From 1380ac821bb23336ab6e1373a68fc80f74fcc686 Mon Sep 17 00:00:00 2001 From: melanson Date: Fri, 28 Dec 2001 22:18:27 +0000 Subject: initial commit for codecs.conf.txt documentation git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@3861 b3059339-0415-0410-9bf9-f77b7e298cf2 --- DOCS/tech/codecs.conf.txt | 122 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 DOCS/tech/codecs.conf.txt (limited to 'DOCS') diff --git a/DOCS/tech/codecs.conf.txt b/DOCS/tech/codecs.conf.txt new file mode 100644 index 0000000000..0b91922c6e --- /dev/null +++ b/DOCS/tech/codecs.conf.txt @@ -0,0 +1,122 @@ +Understanding MPlayer's etc/codecs.conf File + +Introduction +------------ +MPlayer features a very flexible codec architecture which allows it to +use its own open source codecs, as well as open source libraries, Win32 +codec DLLs, and XAnim binary codec modules. To the MPlayer user, the +most visible piece of this architecture is the etc/codecs.conf file. This +is a text-based configuration file that controls which MPlayer components +are in charge of handling particular compressed data formats. + +The codecs.conf file is stored either in a shared directory for all system +users to access, or in the .mplayer directory in a user's home +directory. When MPlayer starts, it first looks for a codecs.conf file in a +user's home directory. Failing that, it searches for the shared file. If +it can't find a codecs.conf file, MPlayer will refuse to run. + +The codecs.conf file is really quite simple. It is simply a collection of +codec definition blocks that define how different media types should be +handled. There are a number of keywords that can occur in a block. Not all +of them are required and there is no particular order enforced. + +Editing codecs.conf +------------------- +You can edit codecs.conf using your favorite text editor. Anything that +comes after a semicolon (;) on a line is regarded as a comment. For +example: +; this is a comment + format 0x34616d69 ; "ima4" (MOV files) + +The codec blocks can be in any order; the file parser doesn't +care. However, they are organized in a particular order for the benefit of +human readers. For example, all of the open source decoders that MPlayer +implements natively are grouped in one section. + +Video Codecs +------------ +Let's jump right in with an example. Here is an example video codec block: + +videocodec indeo5ds + info "Intel Indeo 5" + status working + fourcc IV50,iv50 + driver dshow + dll "ir50_32.dll" + guid 0x30355649, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 + out YV12 + out YUY2 + out BGR32,BGR24,BGR16,BGR15 + cpuflags mmx + +This is a particularly full-featured video codec. The "videocodec" keyword +identifies the fact that this is the start of a new video +codec. "indeo5ds" is MPlayer's unique name for the codec. + +The next line has the keyword "info" which specifies a human-readable +comment accompanies this codec. + +The "status" keyword carries information about the codec's functional +status. MPlayer currently recognizes 4 status levels: working, buggy, +crashing, and untested. + +The next line lists 4-character codes (FOURCCs) that are associated with +this codec. There can be more than one FOURCC specified on a fourcc line +as long as they're separated with a comma. There can also be multiple +fourcc lines in the codec. + +The "driver" keyword associates this codec with an internal MPlayer +decoder module. MPlayer has a module named "dshow" that handles data +encoded by the codec. + +The "dll" keyword specifies which Win32 or XAnim binary module needs to be +loaded in order to handle the specific media type. This keyword is usually +only used in conjunction with the dshow, vfw, acm, and xanim drivers since +they all manage communication with binary-only modules. + +The "guid" keyword identifies a 16-byte Microsoft GUID that some media +files use to identify codecs. + +The "out" keyword identifies which output format that the decoder is known +to output. Just like the fourcc line, there can be multiple out lines or +multiple comma-separated output formats on the same line. The output +formats should be listed in order of preference. + +The "cpuflags" identifies special operating parameters that this codec +requires. For example, this video codec is known to use MMX +instructions. Currently, valid strings for this keyword include mmx, sse, +and 3dnow. + +Audio Codecs +------------ +Here is an example a rather full-featured audio codec block: + +audiocodec mp3 + info "MPEG layer-2, layer-3" + status working + comment "Optimized to MMX/SSE/3Dnow!" + format 0x50 + format 0x55 + format 0x33706d2e ; ".mp3" CBR/VBR MP3 (MOV files) + format 0x5500736d ; "ms\0\x55" older mp3 fcc (MOV files) + driver mp3lib + dll "mp3lib (mpglib)" + flags seekable + +Many of the keywords are the same as a video codec block. However, we see +a few that we haven't seen before. The "comment" keyword identifies +another human-readable note for this codec. + +The "format" keyword performs a similar job as the fourcc line. However, +since certain media file formats (notably AVI) identify audio formats with +16-bit numbers rather than 32-bit FOURCCs, it's necessary to use this +convention to accomodate them. However, as shown in this example, FOURCCs +can also be specified with the format keyword as long as they're converted +to their hex representation. It's important to note that this can be +useful for video codecs as well if a FOURCC contains a space (such as +Apple's "rle " codec). + +The "flags" keywords identifies any additional abilities of this +codec. Currently, seekable is the only flag supported. + +EOF -- cgit v1.2.3