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Rename to Audio and video formats/codecs?
Contents |
Formats
http://www.downloadatoz.com/aplus-video-to-xbox-converter/glossary.html.
What is AVI?
AVI stands for Audio Video Interleave. It is a special case of the RIFF (Resource Interchange File Format). AVI is defined by Microsoft. AVI is the most common format for audio/video data on the PC. AVI is an example of a de facto (by fact) standard.
What is DivX?
Digital Video Express (DivX) is a digital video compression format based on the MPEG-4 technology. DivX files can be downloaded over high-speed lines in a relatively short time without sacrificing the quality of the digital video. Often used on the Internet to exchange video files.Originally developed for DVD encoding (650 mb = 80-90 min. at 640x480, standard bitrate), DivX has become the internet video format of choice for high-quality productions.
What is Xvid?
XviD is a free and open source MPEG-4 video codec. XviD was created by a group of volunteer programmers after the OpenDivX source was closed in July 2001.
XviD features MPEG-4 Advanced Simple Profile features such as b-frames, global and quarter pixel motion compensation, lumi masking, trellis quantization, and H.263, MPEG and custom quantization matrices.
XviD is a primary competitor of DivX (XviD being DivX spelled backwards). While DivX is closed source and may only run on Windows, Mac OS and Linux, XviD is open source and can potentially run on any platform.
What is ASF?
The Advanced Systems Format (ASF) is the file format used by Windows Media. Audio and/or Video content compressed with a wide variety of codecs can be stored in an ASF file and played back with the Windows Media Player (provided the appropriate codecs are installed), streamed with Windows Media Services or optionally packaged with Windows Media Rights Manager.
What is WMV?
WMV is a generic name of Microsoft's video encoding solutions and doesn't necessarily define the technology what it uses -- since version 7, WMV (Windows Media Video) Microsoft's proprietary compression format for motion video, Windows Media Video is used for both streaming and downloading content via the Internet.
What is WMA?
WMA (Windows Media Audio) Developed by Microsoft, Windows Media Audio is one of today's most popular 'Net audio formats. Though not as popular as MP3, WMA tends to outperform MP3 in the area of sound quality, particularly with files encoded at lower bitrates like 64 or 96 Kbps. This performance advantage makes it handy for applications like portable digital audio players, where total play time is limited by a finite amount of internal memory. The Windows Media Audio format features built-in copy protection abilities, unlike MP3. Windows® XP, Microsoft's current flagship operating system software, contains native support for WMA encoding, enabling users to create their own WMA music files.
What is MPEG?
MPEG (pronounced M-peg), which stands for Moving Picture Experts Group, is the name of family of standards used for coding audio-visual information (e.g., movies, video, music) in a digital compressed format. The major advantage of MPEG compared to other video and audio coding formats is that MPEG files are much smaller for the same quality. This is because MPEG uses very sophisticated compression techniques. Current standards that exist include, MPEG-1, MPEG-2, MPEG-3, and MPEG4. MPEG-1 is a standard for CD-ROM video and audio.MPEG-2 is a standard for full-screen, broadcast quality video.MPEG-4 is a standard for video telephony.
What is MOV/QT?
a file format for Quicktime movies and animations, developed by Apple Computer Co. it can actually be used to store both movies and sounds. A file with this extension could thus be either an audio file or a movie file. Both types are supported by many different platforms. Note though that there are several different versions of QuickTime files in use, and not all players will play all versions.
What is RM?
RM (RealMedia) is a digital sound and video file format that is the registered trademark of RealNetworks. This format is typically used to stream media through the net. It can be played with the RealOne player or with other media players using the Real Alternative codec. RealMedia (comprised of RealVideo, RealAudio, and other file formats created by Real) use compression algorithms for eliminating data.
What is RMVB?
Rmvb is an abbreviation for Real Media variable bitrate. It is a type of video file, playable with RealPlayer from RealNetworks
MPEG-4
http://sound.media.mit.edu/mpeg4/audio/faq/mpeg4.html
http://wiki.videolan.org/MPEG-4.
