Encoding with <application>MEncoder</application> For the complete list of available MEncoder options and examples, please see the man page. For a series of hands-on examples and detailed guides on using several encoding parameters, read the encoding-tips that were collected from several mailing list threads on mplayer-users. Search the archives for a wealth of discussions about all aspects of and problems related to encoding with MEncoder. Encoding 2 or 3-pass MPEG-4 ("DivX") 2-pass encoding 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 MPEG-4 ("DivX") AVI. Just two commands are needed: rm frameno.avi remove this file, which can come from a previous 3-pass encoding (it interferes with current one) mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 -oac copy -o movie.avi mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=2 -oac copy -o movie.avi 3-pass encoding This is an extension of 2-pass encoding, where the audio encoding takes place in a separate pass. This method enables estimation of recommended video bitrate in order to fit on a CD. Also, the audio is encoded only once, unlike in 2-pass mode. The schematics: Remove conflicting temporary file: rm frameno.avi First pass: mencoder file/DVD -ovc frameno -oac mp3lame -lameopts vbr=3 -o frameno.avi An audio-only avi file will be created, containing only the requested audio stream. Don't forget , if you need to set it. If you were encoding a long movie, MEncoder prints the recommended bitrate values for 650Mb, 700Mb, and 800Mb destination sizes, after this pass finishes. Second pass: mencoder file/DVD -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vpass=1:vbitrate=bitrate This is the first pass of video encoding. Optionally specify the video bitrate MEncoder printed at the end of the previous pass. Third pass: mencoder file/DVD -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vpass=2:vbitrate=bitrate This is the second pass of video encoding. Specify the same bitrate as in the previous pass unless you really know what you are doing. In this pass, audio from frameno.avi will be inserted into the destination file...and it's all ready! Example of 3-pass encoding rm frameno.avi remove this file, which can come from a previous 3-pass encoding (it interferes with current one) mencoder dvd://2 -ovc frameno -o frameno.avi -oac mp3lame -lameopts vbr=3 mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=1 -oac copy -o movie.avi mencoder dvd://2 -ovc lavc -lavcopts vcodec=mpeg4:vpass=2 -oac copy -o movie.avi Encoding to MPEG format MEncoder can create MPEG (MPEG-PS) format output files. It's probably useful only with libavcodec's mpeg1video codec, because players - except MPlayer - expect MPEG1 video, and MPEG1 layer 2 (MP2) audio streams in MPEG files. This feature is not very useful right now, aside that it probably has many bugs, but the more importantly because MEncoder currently cannot encode MPEG1 layer 2 (MP2) audio, which all other players expect in MPEG files. To change MEncoder's output file format, use the option. Example: mencoder -of mpeg -ovc lavc -lavcopts vcodec=mpeg1video -oac copy other_options media.avi -o output.mpg Rescaling movies Often the need to resize movie images' size emerges. Its reasons can be many: decreasing file size, network bandwidth,etc. Most people even do rescaling when converting DVDs or SVCDs to DivX AVI. This is bad. Instead of even you doing so, read the Preserving aspect ratio section. The scaling process is handled by the scale video filter: . Its quality can be set with the option. If it's not specified, MEncoder will use 0: fast bilinear. Usage: mencoder input.mpg -ovc lavc -lavcopts vcodec=mpeg4 -vf scale=640:480-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 ): 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 ): straightforward. It is possible to take an external audio file (MP3, WAV) and mux it into the output stream. Use the option for this. Fixing AVIs with broken index or interleaving 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. It also fixes files with broken interleaving, thus the option won't be needed for them anymore. Command: mencoder -idx input.avi -ovc copy -oac