--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -1831,16 +1831,29 @@ class Vendor(MachCommandBase):
     @CommandArgument('--build-peers-said-large-imports-were-ok', action='store_true',
         help='Permit overly-large files to be added to the repository',
         default=False)
     def vendor_rust(self, **kwargs):
         from mozbuild.vendor_rust import VendorRust
         vendor_command = self._spawn(VendorRust)
         vendor_command.vendor(**kwargs)
 
+    @SubCommand('vendor', 'aom',
+                description='Vendor av1 video codec reference implementation into the source repository.')
+    @CommandArgument('-r', '--revision',
+        help='Repository tag or commit to update to.')
+    @CommandArgument('--ignore-modified', action='store_true',
+        help='Ignore modified files in current checkout',
+        default=False)
+    def vendor_aom(self, **kwargs):
+        from mozbuild.vendor_aom import VendorAOM
+        vendor_command = self._spawn(VendorAOM)
+        vendor_command.vendor(**kwargs)
+
+
 @CommandProvider
 class WebRTCGTestCommands(GTestCommands):
     @Command('webrtc-gtest', category='testing',
         description='Run WebRTC.org GTest unit tests.')
     @CommandArgument('gtest_filter', default=b"*", nargs='?', metavar='gtest_filter',
         help="test_filter is a ':'-separated list of wildcard patterns (called the positive patterns),"
              "optionally followed by a '-' and another ':'-separated pattern list (called the negative patterns).")
     @CommandArgumentGroup('debugging')

new file mode 100644
--- /dev/null
+++ b/python/mozbuild/mozbuild/vendor_aom.py
@@ -0,0 +1,157 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, # You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+from distutils.version import LooseVersion
+import logging
+from mozbuild.base import (
+    BuildEnvironmentNotFoundException,
+    MozbuildObject,
+)
+import mozfile
+import mozpack.path as mozpath
+import requests
+import re
+import sys
+import tarfile
+
+class VendorAOM(MozbuildObject):
+    base_url = 'https://aomedia.googlesource.com/aom/'
+
+    def upstream_url(self, revision):
+        '''Construct a url for a tarball snapshot of the given revision.'''
+        return mozpath.join(self.base_url, '+archive', revision + '.tar.gz')
+
+    def upstream_commit(self, revision):
+        '''Convert a revision to a git commit and timestamp.
+
+        Ask the upstream repo to convert the requested revision to
+        a git commit id and timestamp, so we can be precise in
+        what we're vendoring.'''
+        url = mozpath.join(self.base_url, '+', revision + '?format=JSON')
+        self.log(logging.INFO, 'fetch', {'url': url},
+                 'Fetching commit id from {url}')
+        req = requests.get(url)
+        req.raise_for_status()
+        try:
+            info = req.json()
+        except ValueError as e:
+            if 'No JSON object' in e.message:
+                # As of 2017 May, googlesource sends 4 garbage characters
+                # at the beginning of the json response. Work around this.
+                # https://bugs.chromium.org/p/chromium/issues/detail?id=718550
+                import json
+                info = json.loads(req.text[4:])
+            else:
+                raise
+        return (info['commit'], info['committer']['time'])
+
+    def fetch_and_unpack(self, revision, target):
+        '''Fetch and unpack upstream source'''
+        url = self.upstream_url(revision)
+        self.log(logging.INFO, 'fetch', {'url': url}, 'Fetching {url}')
+        filename = 'libaom-' + revision + '.tar.gz'
+        with open(filename, 'wb') as f:
+            req = requests.get(url, stream=True)
+            for data in req.iter_content(4096):
+                f.write(data)
+        tar = tarfile.open(filename)
+        bad_paths = filter(lambda name: name.startswith('/') or '..' in name,
+                           tar.getnames())
+        if any(bad_paths):
+            raise Exception("Tar archive contains non-local paths,"
+                            "e.g. '%s'" % bad_paths[0])
+        self.log(logging.INFO, 'rm_vendor_dir', {}, 'rm -rf %s' % target)
+        mozfile.remove(target)
+        self.log(logging.INFO, 'unpack', {}, 'Unpacking upstream files.')
