抖音无水印视频解析思路

分析过程

首先从抖音客户端找一个视频，点击分享-复制链接，粘贴一下发到电脑上，准备进行下一步，这里已经准备好了一个从客户端得到的分享文本。

把其中的链接粘贴到浏览器中访问一下，得到了这样的界面：

同时，地址栏中的链接变成了:

可见其发生了重定向。

F12审查一下播放区域：

发现这个时候播放区域只有一张背景图片和一个播放按钮，点击一下播放试试：

多了一个video标签，其中的src属性的值就是视频的url，所以大胆猜测一下，这个播放地址可能是通过ajax请求得到的。

切换到Network面板，点击xhr，再刷新一下页面，果然有一个ajax请求，这个ajax请求带有一个item_ids的参数，其值应该为视频的id，可以在页面重定向后的url中找到这个id：

响应结果是一个json字符串，复制到编辑器中格式化后如下：

{
    "extra": {
        "now": 1599467301000,
        "logid": "202009071628210101980651031208C5C1"
    },
    "status_code": 0,
    "item_list": [
        {
            "video_labels": null,
            "label_top_text": null,
            "long_video": null,
            "category": 103,
            "aweme_id": "6855476646057643272",
            "desc": "听说集齐碎片可以召唤神龙！#家乡变成二次元 #充能计划 #画画 #夏日打卡挑战",
            "video_text": null,
            "forward_id": "0",
            "mix_info": {
                "statis": {
                    "collect_vv": 0,
                    "current_episode": 35,
                    "updated_to_episode": 35,
                    "play_vv": 0
                },
                "desc": "原创不易，不喜勿喷～",
                "extra": "{\"first_reviewed\":1,\"is_quality_mix\":0,\"next_info\":{\"cover\":\"tos-cn-i-0813/57a48d47c61142748748802d08a75570\",\"desc\":\"原创不易，不喜勿喷～\",\"name\":\"家乡变成二次元\"}}",
                "create_time": 1596724793,
                "mix_id": "6857880767423318030",
                "cover_url": {
                    "uri": "tos-cn-i-0813/57a48d47c61142748748802d08a75570",
                    "url_list": [
                        "https://p6-dy-ipv6.byteimg.com/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570?from=2563711402",
                        "https://p1-dy-ipv6.byteimg.com/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570?from=2563711402",
                        "https://p26-dy.byteimg.com/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570?from=2563711402"
                    ]
                },
                "status": {
                    "status": 2,
                    "is_collected": 0
                },
                "next_info": {
                    "mix_name": "家乡变成二次元",
                    "desc": "原创不易，不喜勿喷～",
                    "cover_url": {
                        "uri": "tos-cn-i-0813/57a48d47c61142748748802d08a75570",
                        "url_list": [
                            "https://p1-dy.bytecdn.cn/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570",
                            "https://p3-dy.bytecdn.cn/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570",
                            "https://p9-dy.bytecdn.cn/obj/tos-cn-i-0813/57a48d47c61142748748802d08a75570"
                        ]
                    }
                },
                "mix_name": "家乡变成二次元"
            },
            "music": {
                "status": 1,
                "id": 6855476868364193000,
                "mid": "6855476868364192519",
                "cover_hd": {
                    "url_list": [
                        "https://p26-dy.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p6-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p3-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ],
                    "uri": "317ca0000ef155aeac0be"
                },
                "cover_large": {
                    "url_list": [
                        "https://p26-dy.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p6-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p3-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ],
                    "uri": "317ca0000ef155aeac0be"
                },
                "play_url": {
                    "uri": "http://p9-dy.byteimg.com/obj/ies-music/6855476835380480781.mp3",
                    "url_list": [
                        "http://p9-dy.byteimg.com/obj/ies-music/6855476835380480781.mp3",
                        "http://p1-dy.byteimg.com/obj/ies-music/6855476835380480781.mp3"
                    ]
                },
                "duration": 135,
                "position": null,
                "title": "@不自由画师团团子创作的原声",
                "author": "不自由画师团团子",
                "cover_medium": {
                    "uri": "317ca0000ef155aeac0be",
                    "url_list": [
                        "https://p29-dy.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p1-dy-ipv6.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p9-dy.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ]
                },
                "cover_thumb": {
                    "uri": "317ca0000ef155aeac0be",
                    "url_list": [
                        "https://p3-dy-ipv6.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p9-dy.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p29-dy.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ]
                }
            },
            "author_user_id": 71884871098,
            "share_info": {
                "share_weibo_desc": "#在抖音，记录美好生活#听说集齐碎片可以召唤神龙！#家乡变成二次元 #充能计划 #画画 #夏日打卡挑战",
                "share_desc": "在抖音，记录美好生活",
                "share_title": "听说集齐碎片可以召唤神龙！#家乡变成二次元 #充能计划 #画画 #夏日打卡挑战"
            },
            "promotions": null,
            "is_preview": 0,
            "group_id": 6855476646057643000,
            "video": {
                "origin_cover": {
                    "uri": "tos-cn-p-0015/ac5c4e77f7c441359a656c68c86926e4_1596165086",
                    "url_list": [
                        "https://p3-dy-ipv6.byteimg.com/tos-cn-p-0015/ac5c4e77f7c441359a656c68c86926e4_1596165086~tplv-dy-360p.jpeg?from=2563711402",
                        "https://p6-dy-ipv6.byteimg.com/tos-cn-p-0015/ac5c4e77f7c441359a656c68c86926e4_1596165086~tplv-dy-360p.jpeg?from=2563711402",
