[Mp4-tech] AMR support in AVI

[R Gomathi]

Hi Sharanu,
     Ya,the 'idx1' in AVI 1.0 is for the purpose of exactly what u said.But
if the file is open DML,then it contains ix## also, which in turn contains
information regarding whether the frame is key frame or not .so we don't
need idx1 in such cases.The opendml specs also tell nothing about this.
Regards
Gomathi.
-----Original Message-----
From: Sharanu [mailto:sharanu sarayusoftech.com]
Sent: Friday, December 29, 2023 12:32 PM
To: rgomathi sarayusoftech.com
Subject: RE: [Mp4-tech] AMR support in AVI
Hi Gomathi,
 Actually the 'idx1' chunk is optional.This list is used to make AVI
playback and seeks more efficient because the location of each frame
of video can be found without scanning through each sub-chunk of the
LIST ‘movi’ data. So I beleive, the basic purpose of 'idx1' is for
seeking.
 The document I had sent earlier has some explaination regarding
the indexes.
Regards,
Sharanu
-----Original Message-----
From: R Gomathi [mailto:rgomathi sarayusoftech.com]
Sent: Friday, December 29, 2023 11:58 AM
To: sharanu sarayusoftech.com; mp4-tech-request lists.mpegif.org;
mp4-tech lists.mpegif.org; audiodsp yahoogroups.com
Subject: RE: [Mp4-tech] AMR support in AVI
Hi Sharanu,
     Thanks for your reply.
   I need some clarification.
1.for the first part i.e whether it supports AMR or not i couldn't get the
exact
	result from the linkas the link to ACM doesn't exit
2.Regarding 2nd point i'm clear now as the RIFF AVIX will contain only the
'movi' init.so no problem while dealing
  with it.
	If the file have both ix00 and idx1 (i have files with both of this) form
where to fetch the address and size
For eg,let us assume the file contains 2 streams. So it will have ix00
having offset n size of 1st stream
and ix01 which has the offset n size of 2nd stream.again at the end of the
file there is 'idx1' with offset n size of both streams.so from where we
should take the values.if it is from ix## then what is the purpose of
'idx1'.
-----Original Message-----
From: Sharanu [mailto:sharanu sarayusoftech.com]
Sent: Friday, December 29, 2023 9:58 AM
To: rgomathi sarayusoftech.com
Subject: RE: [Mp4-tech] AMR support in AVI
Dear Gomathi,
 The following link might help you regarding the first part of your doubt.
http://www.cse.mrt.ac.lk/lecnotes/cs5414/papers/AV%20Encoding/Comparison_of_
container_formats.htm
 I had made some work on AVI(old ver) sometime back. Regarding Open DML AVI,
I could just find this
apart from the pdf file attached. I could not get any standard OpenDML avi
files.
/*
 * heres the general layout of an AVI riff file (new format)
 *
 * RIFF (3F??????) AVI       <- not more than 1 GB in size
 *     LIST (size) hdrl
 *         avih (0038)
 *         LIST (size) strl
 *             strh (0038)
 *             strf (????)
 *             indx (3ff8)   <- size may vary, should be sector sized
 *         LIST (size) strl
 *             strh (0038)
 *             strf (????)
 *             indx (3ff8)   <- size may vary, should be sector sized
 *         LIST (size) odml
 *             dmlh (????)
 *         JUNK (size)       <- fill to align to sector - 12
 *     LIST (7f??????) movi  <- aligned on sector - 12
 *         00dc (size)       <- sector aligned
 *         01wb (size)       <- sector aligned
 *         ix00 (size)       <- sector aligned
 *     idx1 (00??????)       <- sector aligned
 * RIFF (7F??????) AVIX
 *     JUNK (size)           <- fill to align to sector -12
 *     LIST (size) movi
 *         00dc (size)       <- sector aligned
 * RIFF (7F??????) AVIX      <- not more than 2GB in size
 *     JUNK (size)           <- fill to align to sector - 12
 *     LIST (size) movi
 *         00dc (size)       <- sector aligned
 *
 *-===================================================================*/
Hope this might help you.
Regards,
Sharanu
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org
[mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of R Gomathi
Sent: Thursday, December 28, 2023 12:19 PM
To: mp4-tech-request lists.mpegif.org; mp4-tech lists.mpegif.org;
audiodsp yahoogroups.com
Subject: [Mp4-tech] AMR support in AVI
	Hi all,
                 I have some doubts over AVI file format.
	* will AVI container support amr-nb or amr-wb codecs?
	* all open DML AVI file will contain RIFF AVIX in it.if so what are the
fields inside that....... ( becoz ,i don't have any open DML avi file with
RIFF AVIX List init.can somebody tell the site to download such files or
converter to get open DML file with RIFF AVIX).
     I will be if some one replies in this regard.
 Thanks in advance,
 Regards,
 Gomathi
_______________________________________________
NOTE: Please use clear subject lines for your posts. Include [audio,
[video], [systems], [general] or another apppropriate identifier to indicate
the type of question you have.
Note: Conduct on the mailing list is subject to the Antitrust guidelines
found at
http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php