VDEC Performance Specifications
The
Performance Specifications
This section describes only the performance specifications of Ascend AI Processors of each product, which may differ based on the memory and CPU configurations of the respective product. For details about the product performance specifications, see the official descriptions at the Ascend community.
This section uses a single Ascend AI Processor as an example to describe the performance indicators in basic scenarios. The performance indicators of other resolutions can be estimated in the same way.
In the following table, one channel corresponds to one thread, 720p indicates a resolution of 1280 x 720 pixels, 1080p indicates a resolution of 1920 x 1080 pixels, and 4K indicates a resolution of 3840 x 2160 pixels.
Scenario |
Total Frame Rate |
|---|---|
n-channel 720p (1 ≤ n ≤ 12) |
n * 480fps NOTE:
For Atlas 300V video analysis cards, when 1 < n ≤ 12, the total frame rate is n x 400 FPS. |
n-channel 720p (n > 12) |
5760 FPS NOTE:
For Atlas 300V video analysis cards, when n > 12, the total frame rate is 4800 FPS. |
n-channel 1080p (1 ≤ n ≤ 12) |
n * 240fps NOTE:
For Atlas 300V video analysis cards, when 1 < n ≤ 12, the total frame rate is n x 200 FPS. |
n-channel 1080p (n > 12) |
2880 FPS NOTE:
For Atlas 300V video analysis cards, when n > 12, the total frame rate is 2400 FPS. |
n-channel 4K (1 ≤ n ≤ 12) |
n * 60fps |
n-channel 4K (n > 12) |
720 FPS |
Scenario |
Total Frame Rate |
|---|---|
n-channel 720p (1 ≤ n ≤ 4) |
n * 600fps |
n-channel 720p (n > 4) |
2400 FPS |
n-channel 1080p (1 ≤ n ≤ 4) |
n * 300fps |
n-channel 1080p (n > 4) |
n x 1200 FPS |
n-channel 4K (1 ≤ n ≤ 4) |
n * 75fps |
n-channel 4K (n > 4) |
n x 300 FPS |
Scenario |
Total Frame Rate |
|---|---|
n-channel 720p (1 ≤ n ≤ 2) |
n * 480fps |
n-channel 720p (n > 2) |
960 FPS |
n-channel 1080p (1 ≤ n ≤ 2) |
n * 240fps |
n-channel 1080p (n > 2) |
480 FPS |
n-channel 4K (1 ≤ n ≤ 2) |
n * 60fps |
n-channel 4K (n > 2) |
120 FPS |
The following table uses 1080p input streams as an example to describe the formula for calculating the maximum buffer used by each VDEC channel. The buffer usage is calculated as follows:
- Buffer size for the input streams: ≥ 3/4 of the decoding channel size (width x height).
- Frame buffer size for the decoded images: Call acl.himpi.vdec_get_pic_buf_size to obtain the value, which is related to the input stream resolution.
- TMV buffer size for the decoded images: Call acl.himpi.vdec_get_tmv_buf_size to obtain the value, which is related to the input stream resolution.
- The preceding buffer sizes and the number of reference frames should be set after the acl.himpi.vdec_create_chn call.
- The number of buffered frames after decoding should be set after the acl.himpi.vdec_set_chn_param call.
Formula
Scenario
Memory Usage
6 MB + Buffer size for the input streams x 2 + (Frame buffer size for the decoded images + TMV buffer size for the decoded images) x (Number of reference frames + Number of buffered frames after decoding + 1)
- Input stream format: H.264
- Input stream resolution: 1080p
- Buffer size for the input streams: 4 MB
- Frame buffer size for the decoded images: 3 MB
- TMV buffer size for the decoded images: 0.5 MB
- Number of buffered frames after decoding: 2
52.5 MB (eight reference frames)
31.5 MB (two reference frames)
- Input stream format: H.265
- Input stream resolution: 1080p
- Buffer size for the input streams: 4 MB
- Frame buffer size for the decoded images: 3 MB
- TMV buffer size for the decoded images: 1 MB
- Number of buffered frames after decoding: 2
58 MB (eight reference frames)
34 MB (two reference frames)