MPEG-4 is a form of MPEG encoding. It is a flexible audio and video compression format. The format describes audio and video compression, with a container format for streaming across networks and saving to disk. It also contains optional extra features, including DRM and subtitles. These extra features are only included in software if needed. MPEG-4 can provide better quality than MPEG-2 at low bitrates. Here is an example of how to transcode an AVI into an MPEG-4 video from the command prompt % vlc file.avi --sout='#transcode{vcodec=mp4v,acodec=mp4a}:std{access=file,mux=mp4,dst=file.m4v}' MPEG-4 audio is an advanced, complicated audio format. It includes AAC for high bitrates, multilingual tracks, text-to-speech modes for very low bitrates, the ability to synthesize instrumental sounds (similar to MIDI), and more. See also the MPEG-4 Audio FAQ. ...
mp4a is an audio codec. mp4v is a video codec.
http://www.linuxforums.org/forum/wine/12796-divx-quicktime-wine.html.
xine doesn't use DivX or XviD at all. Not even optionally. xine (and all players based on xine - Kaffeine, Totem etc.) uses built-in libavcodec from FFmpeg. MPlayer uses built-in libavcodec from FFmpeg, too. Although it can optionally use DivX and XviD, too, if it was compiled appropriately and you explicitly specify those codecs. But libavcodec is the default. This is a very widespread myth - most people don't know that: 1. DivX is an MPEG-4 codec (commercial, closed-source). 2. XviD is an MPEG-4 codec, too (open-source). 3. MPEG-4 is a standard (that's why MPEG-4 codecs are more or less compatible). 4. There are many other MPEG-4 codecs, DivX and XviD are just [two] of them. 5. The No. 1 codec library in Linux and other open-source systems is libavcodec from FFmpeg (open-source). 6. FFmpeg has their own MPEG-4 codec and that's the codec that most Linux programs use for decoding and encoding. FFmpeg MPEG-4 is what you actually use for MPEG-4 playback in all Linux players. Many people call it "DivX" without knowing it's actually FFmpeg. Other people think the only open-source option is XviD, but it's FFmpeg MPEG-4 that's used the most (and most people don't know that it exists). 7. DivX is irrelevant and useless in Linux - it is officially no longer available for Linux (the Linux version is obsolete, buggy and dead and DivX is now officially Windows and Mac OS only) and it's not needed for anything. And both FFmpeg MPEG-4 and XviD are vastly superior in Linux in every aspect. 8. Installing DivX or XviD for xine, VLC etc. is useless because they don't use them at all. They use built-in FFmpeg MPEG-4 (no external codec needed). 9. There's no such thing as "DivX video" or "XviD format", it's MPEG-4 video.
http://www.linux.com/articles/56642.
The format is MPEG-4, not DivX Please don't spread this DivX nonsense on a public website. You obviously either don't understand basic terms (the difference between software and specification, or codec and format), or you're intentionally lying because of the massive ubiquity of the "DivX myth", which is irresponsible. The compression you're using is called MPEG-4 ASP (MPEG-4 is a standard developed by MPEG) and the codec (i.e. software) you're using for converting it to this format is FFmpeg (libavcodec) MPEG-4. It has absolutely nothing to do with DivX, which is nothing else than a brand name of a commercial closed-source MPEG-4 codec (a piece of software, not a format) that you don't use. XviD is not a format either, XviD is a name of yet another MPEG-4 codec, which is open-source (FFmpeg/libavcodec is open-source, too). XviD is a piece of software, it also encodes and decodes MPEG-4 ASP video, just like all other MPEG-4 ASP codecs.
They have different FourCC values. So while you're right, when you tell Mplayer to write to Xvid or DivX (there's a -xvid option for Mplayer. For Divx you are basically telling it to use mp4 directly), you ARE specifying a different mpeg4 fourcc
Are MPEG-4 audio (.mpa) and AAC the same?
Compared to MPEG-2
http://sound.media.mit.edu/mpeg4/audio/faq/mpeg4.html.
What does MPEG-4 Audio Version 1 provide above MPEG-2 Audio?
