zamba.data.video¶
Classes¶
VideoLoaderConfig (BaseModel)
pydantic-model
¶
Configuration for load_video_frames.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
crop_bottom_pixels |
int |
Number of pixels to crop from the bottom of the video
(prior to resizing to |
required |
i_frames |
bool |
Only load the I-Frames. See https://en.wikipedia.org/wiki/Video_compression_picture_types#Intra-coded_(I)frames/slices(key_frames) |
required |
scene_threshold |
float |
Only load frames that correspond to scene changes. See http://www.ffmpeg.org/ffmpeg-filters.html#select_002c-aselect |
required |
megadetector_lite_config |
MegadetectorLiteYoloXConfig |
Configuration of MegadetectorLiteYoloX frame selection model. |
required |
frame_selection_height |
int |
Resize the video to this height in pixels, prior to frame selection. If None, the full size video will be used for frame selection. Using full size images (setting to None) is recommended for MegadetectorLite, especially if your species of interest are smaller. |
required |
frame_selection_width |
int |
Resize the video to this width in pixels, prior to frame selection. |
required |
total_frames |
int |
Number of frames that should ultimately be returned. |
required |
ensure_total_frames |
bool |
Selecting the number of frames by resampling may result in one more or fewer frames due to rounding. If True, ensure the requested number of frames is returned by either clipping or duplicating the final frame. Raises an error if no frames have been selected. Otherwise, return the array unchanged. |
required |
fps |
int |
Resample the video evenly from the entire duration to a specific number of frames per second. |
required |
early_bias |
bool |
Resamples to 24 fps and selects 16 frames biased toward the front (strategy used by competition winner). |
required |
frame_indices |
list(int) |
Select specific frame numbers. Note: frame selection is done after any resampling. |
required |
evenly_sample_total_frames |
bool |
Reach the total number of frames specified by evenly sampling from the duration of the video. Defaults to False. |
required |
pix_fmt |
str |
ffmpeg pixel format, defaults to 'rgb24' for RGB channels; can be changed to 'bgr24' for BGR. |
required |
model_input_height |
int |
After frame selection, resize the video to this height in pixels. |
required |
model_input_width |
int |
After frame selection, resize the video to this width in pixels. |
required |
cache_dir |
Path |
Cache directory where preprocessed videos will be saved upon first load. Alternatively, can be set with VIDEO_CACHE_DIR environment variable. Defaults to None, which means videos will not be cached. Provided there is enough space on your machine, it is highly encouraged to cache videos for training as this will speed up all subsequent epochs. If you are predicting on the same videos with the same video loader configuration, this will save time on future runs. |
required |
cleanup_cache |
bool |
Whether to delete the cache dir after training or predicting ends. Defaults to False. |
required |
cache_dir: Path
pydantic-field
¶
cleanup_cache: bool
pydantic-field
¶
crop_bottom_pixels: int
pydantic-field
¶
early_bias: bool
pydantic-field
¶
ensure_total_frames: bool
pydantic-field
¶
evenly_sample_total_frames: bool
pydantic-field
¶
fps: float
pydantic-field
¶
frame_indices: List[int]
pydantic-field
¶
frame_selection_height: int
pydantic-field
¶
frame_selection_width: int
pydantic-field
¶
i_frames: bool
pydantic-field
¶
megadetector_lite_config: MegadetectorLiteYoloXConfig
pydantic-field
¶
model_input_height: int
pydantic-field
¶
model_input_width: int
pydantic-field
¶
pix_fmt: str
pydantic-field
¶
scene_threshold: float
pydantic-field
¶
total_frames: int
pydantic-field
¶
Config
¶
Methods¶
check_early_bias_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_early_bias_compatibility(cls, values):
if values["early_bias"] and (
values["i_frames"]
or values["scene_threshold"]
or values["total_frames"]
or values["evenly_sample_total_frames"]
or values["fps"]
):
raise ValueError(
f"early_bias cannot be used with i_frames, scene_threshold, total_frames, evenly_sample_total_frames, or fps. Values provided are {values}."
)
return values
check_evenly_sample_total_frames_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_evenly_sample_total_frames_compatibility(cls, values):
if values["evenly_sample_total_frames"] is True and values["total_frames"] is None:
raise ValueError(
f"total_frames must be specified if evenly_sample_total_frames is used. Values provided are {values}."
