[MPlayer-cvslog] CVS: main/DOCS/tech mpcf.txt,1.72,1.73
Diego Biurrun CVS
syncmail at mplayerhq.hu
Fri Sep 9 11:25:10 CEST 2005
CVS change done by Diego Biurrun CVS
Update of /cvsroot/mplayer/main/DOCS/tech
In directory mail:/var2/tmp/cvs-serv30178/DOCS/tech
Modified Files:
mpcf.txt
Log Message:
spelling/grammar/wording
Index: mpcf.txt
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/tech/mpcf.txt,v
retrieving revision 1.72
retrieving revision 1.73
diff -u -r1.72 -r1.73
--- mpcf.txt 19 Jun 2005 09:17:44 -0000 1.72
+++ mpcf.txt 9 Sep 2005 09:25:07 -0000 1.73
@@ -6,38 +6,37 @@
Intro:
Features / goals:
- (supported by the format, not necessary by a specific implementation)
+ (supported by the format, not necessarily by a specific implementation)
Simple
use the same encoding for nearly all fields
- simple decoding, so slow cpus (and embedded systems) can handle it
+ simple decoding, so slow CPUs (and embedded systems) can handle it
Extendible
- no limit for the possible values for all fields (using universal vlc)
+ no limit for the possible values of all fields (using universal vlc)
allow adding of new headers in the future
allow adding more fields at the end of headers
Compact
~0.2% overhead, for normal bitrates
index is <10kb per hour (1 keyframe every 3sec)
- a usual header for a file is about 100bytes (audio + video headers together)
+ a usual header for a file is about 100 bytes (audio + video headers together)
a packet header is about ~1-8 bytes
Error resistant
seeking / playback without an index
headers & index can be repeated
- damaged files can be played back with minimal data lost and fast
- resyncing times
-
+ damaged files can be played back with minimal data loss and fast
+ resync times
Definitions:
MUST the specific part must be done to conform to this standard
-SHOULD it's recommended to be done that way, but it's not strictly required
+SHOULD it is recommended to be done that way, but not strictly required
Syntax:
-Since nut heavily uses variable length fields, the simplest way to describe it
+Since NUT heavily uses variable length fields, the simplest way to describe it
is using a pseudocode approach.
Conventions:
@@ -59,14 +58,14 @@
[Optional notes]
The in-depth tag description follows the bitstream syntax.
-The functional definition has a C like syntax.
+The functional definition has a C-like syntax.
Type definitions:
f(n) (n fixed bits in big-endian order)
-u(n) (unsigned number encoded in n bits in MSB first order)
+u(n) (unsigned number encoded in n bits in MSB-first order)
v (variable length value, unsigned)
value=0
@@ -86,7 +85,7 @@
for(i=0; i<length; i++){
data[i] u(8)
}
- [Note: strings MUST be encoded in utf8]
+ [Note: strings MUST be encoded in UTF-8]
vb (variable length binary data or string)
length v
@@ -298,7 +297,7 @@
max_distance
max distance of frame_startcodes, the distance may only be larger if
- there is only a single frame between the 2 frame_startcodes this can
+ there is only a single frame between the two frame_startcodes this can
be used by the demuxer to detect damaged frame headers if the damage
results in too long of a chain
@@ -315,8 +314,8 @@
stream_id[FIXME]
Stream identifier
- Note: streams with a lower relative class MUST have a lower relative id
- so a stream with class 0 MUST always have an id which is lower than any
+ Note: streams with a lower relative class MUST have a lower relative ID
+ so a stream with class 0 MUST always have an ID which is lower than any
stream with class > 0
stream_id MUST be < stream_count
@@ -336,7 +335,7 @@
time_base_nom / time_base_denom = time_base
the number of timer ticks per second, this MUST be equal to the fps
- if the fixed_fps is 1
+ if fixed_fps is 1
time_base_denom MUST NOT be 0
time_base_nom and time_base_denom MUST be relatively prime
time_base_nom MUST be < 2^31
@@ -379,8 +378,8 @@
decode_delay
maximum time between input and output for a codec, used to generate
dts from pts
- is set to 0 for streams without b frames, and set to 1 for streams with
- b frames, may be larger for future codecs
+ is set to 0 for streams without B-frames, and set to 1 for streams with
+ B-frames, may be larger for future codecs
fixed_fps
1 indicates that the fps is fixed
@@ -454,7 +453,7 @@
the smallest value is removed, this is then the current dts
this buffer is initalized with decode_delay -1 elements
all frames with dts == timestamp must be monotone, that means a frame
- which occures later in the stream must have a larger or equal dts
+ which occurs later in the stream must have a larger or equal dts
than an earlier frame
FIXME rename timestamp* to pts* ?
