FreeCalypso > hg > gsm-codec-lib
view libgsmhr1/rtp_in.c @ 501:597b39aef484
libgsmhr1/mathhalf.h: rm unused declarations
for non-saturating functions
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Wed, 19 Jun 2024 00:54:44 +0000 |
parents | cc3a831712a4 |
children |
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/* * The function implemented in this module takes whatever HRv1 payload format * came in from RTP (can be RFC 5993 with or without TW-TS-002 extensions, * can be bare TS 101 318, can be zero-length or missing payload) and turns it * into canonical TW-TS-002 format, be it for storage or for immediate * further processing. */ #include <stdint.h> #include <string.h> #include "tw_gsmhr.h" int gsmhr_rtp_in_preen(const uint8_t *rtp_in, unsigned rtp_in_len, uint8_t *canon_pl) { int ft; switch (rtp_in_len) { case 0: /* BFI-no-data, but not an invalid RTP input per se */ canon_pl[0] = 0x70; return 0; case 1: /* * This length is valid only if the payload is in * RFC 5993 or TW-TS-002 format with FT=1 or FT=7. */ if (rtp_in[0] & 0x80) goto bad_rtp_input; ft = rtp_in[0] >> 4; if (ft == 1 || ft == 7) { canon_pl[0] = rtp_in[0]; return 0; } else goto bad_rtp_input; case GSMHR_FRAME_LEN_RPF: /* * The length is that of a TS 101 318 payload. * No further checks can be done: every possible * bit pattern is a valid payload in this format. * But we do need to check for a perfect SID * (the only kind of SID this format allows) * and mark it accordingly in the output. */ canon_pl[0] = gsmhr_ts101318_is_perfect_sid(rtp_in) << 4; memcpy(canon_pl + 1, rtp_in, GSMHR_FRAME_LEN_RPF); return 0; case GSMHR_FRAME_LEN_5993: /* * This length is valid only if the payload is in * RFC 5993 or TW-TS-002 format with FT=0, FT=2 or FT=6. */ if (rtp_in[0] & 0x80) goto bad_rtp_input; ft = rtp_in[0] >> 4; if (ft == 0 || ft == 2 || ft == 6) { memcpy(canon_pl, rtp_in, GSMHR_FRAME_LEN_5993); return 0; } else goto bad_rtp_input; default: bad_rtp_input: /* * Treat it like BFI-no-data, and tell the caller * that we received an invalid RTP payload. */ canon_pl[0] = 0x70; return -1; } }