)
if values["evenly_sample_total_frames"] and (
values["scene_threshold"]
or values["i_frames"]
or values["fps"]
or values["early_bias"]
):
raise ValueError(
f"evenly_sample_total_frames cannot be used with scene_threshold, i_frames, fps, or early_bias. Values provided are {values}."
)
return values
check_fps_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_fps_compatibility(cls, values):
if values["fps"] and (
values["evenly_sample_total_frames"] or values["i_frames"] or values["scene_threshold"]
):
raise ValueError(
f"fps cannot be used with evenly_sample_total_frames, i_frames, or scene_threshold. Values provided are {values}."
)
return values
check_frame_indices_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_frame_indices_compatibility(cls, values):
if values["frame_indices"] and (
values["total_frames"]
or values["scene_threshold"]
or values["i_frames"]
or values["early_bias"]
or values["evenly_sample_total_frames"]
):
raise ValueError(
f"frame_indices cannot be used with total_frames, scene_threshold, i_frames, early_bias, or evenly_sample_total_frames. Values provided are {values}."
)
return values
check_height_and_width(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_height_and_width(cls, values):
if (values["frame_selection_height"] is None) ^ (values["frame_selection_width"] is None):
raise ValueError(
f"Must provide both frame_selection_height and frame_selection_width or neither. Values provided are {values}."
)
if (values["model_input_height"] is None) ^ (values["model_input_width"] is None):
raise ValueError(
f"Must provide both model_input_height and model_input_width or neither. Values provided are {values}."
)
return values
check_i_frame_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_i_frame_compatibility(cls, values):
if values["scene_threshold"] and values["i_frames"]:
raise ValueError(
f"i_frames cannot be used with scene_threshold. Values provided are {values}."
)
return values
check_megadetector_lite_compatibility(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def check_megadetector_lite_compatibility(cls, values):
if values["megadetector_lite_config"] and (
values["early_bias"] or values["evenly_sample_total_frames"]
):
raise ValueError(
f"megadetector_lite_config cannot be used with early_bias or evenly_sample_total_frames. Values provided are {values}."
)
return values
validate_total_frames(values)
classmethod
¶
Source code in zamba/data/video.py
@root_validator(skip_on_failure=True)
def validate_total_frames(cls, values):
if values["megadetector_lite_config"] is not None:
# set n frames for megadetector_lite_config if only specified by total_frames
if values["megadetector_lite_config"].n_frames is None:
values["megadetector_lite_config"].n_frames = values["total_frames"]
# set total frames if only specified in megadetector_lite_config
if values["total_frames"] is None:
values["total_frames"] = values["megadetector_lite_config"].n_frames
return values
validate_video_cache_dir(cache_dir)
classmethod
¶
Set up cache directory for preprocessed videos. Config argument takes precedence over environment variable.
Source code in zamba/data/video.py
@validator("cache_dir", always=True)
def validate_video_cache_dir(cls, cache_dir):
"""Set up cache directory for preprocessed videos. Config argument takes precedence
over environment variable.
"""
if cache_dir is None:
cache_dir = os.getenv("VIDEO_CACHE_DIR", None)
if cache_dir is not None:
cache_dir = Path(cache_dir)
cache_dir.mkdir(parents=True, exist_ok=True)
return cache_dir
VideoMetadata (BaseModel)
pydantic-model
¶
duration_s: float
pydantic-field
required
¶
fps: int
pydantic-field
required
¶
height: int
pydantic-field
required
¶
n_frames: int
pydantic-field
required
¶
width: int
pydantic-field
required
¶
Classes¶
Config
inherited
¶
Classes¶
getter_dict (Representation)
¶Hack to make object's smell just enough like dicts for validate_model.
We can't inherit from Mapping[str, Any] because it upsets cython so we have to implement all methods ourselves.
Methods¶
get_field_info(name: unicode) -> Dict[str, Any]
classmethod
¶Get properties of FieldInfo from the fields property of the config class.
json_dumps(obj, *, skipkeys = False, ensure_ascii = True, check_circular = True, allow_nan = True, cls = None, indent = None, separators = None, default = None, sort_keys = False, **kw)
¶Serialize obj to a JSON formatted str.
If skipkeys is true then dict keys that are not basic types
(str, int, float, bool, None) will be skipped
instead of raising a TypeError.
If ensure_ascii is false, then the return value can contain non-ASCII
characters if they appear in strings contained in obj. Otherwise, all
such characters are escaped in JSON strings.
If check_circular is false, then the circular reference check
for container types will be skipped and a circular reference will
result in an OverflowError (or worse).
