Decoder Software Features - 1.0 English

H.264/H.265 Video Decode Unit Solutions LogiCORE IP Product Guide (PG414)

Document ID
PG414
Release Date
2023-05-16
Version
1.0 English
Table 1. Decoder Features Per Instance
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

Table 2. 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

The Gstreamer and V4L2 Formats are described in this section.
  • 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.
The following table shows the GStreamer and V4L2 related formats that are supported.
Table 3. Gstreamer and V4L2 Formats
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
Note:
  1. The FourCC codes are the last four characters of V4L2 pixel formats (for example, GREY/XY10).
  2. Y_Only 8-bit and Y_Only 10-bit are supported only at the control software layer for the decoder.
  3. For more information on YUV 444 format support, refer this article.