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[Wei Wang <question229419@xxxxxxxxxxxxxxxxxxxxx>]

Question #229419 on rohc changed:
https://answers.launchpad.net/rohc/+question/229419

    Status: Needs information => Open

Wei Wang gave more information on the question:
Hi Didier,

"rtp_decide_state" shows in the 2nd, 3rd, and 4th packets. I just copied
and pasted the log of the 2nd packet.

compress the fake IP packet, j = 1
[ip.c:437 ip_get_totlen()] IP header v4 total len = 56, 14336 
[rohc_comp.c:381 rohc_compress()] size of uncompressed packet = 56 bytes
[rohc_comp.c:409 rohc_compress()] try to find the best profile for packet with transport protocol 17
[ip.c:405 ip_is_fragment()] ip_is_fragment(): is_fragment = 0, 0, 0
[rohc_comp.c:1563 c_get_profile_from_packet()] UDP port = 0x506 (1286)
[rohc_comp.c:416 rohc_compress()] using profile 'RTP / Compressor' (0x0001)
[rohc_comp.c:1795 c_find_context()] using context CID = 0
[rohc_comp.c:1936 rohc_feedback_get()] use 1-byte form factor for feedback length
[rohc_comp.c:1963 rohc_feedback_get()] add 6 byte(s) of feedback data: 0x20 0xb9 0x41 0x41 0x11 0x21 
[rohc_comp.c:1963 rohc_feedback_get()] add 0 byte(s) of feedback data
[rohc_comp.c:481 rohc_compress()] compress the packet #2
[c_rtp.c:1225 rtp_changed_rtp_dynamic()] find changes in RTP dynamic fields
[c_rtp.c:1241 rtp_changed_rtp_dynamic()] UDP checksum field did not change but changed in the last few packets
[c_rtp.c:1291 rtp_changed_rtp_dynamic()] RTP Payload Type (PT) field did not change but changed in the last few packets
[c_rtp.c:1305 rtp_changed_rtp_dynamic()] TS_STRIDE changed now or in the last few packets
[c_rtp.c:1309 rtp_changed_rtp_dynamic()] 2 RTP dynamic fields changed
[c_generic.c:5370 detect_ip_id_behaviour()] 1) old_id = 0x0000 new_id = 0x0000
[c_generic.c:5383 detect_ip_id_behaviour()] 2) old_id = 0x0000 new_id = 0x0000
[c_generic.c:5392 detect_ip_id_behaviour()] RND detected
[c_generic.c:5400 detect_ip_id_behaviour()] NBO = 1, RND = 1
[c_generic.c:788 c_generic_encode()] SN = 47426
[c_generic.c:5037 changed_static_one_hdr()] protocol_count 1
[c_generic.c:5069 changed_dynamic_both_hdr()] check for changed fields in the outer IP header
[c_generic.c:5150 changed_dynamic_one_hdr()] TTL/HL changed in the last few packets
[c_generic.c:5186 changed_dynamic_one_hdr()] RND changed (0 -> 1) in the current packet
[c_generic.c:5211 changed_dynamic_one_hdr()] NBO changed in the last few packets
[c_generic.c:809 c_generic_encode()] send_static = 1, send_dynamic = 2
[c_rtp.c:800 rtp_decide_state()] go back to IR state because UDP checksum behaviour changed in the last few packets
[c_generic.c:820 c_generic_encode()] ip_id = 0x0000, context_sn = 47426
[c_generic.c:5477 encode_uncomp_fields()] compressor is in state 1
[c_generic.c:5481 encode_uncomp_fields()] new SN = 47426 / 0xb942
[c_generic.c:5489 encode_uncomp_fields()] IR state: force using 16 bits to encode new SN
[c_generic.c:5504 encode_uncomp_fields()] 16 bits are required to encode new SN
[c_generic.c:5528 encode_uncomp_fields()] new outer IP-ID delta = 0x46be / 18110 (NBO = 1, RND = 1)
