现在能想到的是几个办法：
1. cdr
增加下面元素：
rtp_audio_in_raw_bytes
rtp_audio_in_media_bytes
rtp_audio_in_packet_count
rtp_audio_in_media_packet_count
rtp_audio_in_skip_packet_count
rtp_audio_in_jb_packet_count
rtp_audio_in_dtmf_packet_count
rtp_audio_in_cng_packet_count
rtp_audio_in_flush_packet_count
rtp_audio_in_largest_jb_size
rtp_audio_out_raw_bytes
rtp_audio_out_media_bytes
rtp_audio_out_packet_count
rtp_audio_out_media_packet_count
rtp_audio_out_skip_packet_count
rtp_audio_out_dtmf_packet_count
rtp_audio_out_cng_packet_count
2. json api
下面是一个例子：
fs_cli -x 'json {"command":"channelData", "data": {"uuid": "9374d6c4-e242-4842-abd8-918515cc97aa"}}'
得到的结果如下（这里仅显示部分）：
"callStats": {
"audio": {
"inbound": {
"raw_bytes": 1059348,
"media_bytes": 1059348,
"packet_count": 6159,
"media_packet_count": 6159,
"skip_packet_count": 7,
"jitter_packet_count": 0,
"dtmf_packet_count": 0,
"cng_packet_count": 0,
"flush_packet_count": 0,
"largest_jb_size": 0,
"jitter_min_variance": 0.464572680788897,
"jitter_max_variance": 180.5,
"jitter_loss_rate": 0,
"jitter_burst_rate": 0,
"mean_interval": 20.003252032520326,
"flaw_total": 0,
"quality_percentage": 100,
"mos": 4.5
},
"outbound": {
"raw_bytes": 1059176,
"media_bytes": 1059176,
"packet_count": 6158,
"media_packet_count": 6158,
"skip_packet_count": 0,
"dtmf_packet_count": 0,
"cng_packet_count": 0,
"rtcp_packet_count": 0,
"rtcp_octet_count": 0
}
}
mod_commands.c 里面有个函数可供参考：
void jsonify_stats(cJSON *json, const char *name, switch_rtp_stats_t *stats)