[Mp4-tech] Re: [audiio] MPEG-4 version 2 AAC rewrite decoder

[Ralph Sperschneider]

Tracy Yang wrote:
> I downloaded and compiled the MPEG-4 version 2 (ISO/IEC 14496-5:2001)
> AAC codec. However, I can't make the decoder in rewrite directory work
> for AAC raw data
> 
> I tried to use the example command lines gave in the readme_usuage in
> version 1 as following:
> 
> Encoding:
> mp4auenc -m tf -c "-aac_raw -aac_tns" -r <bit rate> -o bitstream.aac
> original.wav
> 
> Decoding:
> mp4vaudec -c "-aac_raw" -aaceof bitstream.aac -o output.wav -s <sampling
> freq> -n <num channels>
> 
> But the decoder doesn't work. I found it stops at the function:
> 
> MP4Audio_ProbeFile(bitFileName)
> 
> Can someone give me a pair of sample command lines that can encode and
> decode in plain AAC mode? 
>  

The rewrite decoder only accepts mp4ff files.
The encoder has recently been updated such that it writes mp4ff files (at least 
for the AAC AOTs). However, this software is available to MPEG members only (see 
my E-Mail to the reflector some minutes ago refering to the most recent snapshot).
BTW: The multichannel aac decoder of your software version should be able to 
decode raw aac files.
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/