If allow_nan is false, then it will be a ValueError to
serialize out of range float values (nan, inf, -inf) in
strict compliance of the JSON specification, instead of using the
JavaScript equivalents (NaN, Infinity, -Infinity).
If indent is a non-negative integer, then JSON array elements and
object members will be pretty-printed with that indent level. An indent
level of 0 will only insert newlines. None is the most compact
representation.
If specified, separators should be an (item_separator, key_separator)
tuple. The default is (', ', ': ') if indent is None and
(',', ': ') otherwise. To get the most compact JSON representation,
you should specify (',', ':') to eliminate whitespace.
default(obj) is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
If sort_keys is true (default: False), then the output of
dictionaries will be sorted by key.
To use a custom JSONEncoder subclass (e.g. one that overrides the
.default() method to serialize additional types), specify it with
the cls kwarg; otherwise JSONEncoder is used.
Source code in zamba/data/video.py
def dumps(obj, *, skipkeys=False, ensure_ascii=True, check_circular=True,
allow_nan=True, cls=None, indent=None, separators=None,
default=None, sort_keys=False, **kw):
"""Serialize ``obj`` to a JSON formatted ``str``.
If ``skipkeys`` is true then ``dict`` keys that are not basic types
(``str``, ``int``, ``float``, ``bool``, ``None``) will be skipped
instead of raising a ``TypeError``.
If ``ensure_ascii`` is false, then the return value can contain non-ASCII
characters if they appear in strings contained in ``obj``. Otherwise, all
such characters are escaped in JSON strings.
If ``check_circular`` is false, then the circular reference check
for container types will be skipped and a circular reference will
result in an ``OverflowError`` (or worse).
If ``allow_nan`` is false, then it will be a ``ValueError`` to
serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in
strict compliance of the JSON specification, instead of using the
JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
If ``indent`` is a non-negative integer, then JSON array elements and
object members will be pretty-printed with that indent level. An indent
level of 0 will only insert newlines. ``None`` is the most compact
representation.
If specified, ``separators`` should be an ``(item_separator, key_separator)``
tuple. The default is ``(', ', ': ')`` if *indent* is ``None`` and
``(',', ': ')`` otherwise. To get the most compact JSON representation,
you should specify ``(',', ':')`` to eliminate whitespace.
``default(obj)`` is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
If *sort_keys* is true (default: ``False``), then the output of
dictionaries will be sorted by key.
To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
``.default()`` method to serialize additional types), specify it with
the ``cls`` kwarg; otherwise ``JSONEncoder`` is used.
"""
# cached encoder
if (not skipkeys and ensure_ascii and
check_circular and allow_nan and
cls is None and indent is None and separators is None and
default is None and not sort_keys and not kw):
return _default_encoder.encode(obj)
if cls is None:
cls = JSONEncoder
return cls(
skipkeys=skipkeys, ensure_ascii=ensure_ascii,
check_circular=check_circular, allow_nan=allow_nan, indent=indent,
separators=separators, default=default, sort_keys=sort_keys,
**kw).encode(obj)
json_loads(s, *, cls = None, object_hook = None, parse_float = None, parse_int = None, parse_constant = None, object_pairs_hook = None, **kw)
¶Deserialize s (a str, bytes or bytearray instance
containing a JSON document) to a Python object.
object_hook is an optional function that will be called with the
result of any object literal decode (a dict). The return value of
object_hook will be used instead of the dict. This feature
can be used to implement custom decoders (e.g. JSON-RPC class hinting).
object_pairs_hook is an optional function that will be called with the
result of any object literal decoded with an ordered list of pairs. The
return value of object_pairs_hook will be used instead of the dict.
This feature can be used to implement custom decoders. If object_hook
is also defined, the object_pairs_hook takes priority.
parse_float, if specified, will be called with the string
of every JSON float to be decoded. By default this is equivalent to
float(num_str). This can be used to use another datatype or parser
for JSON floats (e.g. decimal.Decimal).
parse_int, if specified, will be called with the string
of every JSON int to be decoded. By default this is equivalent to
int(num_str). This can be used to use another datatype or parser
for JSON integers (e.g. float).
parse_constant, if specified, will be called with one of the
following strings: -Infinity, Infinity, NaN.
This can be used to raise an exception if invalid JSON numbers
are encountered.
To use a custom JSONDecoder subclass, specify it with the cls
kwarg; otherwise JSONDecoder is used.
