SimpleVideoDecoder

class torchcodec.decoders.SimpleVideoDecoder(source: Union[str, Path, bytes, Tensor], dimension_order: Literal['NCHW', 'NHWC'] = 'NCHW')

A single-stream video decoder.

If the video contains multiple video streams, the best stream is used. This decoder always performs a scan of the video.

Parameters:

• source (str, Pathlib.path, torch.Tensor, or bytes) –

  The source of the video.

  • If str or Pathlib.path: a path to a local video file.

  • If bytes object or torch.Tensor: the raw encoded video data.

• dimension_order (str, optional) –

  The dimension order of the decoded frames. This can be either “NCHW” (default) or “NHWC”, where N is the batch size, C is the number of channels, H is the height, and W is the width of the frames.

  Note

  Frames are natively decoded in NHWC format by the underlying FFmpeg implementation. Converting those into NCHW format is a cheap no-copy operation that allows these frames to be transformed using the torchvision transforms.

Variables:

metadata (VideoStreamMetadata) – Metadata of the video stream.

Examples using SimpleVideoDecoder:

Decoding a video with SimpleVideoDecoder

Decoding a video with SimpleVideoDecoder

__getitem__(key: Union[int, slice]) → Tensor

Return frame or frames as tensors, at the given index or range.

Parameters:

key (int or slice) – The index or range of frame(s) to retrieve.

Returns:

The frame or frames at the given index or range.

Return type:

torch.Tensor

get_frame_at(index: int) → Frame

Return a single frame at the given index.

Parameters:

index (int) – The index of the frame to retrieve.

Returns:

The frame at the given index.

Return type:

Frame

get_frame_displayed_at(seconds: float) → Frame

Return a single frame displayed at the given timestamp in seconds.

Parameters:

seconds (float) – The time stamp in seconds when the frame is displayed.

Returns:

The frame that is displayed at seconds.

Return type:

Frame

get_frames_at(start: int, stop: int, step: int = 1) → FrameBatch

Return multiple frames at the given index range.

Frames are in [start, stop).

Parameters:

• start (int) – Index of the first frame to retrieve.

• stop (int) – End of indexing range (exclusive, as per Python conventions).

• step (int, optional) – Step size between frames. Default: 1.

Returns:

The frames within the specified range.

Return type:

FrameBatch