                        "https://p26-dy.byteimg.com/tos-cn-p-0015/ac5c4e77f7c441359a656c68c86926e4_1596165086~tplv-dy-360p.jpeg?from=2563711402"
                    ]
                },
                "ratio": "540p",
                "has_watermark": true,
                "bit_rate": null,
                "duration": 135302,
                "is_long_video": 1,
                "width": 720,
                "cover": {
                    "uri": "tos-cn-p-0015/b98b9cb496be4379bcb8e283f38f1c9e",
                    "url_list": [
                        "https://p6-dy-ipv6.byteimg.com/img/tos-cn-p-0015/b98b9cb496be4379bcb8e283f38f1c9e~c5_300x400.jpeg?from=2563711402_large",
                        "https://p3-dy-ipv6.byteimg.com/img/tos-cn-p-0015/b98b9cb496be4379bcb8e283f38f1c9e~c5_300x400.jpeg?from=2563711402_large",
                        "https://p9-dy.byteimg.com/img/tos-cn-p-0015/b98b9cb496be4379bcb8e283f38f1c9e~c5_300x400.jpeg?from=2563711402_large"
                    ]
                },
                "height": 1280,
                "dynamic_cover": {
                    "url_list": [
                        "https://p3-dy-ipv6.byteimg.com/obj/tos-cn-p-0015/11e5f3dcb62749a6848a14c01c556f66_1596165086?from=2563711402_large",
                        "https://p29-dy.byteimg.com/obj/tos-cn-p-0015/11e5f3dcb62749a6848a14c01c556f66_1596165086?from=2563711402_large",
                        "https://p9-dy.byteimg.com/obj/tos-cn-p-0015/11e5f3dcb62749a6848a14c01c556f66_1596165086?from=2563711402_large"
                    ],
                    "uri": "tos-cn-p-0015/11e5f3dcb62749a6848a14c01c556f66_1596165086"
                },
                "vid": "v0200fda0000bshokcp94bbr1103bot0",
                "play_addr": {
                    "uri": "v0200fda0000bshokcp94bbr1103bot0",
                    "url_list": [
                        "https://aweme.snssdk.com/aweme/v1/playwm/?video_id=v0200fda0000bshokcp94bbr1103bot0&ratio=720p&line=0"
                    ]
                }
            },
            "share_url": "https://www.iesdouyin.com/share/video/6855476646057643272/?region=&mid=6855476868364192519&u_code=48&titleType=title",
            "aweme_type": 4,
            "image_infos": null,
            "geofencing": null,
            "is_live_replay": false,
            "create_time": 1596165084,
            "duration": 135302,
            "comment_list": null,
            "cha_list": [
                {
                    "is_commerce": false,
                    "cid": "1670532508858382",
                    "desc": "",
                    "connect_music": null,
                    "view_count": 0,
                    "hash_tag_profile": "",
                    "cha_name": "家乡变成二次元",
                    "user_count": 0,
                    "type": 1
                }
            ],
            "risk_infos": {
                "warn": false,
                "type": 0,
                "content": ""
            },
            "text_extra": [
                {
                    "hashtag_id": 1670532508858382,
                    "start": 13,
                    "end": 21,
                    "type": 1,
                    "hashtag_name": "家乡变成二次元"
                },
                {
                    "start": 22,
                    "end": 27,
                    "type": 1,
                    "hashtag_name": "充能计划",
                    "hashtag_id": 1655868948754440
                },
                {
                    "start": 28,
                    "end": 31,
                    "type": 1,
                    "hashtag_name": "画画",
                    "hashtag_id": 1553508302124033
                },
                {
                    "start": 32,
                    "end": 39,
                    "type": 1,
                    "hashtag_name": "夏日打卡挑战",
                    "hashtag_id": 1673117213997070
                }
            ],
            "author": {
                "policy_version": null,
                "uid": "71884871098",
                "short_id": "612124342",
                "signature": "沉迷二次元无法自拔的小姐姐（老阿姨）\n面对骨感的现实，依然满怀希望的走在实现梦想的路上\n————渐行渐远……（画风越来越不对了…）",
                "avatar_thumb": {
                    "uri": "317ca0000ef155aeac0be",
                    "url_list": [
                        "https://p3-dy-ipv6.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p9-dy.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p29-dy.byteimg.com/aweme/100x100/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ]
                },
                "unique_id": "",
                "platform_sync_info": null,
                "nickname": "不自由画师团团子",
                "avatar_larger": {
                    "uri": "317ca0000ef155aeac0be",
                    "url_list": [
                        "https://p1-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p9-dy.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p6-dy-ipv6.byteimg.com/aweme/1080x1080/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ]
                },
                "avatar_medium": {
                    "uri": "317ca0000ef155aeac0be",
                    "url_list": [
                        "https://p6-dy-ipv6.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p29-dy.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038",
                        "https://p3-dy-ipv6.byteimg.com/aweme/720x720/317ca0000ef155aeac0be.jpeg?from=4010531038"
                    ]
                },
                "followers_detail": null,
                "geofencing": null,
                "type_label": null
            },
            "statistics": {
                "aweme_id": "6855476646057643272",
                "comment_count": 6598,
                "digg_count": 74803,
                "play_count": 0
            }
        }
    ],
    "ab_type": 1
}