copy -o output.avi Appending multiple AVI files As a side-effect, the broken AVI fixer function enables MEncoder to append 2 (or more) AVI files: Command: cat 1.avi 2.avi | mencoder -noidx -ovc copy -oac copy -o output.avi - This expects 1.avi and 2.avi to use the same codecs, resolution, stream rate etc, and at least 1.avi must not be broken. You may need to fix your input AVI files first, as described above. Encoding with the <systemitem class="library">libavcodec</systemitem> codec family libavcodec provides simple encoding to a lot of interesting video and audio formats. You can encode to the following codecs (more or less up to date): Codec nameDescription mjpeg Motion JPEG ljpeg Lossless JPEG h263 H263 h263p H263 Plus mpeg4 ISO standard MPEG-4 (DivX 5, XVID compatible) msmpeg4 pre-standard MPEG-4 variant by MS, v3 (aka DivX3) msmpeg4v2 pre-standard MPEG-4 by MS, v2 (used in old asf files) wmv1 Windows Media Video, version 1 (aka WMV7) wmv2 Windows Media Video, version 2 (aka WMV8) rv10 an old RealVideo codec mpeg1video MPEG1 video mpeg2video MPEG2 video huffyuv lossless compression asv1 ASUS Video v1 asv2 ASUS Video v2 ffv1 FFmpeg's lossless video codec The first column contains the codec names that should be passed after the vcodec config, like: An example, with MJPEG compression: mencoder dvd://2 -o title2.avi -ovc lavc -lavcopts vcodec=mjpeg -oac copy Encoding from multiple input image files (JPEGs,PNGs or TGAs) MEncoder is capable of creating movies from one or more JPEG, PNG or TGA files. With simple framecopy it can create MJPEG (Motion JPEG), MPNG (Motion PNG) or MTGA (Motion TGA) files. Explanation of the process: MEncoder decodes the input image(s) with libjpeg (when decoding PNGs, it will use libpng). MEncoder then feeds the decoded image to the chosen video compressor (DivX4, Xvid, ffmpeg msmpeg4, etc.). Examples The explanation of the option can be found below in the man page. Creating a DivX4 file from all the JPEG files in the current dir: mencoder -mf on:w=800:h=600:fps=25 -ovc divx4 -o output.avi \*.jpg Creating a DivX4 file from some JPEG files in the current dir: mencoder -mf on:w=800:h=600:fps=25 -ovc divx4 -o output.avi frame001.jpg,frame002.jpg Creating a Motion JPEG (MJPEG) file from all the JPEG files in the current dir: mencoder -mf on:w=800:h=600:fps=25 -ovc copy -o output.avi \*.jpg Creating an uncompressed file from all the PNG files in the current dir: mencoder -mf on:w=800:h=600:fps=25:type=png -ovc raw -o output.avi \*.png Width must be integer multiple of 4, it's a limitation of the RAW RGB AVI format. Creating a Motion PNG (MPNG) file from all the PNG files in the current dir: mencoder -mf on:w=800:h=600:fps=25:type=png -ovc copy -o output.avi \*.png Creating a Motion TGA (MTGA) file from all the TGA files in the current dir: mencoder -mf on:w=800:h=600:fps=25:type=tga -ovc copy -o output.avi \*.tga Extracting DVD subtitles to Vobsub file MEncoder is capable of extracting subtitles from a DVD into Vobsub formatted files. They consist of a pair of files ending in .idx and .sub and are usually packaged in a single .rar archive. MPlayer can play these with the and options. You specify the basename (i.e without the .idx or .sub extension) of the output files with and the index for this subtitle in the resulting files with . If the input is not from a DVD you should use to indicate the .ifo file needed to construct the resulting .idx file. If the input is not from a DVD and you do not have the .ifo file you will need to use the option to let it know what language id to put in the .idx file. Each run will append the running subtitle if the .idx and .sub files already exist. So you should remove any before starting. Copying two subtitles from a DVD while doing 3-pass encoding rm subtitles.idx subtitles.sub mencoder dvd://1 -vobsubout subtitles -vobsuboutindex 0 -sid 2 -o frameno.avi -ovc frameno mencoder dvd://1 -oac copy -ovc divx4 -pass 1 mencoder dvd://1 -oac copy -ovc divx4 -pass 2 -vobsubout subtitles -vobsuboutindex 1 -sid 5 Copying a french subtitle from an MPEG file rm subtitles.idx subtitles.sub mencoder movie.mpg -ifo movie.ifo -vobsubout subtitles -vobsuboutindex 0 -vobsuboutid