１月にTwitterの公式アプリから動画(30秒まで)がアップロードできるようになりました。

https://twitter.com/n428dev/status/561814427150741505

２月からTwitter公式で開発者向けにビデオのURLをツイートのJSONから取得できるようになるというアナウンスがありましたが、私が試したところ２月７日にはビデオ情報がツイートのJSONに格納され返却されるようになっていました。

これをTwitterクライアントで生のJSONで取得すると以下になります

video_tweet.json

{
  "contributors": null,
  "text": "ツイッター動画投稿テスト http://t.co/y9hjEfABw1",
  "geo": null,
  "retweeted": false,
  "in_reply_to_screen_name": null,
  "possibly_sensitive": false,
  "truncated": false,
  "lang": "ja",
  "entities": {
    "symbols": [],
    "urls": [],
    "hashtags": [],
    "media": [
      {
        "sizes": {
          "thumb": {
            "w": 150,
            "resize": "crop",
            "h": 150
          },
          "small": {
            "w": 340,
            "resize": "fit",
            "h": 340
          },
          "large": {
            "w": 720,
            "resize": "fit",
            "h": 720
          },
          "medium": {
            "w": 600,
            "resize": "fit",
            "h": 600
          }
        },
        "id": 561814337585569800,
        "media_url_https": "https://pbs.twimg.com/ext_tw_video_thumb/561814337585569793/pu/img/ZyW1taT-3_AkDB-4.jpg",
        "media_url": "http://pbs.twimg.com/ext_tw_video_thumb/561814337585569793/pu/img/ZyW1taT-3_AkDB-4.jpg",
        "expanded_url": "http://twitter.com/n428dev/status/561814427150741505/video/1",
        "indices": [
          13,
          35
        ],
        "id_str": "561814337585569793",
        "type": "photo",
        "display_url": "pic.twitter.com/y9hjEfABw1",
        "url": "http://t.co/y9hjEfABw1"
      }
    ],
    "user_mentions": []
  },
  "in_reply_to_status_id_str": null,
  "id": 561814427150741500,
  "extended_entities": {
    "media": [
      {
        "sizes": {
          "thumb": {
            "w": 150,
            "resize": "crop",
            "h": 150
          },
          "small": {
            "w": 340,
            "resize": "fit",
            "h": 340
          },
          "large": {
            "w": 720,
            "resize": "fit",
            "h": 720
          },
          "medium": {
            "w": 600,
            "resize": "fit",
            "h": 600
          }
        },
        "id": 561814337585569800,
        "media_url_https": "https://pbs.twimg.com/ext_tw_video_thumb/561814337585569793/pu/img/ZyW1taT-3_AkDB-4.jpg",
        "video_info": {
          "duration_millis": 11965,
          "variants": [
            {
              "bitrate": 832000,
              "content_type": "video/webm",
              "url": "https://video.twimg.com/ext_tw_video/561814337585569793/pu/vid/480x480/QKhWzHdEK0QDPtg8.webm"
            },
            {
              "bitrate": 1280000,
              "content_type": "video/mp4",
              "url": "https://video.twimg.com/ext_tw_video/561814337585569793/pu/vid/720x720/IdBKWbELa8D8cqLD.mp4"
            },
            {
              "bitrate": 320000,
              "content_type": "video/mp4",
              "url": "https://video.twimg.com/ext_tw_video/561814337585569793/pu/vid/240x240/7EK_gSEEPFBATzXI.mp4"
            },
            {
              "bitrate": 832000,
              "content_type": "video/mp4",
              "url": "https://video.twimg.com/ext_tw_video/561814337585569793/pu/vid/480x480/QKhWzHdEK0QDPtg8.mp4"
            },
            {
              "content_type": "application/x-mpegURL",
              "url": "https://video.twimg.com/ext_tw_video/561814337585569793/pu/pl/6G6kgS5lRXAOiCcg.m3u8"
            }
          ],
          "aspect_ratio": [
            1,
            1
          ]
        },
        "media_url": "http://pbs.twimg.com/ext_tw_video_thumb/561814337585569793/pu/img/ZyW1taT-3_AkDB-4.jpg",
        "expanded_url": "http://twitter.com/n428dev/status/561814427150741505/video/1",
        "indices": [
          13,
          35
        ],
        "id_str": "561814337585569793",
        "type": "video",
        "display_url": "pic.twitter.com/y9hjEfABw1",
        "url": "http://t.co/y9hjEfABw1"
      }
    ]
  },
  "source": "<a href=\"http://twitter.com/download/iphone\" rel=\"nofollow\">Twitter for iPhone</a>",
  "in_reply_to_user_id_str": null,
  "favorited": false,
  "in_reply_to_status_id": null,
  "retweet_count": 0,
  "created_at": "Sun Feb 01 09:12:52 +0000 2015",
  "in_reply_to_user_id": null,
  "favorite_count": 0,
  "id_str": "561814427150741505",
  "place": null,
  "user": {
    "location": "",
    "default_profile": true,
    "profile_background_tile": false,
    "statuses_count": 66,
    "lang": "ja",
    "profile_link_color": "0084B4",
    "id": 826661216,
    "following": false,
    "protected": false,
    "profile_location": null,
    "favourites_count": 5,
    "profile_text_color": "333333",
    "description": "428で働くプログラマー",
    "verified": false,
    "contributors_enabled": false,
    "profile_sidebar_border_color": "C0DEED",
    "name": "AKB428",
    "profile_background_color": "C0DEED",
    "created_at": "Sun Sep 16 07:06:52 +0000 2012",
    "is_translation_enabled": false,
    "default_profile_image": false,
    "followers_count": 9,
    "profile_image_url_https": "https://pbs.twimg.com/profile_images/507934202185011200/HcQGt2_r_normal.jpeg",
    "geo_enabled": false,
    "profile_background_image_url": "http://abs.twimg.com/images/themes/theme1/bg.png",
    "profile_background_image_url_https": "https://abs.twimg.com/images/themes/theme1/bg.png",
    "follow_request_sent": false,
    "entities": {
      "description": {
        "urls": []
      }
    },
    "url": null,
    "utc_offset": 32400,
    "time_zone": "Irkutsk",
    "notifications": false,
    "profile_use_background_image": true,
    "friends_count": 40,
    "profile_sidebar_fill_color": "DDEEF6",
    "screen_name": "n428dev",
    "id_str": "826661216",
    "profile_image_url": "http://pbs.twimg.com/profile_images/507934202185011200/HcQGt2_r_normal.jpeg",
    "listed_count": 0,
    "is_translator": false
  },
  "coordinates": null
}

JSONの階層的に extended_entities -> media -> video_info

に動画情報が格納されています。
Youtubeのように各種のビットレート、各種の動画フォーマットにエンコードされた動画ファイルのURLが用意されています・

各種言語のTwitterのクライアントライブラリが対応するまではこのJSONを元に自前でゴリゴリパーサーを書くか、各種言語のライブラリを書き換えちゃいましょう。