[Mp4-tech] Re: How to find the multilingual status in AAC audio stream

[Ralph Sperschneider]

Song wrote:
> Dear experts,
> I am meeting some special AAC streams which have two different
> language seperately on Left and Right channel.

This needs some further investigation:
Are those two channels encoded by one CPE (channel pair element) or two
SCEs (single channel elements)? Two SCEs would mimic the 'dual mono
mode' available in mp3.
Which channel_config is signaled?
> How can I detect this status from the normal streams by my source
> code? Which syntax element should I check?
> I remember that some old specification define this status as Dual Mono
> mode. I am reading the ISO/IEC 13818-7, try to find the similar
> definition, but I have not find the answer yet. Could you please help
> me clarify this concept?
> Thank you in advance,
> and Best Regards.
> Song
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Dipl.-Ing. Ralph Sperschneider  | Phone: +49 9131 776 344
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