fr -sid 1 Preserving aspect ratio DVDs and SVCDs (i.e. MPEG1/2) files contain an aspect ratio value, which describes how the player should scale the video stream, so humans won't have egg heads (ex.: 480x480 + 4:3 = 640x480). However when encoding to AVI (DivX) files, you have be aware that AVI headers don't store this value. Rescaling the movie is disgusting and time consuming, there has to be a better way! There is MPEG4 has an unique feature: the video stream can contain its needed aspect ratio. Yes, just like MPEG1/2 (DVD, SVCD) and H263 files. Regretfully, there are no video players outside which support this attribute of MPEG4, except MPlayer. This feature can be used only with libavcodec's mpeg4 codec. Keep in mind: although MPlayer will correctly play the created file, other players will use the wrong aspect ratio. You seriously should crop the black bands over and below the movie image. See the man page for the usage of the cropdetect and crop filters. Usage mencoder sample-svcd.mpg -ovc lavc -lavcopts vcodec=mpeg4:autoaspect -vf crop=714:548:0:14 -oac copy -o output.avi Custom inter/intra matrices With this feature of libavcodec you are able to set custom inter (I-frames/key frames) and intra (P-frames/predicted frames) matrices. It is supported by many of the codecs: mpeg1video and mpeg2video are reported as working. A typical usage of this feature is to set the matrices preferred by the KVCD specifications. The KVCD "Notch" Quantization Matrix: Intra: 8 9 12 22 26 27 29 34 9 10 14 26 27 29 34 37 12 14 18 27 29 34 37 38 22 26 27 31 36 37 38 40 26 27 29 36 39 38 40 48 27 29 34 37 38 40 48 58 29 34 37 38 40 48 58 69 34 37 38 40 48 58 69 79 Inter: 16 18 20 22 24 26 28 30 18 20 22 24 26 28 30 32 20 22 24 26 28 30 32 34 22 24 26 30 32 32 34 36 24 26 28 32 34 34 36 38 26 28 30 32 34 36 38 40 28 30 32 34 36 38 42 42 30 32 34 36 38 40 42 44 Usage: $ mencoder input.avi -o output.avi -oac copy -ovc lavc -lavcopts inter_matrix=...:intra_matrix=... $ mencoder input.avi -ovc lavc -lavcopts vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37, 12,14,18,27,29,34,37,38,22,26,27,31,36,37,38,40,26,27,29,36,39,38,40,48,27, 29,34,37,38,40,48,58,29,34,37,38,40,48,58,69,34,37,38,40,48,58,69,79 :inter_matrix=16,18,20,22,24,26,28,30,18,20,22,24,26,28,30,32,20,22,24,26, 28,30,32,34,22,24,26,30,32,32,34,36,24,26,28,32,34,34,36,38,26,28,30,32,34, 36,38,40,28,30,32,34,36,38,42,42,30,32,34,36,38,40,42,44 -oac copy -o svcd.mpg Making a high quality MPEG4 ("DivX") rip of a DVD movie Ripping a DVD title into a maximally high quality MPEG4 (DivX) file involves many considerations. Below is an example of the process when there is no file size goal (other than perhaps fitting the result into 2GB). libavcodec will be used for the video, and the audio will be copied as is without any changes. Cropping Play the DVD and run the crop detection filter () on it. This gives you a crop rectangle to use for encoding. The reason for cropping is that many movies are not shot in a standard DVD aspect ratio (16/9 or 4/3), or, for whatever reason, the picture does not properly fill the frame. So you want to crop out the pointless black bars when you rip. It also improves the quality of the rip since the sharp edge of the black bars wastes a lot of bits. A common aspect is 2.35, which is cinescope. Most big blockbuster movies have this aspect ratio. Quality level Next you need to choose the desired quality level. When there is no need to fit the resulting file on CDs or the like, using constant quantizing AKA constant quality is a good choice. That way each frame is given as much bits as its needs to keep the quality at the desired level, but multiple encoding passes are not needed. With libavcodec, you get constant quality by using . should give you a file below 2GB in size, depending mainly on the movie length and video noisiness (the more noise, the harder it is to compress). Files over 2GB If the file resulting from constant quality encoding is over 2GB big, you will have to create an index to be able to view it properly. Either play the file with to create an index on the fly or use to write an index to a file once and to use it when playing