[NUT-devel] Patch for info packets
Oded Shimon
ods15 at ods15.dyndns.org
Thu Feb 23 19:18:32 CET 2006
On Thu, Feb 23, 2006 at 12:11:25PM -0500, Rich Felker wrote:
> On Thu, Feb 23, 2006 at 12:10:13PM +0200, Oded Shimon wrote:
> > On Wed, Feb 22, 2006 at 03:15:24PM +0100, Michael Niedermayer wrote:
> > > On Tue, Feb 21, 2006 at 07:26:07PM -0500, Rich Felker wrote:
> > > > > > - "TotalTime"
> > > > > > - total length of the stream in msecs
> > > > >
> > > > > hmmmmm, global info packets dont have chapter_len, index is optional and
> > > > > you remove this umm ...
> > > >
> > > > I thought it was our intent that index would not be "optional". IIRC I
> > > > suggested defining in the spec a 'NUT stream authored for permenant
> > > > storage' or something similar, and requiring such a stream to conform
> > > > to several conditions such as: repeated headers, index present, ...
> > > >
> > > > The idea is that a partially written, truncated, streamed, etc. NUT
> > > > file would not be a a "NUT stream authored for permenant storage" and
> > > > would not be subject to these requirements, but NUTlint would check
> > > > these things and indicate to the user that the file is not conformant
> > > > to the more restrictive requirements.
> > > >
> > > > BTW in the case of a truncated file where the index is lost, knowing
> > > > TotalTime is not useful anyway since it will be wrong.
> > >
> > > and the chapter lengthes? its a PITA to go and read the index to find
> > > the last chapter length
> >
> > I'm ok with bringing back 'totaltime' or having some other solution for
> > having the length for the last chapter...
>
> Why not just store the length in the info???
> This is where they belong. If someone has indexed segments of the file
> as chapters, they probably want an idea of total time. If not the file
> should be treated as a pure stream and TotalTime is nonsense. In the
> trivial case where someone wants TotalTime but no chapter divisions
> they can just make one big chapter/segment.
New patch. One kink left to sort out is info frames. My suggestion for it
is to use negative chapter id's..
Can I commit this patch?
- ods15
-------------- next part --------------
Index: DOCS/tech/mpcf.txt
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/tech/mpcf.txt,v
retrieving revision 1.108
diff -u -r1.108 mpcf.txt
--- DOCS/tech/mpcf.txt 20 Feb 2006 04:49:06 -0000 1.108
+++ DOCS/tech/mpcf.txt 23 Feb 2006 18:16:21 -0000
@@ -262,21 +262,32 @@
checksum u(32)
info_frame: (optional)
- for(;;){
- id v
- if(id==0) break
- name= info_table[id][0]
- type= info_table[id][1]
- if(type==NULL)
+ stream_id_plus1 v
+ chapter_id v
+ if (chapter_id) {
+ chapter_start v
+ chapter_len v
+ }
+ count v
+ for(i=0; i<count; i++){
+ name vb
+ value s
+ if (value==-1){
+ type= "UTF-8"
+ value vb
+ }else if (value==-2){
type vb
- if(name==NULL)
- name vb
- if(type=="v")
- value v
- else if(type=="s")
- value s
- else
value vb
+ }else if (value==-3){
+ type= "signed integer"
+ value s
+ }else if (value<-3){
+ type= "rational"
+ value.den= -value-2
+ value.num s
+ }else{
+ type= "unsigned integer"
+ }
}
reserved_bytes
checksum u(32)
@@ -609,9 +620,23 @@
Info tags:
----------
-id
- the ID of the type/name pair, so it is more compact
- 0 means end
+stream_id_plus1
+ Stream this info packet applies to. If zero, packet applies to whole
+ file.
+
+chapter_id
+ Id of chapter this packet applies to. If zero, packet applies to whole
+ file. Positive chapter_id's are real chapters and MUST NOT overlap.
+ Negative chapter_id indicate a sub region of file and not a real
+ chapter. chapter_id MUST be unique to the region it represents.
+
+chapter_start
+ s= chapter_start % stream_count
+ timestamp= chapter_start / stream_count
+ timestamp of start of chapter in timebase of stream 's'.
+
+chapter_len
+ Length of chapter in same timebase of chapter_start.
type
for example: "UTF8" -> string or "JPEG" -> JPEG image
@@ -620,15 +645,13 @@
info packet types
the name of the info entry, valid names are
- "StreamId"
- the stream(s) to which the info packet applies
"Author"
"Description"
"Copyright"
"Encoder"
the name & version of the software used for encoding
"Title"
- "Cover"
+ "Cover" (allowed types are "PNG" and "JPEG")
image of the (CD, DVD, VHS, ..) cover (preferably PNG or JPEG)
"Source"
"DVD", "VCD", "CD", "MD", "FM radio", "VHS", "TV", "LD"
@@ -640,8 +663,6 @@
(ISO 8601 format, see http://www.cl.cam.ac.uk/~mgk25/iso-time.html)
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
something like "eng" (US english), can be 0 if unknown
@@ -664,24 +685,6 @@
stuffing
0x80 can be placed in front of any type v entry for stuffing purposes
-info_table[][2]={
- {NULL , NULL }, // end
- {NULL , NULL },
- {NULL , "UTF8"},
- {NULL , "v"},
- {NULL , "s"},
- {"StreamId" , "v"},
- {"Author" , "UTF8"},
- {"Title" , "UTF8"},
- {"Language" , "UTF8"},
- {"Description" , "UTF8"},
- {"Copyright" , "UTF8"},
- {"Encoder" , "UTF8"},
- {"Keyword" , "UTF8"},
- {"Cover" , "JPEG"},
- {"Cover" , "PNG"},
- {"Disposition" , "UTF8"},
-};
Structure:
@@ -721,8 +724,14 @@
file as well.
-Info frames:
-------------
+Info:
+-----
+
+All info packets with the same chapter_id and stream_id are repeated info
+packets and MUST be binary identical.
+
+All info packets MUST appear after main headers at begginning of file, and
+SHOULD be repeated after all main headers unless they are very large.
Info frames can be used to describe the file or some part of it (chapters)
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