From 5461fc33baed9455a39b7ae1a4793a330251758c Mon Sep 17 00:00:00 2001
From: gabucino It is important to clarify a common mistake. When people see a file with a
-.AVI extension, they immediately conclude that it is not an MPEG file.
-That is not true. At least not entirely. Contrary to popular belief such a file
-can contain MPEG1 video.
You see, a codec is not the same as a file format.
-Examples of video codecs are: MPEG1, MPEG2, DivX, Indeo5, 3ivx.
-Examples of file formats are: MPG, AVI, ASF.
+ Examples of video codecs are: MPEG1, MPEG2, DivX, Indeo5, 3ivx.
+ Examples of file formats are: MPG, AVI, ASF.
In theory, you can put an OpenDivX video and MP3 audio -into an MPG format file. However, most players will not play it, since -they expect MPEG1 video and MP2 audio (unlike AVI, MPG does not have the -necessary fields to describe its video and audio streams). -Or you might put MPEG1 video into an AVI file. FFmpeg -and MEncoder can create these files.
+In theory, you can put an OpenDivX video and MP3 audio into an MPG + format file. However, most players will not play it, since they expect MPEG1 + video and MP2 audio (unlike AVI, MPG does not have the + necessary fields to describe its video and audio streams). Or you might put + MPEG1 video into an AVI file. + FFmpeg and + MEncoder can create these files.
@@ -39,38 +40,39 @@ and MEncoder can create these files.MPEG files come in different guises:
-vcd
option to play the Video CD.-vcd
option to play the Video CD.Series of frames form independent groups in MPEG files. This means that you
-can cut/join an MPEG file with standard file tools (like dd
,
-cut
), and it remains completely functional.
dd
,
+ cut
), and it remains completely functional.
-One important feature of MPGs is that they have a field to describe
-the aspect ratio of the video stream within. For example SVCDs have
-480x480 resolution video, and in the header that field is set to 4:3, so that
-it is played at 640x480. AVI files do not have this field, so they have to be
-rescaled during encoding or played with the -aspect
option.
One important feature of MPGs is that they have a field to describe the
+ aspect ratio of the video stream within. For example SVCDs have 480x480
+ resolution video, and in the header that field is set to 4:3, so that it is
+ played at 640x480. AVI files do not have this field, so they have to be
+ rescaled during encoding or played with the -aspect
option.
Designed by Microsoft, AVI (Audio Video Interleaved) is a
-widespread multipurpose format currently used mostly for DivX and DivX4
-video. It has many known drawbacks and shortcomings (for example in streaming).
-It supports one video stream and 0 to 99 audio streams. File size is limited to
-2GB, but there exists an extension allowing bigger files called OpenDMS.
-Microsoft currently strongly discourages its use and encourages ASF/WMV. Not that
-anybody cares.
+
Designed by Microsoft, AVI (Audio Video Interleaved) is a widespread
+ multipurpose format currently used mostly for DivX and DivX4 video. It has
+ many known drawbacks and shortcomings (for example in streaming). It
+ supports one video stream and 0 to 99 audio streams. File size is limited to
+ 2GB, but there exists an extension allowing bigger files called
+ OpenDMS. Microsoft currently strongly discourages its use and
+ encourages ASF/WMV. Not that anybody cares.
There is a hack that allows AVI files to contain an Ogg Vorbis audio
stream, but makes them incompatible with standard AVI. MPlayer
@@ -80,9 +82,9 @@ anybody cares.
problem.
Note: DV cameras create raw DV streams that DV grabbing utilities -convert to two different types of AVI files. The AVI will then contain either -separate audio and video streams that MPlayer can play or the raw DV -stream for which support is under development.
+ convert to two different types of AVI files. The AVI will then contain either + separate audio and video streams that MPlayer can play or the raw DV + stream for which support is under development.There are two kinds of AVI files:
Any audio and video codec is allowed, but note that VBR audio is not well -supported by most players. The file format makes it possible to use VBR -audio, but most players expect CBR audio, thus they fail with VBR. VBR is -uncommon and the Microsoft AVI specs only describe CBR audio. Most AVI -encoders/multiplexers create bad files when using VBR audio. There are only -two known exceptions: NanDub and MEncoder.
+ supported by most players. The file format makes it possible to use VBR + audio, but most players expect CBR audio, thus they fail with VBR. VBR is + uncommon and the Microsoft AVI specs only describe CBR audio. Most AVI + encoders/multiplexers create bad files when using VBR audio. There are only + two known exceptions: NanDub and MEncoder.ASF (active streaming format) comes from Microsoft. They developed two -variants of ASF, v1.0 and v2.0. v1.0 is used by their media tools (Windows -Media Player and Windows Media Encoder) and is very secret. v2.0 is published -and patented :). Of course they differ, there is no compatibility at all (it is -just another legal game). MPlayer supports only v1.0, as nobody has ever seen -v2.0 files :). Note that ASF files nowadays come with the extension .WMA or -.WMV.
