-- string.explode(string, separator)
function string.explode(p, d)
  local t, i
  t={}
  i=0
  if(#p == 1) then return {p} end
    while true do
      l=string.find(p,d,i,true)
      if l~=nil then
        table.insert(t, string.sub(p,i,l-1))
        i=l+1
      else
        table.insert(t, string.sub(p,i))
        break
      end
    end
  return t
end

-- string.begin_with
function string.begin_with(str, sub_str)
   return string.find(str, sub_str)==1
end

-- string.url_decode
function string.url_decode(str)
  str = string.gsub (str, "+", " ")
  str = string.gsub (str, "%%(%x%x)", function(h) return string.char(tonumber(h,16)) end)
  str = string.gsub (str, "\r\n", "\n")
  return str
end

-- string.url_query_parameter_map
function string.url_query_parameter_map(str)
    local params_kv = {}
    for k,v in pairs(string.explode(str, "&")) do
        local eqmark_idx = string.find(v, "=")
        if eqmark_idx ~= nil and eqmark_idx > 1 and eqmark_idx < string.len(v) then
            local param_name = string.sub(v, 1, eqmark_idx-1)
            local param_value = string.sub(v, eqmark_idx+1)
            param_name = string.url_decode(param_name)
            param_value = string.url_decode(param_value)
            --print (param_name .." => " .. param_value)
            params_kv[param_name] = param_value
        else
            params_kv[string.url_decode(v)] = ""
        end
    end
    return params_kv
end

function string.ytb_sig_charswap(str, pos)
    local c1 = string.sub(str,1,1)
    local pos2 = (pos-1)%string.len(str)+1--lua has index begun at 1!
    local c2 = string.sub(str,pos2,pos2)

    return c2..string.sub(str,2,pos2-1)..c1..string.sub(str,pos2+1)
end

-- string.ytb_sig_decrypt
function string.ytb_sig_decrypt(str)
    local sig = str
    sig = string.sub(sig, 3)
    sig = string.reverse(sig)
    sig = string.sub(sig, 4)
    sig = string.ytb_sig_charswap(sig, 10)
    sig = string.sub(sig, 4)
    sig = string.ytb_sig_charswap(sig, 44)
    sig = string.sub(sig, 4)
    sig = string.reverse(sig)
    sig = string.ytb_sig_charswap(sig, 24)
    return sig
end

--local s = "YFRHVIIsjrkkiGDtqKXrh847DI5GKDKokWjjgougGDLanT2rw92V6cuXY5BfPGMsaLwgGUYV76wr1T6W"
--print(string.ytb_sig_decrypt(s))

-- define the parser function
-- return: number of video resource, table of video resources, failed reason text.
parse = function (s)
    local params_kv = string.url_query_parameter_map(s)
    -- print(params_kv["fmt_list"]);
    local fmt_list, fmt_stream = params_kv["fmt_list"],  params_kv["url_encoded_fmt_stream_map"]
    local reason, rental_bar = params_kv["reason"], params_kv["ypc_video_rental_bar_text"]

    if (fmt_list == nil or fmt_stream == nil) then
        local reason_text = "reason="
        if (reason ~= nil) then 
            reason_text = reason_text .. reason
        elseif (rental_bar ~= nil) then 
            reason_text = reason_text .. rental_bar
        else 
            reason_text = "reason=This video cannot be played for some unknown reason(unexpected)"
        end
        return 0, {}, reason_text
    end

    print(fmt_list)
    --local fmt_infos = {}
    --for k,v in pairs(string.explode(fmt_list, ",")) do
    --  local fmt_info = string.explode(v, "/")
    --  local v_itag, v_reso = fmt_info[1], fmt_info[2] 
    --  fmt_infos[v_itag]=v_reso
    --  print (v_itag.." => "..v_reso)
    --end

    local stream_n, stream_infos = 0, {}
    for k,v in pairs(string.explode(fmt_stream, ",")) do
        local s_info = string.url_query_parameter_map(v)
        local v_itag, v_url, v_s, v_sig = s_info["itag"], s_info["url"], s_info["s"], s_info["sig"]
        --print (v_itag.." => "..v_url)
        --print ((v_s or "nil").." ~ "..(v_sig or "nil"))
        if (string.find(v_url, "signature=") ~= nil) then
            v_url = v_url
        elseif (v_sig ~= nil) then
            v_url = v_url.."&signature="..v_sig
        elseif (v_s ~= nil) then
            v_url = v_url.."&signature="..string.ytb_sig_decrypt(v_s)
        else
            v_url = v_url
        end
        stream_infos[v_itag] = v_url
        stream_n=stream_n+1
        print (v_itag.." => "..v_url)
    end

    return stream_n, stream_infos, ""
end

-- multiple return values:
-- the first one is script version number.
-- the second one is remote YouTube URL for fetching, with one parameter placeholder "%s".
-- the third one is the parser entry function object.
return "14.3.5", "https://www.youtube.com/get_video_info?video_id=%s&el=vevo&el=embedded&asv=3&sts=15902", parse

你可以翻译＆＃39;它成为Objective-C代码。

希望这有帮助。

Answer 2

Youtube 不允许您播放包含版权的视频。所有可播放的视频都将是免费使用且无权利的视频。从 2021 年 7 月“get_video_info”返回“410 -消失”，我猜谷歌有人遇到了视频可以在 youtube 之外播放的危机。需要“get_video_info”？你可以使用我的 NuGet https://www.nuget.org/packages/Youtube.VideoInfo/1.0.0

享受吧！

Answer 3

这种类型的视频只有在真实网站上嵌入时才能播放。我们不会通过API公开这些列表。

此博客文章还有更多细节：

http://apiblog.youtube.com/2011/12/understanding-playback-restrictions.html

大多数视频都没有从YouTube获取VideoUrl

3 个答案: