Repository: streamlink/streamlink (python)

Issue:
How to Stream Akamai (?) Video from Senate Foreign Relations Committee Website
## Issue

<!-- Replace [ ] with [x] in order to check the box -->
- [x] This is not a bug report, feature request, or plugin issue/request.
- [x] I have read the contribution guidelines.

### Description

I am attempting to load archived video and live video streams of the US Senate Foreign Relations Committee ([Example](https://www.foreign.senate.gov/hearings/business-meeting-082218)) in VLC via streamlink. It appears their video streaming is done via Akamai and AMP v4.90.9 from right-clicking the player embedded in provided examples.

### Expected / Actual behavior

Ideally, pointing streamlink to the hearing page containing an embedded player would automagically identify available streams and open the best quality stream in VLC:

`streamlink "https://www.foreign.senate.gov/hearings/business-meeting-082218" best`   

What actually happens is that streamlink fails with an error `error: No plugin can handle URL: https://www.foreign.senate.gov/hearings/business-meeting-082218`

### Reproduction steps / Explicit stream URLs to test

I have discovered that the URL for their embedded player gets a little closer ([Example](http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218)), but streamlink still doesn't find any streams at this URL. That is, until I replace https:// with *akamaihd://*:

`streamlink "akamaihd://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218"`   

Results in:

```[cli][info] Found matching plugin akamaihd for URL akamaihd://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218
Available streams: live (worst, best)
```

When I specify "best" and run the command again, the result is:

```[cli][info] Found matching plugin akamaihd for URL akamaihd://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218
[cli][info] Available streams: live (worst, best)
[cli][info] Opening stream: live (akamaihd)
[cli][error] Try 1/1: Could not open stream <AkamaiHDStream('http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218', swf=None)> (Could not open stream: Unable to open URL: http://www.senate.gov/isvp/ (503 Server Error: Service Unavailable for url: http://www.senate.gov/isvp/?fp=LNX+11%2C1%2C102%2C63&r=PPJRC&g=VFVQOIITOQRF&v=2.5.8))
error: Could not open stream <AkamaiHDStream('http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218', swf=None)>, tried 1 times, exiting
```
### Logs

```
[cli][debug] OS:         macOS 10.13.6
[cli][debug] Python:     2.7.15
[cli][debug] Streamlink: 0.14.2
[cli][debug] Requests(2.19.1), Socks(1.6.7), Websocket(0.48.0)
[cli][info] Found matching plugin akamaihd for URL akamaihd://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218
[plugin.akamaihd][debug] URL=http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218; params={}
[cli][info] Available streams: live (worst, best)
[cli][info] Opening stream: live (akamaihd)
[stream.akamaihd][debug] Opening host=http://www.senate.gov streamname=isvp/
[cli][error] Try 1/1: Could not open stream <AkamaiHDStream('http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218', swf=None)> (Could not open stream: Unable to open URL: http://www.senate.gov/isvp/ (503 Server Error: Service Unavailable for url: http://www.senate.gov/isvp/?fp=LNX+11%2C1%2C102%2C63&r=VREJP&g=JOHWJGPLHFNA&v=2.5.8))
error: Could not open stream <AkamaiHDStream('http://www.senate.gov/isvp/?comm=foreign&type=live&filename=foreign082218', swf=None)>, tried 1 times, exiting
```

### Additional comments, screenshots, etc.

It appears the Senate Foreign Relations Committee uses the date of the hearing as the main reference ID. Since the committee only meets once a day, there's only ever one stream on any given day.

There's possibly useful information in the source of each player page. In the source code for the example link I've used above, there's this snippet:

```
<a id="watch-live-now" class="small btn" href="javascript:openVideoWin('/hearings/watch?hearingid=AA0FF459-5056-A066-60A0-8B11F704E85E');">Open New Window</a>
```

Also, from the source code the video player code can have a lot of parameters specified:

```
https://www.senate.gov/isvp/?comm=foreign&type=arch&stt=21:50&filename=foreign082218&auto_play=false&wmode=transparent&poster=https%3A%2F%2Fwww%2Eforeign%2Esenate%2Egov%2Fthemes%2Fforeign%2Fimages%2Fvideo%2Dposter%2Dflash%2Dfit%2Epng
```

[Love Streamlink? Please consider supporting our collective. Thanks!](https://opencollective.com/streamlink/donate)

Pull request description:
plugins.senategov: support for hearing streams on senate.gov
Only supports the senate hearing streams (as far as i know).

Fixes #2042

Patch:
diff --git a/docs/plugin_matrix.rst b/docs/plugin_matrix.rst
index 0bb62885..5f27e220 100644
--- a/docs/plugin_matrix.rst
+++ b/docs/plugin_matrix.rst
@@ -164,6 +164,7 @@ rtve                    rtve.es              Yes   No
 rtvs                    rtvs.sk              Yes   No    Streams may be geo-restricted to Slovakia.
 ruv                     ruv.is               Yes   Yes   Streams may be geo-restricted to Iceland.
 schoolism               schoolism.com        --    Yes   Requires a login and a subscription.
+senategov               senate.gov           --    Yes   Supports hearing streams.
 showroom                showroom-live.com    Yes   No    Only RTMP streams are available.
 skai                    skai.gr              Yes   No    Only embedded youtube live streams are supported
 sportal                 sportal.bg           Yes   No
diff --git a/src/streamlink/plugins/senategov.py b/src/streamlink/plugins/senategov.py
new file mode 100644
index 00000000..2942b288
--- /dev/null
+++ b/src/streamlink/plugins/senategov.py
@@ -0,0 +1,113 @@
+import re
+import logging
+
+from streamlink.plugin import Plugin
+from streamlink.plugin.api import useragents
+from streamlink.plugin.api.utils import itertags
+from streamlink.stream import HLSStream
+from streamlink.utils import parse_json
+from streamlink.compat import urlparse, parse_qsl
+from streamlink.utils.times import hours_minutes_seconds
+
+log = logging.getLogger(__name__)
+
+
+class SenateGov(Plugin):
+    url_re = re.compile(r"""https?://(?:.+\.)?senate\.gov/(isvp)?""")
+    streaminfo_re = re.compile(r"""var\s+streamInfo\s+=\s+new\s+Array\s*\(\s*(\[.*\])\);""")
+    stt_re = re.compile(r"""^(?:(?P<hours>\d+):)?(?P<minutes>\d+):(?P<seconds>\d+)$""")
+    url_lookup = {
+        "ag": ["76440", "https://ag-f.akamaihd.net"],
+        "aging": ["76442", "https://aging-f.akamaihd.net"],
+        "approps": ["76441", "https://approps-f.akamaihd.net"],
+        "armed": ["76445", "https://armed-f.akamaihd.net"],
+        "banking": ["76446", "https://banking-f.akamaihd.net"],
+        "budget": ["76447", "https://budget-f.akamaihd.net"],
+        "cecc": ["76486", "https://srs-f.akamaihd.net"],
+        "commerce": ["80177", "https://commerce1-f.akamaihd.net"],
+        "csce": ["75229", "https://srs-f.akamaihd.net"],
+        "dpc": ["76590", "https://dpc-f.akamaihd.net"],
+        "energy": ["76448", "https://energy-f.akamaihd.net"],
+        "epw": ["76478", "https://epw-f.akamaihd.net"],
+        "ethics": ["76449", "https://ethics-f.akamaihd.net"],
+        "finance": ["76450", "https://finance-f.akamaihd.net"],
+        "foreign": ["76451", "https://foreign-f.akamaihd.net"],
+        "govtaff": ["76453", "https://govtaff-f.akamaihd.net"],
+        "help": ["76452", "https://help-f.akamaihd.net"],
+        "indian": ["76455", "https://indian-f.akamaihd.net"],
+        "intel": ["76456", "https://intel-f.akamaihd.net"],
+        "intlnarc": ["76457", "https://intlnarc-f.akamaihd.net"],
+        "jccic": ["85180", "https://jccic-f.akamaihd.net"],
+        "jec": ["76458", "https://jec-f.akamaihd.net"],
+        "judiciary": ["76459", "https://judiciary-f.akamaihd.net"],
+        "rpc": ["76591", "https://rpc-f.akamaihd.net"],
+        "rules": ["76460", "https://rules-f.akamaihd.net"],
+        "saa": ["76489", "https://srs-f.akamaihd.net"],
+        "smbiz": ["76461", "https://smbiz-f.akamaihd.net"],
+        "srs": ["75229", "https://srs-f.akamaihd.net"],
+        "uscc": ["76487", "https://srs-f.akamaihd.net"],
+        "vetaff": ["76462", "https://vetaff-f.akamaihd.net"],
+    }
+
+    hls_url = "{base}/i/{filename}_1@{number}/master.m3u8?"
+    hlsarch_url = "https://ussenate-f.akamaihd.net/i/{filename}.mp4/master.m3u8"
+
+    @classmethod
+    def can_handle_url(cls, url):
+        return cls.url_re.match(url) is not None
+
+    def _isvp_to_m3u8(self, url):
+        qs = dict(parse_qsl(urlparse(url).query))
+        if "comm" not in qs:
+            log.error("Missing `comm` value")
+        if "filename" not in qs:
+            log.error("Missing `filename` value")
+
+        d = self.url_lookup.get(qs['comm'])
+        if d:
+            snumber, baseurl = d
+            stream_url = self.hls_url.format(filename=qs['filename'], number=snumber, base=baseurl)
+        else:
+            stream_url = self.hlsarch_url.format(filename=qs['filename'])
+
+        return stream_url, self.parse_stt(qs.get('stt', 0))
+
+    def _get_streams(self):
+        self.session.http.headers.update({
+            "User-Agent": useragents.CHROME,
+        })
+        m = self.url_re.match(self.url)
+        if m and not m.group(1):
+            log.debug("Searching for ISVP URL")
+            isvp_url = self._get_isvp_url()
+        else:
+            isvp_url = self.url
+
+        if not isvp_url:
+            log.error("Could not find the ISVP URL")
+            return
+        else:
+            log.debug("ISVP URL: {0}".format(isvp_url))
+
+        stream_url, start_offset = self._isvp_to_m3u8(isvp_url)
+        log.debug("Start offset is: {0}s".format(start_offset))
+        return HLSStream.parse_variant_playlist(self.session, stream_url, start_offset=start_offset)
+
+    def _get_isvp_url(self):
+        res = self.session.http.get(self.url)
+        for iframe in itertags(res.text, 'iframe'):
+            m = self.url_re.match(iframe.attributes.get('src'))
+            return m and m.group(1) is not None and iframe.attributes.get('src')
+
+    @classmethod
+    def parse_stt(cls, param):
+        m = cls.stt_re.match(param)
+        if m:
+            return int(m.group('hours') or 0) * 3600 + \
+                   int(m.group('minutes')) * 60 + \
+                   int(m.group('seconds'))
+        else:
+            return 0
+
+
+__plugin__ = SenateGov


