MEncoder
Encyclopedia
MEncoder is a free
command line video decoding, encoding and filtering tool released under the GNU General Public License
. It is a close sibling to MPlayer
and can convert all the formats that MPlayer understands into a variety of compressed and uncompressed formats using different codec
s.
MEncoder is included in the MPlayer distribution.
It is also possible to copy audio and/or video unmodified into the output file to avoid quality loss because of re-encoding for example, to only modify the audio or video, or to simply put the audio/video data unmodified into a different container format.
Since it uses the same code as MPlayer, it also features the same huge number of highly-configurable video and audio filters to transform the video and audio stream: Filters include Cropping
, Scaling
, Vertical Flipping, horizontal mirroring, expanding to create letterbox
es, rotating, brightness
/contrast
, changing the aspect ratio
of the video's pixels, colorspace conversion, hue
/saturation
, color-specific Gamma correction
, filters for reducting the visibility of compression artifacts caused by MPEG compression (deblocking, deringing), automatic brightness/contrast enhancement (autolevel), sharpness
/blur
, denoising filters, several different ways of deinterlacing
, and reversing telecine.
Doubling the frame rate of interlaced footage without duplicating or morphing frames is possible using the tfields filter to create two different frames from each of the two fields in one frame of interlaced video. This allows playback on progressive displays, while preserving the full resolution and framerate of interlaced video, unlike other deinterlacing
methods. It also makes the footage more usable for framerate conversion, and creating slow-motion scenes from footage taken at standard video/TV frame rates, e.g. using cheap consumer camcorders. If the filter gets wrong information about the top/bottom field order, the resulting output video will have juddering motion, because the two frames created would be displayed in the wrong order.
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
command line video decoding, encoding and filtering tool released under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
. It is a close sibling to MPlayer
MPlayer
MPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...
and can convert all the formats that MPlayer understands into a variety of compressed and uncompressed formats using different codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
s.
MEncoder is included in the MPlayer distribution.
Capabilities
As it is built from the same code as MPlayer, it can read from every source which MPlayer can read, decode all media which MPlayer can decode and it supports all filters which MPlayer can use. MPlayer can also be used to view the output of most of the filters (or of a whole pipeline of filters) before running MEncoder. If the system is not able to process this in realtime, audio can be disabled using -nosound to allow a smooth review of the video filtering results.It is also possible to copy audio and/or video unmodified into the output file to avoid quality loss because of re-encoding for example, to only modify the audio or video, or to simply put the audio/video data unmodified into a different container format.
Since it uses the same code as MPlayer, it also features the same huge number of highly-configurable video and audio filters to transform the video and audio stream: Filters include Cropping
Cropping (image)
Cropping refers to the removal of the outer parts of an image to improve framing, accentuate subject matter or change aspect ratio. Depending on the application, this may be performed on a physical photograph, artwork or film footage, or achieved digitally using image editing software...
, Scaling
Scaling
Scaling may refer to:* Scaling , a linear transformation that enlarges or diminishes objects* Reduced scales of semiconductor device fabrication processes...
, Vertical Flipping, horizontal mirroring, expanding to create letterbox
Letterbox
Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes above and below it; these mattes are part of the image...
es, rotating, brightness
Brightness
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target...
/contrast
Contrast (vision)
Contrast is the difference in visual properties that makes an object distinguishable from other objects and the background. In visual perception of the real world, contrast is determined by the difference in the color and brightness of the object and other objects within the same field of view...
, changing the aspect ratio
Aspect ratio (image)
The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this...
of the video's pixels, colorspace conversion, hue
Hue
Hue is one of the main properties of a color, defined technically , as "the degree to which a stimulus can be describedas similar to or different from stimuli that are described as red, green, blue, and yellow,"...
/saturation
Saturation
Saturation or saturated may refer to:- Meteorology :* Dew point, which is a temperature that occurs when atmospheric humidity reaches 100% and the air is saturated with moisture- Physics :...
, color-specific Gamma correction
Gamma correction
Gamma correction, gamma nonlinearity, gamma encoding, or often simply gamma, is the name of a nonlinear operation used to code and decode luminance or tristimulus values in video or still image systems...
, filters for reducting the visibility of compression artifacts caused by MPEG compression (deblocking, deringing), automatic brightness/contrast enhancement (autolevel), sharpness
Sharpness
Sharpness is an English port in Gloucestershire, one of the most inland in Britain, and eighth largest in the South West. It is on the River Severn at , at a point where the tidal range, though less than at Avonmouth downstream , is still large .The village of Sharpness is pronounced with the...
/blur
Focus (optics)
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
, denoising filters, several different ways of deinterlacing
Deinterlacing
Deinterlacing is the process of converting interlaced video, such as common analog television signals or 1080i format HDTV signals, into a non-interlaced form....
, and reversing telecine.
Frame rate conversions and slow-motion
Also, changing the frame rate is possible using the -ofps or -speed options and, in addition, by using the framestep filter for skipping frames. Reducing the frame rate can be used to create fast-motion "speed" effects which are sometimes seen in films.Doubling the frame rate of interlaced footage without duplicating or morphing frames is possible using the tfields filter to create two different frames from each of the two fields in one frame of interlaced video. This allows playback on progressive displays, while preserving the full resolution and framerate of interlaced video, unlike other deinterlacing
Deinterlacing
Deinterlacing is the process of converting interlaced video, such as common analog television signals or 1080i format HDTV signals, into a non-interlaced form....
methods. It also makes the footage more usable for framerate conversion, and creating slow-motion scenes from footage taken at standard video/TV frame rates, e.g. using cheap consumer camcorders. If the filter gets wrong information about the top/bottom field order, the resulting output video will have juddering motion, because the two frames created would be displayed in the wrong order.
See also
- MPlayerMPlayerMPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...
, the media player built from the same source codeSource codeIn computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
as MEncoder - FFmpegFFmpegFFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
, similar to MEncoder - MediaCoderMediaCoderMediaCoder is a transcoding program for Microsoft Windows. It has been developed by Stanley Huang since 2005.MediaCoder uses various open source audio and video codecs, among several proprietary codecs and tools to transcode different audio/video formats and has many extra features...
, a media transcoding application for Windows OSs, uses MEncoder as one of its backends - TranscodeTranscode (software)Transcode is a free audio/video transcoder with a command-line interface for Unix-like operating systems. It uses FFmpeg's libavcodec library, and supports numerous formats . It also includes a variety of pre/post filters for denoising, deinterlacing, smoothing, sharpening, etc...
, a command-line transcoding application for Unix-likeUnix-likeA Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
OSs - MPlayer Wikibook- almost all decoding-related and filtering arguments are shared with mencoder
- RetroCodeRetroCodeRetroCode is a universal mobile content converter originally created by Retro Ringtones LLC. RetroCode is able to read and write most common sample based ringtone formats including meta-data.- Overview :...
, a universal mobile content encoder/decoder