Overview

MEncoder (MPlayer's Movie Encoder) is a simple movie encoder, designed to encode MPlayer-playable movies (AVI/DVD/VCD/VOB/MPG/MOV/VIV/NET) to other MPlayer-playable formats (see below). Currently it's in beta stage, and encodes only to DivX4 (1 or 2 passes) video, PCM/MP3/VBRMP3 audio. Also has stream copying abilities. In the future, there will be cropping, resizing filters, and other interesting stuff.

Compiling

MEncoder features :

• encoding from the wide range of fileformats and decoders of MPlayer
• encoding from V4L compatible TV tuners
• encoding/multiplexing to interleaved AVI files with proper index
• 1 or 2 pass DivX4 video
• VBR MP3 audio
• PCM audio
• stream copying (CBR audio only)
• input A/V synchronizing (PTS-based, can be disabled with -mc 0 option)
• FPS correction with -ofps option (useful when encoding 29.97fps VOB to 24fps AVI)
• movie rescaling

Planned features :

• using audio from separate file (AC3, MP3, OGG)
• VBR audio stream copy
• even wider variety of available en/decoding formats/codecs (creating VOB files with DivX4/Indeo5/VIVO streams :)

Encoding 2-pass DivX4

The name comes from the fact that this method encodes the file twice. The first encoding (dubbed pass) creates some temporary files (*.log) with a size of few megabytes, do not delete them yet (you can delete the AVI). In the second pass, the 2-pass output file is created, using the bitrate data from the temporary files. The resulting file will have much better image quality. If this is the first time you heard about this, you should consult some guides available on the Net.

This example shows how to encode a DVD to a 2-pass DivX4 AVI. Just two commands are needed :
    mencoder -dvd 2 -ovc divx4 -oac mp3lame -divx4opts br=1100 -o movie.avi -pass 1
    mencoder -dvd 2 -ovc divx4 -oac mp3lame -divx4opts br=1100 -o movie.avi -pass 2

Rescaling movies

Often the need to resize movie images' size emerges. Its reasons can be many, examples are decreasing output file size, encoding SVCDs to DivX. Ripped DVDs are mostly rescaled, for example a 4:3 DVD should be 640x480, especially when you want it to fit to 1 CD, and have good quality at the same time. SVCDs have 480x480 size, and their header contains the aspect ratio the player should use (Ex.: 480x480 + 4:3 = 640x480). However when encoding to AVI (DivX) files, you have be aware that AVI headers don't store this value. Thus, the only solution is rescaling.

The output size is specified with the -x, and -y options. Furthermore, there are 3 rescaling filters in MEncoder, 0 : fast 1 : bilinear, 2 : bilinear, bicubic (best quality). They can be specified with the -sws option. If not specified, MEncoder will use 0 : fast bilinear.

Rescaling is very simple :
    mencoder sample-svcd.mpg -divx4opts br=1300 -x 640 -y 480 -sws 2 -o output.avi

Stream copying

MEncoder can handle input streams in two ways : encode or copy them. This section is about copying.

• Video stream (option -ovc copy) : nice stuff can be done :)
  Like, putting (not converting!) FLI or VIVO or MPEG1 video into an AVI file ! Of course only MPlayer can play such files :) And it probably has no real life value at all. Rationally : video stream copying can be useful for example when only the audio stream has to be encoded (like, uncompressed PCM to MP3).
• Audio stream (option -oac copy) : straightforward.

Fixing AVIs with broken index

Easiest thing. We simply copy the video and audio streams, and MEncoder generates the index. Of course this cannot fix possible bugs in the video and/or audio streams.

Command : mencoder input.avi -ovc copy -oac copy -o output.avi

Syntax

  mencoder [options] [input file] [options] ...