[vlc-devel] [PATCH 1/1] opus: handle RTP depayloading (fixes #11938)

Timothy B. Terriberry tterribe at xiph.org
Sun Jan 11 19:19:23 CET 2015

Rémi Denis-Courmont wrote:
> Le 2015-01-11 20:52, Rémi Denis-Courmont a écrit :
>> In theory, the RTP clock rate could be different from the decoder
>> sample rate though. I do not know any payload format that would
>> operate that way, but it is theoretically possible.

G.722 is the famous example.

> P.S.: Based on Ross statement, that is in fact what Opus does. The RTP
> clock rate is 48000, but the Opus sample rate may be anything. I think
> the decoder should handle it, not the demux.

Opus can always be decoded at 48 kHz, regardless of what the other side 
is doing. The audio bandwidth can change on a packet-by-packet basis as 
bitrate changes, but that doesn't mean the decoder has to change the 
sampling rate it's using. Generally, you should always decode at 48 kHz 
absent knowledge of limitations of your playback device or of the 
capture device on the other side.

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