X-Git-Url: http://research.m1stereo.tv/gitweb?a=blobdiff_plain;f=docs%2Finigo.txt;h=ed417d99b65902fff90fe1bf637c50ff8f3cf9cf;hb=2a800ec4c840132c7a629b764b673dce09771637;hp=4b82dd518ffb7e01f42ddd82682728e3e086cd33;hpb=c63b98c399b13d0672beb9cabba832a71d45a2ea;p=melted diff --git a/docs/inigo.txt b/docs/inigo.txt index 4b82dd5..ed417d9 100644 --- a/docs/inigo.txt +++ b/docs/inigo.txt @@ -1,3 +1,16 @@ +INIGO +----- + +Preamble: + + inigo was developed as a test tool for the MLT framework. It can + be thought of as a powerful, if somewhat obscure, multitrack + command line oriented video editor. + + The following details the usage of the tool and as a result, + provides a lot of insight into the workings of the MLT framework. + + Usage: inigo [ -group [ name=value ]* ] @@ -8,20 +21,33 @@ Usage: [ -track ] [ producer [ name=value ] * ]+ [ -serialise file.inigo ] - + + General rules: 1. Order is incredibly important; + 2. Error checking on command line parsing is weak; - 3. This document does not duplicate the information in services.txt. -Terminoligy: + 3. Please refer to services.txt for details on services + available; + + 4. The MLT framework, from which inigo has inherited its + naming convention, is very mlt-centric. Producers produce + MLT frame objects and consumers consume MLT frame objects. + The distinction is important - a DV producer does not produce + DV, it produces MLT frames from a DV source, and similarly a + DV consumer does not consume DV, it consumes MLT frames and + produces DV frames. + + +Terminology: 'Producers' typically refer to files but may also indicate devices (such as dv1394 input or video4linux). Hence, the more generic term is used [yes, the more generic usage is out of scope for now...]. - + 'Filters' are frame modifiers - they always guarantee that for every frame they receive, they output *precisely* one frame. Never more, never less, ever. @@ -44,7 +70,8 @@ Terminoligy: Consumers have no say in the flow of frames [though they may give the illusion that they do]. They get frames from a connected producer, use them, destroy them and get more. - + + Basics: To play a file with the default SDL PAL consumer, usage is: @@ -55,6 +82,7 @@ Basics: 'producer' mapping for (so this can be anything from .dv to .txt). + Properties: Properties can be assigned to the producer by adding additional @@ -62,13 +90,13 @@ Properties: $ inigo file in=50 out=100 something="something else" - Note that while some properties have meaning to all producers - (for example: in, out and length are guaranteed to be valid for - all, though typically, length is determined automatically), the - validity of others are dependent on the producer - however, - properties will always be assigned, but it doesn't mean they - will be used. - + Note that while some properties have meaning to all producers (for + example: in, out and length are guaranteed to be valid for all, though + typically, length is determined automatically), the validity of others + are dependent on the producer - however, properties will always be + assigned and silently ignored if they won't be used. + + Multiple Files: Multiple files of different types can be used: @@ -78,36 +106,32 @@ Multiple Files: Properties can be assigned to each file: $ inigo a.dv in=50 out=100 b.mpg out=500 c.png out=500 - + + MLT will take care of 'normalising' the output of a producer to ensure + that the consumer gets what it needs. So, in the case above, the mlt + framework will ensure that images are rescaled and audio resampled to meet + the requirements of your configuration (which, by default, will be PAL). + See 'Appendix A: Normalisation Rules' below. + + Filters: - The Multiple Files examples above will logically playout one - after the other. - - However, inigo doesn't care too much about changes in frame - dimensions or audio specification, so you may need to add - additional normalising filters to that, ie: - - $ inigo a.dv b.mpg c.png -filter resize -filter resample - - These filters are designed to guarantee that the consumer gets - what it asks for. + Filters are frame modifiers - they can change the contents of the audio or + the images associated to a frame. - It should also be stressed that filters are applied in the order - in which they're specified. - -Filter Properties: + $ inigo a.dv -filter greyscale As with producers, properties may be specified on filters too. - Again, in and out properties are common to all, so to apply a - filter to a range of frames, you would use something like: + Again, in and out properties are common to all, so to apply a filter to a + range of frames, you would use something like: $ inigo a.dv -filter greyscale in=0 out=50 - Again, filters have their own set of rules about properties and - will silently ignore properties that do not