[Mp4-tech] RE: [Map-tech] [Audio] AMR payload Storage format

Mody, Mihir mihir ti.com
Tue Sep 28 13:09:58 EDT 2004


Hi Mehdi,
It is Octet_Aligned mode for storage format .
Regards,
Mihir Mody,
Multimedia codecs group,
Texas Instruments India, Ltd,
Email : Mihir it.com
Phone : +91-80-25099307
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of Mehdi Sharifi
Sent: Sunday, September 26, 2023 8:29 PM
To: Dave Singer
Cc: mp4-tech lists.mpegif.org
Subject: RE: [Mp4-tech] [Audio] AMR payload&Storage format
hi dear ,
  thanks for everything!
 there are two modes for AMR payload :  Octet-Aligned mode &  bandwidth efficient mode ;  but  how can I  recognize these two modes? I mean if there is some indicating value in  payload header to  determine the specific mode.
in 3GPP TS 26.101 "Adaptive Multi-Rate (AMR) speech codec frame structure"  , is the format of AMR frame  in  payload or in storage format ?
waiting for reply
--mehdi
Dave Singer <singer apple.com> wrote:
At 8:05 AM -0700 9/20/04, Mehdi Sharifi wrote:
Hi ,
thanks for replying ,
  in 3GPP file format  it is said that  format of  AMR samples  is  according to RFC 3267 ; I read RFC 3267 ; it was alittle complicated ; I am looking for a source or some contribution  to convert  this payload format to  ordinary AMR format  in order to  play it with QuickTime  or  another  player
if you can help me , it's very appriciated
thank you alot
--mehdi
Well converting an RTP stream to a file format is a moderate amount of work.  In a 3GPP file, each media track is constructed as a sequence of timed samples.  The duration of AMR frames is constant (20ms as I recall).  The media data (as represented by the sample sizes etc.) is stored as 'samples' (frames).  Each sample consists of a set of AMR frames (as indicated by the frames-per-sample value), contiguously stored, in the 'storage format' , however, there is no magic number stored within the samples;  that is, each sample is just a contiguous set of AMR frames.
"Mody, Mihir" <mihir ti.com> wrote:
Hi Mehdi,
Are you refering to storage format as per RFC 3267 or 3GPP file format based on MPEG4 File format?
Regards,
Mihir Mody,
Multimedia codecs group,
Texas Instruments India, Ltd,
Email :  <mailto:mihir ti.com> mihir ti.com
Phone : +91-80-25099307
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of Mehdi Sharifi
Sent: Monday, September 20, 2023 7:07 PM
To: mp4-tech lists.mpegif.org
Subject: [Mp4-tech] AMR payload&Storage format
  Hi dear all,
  format of AMR  in storage is abit different from it's format  in payload or streaming .  is there any source code  that I can use to  convert  payload format to storage format ?
thanx
    --mehdi
  _____  
Do you Yahoo!?
 <http://us.rd.yahoo.com/mail_us/taglines/100/*http://promotions.yahoo.com/new_mail/static/efficiency.html> New and Improved Yahoo! Mail - 100MB free storage!
  _____  
Do you Yahoo!?
 <http://us.rd.yahoo.com/mail_us/taglines/50x/*http://promotions.yahoo.com/new_mail/static/efficiency.html> Yahoo! Mail - 50x more storage than other providers!
_______________________________________________
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
-- 
David Singer
Apple Computer/QuickTime
_______________________________________________
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
  _____  
Do you Yahoo!?
New  <http://us.rd.yahoo.com/mail_us/taglines/10/*http://promotions.yahoo.com/new_mail/static/efficiency.html> and Improved Yahoo! Mail - Send 10MB messages!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/mp4-tech/attachments/20040928/bd236acb/attachment-0001.html


More information about the Mp4-tech mailing list