The encoding argument is ignored and deprecated since Python 3.1.
Source code in zamba/data/video.py
def loads(s, *, cls=None, object_hook=None, parse_float=None,
parse_int=None, parse_constant=None, object_pairs_hook=None, **kw):
"""Deserialize ``s`` (a ``str``, ``bytes`` or ``bytearray`` instance
containing a JSON document) to a Python object.
``object_hook`` is an optional function that will be called with the
result of any object literal decode (a ``dict``). The return value of
``object_hook`` will be used instead of the ``dict``. This feature
can be used to implement custom decoders (e.g. JSON-RPC class hinting).
``object_pairs_hook`` is an optional function that will be called with the
result of any object literal decoded with an ordered list of pairs. The
return value of ``object_pairs_hook`` will be used instead of the ``dict``.
This feature can be used to implement custom decoders. If ``object_hook``
is also defined, the ``object_pairs_hook`` takes priority.
``parse_float``, if specified, will be called with the string
of every JSON float to be decoded. By default this is equivalent to
float(num_str). This can be used to use another datatype or parser
for JSON floats (e.g. decimal.Decimal).
``parse_int``, if specified, will be called with the string
of every JSON int to be decoded. By default this is equivalent to
int(num_str). This can be used to use another datatype or parser
for JSON integers (e.g. float).
``parse_constant``, if specified, will be called with one of the
following strings: -Infinity, Infinity, NaN.
This can be used to raise an exception if invalid JSON numbers
are encountered.
To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
kwarg; otherwise ``JSONDecoder`` is used.
The ``encoding`` argument is ignored and deprecated since Python 3.1.
"""
if isinstance(s, str):
if s.startswith('\ufeff'):
raise JSONDecodeError("Unexpected UTF-8 BOM (decode using utf-8-sig)",
s, 0)
else:
if not isinstance(s, (bytes, bytearray)):
raise TypeError(f'the JSON object must be str, bytes or bytearray, '
f'not {s.__class__.__name__}')
s = s.decode(detect_encoding(s), 'surrogatepass')
if "encoding" in kw:
import warnings
warnings.warn(
"'encoding' is ignored and deprecated. It will be removed in Python 3.9",
DeprecationWarning,
stacklevel=2
)
del kw['encoding']
if (cls is None and object_hook is None and
parse_int is None and parse_float is None and
parse_constant is None and object_pairs_hook is None and not kw):
return _default_decoder.decode(s)
if cls is None:
cls = JSONDecoder
if object_hook is not None:
kw['object_hook'] = object_hook
if object_pairs_hook is not None:
kw['object_pairs_hook'] = object_pairs_hook
if parse_float is not None:
kw['parse_float'] = parse_float
if parse_int is not None:
kw['parse_int'] = parse_int
if parse_constant is not None:
kw['parse_constant'] = parse_constant
return cls(**kw).decode(s)
prepare_field(field: ModelField) -> None
classmethod
¶Optional hook to check or modify fields during model creation.
from_video(path: PathLike)
classmethod
¶
Source code in zamba/data/video.py
@classmethod
def from_video(cls, path: os.PathLike):
stream = get_video_stream(path)
return cls(
height=int(stream["height"]),
width=int(stream["width"]),
n_frames=int(stream["nb_frames"]),
duration_s=float(stream["duration"]),
fps=int(Fraction(stream["r_frame_rate"])), # reported, not average
)
npy_cache
¶
__init__(self, path: Optional[pathlib.Path] = None, cleanup: bool = False)
special
¶
Source code in zamba/data/video.py
def __init__(self, path: Optional[Path] = None, cleanup: bool = False):
self.tmp_path = path
self.cleanup = cleanup
Functions¶
cached_load_video_frames(filepath: PathLike, config: Optional[zamba.data.video.VideoLoaderConfig] = None)
¶
Loads frames from videos using fast ffmpeg commands and caches to .npy file if config.cache_dir is not None.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
filepath |
os.PathLike |
Path to the video. |
required |
config |
VideoLoaderConfig |
Configuration for video loading. |
None |
Source code in zamba/data/video.py
def cached_load_video_frames(filepath: os.PathLike, config: Optional[VideoLoaderConfig] = None):
"""Loads frames from videos using fast ffmpeg commands and caches to .npy file
if config.cache_dir is not None.
Args:
filepath (os.PathLike): Path to the video.
config (VideoLoaderConfig): Configuration for video loading.
