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