the file. If this bothers you, you may want to keep the file size below 2GB. There are three ways to avoid this. You can try encoding again using and see if both the resulting file size and picture quality are acceptable. You can also use 2 pass encoding. As you will be copying the audio track as is and hence know its bitrate, and you know the running time of the movie, you can compute the required video bitrate to give to the option without using 3 pass encoding. The third and possibly the best option may be to slightly scale down the resolution. The uniform slight softening and loss of detail is visually more appealing than the blockiness and other artifacts caused by MPEG compression. Scaling down also effectively reduces the noise of the picture, which is good, as noise is hard to compress. Deinterlacing If the movie is interlaced, you may want to deinterlace it as part of the ripping. It is debatable whether deinterlacing should be done at this stage. The benefit is that deinterlacing when converting to MPEG4 makes compression better, and viewing easier and less CPU intensive on computer monitors as no deinterlacing is required at that stage. If deinterlacing at the ripping stage is a good idea depends on the DVD. If the DVD is made from film, which was shot at 24 fps, you can as well deinterlace while ripping. If, however, the original was 50/60 fps video, converting into deinterlaced 23.976/25 fps video will lose information. If you do decide to deinterlace, you can further experiment with different deinterlacing filters. See http://www.wieser-web.de/MPlayer/ for examples. A good starting point is . If you are both cropping and deinterlacing, deinterlace before cropping. Actually, this is not necessary if the crop offset is vertically a multiple of 2 pixels. However with some other filters, like dering, you should always crop last, so it's a good habit to put the crop filter last. Inverse telecine If you are ripping a PAL DVD, which is 25 fps, you do not need to think about the fps. Just use 25 fps. NTSC DVDs on the other hand are 29.97 fps (often rounded to 30 fps, but that is not what they are). If the movie was shot for TV, you again do not need to touch the fps. But if the movie was shot on film, and hence at (exactly) 24 fps, it has been converted to 29.97 fps when making the DVD. That conversion where 12 fields are added to each 24 frames of film is called telecine. For more info about telecine, see a Google search for "telecine field 23.976". In case you have such a telecined DVD, you will want to do inverse telecine, that is convert the movie to 23.976 fps (29.97*4/5). Otherwise camera panning will look jerky and awful. You can use for this. Anything that is shown in theatres is shot on film and needs inverse telecine, TV shows do not. Scaling and aspect ratio For best quality, do not scale the movie while ripping. Scaling down obviously loses detail, and scaling up causes artifacts and obviously makes the file larger. Pixels in DVD movies are not square, so DVD movies include info about the correct aspect ratio. It is possible to store the aspect ratio in the MPEG4 header of the output file. Most video players ignore this info, but MPlayer honors it. So if you are only going to use MPlayer for viewing the ripped file, you do not need to scale the movie, just pass to MEncoder and things will automagically work right. If you must scale the movie, be careful about getting the size right especially if you do cropping. Summing it up With all of the above mentioned in mind, a suitable encoding command might be mencoder dvd://1 -aid 128 -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vqscale=3:vhq:v4mv:trell:autoaspect \ -ofps 23.976 -vf crop=720:364:0:56 -o Harry_Potter_2.avi Here gives the DVD title to rip. Option says to use audio track 128, and to copy it as is. You'll have to use MPlayer to find out the right values for these options. Options for improve quality versus bitrate, but make encoding take longer. Especially slows encoding down but also increases quality visibly. If you want to deinterlace, add a filter to , for example (in that order). If you don't need inverse telecine, leave out the .