"""
if config is None:
# get environment variable for cache if it exists
config = VideoLoaderConfig()
decorated_load_video_frames = npy_cache_factory(
path=config.cache_dir, callable=load_video_frames, cleanup=config.cleanup_cache
)
return decorated_load_video_frames(filepath=filepath, config=config)
ensure_frame_number(arr, total_frames: int)
¶
Ensures the array contains the requested number of frames either by clipping frames from the end or dulpicating the last frame.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
arr |
np.ndarray |
Array of video frames with shape (frames, height, width, channel). |
required |
total_frames |
int |
Desired number of frames in output array. |
required |
Source code in zamba/data/video.py
def ensure_frame_number(arr, total_frames: int):
"""Ensures the array contains the requested number of frames either by clipping frames from
the end or dulpicating the last frame.
Args:
arr (np.ndarray): Array of video frames with shape (frames, height, width, channel).
total_frames (int): Desired number of frames in output array.
"""
if (total_frames is None) or (arr.shape[0] == total_frames):
return arr
elif arr.shape[0] == 0:
logger.warning(
"No frames selected. Returning an array in the desired shape with all zeros."
)
return np.zeros((total_frames, arr.shape[1], arr.shape[2], arr.shape[3]), dtype="int")
elif arr.shape[0] > total_frames:
logger.info(
f"Clipping {arr.shape[0] - total_frames} frames "
f"(original: {arr.shape[0]}, requested: {total_frames})."
)
return arr[:total_frames]
elif arr.shape[0] < total_frames:
logger.info(
f"Duplicating last frame {total_frames - arr.shape[0]} times "
f"(original: {arr.shape[0]}, requested: {total_frames})."
)
return np.concatenate(
[arr, np.tile(arr[-1], (total_frames - arr.shape[0], 1, 1, 1))], axis=0
)
ffprobe(path: PathLike) -> Series
¶
Source code in zamba/data/video.py
def ffprobe(path: os.PathLike) -> pd.Series:
def flatten_json(j, name=""):
for k in j:
if isinstance(j[k], dict):
yield from flatten_json(j[k], f"{name}.{k}")
elif isinstance(j[k], list):
for i in range(len(j[k])):
yield from flatten_json(j[k][i], f"{name}.{k}[{i}]")
else:
yield {f"{name}.{k}".strip("."): j[k]}
output = subprocess.check_output(
[
"ffprobe",
"-v",
"quiet",
"-show_entries",
"stream:format",
"-select_streams",
"v",
"-of",
"json",
path,
]
)
output = json.loads(output)
result = reduce(lambda a, b: {**a, **b}, flatten_json(output))
return pd.Series(result)
get_frame_time_estimates(path: PathLike)
¶
Source code in zamba/data/video.py
def get_frame_time_estimates(path: os.PathLike):
probe = ffmpeg.probe(str(path), show_entries="frame=best_effort_timestamp_time")
return [float(x["best_effort_timestamp_time"]) for x in probe["frames"]]
get_video_stream(path: Union[os.PathLike, cloudpathlib.s3.s3path.S3Path]) -> dict
¶
Source code in zamba/data/video.py
def get_video_stream(path: Union[os.PathLike, S3Path]) -> dict:
try:
probe = ffmpeg.probe(str(path))
except ffmpeg.Error as exc:
raise ZambaFfmpegException(exc.stderr)
return next((stream for stream in probe["streams"] if stream["codec_type"] == "video"), None)
load_video_frames(filepath: PathLike, config: Optional[zamba.data.video.VideoLoaderConfig] = None, **kwargs)
¶
Loads frames from videos using fast ffmpeg commands.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
filepath |
os.PathLike |
Path to the video. |
required |
config |
VideoLoaderConfig |
Configuration for video loading. |
None |
**kwargs |
Optionally, arguments for VideoLoaderConfig can be passed in directly. |
{} |
Returns:
| Type | Description |
|---|---|
np.ndarray |
An array of video frames with dimensions (time x height x width x channels). |
Source code in zamba/data/video.py
def load_video_frames(
filepath: os.PathLike,
config: Optional[VideoLoaderConfig] = None,
**kwargs,
):
"""Loads frames from videos using fast ffmpeg commands.
Args:
filepath (os.PathLike): Path to the video.
config (VideoLoaderConfig, optional): Configuration for video loading.
**kwargs: Optionally, arguments for VideoLoaderConfig can be passed in directly.
Returns:
np.ndarray: An array of video frames with dimensions (time x height x width x channels).