Test patch:
diff --git a/tests/plugins/test_senategov.py b/tests/plugins/test_senategov.py
new file mode 100644
index 00000000..6fb5eda8
--- /dev/null
+++ b/tests/plugins/test_senategov.py
@@ -0,0 +1,18 @@
+from streamlink.plugins.senategov import SenateGov
+import unittest
+
+
+class TestPluginSenateGov(unittest.TestCase):
+    def test_can_handle_url(self):
+        # should match
+        self.assertTrue(SenateGov.can_handle_url("https://www.foreign.senate.gov/hearings/business-meeting-082218"))
+        self.assertTrue(SenateGov.can_handle_url("https://www.senate.gov/isvp/?comm=foreign&type=arch&stt=21:50&filename=foreign082218&auto_play=false&wmode=transparent&poster=https%3A%2F%2Fwww%2Eforeign%2Esenate%2Egov%2Fthemes%2Fforeign%2Fimages%2Fvideo-poster-flash-fit%2Epng"))
+
+        # shouldn't match
+        self.assertFalse(SenateGov.can_handle_url("http://www.tvcatchup.com/"))
+        self.assertFalse(SenateGov.can_handle_url("http://www.youtube.com/"))
+
+    def test_stt_parse(self):
+        self.assertEqual(600, SenateGov.parse_stt("10:00"))
+        self.assertEqual(3600, SenateGov.parse_stt("01:00:00"))
+        self.assertEqual(70, SenateGov.parse_stt("1:10"))