+        tar.extractall(target)
+        mozfile.remove(filename)
+
+    def update_readme(self, revision, timestamp, target):
+        filename = mozpath.join(target, 'README_MOZILLA')
+        with open(filename) as f:
+            readme = f.read()
+
+        prefix = 'The git commit ID used was'
+        if prefix in readme:
+            new_readme = re.sub(prefix + ' [v\.a-f0-9]+.*$',
+                                prefix + ' %s (%s).' % (revision, timestamp),
+                                readme)
+        else:
+            new_readme = '%s\n\n%s %s.' % (readme, prefix, revision)
+
+        if readme != new_readme:
+            with open(filename, 'w') as f:
+                f.write(new_readme)
+
+    def clean_upstream(self, target):
+        '''Remove files we don't want to import.'''
+        mozfile.remove(mozpath.join(target, '.gitattributes'))
+        mozfile.remove(mozpath.join(target, '.gitignore'))
+        mozfile.remove(mozpath.join(target, 'build', '.gitattributes'))
+        mozfile.remove(mozpath.join(target, 'build' ,'.gitignore'))
+
+    def generate_sources(self, target):
+        '''
+        Run the library's native build system to update ours.
+
+        Invoke configure for each supported platform to generate
+        appropriate config and header files, then invoke the
+        makefile to obtain a list of source files, writing
+        these out in the appropriate format for our build
+        system to use.
+        '''
+        config_dir = mozpath.join(target, 'config')
+        self.log(logging.INFO, 'rm_confg_dir', {}, 'rm -rf %s' % config_dir)
+        mozfile.remove(config_dir)
+        self.run_process(args=['./generate_sources_mozbuild.sh'],
+                         cwd=target)
+
+    def check_modified_files(self):
+        '''
+        Ensure that there aren't any uncommitted changes to files
+        in the working copy, since we're going to change some state
+        on the user.
+        '''
+        modified = self.repository.get_modified_files()
+        if modified:
+            self.log(logging.ERROR, 'modified_files', {},
+                     '''You have uncommitted changes to the following files:
+
+{files}
+
+Please commit or stash these changes before vendoring, or re-run with `--ignore-modified`.
+'''.format(files='\n'.join(sorted(modified))))
+            sys.exit(1)
+
+    def vendor(self, revision, ignore_modified=False):
+        self.populate_logger()
+        self.log_manager.enable_unstructured()
+
+        if not ignore_modified:
+            self.check_modified_files()
+        if not revision:
+            revision = 'master'
+        commit, timestamp = self.upstream_commit(revision)
+
+        vendor_dir = mozpath.join(self.topsrcdir, 'third_party/aom')
+        self.fetch_and_unpack(commit, vendor_dir)
+        self.log(logging.INFO, 'clean_upstream', {},
+                 '''Removing unnecessary files.''')
+        self.clean_upstream(vendor_dir)
+        glue_dir = mozpath.join(self.topsrcdir, 'media/libaom')
+        self.log(logging.INFO, 'generate_sources', {},
+                 '''Generating build files...''')
+        self.generate_sources(glue_dir)
+        self.log(logging.INFO, 'update_readme', {},
+                 '''Updating README_MOZILLA.''')
+        self.update_readme(commit, timestamp, glue_dir)
+        self.repository.add_remove_files(vendor_dir)
+        self.log(logging.INFO, 'add_remove_files', {},
+                 '''Registering changes with version control.''')
+        self.repository.add_remove_files(vendor_dir)
+        self.repository.add_remove_files(glue_dir)
+        self.log(logging.INFO, 'done', {'revision': revision},
+                 '''Update to aom version '{revision}' ready to commit.''')