调试rtsp收发流时，经常会需要抓包以确认是网络问题还是程序问题还是其它问题。通过tcpdump或者wireshark抓到的包通常是rtp流，保存为.pcap格式文件后中，可通过wireshark进行解析，得出h264裸流，并保存为文件。
1.wireshark配置
从gitee上可以直接下载的
WiresharkPlugin: The H265 H264 PS PCM AMR SILK plugin for Wireshark Lua (gitee.com)
1.1 下载rtp_h365_extractor.lua
-- Dump RTP h.265 payload to raw h.265 file (*.265)
-- According to RFC7798 to dissector H265 payload of RTP to NALU, and write it
-- to from<sourceIp_sourcePort>to<dstIp_dstPort>.265 file.
-- By now, we support Single NAL Unit Packets, Aggregation Packets (APs)
-- and Fragmentation Units (FUs) format RTP payload for H.265.
-- You can access this feature by menu "Tools"
-- Reference from Huang Qiangxiong (qiangxiong.huang@gmail.com)
-- Author: Yang Xing (hongch_911@126.com)
------------------------------------------------------------------------------------------------
do
local version_str = string.match(_VERSION, "%d+[.]%d*")
local version_num = version_str and tonumber(version_str) or 5.1
local bit = (version_num >= 5.2) and require("bit32") or require("bit")
function string.starts(String,Start)
return string.sub(String,1,string.len(Start))==Start
end
function string.ends(String,End)
return End=='' or string.sub(String,-string.len(End))==End
end
function get_temp_path()
local tmp = nil
if tmp == nil or tmp == '' then
tmp = os.getenv('HOME')
if tmp == nil or tmp == '' then
tmp = os.getenv('USERPROFILE')
if tmp == nil or tmp == '' then
tmp = persconffile_path('temp')
else
tmp = tmp .. "/wireshark_temp"
end
else
tmp = tmp .. "/wireshark_temp"
end
end
return tmp
end
function get_ffmpeg_path()
local tmp = nil
if tmp == nil or tmp == '' then
tmp = os.getenv('FFMPEG')
if tmp == nil or tmp == '' then
tmp = ""
else
if not string.ends(tmp, "/bin/") then
tmp = tmp .. "/bin/"
end
end
end
return tmp
end
-- for geting h265 data (the field's value is type of ByteArray)
local f_h265 = Field.new("h265")
local f_rtp = Field.new("rtp")
local f_rtp_seq = Field.new("rtp.seq")
local f_rtp_timestamp = Field.new("rtp.timestamp")
local filter_string = nil
-- menu action. When you click "Tools->Export H265 to file" will run this function
local function export_h265_to_file()
-- window for showing information
local tw = TextWindow.new("Export H265 to File Info Win")
local pgtw;
-- add message to information window
function twappend(str)
tw:append(str)
tw:append("\n")
end
local ffmpeg_path = get_ffmpeg_path()
-- temp path
local temp_path = get_temp_path()
-- running first time for counting and finding sps+pps, second time for real saving
local first_run = true
local writed_nalu_begin = false
-- variable for storing rtp stream and dumping parameters
local stream_infos = nil
-- trigered by all h265 packats
local list_filter = ''
if filter_string == nil or filter_string == '' then
list_filter = "h265"
elseif string.find(filter_string,"h265")~=nil then
list_filter = filter_string
else
list_filter = "h265 && "..filter_string
end
twappend("Listener filter: " .. list_filter .. "\n")
local my_h265_tap = Listener.new("frame", list_filter)
-- get rtp stream info by src and dst address
function get_stream_info(pinfo)
local key = "from_" .. tostring(pinfo.src) .. "_" .. tostring(pinfo.src_port) .. "_to_" .. tostring(pinfo.dst) .. "_" .. tostring(pinfo.dst_port)
key = key:gsub(":", ".")