[c_generic.c:5536 encode_uncomp_fields()] IR state: force using 16 bits to encode new outer IP-ID delta
[c_generic.c:5552 encode_uncomp_fields()] 16 bits are required to encode new outer IP-ID delta
[ts_sc_comp.c:98 c_add_ts()] Timestamp = 1266870252
[ts_sc_comp.c:110 c_add_ts()] TS delta = 320
[ts_sc_comp.c:122 c_add_ts()] state INIT_STRIDE
[ts_sc_comp.c:147 c_add_ts()] /!\ TS_STRIDE changed
[ts_sc_comp.c:151 c_add_ts()] ts_stride = 320
[ts_sc_comp.c:156 c_add_ts()] ts_offset = 1266870252 modulo 320 = 172
[ts_sc_comp.c:159 c_add_ts()] ts_scaled = (1266870252 - 172) / 320 = 3958969
[c_rtp.c:914 rtp_encode_uncomp_fields()] cannot send TS scaled, send TS and TS_STRIDE
[c_rtp.c:950 rtp_encode_uncomp_fields()] 32 bits are required to encode new TS
[c_generic.c:1220 decide_packet()] IR state
[c_generic.c:1263 decide_packet()] packet 'IR' chosen
[c_generic.c:1456 code_IR_packet()] code IR packet (CID = 0)
[cid.c:76 code_cid_values()] CID = 0 => no add-CID
[c_generic.c:1475 code_IR_packet()] type of packet + D flag = 0xfd
[c_generic.c:1479 code_IR_packet()] profile ID = 0x01
[c_generic.c:1485 code_IR_packet()] CRC = 0x00 for CRC calculation
[c_generic.c:1781 code_ipv4_static_part()] version = 0x40
[c_generic.c:1786 code_ipv4_static_part()] protocol = 0x11
[c_generic.c:1795 code_ipv4_static_part()] src addr = 01020304 (1.2.3.4)
[c_generic.c:1802 code_ipv4_static_part()] dst addr = 05060708 (5.6.7.8)
[c_udp.c:521 udp_code_static_udp_part()] UDP source port = 0x201
[c_udp.c:526 udp_code_static_udp_part()] UDP dest port = 0x605
[c_rtp.c:1003 rtp_code_static_rtp_part()] RTP SSRC = 0x2be56850
[c_generic.c:2002 code_ipv4_dynamic_part()] TOS = 0x00, TTL = 0x01, IP-ID = 0x0000, df_rnd_nbo = 0x60 (DF = 0, RND = 1, NBO = 1)
[c_rtp.c:1071 rtp_code_dynamic_rtp_part()] UDP checksum = 0xefbe
[c_rtp.c:1088 rtp_code_dynamic_rtp_part()] part 2 = 0x90
[c_rtp.c:1096 rtp_code_dynamic_rtp_part()] part 3 = 0x01
[c_rtp.c:1102 rtp_code_dynamic_rtp_part()] part 4 = 0xb9 0x42
[c_rtp.c:1108 rtp_code_dynamic_rtp_part()] part 5 = 0x4b 0x82 0xe7 0xec
[c_rtp.c:1114 rtp_code_dynamic_rtp_part()] Generic CSRC list not supported yet, put a 0x00 byte
[c_rtp.c:1133 rtp_code_dynamic_rtp_part()] part 7 = 0x05
[c_rtp.c:1158 rtp_code_dynamic_rtp_part()] send ts_stride = 0x00000140 encoded with SDVL on 2 bytes
[c_rtp.c:1187 rtp_code_dynamic_rtp_part()] TS_STRIDE transmitted only 1 times, so stay in state INIT_STRIDE (at least 3 times are required to change to state SEND_SCALED)
[c_generic.c:1565 code_IR_packet()] CRC (header length = 41, crc = 0x69)
[ip.c:437 ip_get_totlen()] IP header v4 total len = 56, 14336 
[rohc_comp.c:564 rohc_compress()] ROHC size = 64 (feedback = 0, header = 41, payload = 16), output buffer size = 2048

ROHC packet resulting from the ROHC compression:
0xf6 0x20 0xb9 0x41 0x41 0x11 0x21 0xfd 
0x01 0x69 0x40 0x11 0x01 0x02 0x03 0x04 
0x05 0x06 0x07 0x08 0x01 0x02 0x05 0x06 
0x50 0x68 0xe5 0x2b 0x00 0x01 0x00 0x00 
0x60 0x00 0xbe 0xef 0x90 0x01 0xb9 0x42 
0x4b 0x82 0xe7 0xec 0x00 0x05 0x81 0x40 
0x0c 0x3e 0x8e 0x4a 0x69 0x52 0x1b 0xfa 
0x02 0xe0 0xb0 0x37 0x9f 0xd8 0x74 0x10

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