Allow upload of videos > 1080p

Videos that are larger than 1920x1080 pixels are scaled down so that they
fit that size. Care is taken to keep the width a multiple of 16 pixels and
the height a multiple of 8.

pillar/api/file_storage/__init__.py

@@ -129,14 +129,99 @@ def _process_image(bucket: Bucket,
     src_file['status'] = 'complete'
 
 
+def _video_size_pixels(filename: pathlib.Path) -> typing.Tuple[int, int]:
+    """Figures out the size (in pixels) of the video file.
+
+    Returns (0, 0) if there was any error detecting the size.
+    """
+
+    import json
+    import subprocess
+
+    cli_args = [
+        current_app.config['BIN_FFPROBE'],
+        '-loglevel', 'error',
+        '-hide_banner',
+        '-print_format', 'json',
+        '-select_streams', 'v:0',  # we only care about the first video stream
+        '-show_streams',
+        str(filename),
+    ]
+
+    if log.isEnabledFor(logging.INFO):
+        import shlex
+        cmd = ' '.join(shlex.quote(s) for s in cli_args)
+        log.info('Calling %s', cmd)
+
+    ffprobe = subprocess.run(
+        cli_args,
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        timeout=10,  # seconds
+    )
+
+    if ffprobe.returncode:
+        import shlex
+        cmd = ' '.join(shlex.quote(s) for s in cli_args)
+        log.error('Error running %s: stopped with return code %i',
+                  cmd, ffprobe.returncode)
+        log.error('Output was: %s', ffprobe.stdout)
+        return 0, 0
+
+    try:
+        ffprobe_info = json.loads(ffprobe.stdout)
+    except json.JSONDecodeError:
+        log.exception('ffprobe produced invalid JSON: %s', ffprobe.stdout)
+        return 0, 0
+
+    try:
+        stream_info = ffprobe_info['streams'][0]
+        return stream_info['width'], stream_info['height']
+    except (KeyError, IndexError):
+        log.exception('ffprobe produced unexpected JSON: %s', ffprobe.stdout)
+        return 0, 0
+
+
+def _video_cap_at_1080(width: int, height: int) -> typing.Tuple[int, int]:
+    """Returns an appropriate width/height for a video capped at 1920x1080.
+
+    Takes into account that h264 has limitations:
+        - the width must be a multiple of 16
+        - the height must be a multiple of 8
+    """
+
+    if width > 1920:
+        # The height must be a multiple of 8
+        new_height = height / width * 1920
+        height = new_height - (new_height % 8)
+        width = 1920
+
+    if height > 1080:
+        # The width must be a multiple of 16
+        new_width = width / height * 1080
+        width = new_width - (new_width % 16)
+        height = 1080
+
+    return int(width), int(height)
+
+
 def _process_video(gcs,
                    file_id: ObjectId,
                    local_file: tempfile._TemporaryFileWrapper,
                    src_file: dict):
-    """Video is processed by Zencoder; the file isn't even stored locally."""
+    """Video is processed by Zencoder."""
 
     log.info('Processing video for file %s', file_id)
 
+    # Use ffprobe to find the size (in pixels) of the video.
+    # Even though Zencoder can do resizing to a maximum resolution without upscaling,
+    # by determining the video size here we already have this information in the file
+    # document before Zencoder calls our notification URL. It also opens up possibilities
+    # for other encoding backends that don't support this functionality.
+    video_width, video_height = _video_size_pixels(pathlib.Path(local_file.name))
+    capped_video_width, capped_video_height = _video_cap_at_1080(video_width, video_height)
+
     # Create variations
     root, _ = os.path.splitext(src_file['file_path'])
     src_file['variations'] = []
@@ -149,8 +234,8 @@ def _process_video(gcs,
         file_path='{}-{}.{}'.format(root, v, v),
         size='',
         duration=0,
-        width=0,
+        width=capped_video_width,
-        height=0,
+        height=capped_video_height,
         length=0,
         md5='',
     )
@@ -624,8 +709,9 @@ def stream_to_storage(project_id):
                     project_oid)
         raise wz_exceptions.BadRequest('Missing content type.')
 
-    if uploaded_file.content_type.startswith('image/'):
+    if uploaded_file.content_type.startswith('image/') or uploaded_file.content_type.startswith(
-        # We need to do local thumbnailing, so we have to write the stream
+            'video/'):
+        # We need to do local thumbnailing and ffprobe, so we have to write the stream
         # both to Google Cloud Storage and to local storage.
         local_file = tempfile.NamedTemporaryFile(
             dir=current_app.config['STORAGE_DIR'])

pillar/api/utils/encoding.py

@@ -31,7 +31,10 @@ class Encoder:
         options = dict(notifications=current_app.config['ZENCODER_NOTIFICATIONS_URL'])
 
         outputs = [{'format': v['format'],
-                    'url': os.path.join(storage_base, v['file_path'])}
+                    'url': os.path.join(storage_base, v['file_path']),
+                    'upscale': False,
+                    'size': '{width}x{height}'.format(**v),
+                    }
                    for v in src_file['variations']]
         r = current_app.encoding_service_client.job.create(file_input,
                                                            outputs=outputs,

tests/test_api/test_file_storage.py

@@ -233,3 +233,50 @@ class FileMaxSizeTest(AbstractPillarTest):
     def create_test_file(self, file_size_bytes):
         fileob = io.BytesIO(rsa.randnum.read_random_bits(file_size_bytes * 8))
         return fileob
+
+
+class VideoSizeTest(AbstractPillarTest):
+    def test_video_size(self):
+        from pillar.api import file_storage
+        from pathlib import Path
+
+        fname = Path(__file__).with_name('video-tiny.mkv')
+
+        with self.app.test_request_context():
+            size = file_storage._video_size_pixels(fname)
+
+        self.assertEqual((960, 540), size)
+
+    def test_video_size_nonexistant(self):
+        from pillar.api import file_storage
+        from pathlib import Path
+
+        fname = Path(__file__).with_name('video-nonexistant.mkv')
+
+        with self.app.test_request_context():
+            size = file_storage._video_size_pixels(fname)
+
+        self.assertEqual((0, 0), size)
+
+    def test_video_cap_at_1080(self):
+        from pillar.api import file_storage
+
+        # Up to 1920x1080, the input should be returned as-is.
+        self.assertEqual((0, 0), file_storage._video_cap_at_1080(0, 0))
+        self.assertEqual((1, 1), file_storage._video_cap_at_1080(1, 1))
+        self.assertEqual((960, 540), file_storage._video_cap_at_1080(960, 540))
+        self.assertEqual((1920, 540), file_storage._video_cap_at_1080(1920, 540))
+
+        # The height must be multiple of 8
+        self.assertEqual((1920, 784), file_storage._video_cap_at_1080(2048, 840))
+
+        # The width must be multiple of 16
+        self.assertEqual((1024, 1080), file_storage._video_cap_at_1080(1920, 2000))
+
+        # Resizing the height based on the width will still produce a too high video,
+        # so this one hits both resize branches in one call:
+        self.assertEqual((1104, 1080), file_storage._video_cap_at_1080(2048, 2000))
+
+        size = file_storage._video_cap_at_1080(2048, 2000)
+        self.assertIsInstance(size[0], int)
+        self.assertIsInstance(size[1], int)