"""
if not Path(filepath).exists():
raise FileNotFoundError(f"No file found at {filepath}")
if config is None:
config = VideoLoaderConfig(**kwargs)
video_stream = get_video_stream(filepath)
w = int(video_stream["width"])
h = int(video_stream["height"])
pipeline = ffmpeg.input(str(filepath))
pipeline_kwargs = {}
if (config.crop_bottom_pixels is not None) and (config.crop_bottom_pixels > 0):
# scale to ensure all frames are the same height and we can crop
pipeline = pipeline.filter("scale", f"{w},{h}")
pipeline = pipeline.crop("0", "0", "iw", f"ih-{config.crop_bottom_pixels}")
h = h - config.crop_bottom_pixels
if config.evenly_sample_total_frames:
config.fps = config.total_frames / float(video_stream["duration"])
if config.early_bias:
config.fps = 24 # competition frame selection assumes 24 frames per second
config.total_frames = 16 # used for ensure_total_frames
if config.fps:
pipeline = pipeline.filter("fps", fps=config.fps, round="up")
if config.i_frames:
pipeline = pipeline.filter("select", "eq(pict_type,PICT_TYPE_I)")
if config.scene_threshold:
pipeline = pipeline.filter("select", f"gt(scene,{config.scene_threshold})")
if config.frame_selection_height and config.frame_selection_width:
pipeline = pipeline.filter(
"scale", f"{config.frame_selection_width},{config.frame_selection_height}"
)
w, h = config.frame_selection_width, config.frame_selection_height
if config.early_bias:
config.frame_indices = [2, 8, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156]
if config.frame_indices:
pipeline = pipeline.filter("select", "+".join(f"eq(n,{f})" for f in config.frame_indices))
pipeline_kwargs = {"vsync": 0}
pipeline = pipeline.output(
"pipe:", format="rawvideo", pix_fmt=config.pix_fmt, **pipeline_kwargs
)
try:
out, err = pipeline.run(capture_stdout=True, capture_stderr=True)
except ffmpeg.Error as exc:
raise ZambaFfmpegException(exc.stderr)
arr = np.frombuffer(out, np.uint8).reshape([-1, h, w, 3])
if config.megadetector_lite_config is not None:
mdlite = MegadetectorLiteYoloX(config=config.megadetector_lite_config)
detection_probs = mdlite.detect_video(frames=arr)
arr = mdlite.filter_frames(arr, detection_probs)
if (config.model_input_height is not None) and (config.model_input_width is not None):
resized_frames = np.zeros(
(arr.shape[0], config.model_input_height, config.model_input_width, 3), np.uint8
)
for ix, f in enumerate(arr):
if (f.shape[0] != config.model_input_height) or (
f.shape[1] != config.model_input_width
):
f = cv2.resize(
f,
(config.model_input_width, config.model_input_height),
# https://stackoverflow.com/a/51042104/1692709
interpolation=(
cv2.INTER_LINEAR
if f.shape[1] < config.model_input_width
else cv2.INTER_AREA
),
)
resized_frames[ix, ...] = f
arr = np.array(resized_frames)
if config.ensure_total_frames:
arr = ensure_frame_number(arr, total_frames=config.total_frames)
return arr
npy_cache_factory(path, callable, cleanup)
¶
Source code in zamba/data/video.py
def npy_cache_factory(path, callable, cleanup):
@npy_cache(path=path, cleanup=cleanup)
def decorated_callable(*args, **kwargs):
return callable(*args, **kwargs)
return decorated_callable
num_frames(stream_or_path: Union[dict, os.PathLike, cloudpathlib.s3.s3path.S3Path]) -> Optional[int]
¶
Source code in zamba/data/video.py
def num_frames(stream_or_path: Union[dict, os.PathLike, S3Path]) -> Optional[int]:
if not isinstance(stream_or_path, dict):
stream = get_video_stream(stream_or_path)
else:
stream = stream_or_path
if not stream:
return
if "nb_frames" in stream:
return int(stream["nb_frames"])
if "duration" in stream:
duration = float(stream["duration"])
if "r_frame_rate" in stream:
frame_rate = float(Fraction(stream["r_frame_rate"]))
elif "avg_frame_rate" in stream:
frame_rate = float(stream["avg_frame_rate"])
duration -= float(stream.get("start_time", 0))
return floor(duration * frame_rate)