+ variants of ASF, v1.0 and v2.0. v1.0 is used by their media tools (Windows + Media Player and Windows Media Encoder) and is very secret. v2.0 is published + and patented :). Of course they differ, there is no compatibility at all (it + is just another legal game). MPlayer supports only v1.0, as nobody has + ever seen v2.0 files :). Note that ASF files nowadays come with the extension + .WMA or .WMV. -These formats were designed by Apple and can contain any codec, CBR or VBR.
-They usually have a .QT or .MOV extension. Ever since the MPEG4 group chose
-QuickTime as the recommended file format for MPEG4, their MOV files come with a
-.MPG or .MP4 extension (Interestingly the video and audio streams in these
-files are real MPG and AAC files. You can even extract them with the
--dumpvideo
and -dumpaudio
options.).
These formats were designed by Apple and can contain any codec, CBR or VBR.
+ They usually have a .QT or .MOV extension. Ever since the MPEG4 group chose
+ QuickTime as the recommended file format for MPEG4, their MOV files come with
+ an
+ .MPG or .MP4 extension (Interestingly the video and audio streams in these
+ files are real MPG and AAC files. You can even extract them with the
+ -dumpvideo
and -dumpaudio
options.).
Note: Most new QuickTime files use Sorenson video and QDesign Music audio. See our Sorenson codec @@ -144,26 +147,26 @@ files are real MPG and AAC files. You can even extract them with the
-MPlayer happily demuxes VIVO file formats. The biggest disadvantage of -the format is that it has no index block, nor a fixed packet size or sync bytes -and most files lack even keyframes, so forget seeking!
+MPlayer happily demuxes VIVO file formats. The biggest disadvantage + of the format is that it has no index block, nor a fixed packet size or sync + bytes and most files lack even keyframes, so forget seeking!
The video codec of VIVO/1.0 files is standard h.263. The video codec -of VIVO/2.0 files is a modified, nonstandard h.263v2. The audio is the same, -it may be g.723 (standard), or Vivo Siren.
+ of VIVO/2.0 files is a modified, nonstandard h.263v2. The audio is the + same, it may be g.723 (standard), or Vivo Siren. -See the VIVO video codec -and VIVO audio codec sections for installation -instructions.
+See the VIVO video codec and + VIVO audio codec sections for installation + instructions.
-FLI is a very old file format used by Autodesk Animator, but it is
-a common file format for short animations on the net. MPlayer demuxes
-and decodes FLI movies and is even able to seek within them (useful when
-looping with the -loop
option). FLI files do not have keyframes, so the picture
-will be messy for a short time after seeking.
FLI is a very old file format used by Autodesk Animator, but it is a
+ common file format for short animations on the net. MPlayer demuxes
+ and decodes FLI movies and is even able to seek within them (useful when
+ looping with the -loop
option). FLI files do not have keyframes,
+ so the picture will be messy for a short time after seeking.
NuppelVideo -is a TV grabber tool (AFAIK:). MPlayer can read its .NUV -files (only NuppelVideo 5.0). Those files can contain uncompressed YV12, -YV12+RTJpeg compressed, YV12 RTJpeg+lzo compressed, and YV12+lzo compressed -frames. MPlayer decodes them all (and also encodes them with -MEncoder to DivX/etc!). Seeking works.
+ is a TV grabber tool (AFAIK:). MPlayer can read its .NUV files (only + NuppelVideo 5.0). Those files can contain uncompressed YV12, YV12+RTJpeg + compressed, YV12 RTJpeg+lzo compressed, and YV12+lzo compressed frames. + MPlayer decodes them all (and also encodes them with + MEncoder to DivX/etc!). Seeking works. -yuv4mpeg / yuv4mpeg2 is -a file format used by the mjpegtools programs. -You can grab, produce, filter or encode video in this format using these tools. -The file format is really a sequence of uncompressed YUV 4:2:0 images. +
yuv4mpeg / yuv4mpeg2 is a file + format used by the mjpegtools programs. + You can grab, produce, filter or encode video in this format using these + tools. The file format is really a sequence of uncompressed YUV 4:2:0 + images.
@@ -224,10 +228,10 @@ The file format is really a sequence of uncompressed YUV 4:2:0 images.You may have problems playing certain MP3 files that MPlayer will
-misdetect as MPEGs and play incorrectly or not at all. This cannot be fixed
-without dropping support for certain broken MPEG files and thus will remain
-like this for the foreseeable future. The -demuxer
flag described
-in the manpage may help you in these cases.
-demuxer
flag
+ described in the manpage may help you in these cases.
--
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