| Video Coding Parameter | H.265 (HEVC) | H.264 (AVC) |
|---|---|---|
| Profiles | Main | Baseline (Except FMO/ASO) |
| Main Intra | Main | |
| Main10 | High | |
| Main10 Intra | High10 | |
| Main 4:2:2 10 | High 4:2:2 | |
| Main 4:2:2 10 Intra | High10 Intra | |
| High 4:2:2 Intra | ||
| Levels | Up to 5.1 High Tier | Up to 5.2 |
| Resolutions | 4096x2160p60 with specific device(-2,-3) | 4096x2160p60 with specific device(-2,-3) |
| Up to 3840x2160p60 | Up to 3840x2160p60 | |
| Chroma format | 4:0:0, 4:2:0, 4:2:2 | 4:0:0, 4:2:0, 4:2:2 |
| Bit Depth | 8-bit, 10-bit | 8-bit, 10-bit |
GStreamer Decoding Parameters
| Parameter | GStreamer property | Description |
|---|---|---|
| Entropy Buffers | internal-entropy-buffers |
Specifies decoder internal entropy buffers, used to smooth out entropy decoding performance. Specify values in integer between 2 and 16. Increasing buffering-count increases decoder memory footprint. Default value: 5. Set this value to 10 for higher bit-rate use cases. For example,uses cases where the bitrate is more than 100 Mb/s. |
| Latency | latency-mode |
Specifies decoder latency mode. (0) : false - Normal mode (1) : true- If alignment is AU, reduced-latency mode and if alignment is NAL, low-latency mode Default value: 0. |
| Split-input mode | split-input |
When enabled, the decoder has 1 to 1 mapping for input and output buffers. When disabled, the decoder copies all the input buffers to internal circular buffer and processes them. Default: FALSE |
| QoS | Qos |
Drop late frames based on QOS events. Default:FALSE |
| Device | device |
Select appropriate VDU device. device=/dev/allegroDecodeIP0 or 1, 2, 3 Default value: /dev/allegroDecadeIP0 |
Gstreamer and V4L2 Formats
- These formats signify the memory layout of pixels. It applies at the decoder output side.
- For the decoder, you can specify the format to be used to write the pixel in memory by specifying the corresponding Gstreamer video format using caps at decoder source pad.
- When the format is not supported between two elements, the cap negotiation fails and Gstreamer returns an error. In that case, you can use the video convert element to perform software conversion from one format to another.
| Pixel Format | V4L2 | GStreamer |
|---|---|---|
| YUV 400 8-bit | V4L2_PIX_FMT_GREY | GST_VIDEO_FORMAT_GRAY8 |
| YUV 400 10-bit | V4L2_PIX_FMT_XY10 | GST_VIDEO_FORMAT_GRAY10_LE32 |
| YUV 420 8-bit | V4L2_PIX_FMT_NV12 | GST_VIDEO_FORMAT_NV12 |
| YUV 420 10-bit | V4L2_PIX_FMT_XV15 | GST_VIDEO_FORMAT_NV12_10LE32 |
| YUV 422 8-bit | V4L2_PIX_FMT_NV16 | GST_VIDEO_FORMAT_NV16 |
| YUV 422 10-bit | V4L2_PIX_FMT_XV20 | GST_VIDEO_FORMAT_NV16_10LE32 |
- The FourCC codes are the last four characters of V4L2 pixel formats (for example, GREY/XY10).
- Y_Only 8-bit and Y_Only 10-bit are supported only at the control software layer for the decoder.
- For more information on YUV 444 format support, refer this article.