apply. - + Again, filters have their own set of rules about properties and will + silently ignore properties that do not apply. + + Groups: The -group switch is provided to force default properties on the @@ -129,11 +153,12 @@ Groups: To shed the group properties, you can use any empty group: $ inigo -group in=0 out=49 clip* -group -filter greyscale - + + Introducing Tracks and Blanks: - So far, all of the examples have shown the definition of a - single playlist, or more accurately, track. + So far, all of the examples have shown the definition of a single + playlist, or more accurately, track. When multiple tracks exist, the consumer will receive a frame from the 'lowest numbered' track that is generating a non-blank @@ -142,7 +167,7 @@ Introducing Tracks and Blanks: It is best to visualise a track arrangement, so we'll start with an example: - $ inigo a.dv out=49 -track b.dv + $ inigo a.dv in=0 out=49 -track b.dv This can be visualised as follows: @@ -155,8 +180,8 @@ Introducing Tracks and Blanks: Playout will show the first 50 frames of a and the 51st frame shown will be the 51st frame of b. - To show have the 51st frame be the first frame of b, we can use - the -blank switch: + To have the 51st frame be the first frame of b, we can use the + -blank switch: $ inigo a.dv out=49 -track -blank 49 b.dv @@ -169,9 +194,10 @@ Introducing Tracks and Blanks: +-------------------+ Now playout will continue as though a and b clips are on the - same track (which is about as useful as reversing the process of - slicing bread). - + same track (which on its own, is about as useful as reversing the + process of slicing bread). + + Transitions: Where tracks become useful is in the placing of transitions. @@ -179,22 +205,24 @@ Transitions: Here we need tracks to overlap, so a useful multitrack definition could be given as: - $ inigo a.dv out=49 -transition luma in=25 out=49 \ + $ inigo a.dv out=49 \ -track \ - -blank 24 b.dv + -blank 24 b.dv \ + -transition luma in=25 out=49 a_track=0 b_track=1 Now we're cooking - our visualisation would be something like: +-------+ |a | - +----+--+---------------+ - |b | - +------------------+ + +---+---+--------------+ + |b | + +------------------+ Playout will now show the first 25 frames of a and then a fade transition for 25 frames between a and b, and will finally playout the remainder of b. - + + Reversing a Transition: When we visualise a track definition, we also see situtations @@ -202,32 +230,21 @@ Reversing a Transition: +-------+ +----------+ |a1 | |a2 | - +----+--+--------------+----+-----+ - |b | - +----------------------+ + +---+---+--------------+----+-----+ + |b | + +-----------------------+ In this case, we have two transitions, a1 to b and b to a2. In this scenario, we define a command line as follows: $ inigo a.dv out=49 -blank 49 a2.dv \ - -transition luma in=25 out=49 \ - -transition luma in=100 out=124 reverse=1 \ -track \ - -blank 24 b.dv out=99 - -Filters and Tracks: + -blank 24 b.dv out=99 \ + -transition luma in=25 out=49 a_track=0 b_track=1 \ + -transition luma in=100 out=124 reverse=1 a_track=0 b_track=1 + - A filter applies to a [specified region of a] single track, so - normalisation filters need to be applied to each track when - applicable. - - This user specification is a necessary evil (you do not want to - resize a text or png overlay to be the size of the frame that - the consumer is requesting, and you may not want to unecessarily - resize a video track if you will be later rescaling it for - composition). - Serialisation: Inigo has a built in serialisation mechanism - you can build up @@ -237,14 +254,23 @@ Serialisation: The saved file can be subsequently used as a clip by either miracle or inigo. Take care though - paths to files are saved as provided on the command line.... - + + A more expressive serialisation can be obtained with the westley consumer + - this will provide an xml document which can be used freely in inigo and + miracle. + + See westley.txt for more information. + + Missing Features: - Some filters/transitions should be applied on the output frame - regardless of which track it comes from - for example, you might - have a 3rd text track or a watermark which you want composited - on every frame, and of course, there's the obscure feature.... + Some filters/transitions should be applied on the output frame regardless + of which track it comes from - for example, you might have a 3rd text + track or a watermark which you want composited on every frame, and of + course, there's the obscure filter.... - A -post switch will be added to provided this feature at some - point soon. + inigo only supports this in two invocations - as a simple example: + + $ inigo a.dv -track -blank 100 b.dv -consumer westley:basic.westley + $ inigo basic.westley -filter watermark:watermark.png