SDP: clarify that the G722 sample rate is actually 16000

The actual sampling rate in plugins/codecs/G722/G722decode.c is reported
as 16000 while the RTP clock rate as included in the SDP message is 8000
for historical reasons. Add some text to help people understand where
this difference comes from.

Example dissection for this cosmetic change:

    Session Description Protocol
        ...
        Media Attribute (a): rtpmap:9 G722/8000
            Media Attribute Fieldname: rtpmap
            Media Format: 9
            MIME Type: G722
            Sample Rate: 8000 (RTP clock rate is 8kHz, actual sampling rate is 16kHz)
        Media Attribute (a): rtpmap:101 telephone-event/8000
            Media Attribute Fieldname: rtpmap
            Media Format: 101
            MIME Type: telephone-event
            Sample Rate: 8000

Change-Id: I47ccb798719a23713f28ae36fff6716b6dfbb22b
Reviewed-on: https://code.wireshark.org/review/36073
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

0 files changed, 0 insertions, 0 deletions