| /* HR RTP Payload according to RFC5993. Incompatible with ETSI TS 101 318! */ |
| /* (C) 2017 by Harald Welte <laforge@gnumonks.org> */ |
| |
| /* |
| * This file is part of gapk (GSM Audio Pocket Knife). |
| * |
| * gapk is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * gapk is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with gapk. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <stdint.h> |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <osmocom/gapk/codecs.h> |
| #include <osmocom/gapk/formats.h> |
| #include <osmocom/gapk/utils.h> |
| |
| #define HR_LEN (HR_CANON_LEN+1) |
| |
| /* See Section 5.2 of RFC5993 */ |
| enum rtp_hr_ietf_ft { |
| FT_GOOD_SPEECH = 0, |
| FT_GOOD_SID = 2, |
| FT_NO_DATA = 7, |
| }; |
| |
| /* conversion function: RTP payload -> canonical format */ |
| static int |
| rtp_hr_ietf_from_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len) |
| { |
| enum rtp_hr_ietf_ft ft; |
| |
| /* according to RFC5993 */ |
| assert(src_len == HR_CANON_LEN); |
| |
| /* TODO: Determine SID frames / NO_DATA frames */ |
| ft = FT_GOOD_SPEECH; |
| /* Add ToC byte */ |
| dst[0] = ((ft & 0x7) << 4); |
| |
| /* copy codec payload */ |
| memcpy(dst+1, src, src_len); |
| |
| return HR_LEN; |
| } |
| |
| /* conversion function: canonical format -> RTP payload */ |
| static int |
| rtp_hr_ietf_to_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len) |
| { |
| /* according to RFC5993 */ |
| /* broken RTP frames may be short; substitute empty frame */ |
| if (src_len != HR_LEN) { |
| memset(dst, 0, HR_LEN); |
| return HR_CANON_LEN; |
| } |
| |
| /* Remove ToC byte */ |
| memcpy(dst, src+1, HR_CANON_LEN); |
| |
| return HR_CANON_LEN; |
| } |
| |
| const struct osmo_gapk_format_desc fmt_rtp_hr_ietf = { |
| .type = FMT_RTP_HR_IETF, |
| .codec_type = CODEC_HR, |
| .name = "rtp-hr-ietf", |
| .description = "RTP payload for HR according to IETF RFC5993", |
| |
| .frame_len = HR_LEN, |
| .conv_from_canon = rtp_hr_ietf_from_canon, |
| .conv_to_canon = rtp_hr_ietf_to_canon, |
| }; |