.
- This filter is designed for use as a Fezzik normaliser.
+ This filter is designed for use as a normaliser for the loader producer.
Constructor Argument
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
Adjust an audio stream's sampling rate, and duplicate channels if
producer provides less than consumer requested.
- This filter is automatically invoked by Fezzik for the sake of
- normalisation over inputs and with the consumer.
+ This filter is automatically invoked by the loader producer for the
+ sake of normalisation over inputs and with the consumer.
Constructor Argument
Description
Scale the producer video frame size to match the consumer.
- This filter is designed for use as a Fezzik normaliser.
+ This filter is designed for use as a normaliser for the loader producer.
Constructor Argument
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 Fezzik as part of image
+ This filter is automatically invoked by the loader as part of image
sample aspect ratio normalisation.
Constructor Argument
Initialisation Properties
string resource - the producer to use
- string factory - producer required for the resource ('fezzik')
+ string factory - producer required for the resource (default: 'loader')
string geometry - composite geometry
string distort - control scaling
int in - in point
Dependencies
- mlt core modules and optionally, fezzik
+ mlt core modules and optionally, loader
Known Bugs
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 fezzik.
+ producer loader. The default is 'loader'.
Read Only 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 Fezzik.
+ producer loader. The default is 'loader'.
Mutable 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 fezzik.
+ - 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
none
- westley
+ xml
Description
Serialise the service network to XML.
- See docs/westley.txt for more information.
+ See docs/mlt-xml.txt for more information.
Constructor Argument
projects / mlt / blobdiff