GStreamer Entrans Plugins Manual

The collective intent of the provided plugins is to provide the GStreamer framework with a set of filters as already available in various other multimedia applications, e.g. MPlayer/MEncoder, transcode, avidemux, many of them often duplicated over and over again. Once so available in the GStreamer framework, they are accessible by a common API, so that the very same code can be used repeatedly (as opposed to duplicated), in line with GStreamer Motivation and Goals.

There are a number of ways to make such filters available, each requiring more or less effort, and providing less or more quality (typically in that order). Foremost, of course, is to perform a code-level port, making the filter (operation) natively available in GStreamer. Alternatively, one could resort to dynamic or runtime "binding".

Code Ports

Clearly, when done properly, this leads to most robust quality results. As it also requires most effort and maintenance, priority focus is given to the "popular" ones, defined here as roughly proportional to occurrence across various existing applications.

The following table compares some filter operations that implement an identical or very similar algorithm.

mencoder	transcode	avidemux	virtualdub	GStreamer
rectangle	mask	Blacken borders	?	entransmask
swapuv	videocore rgbswap	Swap U and V	?	entransrbswap
eq2	gamma	MPlayer eq2	?	gamma gamma=1/(transcode value), videobalance
field, phase	fields, doublefps	drop, * fields	?	entransfields
-	decimate	Decomb decimate	Decomb	entransdecimate
-	32detect	-	?	entransdetectinter
-	ivtc	Decomb telecide	Decomb	entransivtc
kerndeint	-	kernel deinterlace	kerndeint	entranskerneldeint
unsharp	unsharp	-	?	entransunsharp
hqdn3d	hqdn3d	MPlayer hqdn3d	?	entranshqdn3d
denoise3d	denoise3d	MPlayer denoise3d	?	entranshqdn3d high-quality=false
-	dnr	Denoise	?	entransdnr
-	smooth	-	?	entranssmooth
-	msharpen	MSharpen	msharpen	entransmsharpen
-	xsharpen	-	xsharpen	entransxsharpen
-	cshift	Chroma shift	?	entranscshift
-	csub	-	?	entranscsub
?	whitebalance	?	?	entranswhitebalance
-	divxkey	-	?	entransdivxkey
delogo	-	MPlayer delogo	?	entransdelogo
volume	astat	-	?	entransastat

The above table by no means intends to suggest that GStreamer offers the widest collection of filters available (at present?). Indeed, other programs as mentioned above often have many alternative implementations and algorithms with similar goals. The above merely considers the GStreamer perspective/intersection, and if anything, simply illustrates there is a great deal of duplicating, copying and reworking out there.

Runtime Binding

The netpbm and mjpegtools suites provide long since a number of image/video processing operations as stand-alone programs.

If so desired, and these programs are present and PATH accessible, they can be used in a pipeline. For example, one or more mjpegtools filters can appear as follows:

entransy4menc ! entransy4mtrans command=yuvdenoise ! entransy4mparse

entransy4menc ! entransy4mtrans command=y4mdenoise \
    ! entransy4mtrans command=yuvmedianfilter ! entransy4mparse

Be aware that the above pipeline fragments have timestamp resequencing as a side-effect. So, take care not to cause an "imbalance" when muxing, e.g. by using entransstamp if needed in other streams.

The elements used above can also be put to use in dealing with a set of files (as input or output). For example,

jpeg2yuv -f 25 -j image-%05.jpg > image.yuv
# then run following pipeline
filesrc location=image.yuv ! entransy4mparse ! videoflip ! \
  y4menc ! filesink location=image-out.yuv
# if desired:
# y4mtopnm and pnmtojpeg processing

Of course, the intermediate file could be omitted by means of some piping, and entransprocpipe may come in handy as well.

Subpages:

Plugins – GEntrans plugins