@@ -487,15 +486,15 @@
position in bytes of the first byte of a keyframe, relative to the
last keyframe stored in this index
there MUST be no keyframe with the same stream_id as this index between
- 2 consecutive index entries if they are more than max_index_distance
+ two consecutive index entries if they are more than max_index_distance
apart
id
- the id of the type/name pair, so it's more compact
+ the ID of the type/name pair, so it is more compact
0 means end
type
- for example: "UTF8" -> String or "JPEG" -> jpeg image
+ for example: "UTF8" -> string or "JPEG" -> JPEG image
Note: nonstandard fields should be prefixed by "X-"
Note: MUST be less than 6 byte long (might be increased to 64 later)
@@ -508,14 +507,14 @@
"Copyright"
"Encoder" the name & version of the software used for encoding
"Title"
- "Cover" an image of the (cd,dvd,vhs,..) cover (preferable PNG or JPEG)
+ "Cover" an image of the (CD, DVD, VHS, ..) cover (preferably PNG or JPEG)
"Source" "DVD", "VCD", "CD", "MD", "FM radio", "VHS", "TV",
"LD"
- Optional: appended PAL,NTSC,SECAM, ... in parentheses
+ Optional: appended PAL, NTSC, SECAM, ... in parentheses
"CaptureDevice" "BT878", "BT848", "webcam", ... (more exact names are fine too)
"CreationTime" "2003-01-20 20:13:15Z", ...
(ISO 8601 format, see http://www.cl.cam.ac.uk/~mgk25/iso-time.html)
- Note: don't forget the timezone
+ Note: do not forget the timezone
"Keywords"
"TotalTime" total length of the stream in msecs
"Language" ISO 639 and ISO 3166 for language/country code
@@ -571,7 +570,7 @@
headers MUST be placed at least at the start of the file and immediately before
the index or at the file end if there is no index
-headers MUST be repeated at least twice (so they exist 3 times in a file)
+headers MUST be repeated at least twice (so they exist three times in a file)
a demuxer MUST NOT demux a stream which contains more than one stream, or which
is wrapped in a structure to facilitate more than one stream or otherwise
@@ -597,9 +596,9 @@
demuxer (non-normative)
-in the absence of valid header at beginning, players SHOULD search for backup
-headers starting at offset 2^x for each x players SHOULD end their search from
-a particular offset when any startcode is found (including syncpoint)
+in the absence of a valid header at the beginning, players SHOULD search for
+backup headers starting at offset 2^x; for each x players SHOULD end their
+search at a particular offset when any startcode is found (including syncpoint)
Sample code (GPL, & untested)
@@ -682,8 +681,8 @@
Authors
-Folks from MPlayer Developers Mailinglist (http://www.mplayehrq.hu/).
-Authors in ABC-order: (FIXME! Tell us if we left you out)
+Folks from the MPlayer developers mailing list (http://www.mplayerhq.hu/).
+Authors in alphabetical order: (FIXME! Tell us if we left you out)
Beregszaszi, Alex (alex at fsn.hu)
Bunkus, Moritz (moritz at bunkus.org)
Diedrich, Tobias (ranma+mplayer at tdiedrich.de)
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