[Mp4-tech] Re: [Audio] MPEG 4 AAC LD Decoder Reference Software

[Ralph Sperschneider]

Kishor K L wrote:
> Hi all,
> 
> I am trying to run ER-AAC-LD file er_ad100_44_ep0.mp4
> using MPEG4 reference audio decoder (rewrite on
> win32). I am using the reference software second
> edition dated 2001-12-15. 
> 
> In this decoder, with the default configuration, the
> file does not run, MP4Audio_ProbeFile() returns a zero
> value and the win32 project displays error message and
> exits. If I exclude the libisomp4.lib and instead
> include libisomedia workspace in the project
> (available at
> systems\mp4_file_format\libisomediafile\w32), the file
> is decoded upto the upto an output size of 31kB and
> then exit with an error condition. Below given warning
> messages appear repeatedly.
> 
> mp4audec: WARNING: BsReadByte: not enough bits left in
> stream
> 
> mp4audec: WARNING: BsGetBit: error reading bit stream
> 
> Finally the below message is displayed and the decoder
> exits:
> 
> mp4audec: ERROR[-1]: more bits decoded than in AU
> !!!!!
> 
> The input mp4 file is of size 560 kB and the output
> .wav generated is of size 31 kB
> 
> Following is the command line options given by me to
> the reference decoder: 
> 
> -d 1 -ed .wav -eb .mp4
> D:\aac_ld\test_files\er_ad100_44_ep0.mp4 -o
> D:\aac_ld\test_files\er_ad100_44_cd.wav -db 2 -da 2
> 
> Can you please tell me what to do to correct this
> issue, and be able to decode all the ER-AAC-LD files
> using the ISO reference decoder?
> 
> Thanks and regards,
> 
> Kishor K L 
> 

Dear Kishor K L,
you are using a rather old version of the reference software. Just have a try 
with a more recent version. The most recent verions publicly available seems to 
be this one:
http://standards.iso.org/ittf/PubliclyAvailableStandards/c043465_ISO_IEC_14496-5_2001_Amd_10_2007_Reference_Software.zip
Best regards,
Ralph
-- 
Dipl.-Ing. Ralph Sperschneider  | Phone: +49 9131 776 344
Fraunhofer IIS                  | Fax:   +49 9131 776 398
Am Wolfsmantel 33               | mailto:ralph.sperschneider iis.fraunhofer.de
D 91058 Erlangen                | http://www.iis.fraunhofer.de/amm/