mirror of https://gerrit.osmocom.org/gapk
85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
/* 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,
|
|
};
|