VDEC Functions and Restrictions

The Atlas 200/300/500 Inference Product does not support the JPEGD function described in this section.

The Atlas Training Series Product does not support the JPEGD function described in this section.

Functions

Video Decoder (VDEC) decodes videos.

Restrictions on Stream/Image Formats, Width and Height Alignment, and Buffers

  • Input stream formats:
    • H.264 BP/MP/HP level 5.1 YUV420 streams (Annex-B raw video streams only)
    • H.265 8-/10-bit level 5.1 YUV420 streams (Annex-B raw video streams only)
  • Output image requirements:
    Table 1 Restrictions on the stream/image format, width and height alignment, and buffer size

    Output Format

    Output Width and Height

    YUV420SP NV12 8-bit

    Width: Must be a multiple of 2.

    Height: Must be a multiple of 2.

    YUV420SP NV21 8-bit

    Width: Must be a multiple of 2.

    Height: Must be a multiple of 2.

    RGB888

    No alignment requirement.

    BGR888

    No alignment requirement.

    For details about the definition of the output image format, see hi_pixel_format. For details about the concepts such as width stride and height stride, see Terminology.

Other Restrictions

  • VDEC decodes a stream fed in frame mode.
  • If there are bad frames or frame loss in the stream, VDEC will mark the frames as a decoding failure and report an exception.
  • VDEC decodes only H.264 8-bit streams coded in interlaced mode.
  • The combined use of stream feeding in frame mode and output in the decoding sequence enables both fast decoding and output. However, this is no applicable to streams containing B-frames.