local stream_info = stream_infos[key]
if not stream_info then -- if not exists, create one
stream_info = { }
stream_info.filename = key.. ".265"
-- stream_info.filepath = stream_info.filename
-- stream_info.file,msg = io.open(stream_info.filename, "wb")
if not Dir.exists(temp_path) then
Dir.make(temp_path)
end
stream_info.filepath = temp_path.."/"..stream_info.filename
stream_info.file,msg = io.open(temp_path.."/"..stream_info.filename, "wb")
if msg then
twappend("io.open "..stream_info.filepath..", error "..msg)
end
-- twappend("Output file path:" .. stream_info.filepath)
stream_info.counter = 0 -- counting h265 total NALUs
stream_info.counter2 = 0 -- for second time running
stream_infos[key] = stream_info
twappend("Ready to export H.265 data (RTP from " .. tostring(pinfo.src) .. ":" .. tostring(pinfo.src_port)
.. " to " .. tostring(pinfo.dst) .. ":" .. tostring(pinfo.dst_port) .. " write to file:[" .. stream_info.filename .. "] ...")
end
return stream_info
end
-- write a NALU or part of NALU to file.
local function write_to_file(stream_info, str_bytes, begin_with_nalu_hdr, end_of_nalu)
if first_run then
stream_info.counter = stream_info.counter + 1
if begin_with_nalu_hdr then
-- save VPS SPS PPS
local nalu_type = bit.rshift(bit.band(str_bytes:byte(0,1), 0x7e),1)
if not stream_info.vps and nalu_type == 32 then
stream_info.vps = str_bytes
elseif not stream_info.sps and nalu_type == 33 then
stream_info.sps = str_bytes
elseif not stream_info.pps and nalu_type == 34 then
stream_info.pps = str_bytes
end
end
else -- second time running
if not writed_nalu_begin then
if begin_with_nalu_hdr then
writed_nalu_begin = true
else
return
end
end
if stream_info.counter2 == 0 then
local nalu_type = bit.rshift(bit.band(str_bytes:byte(0,1), 0x7e),1)
if nalu_type ~= 32 then
-- write VPS SPS and PPS to file header first
if stream_info.vps then
stream_info.file:write("\x00\x00\x00\x01")
stream_info.file:write(stream_info.vps)
else
twappend("Not found VPS for [" .. stream_info.filename .. "], it might not be played!")
end
if stream_info.sps then
stream_info.file:write("\x00\x00\x00\x01")
stream_info.file:write(stream_info.sps)
else
twappend("Not found SPS for [" .. stream_info.filename .. "], it might not be played!")
end
if stream_info.pps then
stream_info.file:write("\x00\x00\x00\x01")
stream_info.file:write(stream_info.pps)
else
twappend("Not found PPS for [" .. stream_info.filename .. "], it might not be played!")
end
end
end
if begin_with_nalu_hdr then
-- *.265 raw file format seams that every nalu start with 0x00000001
stream_info.file:write("\x00\x00\x00\x01")
end
stream_info.file:write(str_bytes)
stream_info.counter2 = stream_info.counter2 + 1
-- update progress window's progress bar
if stream_info.counter > 0 and stream_info.counter2 < stream_info.counter then
pgtw:update(stream_info.counter2 / stream_info.counter)
end
end
end
-- read RFC3984 about single nalu/ap/fu H265 payload format of rtp
-- single NALU: one rtp payload contains only NALU
local function process_single_nalu(stream_info, h265)
write_to_file(stream_info, h265:tvb():raw(), true, true)
end
-- APs: one rtp payload contains more than one NALUs
local function process_ap(stream_info, h265)
local h265tvb = h265:tvb()
local offset = 2
repeat
local size = h265tvb(offset,2):uint()
write_to_file(stream_info, h265tvb:raw(offset+2, size), true, true)
offset = offset + 2 + size
until offset >= h265tvb:len()
end
-- FUs: one rtp payload contains only one part of a NALU (might be begin, middle and end part of a NALU)
local function process_fu(stream_info, h265)
local h265tvb = h265:tvb()
local start_of_nalu = (h265tvb:range(2, 1):bitfield(0,1) ~= 0)
local end_of_nalu = (h265tvb:range(2, 1):bitfield(1,1) ~= 0)
if start_of_nalu then
-- start bit is set then save nalu header and body
local nalu_hdr_0 = bit.bor(bit.band(h265:get_index(0), 0x81), bit.lshift(bit.band(h265:get_index(2),0x3F), 1))
local nalu_hdr_1 = h265:get_index(1)
write_to_file(stream_info, string.char(nalu_hdr_0, nalu_hdr_1) .. h265tvb:raw(3), start_of_nalu, end_of_nalu)
else
-- start bit not set, just write part of nalu body
write_to_file(stream_info, h265tvb:raw(3), start_of_nalu, end_of_nalu)
end
end
-- call this function if a packet contains h265 payload
function my_h265_tap.packet(pinfo,tvb)
if stream_infos == nil then
-- not triggered by button event, so do nothing.
