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comparison doc/Calypso-TCH-downlink @ 556:18aca50d68df

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doc/Calypso-TCH-downlink: update for FR1 BFI-with-data
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 11 Oct 2024 01:54:00 +0000
parents 5e2d849a4fbc
children
comparison
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555:62943a1ad64e 556:18aca50d68df
108 Therefore, in the case of FR1 codec there is nothing to be gained by skipping 108 Therefore, in the case of FR1 codec there is nothing to be gained by skipping
109 gsmx and calling library functions directly, and thus there is no FR1 109 gsmx and calling library functions directly, and thus there is no FR1
110 counterpart to gsmefr-dlcap-dec - just use gsmfr-dlcap-gsmx followed by 110 counterpart to gsmefr-dlcap-dec - just use gsmfr-dlcap-gsmx followed by
111 gsmfr-decode or gsmfr-decode-r. 111 gsmfr-decode or gsmfr-decode-r.
112 112
113 [Update: as of libgsmfr2 version 2.1.0, the above paragraph is no longer fully
114 correct. The new version of our Rx DTX handler does look at bad traffic frames
115 (BFI=1) in order to catch those that should be handled as invalid SID rather
116 than unusable frame classification, and our original gsmx binary file format
117 is thus no longer sufficient to match the full capabilities of our library.
118 The new hexadecimal file format of TW-TS-005 Annex A solves this shortcoming -
119 but the present suite of Calypso TCH downlink utilities is currently a low
120 priority, hence no code updates are currently being worked on in this area.]
121
113 * In addition to TCH DL capture files, gsmfr-dlcap-parse also accepts the hex 122 * In addition to TCH DL capture files, gsmfr-dlcap-parse also accepts the hex
114 output from fc-vm2hex, originating from TCS211 voice memo recordings, 123 output from fc-vm2hex, originating from TCS211 voice memo recordings,
115 including fc-vm2hex output in the case of VM recordings made in DTX mode. 124 including fc-vm2hex output in the case of VM recordings made in DTX mode.
116 However, if the objective is to play that VM recording and not just look at 125 However, if the objective is to play that VM recording and not just look at
117 parsed bits, the correct approach is to convert the VM file to gsmx with 126 parsed bits, the correct approach is to convert the VM file to gsmx with