信息还是蛮丰富的，作者信息、视频信息、音乐信息、封面信息等一应俱全，视频的地址是在item_list下video.play_addr.url_list中，复制下这个地址用浏览器访问一下果然得到了视频：

不过这个视频还是带水印的，如何获得没有水印的视频呢，来看看从json字符串中得到的视频地址：

觉不觉得这个playwm中的wm是water mask的简写呢，把wm删掉再访问一下试试。即：

结果一片空白，是不是这样行不通呢，不应该啊，不然直接写play多好，何必又搞个playwm呢，一定是访问姿势有问题，点击左上角的设备切换按钮切换到移动端访问一下，哇，amazing，竟然真的访问到了！

同时可以看到原本左上角的抖音水印消失了。成功！

思路总结

1. 访问客户端分享文本中的链接，从重定向后的url中提取视频id，https://www.iesdouyin.com/share/video/后的数字就是视频id。
2. 访问https://www.iesdouyin.com/web/api/v2/aweme/iteminfo/?item_ids=视频id获取有关该视频的json字符串。
3. 从得到的json字符串中提取视频播放地址，在item_list下video.play_addr.url_list中。
4. 将视频地址中的playwm替换为play。
5. 使用移动端的user-agent访问替换后的视频地址即可得到无抖音水印的视频。