MPEG-4 Audio Version 1 integrates the worlds of synthetic and natural coding of audio. The synthetic coding part is comprised of tools for the realisation of symbolically defined music and speech. This includes MIDI and Text-to-Speech systems. Furthermore, tools for the 3-D localisation of sound are included, allowing the creation of artificial sound environments using artificial and natural sources. MPEG-4 Audio also standardises natural audio coding at bit rates ranging from 2 kbit/s up to 64 kbit/s. In order to achieve the highest audio quality within the full range of bit rates, three types of codecs have been defined: a parametric codec for the lower bit rates in the range, a Code Excited Linear Predictive (CELP) codec for the medium bit rates in the range, and Time to Frequency (TF) codecs, including MPEG-2 AAC and Vector-Quantiser based, for the higher bit rates in the range. Furthermore, a number of functionalities are provided to facilitate a wide variety of applications which would range from intelligible speech to high quality multichannel audio.
What is the difference between MPEG-2 AAC and MPEG-4 AAC?
MPEG-4 AAC has all the tools and functions of MPEG-2 AAC plus the Perceptual Noise Substitution (PNS) tool, a Long Term Predictor (LTP) as well as extensions to support scalability. Therefore all MPEG-4 AAC decoders can decode MPEG-2 AAC bitstreams, and conversely MPEG-2 AAC decoders can decode MPEG-4 AAC bitstreams if none of the MPEG-4 extensions are signalled.
Which video format to use?
An open format, of course!
Open:
- xvid
- Ogg Theora
Proprietary:
- RealVideo, WMV, QuickTime (Mov)
- MPEG-4
- DivX
- 3ivx (http://3ivx.com/)
Why convert it to another proprietary format [MPEG-4]? Convert it to Ogg Theora.
Converting
Using mencoder
http://forums.suselinuxsupport.de/index.php?showtopic=46053.
Convert Quicktime to avi
mencoder -ovc copy -oac pcm -o output.avi input.movYou could play around with mplayer and see if you can go direct from .mov to .mpg. Failing that, you could use "tovid" to go from .mov to .mpg
I just tested using "tovid" to convert a .mov to .mpeg, and it works well. For example:
tovid -dvd -ntsc -in inputmovfile.mov -out outputmpegfile
http://nerds-central.blogspot.com/2008/01/processing-mov-files-on-ubunutu-linux.html.
... The final step is to make an output file. For a h264 (like mp4 but considered to be a bit better) I use this:
mencoder -oac mp3lame -ovc x264 input.avi -o out.aviTo make a mpg1 (which is still the most universally usable format, though getting rather old and so portly performing compared to newer ones):
ffmpeg -i /media/store/temp/vanr-raw-clipped.avi -sameq -vcodec mpeg1video out.mpgHowever, I found that the xvid codec from Virtual-Dub (I did blog on how to install this under wine) does a really good job as well though makes much bigger files than h264 from mencoder. To make an avi to upload to Youtube or Blogger this is the way to go because it does not seems that the Google kit understands the h264 files.
...
http://www.linux.com/articles/56642.
Now save the following lines as flv2avi.sh. Make the file executable with chmod 755 flv2avi.sh and copy it in a directory in your PATH (/usr/local/bin is a good candidate):
#!/bin/sh if [ -z "$1" ]; then echo "Usage: $0 {-divx|-xvid} list_of_flv_files" exit 1 fi # video encoding bit rate V_BITRATE=1000 while [ "$1" ]; do case "$1" in -divx) MENC_OPTS="-ovc lavc -lavcopts \ vcodec=mpeg4:vbitrate=$V_BITRATE:mbd=2:v4mv:autoaspect" ;; -xvid) MENC_OPTS="-ovc xvid -xvidencopts bitrate=$V_BITRATE:autoaspect" ;; *) if file "$1" | grep -q "Macromedia Flash Video"; then mencoder "$1" $MENC_OPTS -vf pp=lb -oac mp3lame \ -lameopts fast:preset=standard -o \ "`basename $1 .flv`.avi" else echo "$1 is not Flash Video. Skipping" fi ;; esac shift doneThis script converts a list of .flv files to either DivX or XviD, depending on whether you give the -divx or -xvid option, and saves them with their original file name followed by the .avi extension. Usage is very simple: flv2avi.sh -divx first_vid.flv second_vid.flv etc.flv. For more information about the options used on the mencoder commands you can read its man page.
http://www.linux.com/feature/121385
To theora
ffmpeg2theora is a simple app that works well for most files
To DVD
http://www.linux.com/articles/53702.
... Unfortunately, the video is encoded in XviD or QuickTime format, which your DVD player doesn't support. Don't worry -- here's how you can convert any video file to DVD using dvdauthor and MPlayer. ...