return
end
local h265s = { f_h265() } -- using table because one packet may contains more than one RTP
for i,h265_f in ipairs(h265s) do
if h265_f.len < 5 then
return
end
local h265 = h265_f.range:bytes()
local hdr_type = h265_f.range(0,1):bitfield(1,6)
local stream_info = get_stream_info(pinfo)
if hdr_type > 0 and hdr_type < 48 then
-- Single NALU
process_single_nalu(stream_info, h265)
elseif hdr_type == 48 then
-- APs
process_ap(stream_info, h265)
elseif hdr_type == 49 then
-- FUs
process_fu(stream_info, h265)
else
twappend("Error: No.=" .. tostring(pinfo.number) .. " unknown type=" .. hdr_type .. " ; we only know 1-47(Single NALU),48(APs),49(FUs)!")
end
end
end
-- close all open files
local function close_all_files()
twappend("")
local index = 0;
if stream_infos then
local no_streams = true
for id,stream in pairs(stream_infos) do
if stream and stream.file then
stream.file:flush()
stream.file:close()
stream.file = nil
index = index + 1
twappend(index .. ": [" .. stream.filename .. "] generated OK!")
local anony_fuc = function ()
twappend("ffplay -x 640 -y 640 -autoexit "..stream.filename)
--copy_to_clipboard("ffplay -x 640 -y 640 -autoexit "..stream.filepath)
os.execute(ffmpeg_path.."ffplay -x 640 -y 640 -autoexit "..stream.filepath)
end
tw:add_button("Play "..index, anony_fuc)
no_streams = false
end
end
if no_streams then
twappend("Not found any H.265 over RTP streams!")
else
tw:add_button("Browser", function () browser_open_data_file(temp_path) end)
end
end
end
function my_h265_tap.reset()
-- do nothing now
end
tw:set_atclose(function ()
my_h265_tap:remove()
if Dir.exists(temp_path) then
Dir.remove_all(temp_path)
end
end)
local function export_h265()
pgtw = ProgDlg.new("Export H265 to File Process", "Dumping H265 data to file...")
first_run = true
stream_infos = {}
-- first time it runs for counting h.265 packets and finding SPS and PPS
retap_packets()
first_run = false
-- second time it runs for saving h265 data to target file.
retap_packets()
close_all_files()
-- close progress window
pgtw:close()
stream_infos = nil
end
tw:add_button("Export All", function ()
export_h265()
end)
tw:add_button("Set Filter", function ()
tw:close()
dialog_menu()
end)
end
local function dialog_func(str)
filter_string = str
export_h265_to_file()
end
function dialog_menu()
new_dialog("Filter Dialog",dialog_func,"Filter")
end
local function dialog_default()
filter_string = get_filter()
export_h265_to_file()
end
-- Find this feature in menu "Tools"
register_menu("Video/Export H265", dialog_default, MENU_TOOLS_UNSORTED)
end1.2 rtp_h365_extractor.lua放在 Wireshark 安装目录中
1.3 修改init.lua配置文件
2. 流分析
2.1. 解码为RTP数据包
使用wireshark抓包工具抓取码流包（如下图），基于UDP传输。
选中其中一个数据包(包要选择正确,可根据protocol的类型选择)，右键选择解码为（如下图）。
新增解码规则，选择解码为RTP流（如下图）。
解码后，可看到数据包解码成了RTP包（如下图）。
导出h265视频流
2.2. vlc播放视频流
