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  1. 10 May, 2022 1 commit
    • moto's avatar
      Add HW acceleration support on Streamer (#2331) · 54d2d04f
      moto authored 
      Summary:
This commits add `hw_accel` option to `Streamer::add_video_stream` method.
Specifying `hw_accel="cuda"` allows to create the chunk Tensor directly from CUDA,
when the following conditions are met.
1. the video format is H264,
2. underlying ffmpeg is compiled with NVENC, and
3. the client code specifies `decoder="h264_cuvid"`.

A simple benchmark yields x7 improvement in the decoding speed.

<details>

```python
import time

from torchaudio.prototype.io import Streamer

srcs = [
    "https://download.pytorch.org/torchaudio/tutorial-assets/stream-api/NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4",
    "./NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4",  # offline version
]

patterns = [
    ("h264_cuvid", None, "cuda:0"),  # NVDEC on CUDA:0 -> CUDA:0
    ("h264_cuvid", None, "cuda:1"),  # NVDEC on CUDA:1 -> CUDA:1
    ("h264_cuvid", None, None),  # NVDEC -> CPU
    (None, None, None),  # CPU
]

for src in srcs:
    print(src, flush=True)
    for (decoder, decoder_options, hw_accel) in patterns:
        s = Streamer(src)
        s.add_video_stream(5, decoder=decoder, decoder_options=decoder_options, hw_accel=hw_accel)

        t0 = time.monotonic()
        num_frames = 0
	for i, (chunk, ) in enumerate(s.stream()):
	    num_frames += chunk.shape[0]
        t1 = time.monotonic()
        print(chunk.dtype, chunk.shape, chunk.device)
        print(time.monotonic() - t0, num_frames, flush=True)
```
</details>

```
https://download.pytorch.org/torchaudio/tutorial-assets/stream-api/NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4
torch.uint8 torch.Size([5, 3, 1080, 1920]) cuda:0
10.781158386962488 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cuda:1
10.771313901990652 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cpu
27.88662809302332 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cpu
83.22728440898936 6175
./NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4
torch.uint8 torch.Size([5, 3, 1080, 1920]) cuda:0
12.945253834011964 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cuda:1
12.870224556012545 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cpu
28.03406483103754 6175
torch.uint8 torch.Size([5, 3, 1080, 1920]) cpu
82.6120332319988 6175
```

With HW resizing

<details>

```python
import time

from torchaudio.prototype.io import Streamer

srcs = [
    "./NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4",
    "https://download.pytorch.org/torchaudio/tutorial-assets/stream-api/NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4",
]

patterns = [
    # Decode with NVDEC, CUDA HW scaling -> CUDA:0
    ("h264_cuvid", {"resize": "960x540"}, "", "cuda:0"),
    # Decoded with NVDEC, CUDA HW scaling -> CPU
    ("h264_cuvid", {"resize": "960x540"}, "", None),
    # CPU decoding, CPU scaling
    (None, None, "scale=width=960:height=540", None),
]

for src in srcs:
    print(src, flush=True)
    for (decoder, decoder_options, filter_desc, hw_accel) in patterns:
        s = Streamer(src)
        s.add_video_stream(
            5,
            decoder=decoder,
            decoder_options=decoder_options,
            filter_desc=filter_desc,
            hw_accel=hw_accel,
        )

        t0 = time.monotonic()
        num_frames = 0
        for i, (chunk, ) in enumerate(s.stream()):
            num_frames += chunk.shape[0]
        t1 = time.monotonic()
        print(chunk.dtype, chunk.shape, chunk.device)
        print(time.monotonic() - t0, num_frames, flush=True)
```

</details>

```
./NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4
torch.uint8 torch.Size([5, 3, 540, 960]) cuda:0
12.890056837990414 6175
torch.uint8 torch.Size([5, 3, 540, 960]) cpu
10.697489063022658 6175
torch.uint8 torch.Size([5, 3, 540, 960]) cpu
85.19899423001334 6175

https://download.pytorch.org/torchaudio/tutorial-assets/stream-api/NASAs_Most_Scientifically_Complex_Space_Observatory_Requires_Precision-MP4.mp4
torch.uint8 torch.Size([5, 3, 540, 960]) cuda:0
10.712715593050234 6175
torch.uint8 torch.Size([5, 3, 540, 960]) cpu
11.030170071986504 6175
torch.uint8 torch.Size([5, 3, 540, 960]) cpu
84.8515750519582 6175
```

Pull Request resolved: https://github.com/pytorch/audio/pull/2331

Reviewed By: hwangjeff

Differential Revision: D36217169

Pulled By: mthrok

fbshipit-source-id: 7979570b083cfc238ad4735b44305d8649f0607b
      54d2d04f
  3. 14 Apr, 2022 1 commit
    • moto's avatar
      Support specifying decoder and its options (#2327) · be243c59
      moto authored 
      Summary:
This commit adds support to specify decoder to Streamer's add stream method.
This is roughly equivalent to `ffmpeg`'s `-c:v foo` and `-c:a foo` options.

This allows to override the decoder codec and/or specify the option of
the decoder.

This change allows to specify Nvidia NVDEC codec for supported formats,
which uses dedicated hardware for decoding the video.

 ---

Note: The CL might look overwhelming, but it's essentially, add new parameters in Python, and pass them down all the way to  `AVCodecContextPtr`, which initializes the actual decoder implementation (`AVCodecContext`.)

Pull Request resolved: https://github.com/pytorch/audio/pull/2327

Reviewed By: carolineechen

Differential Revision: D35626904

Pulled By: mthrok

fbshipit-source-id: a115ed548624e53c16bacfecff5aa6c9d4e8bede
      be243c59
  5. 04 Mar, 2022 1 commit
    • moto's avatar
      Flush and reset internal state after seek (#2264) · 7e1afc40
      moto authored 
      Summary:
This commit adds the following behavior to `seek` so that `seek`
works after a frame is decoded.

1. Flush the decoder buffer.
2. Recreate filter graphs (so that internal state is re-initialized)
3. Discard the buffered tensor. (decoded chunks)

Also it disallows negative values for seek timestamp.

Pull Request resolved: https://github.com/pytorch/audio/pull/2264

Reviewed By: carolineechen

Differential Revision: D34497826

Pulled By: mthrok

fbshipit-source-id: 8b9a5bf160dfeb15f5cced3eed2288c33e2eb35d
      7e1afc40
  7. 21 Jan, 2022 1 commit
  9. 05 Jan, 2022 1 commit
  11. 29 Dec, 2021 1 commit