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Supported Video Formats

The NDI Encode and Decode FPGA cores support a variety of standard and custom in-memory video formats for 4:2:2 and 4:2:0 YUV video. Planar alpha is also supported for 4:2:2 formats. For further details, see the generate_video() routine in src/cpp/ndi_encode/video_pattern.cpp.

UYVY

4:2:2 Packed 8-bit

Addr : Component
  00 : U0
  01 : Y0
  02 : V0
  03 : Y1
  ...

YUYV

4:2:2 Packed 8-bit, Y first

Addr : Component
  00 : Y0
  01 : U0
  02 : Y1
  03 : V0
  ...

NV16

4:2:2 Semi-planar 8-bit - luma then packed chroma

UYVW

4:2:2 Packed 16-bit (custom format) - 16-bit version of UYVY

Y216

4:2:2 Packed 16-bit, Y first - 16-bit version of YUYV

P216

4:2:2 Semi-planar 16-bit - luma then packed chroma

420

4:2:0 Packed 8-bit (custom format) - Macroblock interleaved, 16 pixels of Y followed by 8 pixels of U (even lines) or V (odd lines)

NV12

4:2:0 Semi-planar 8-bit - Luma then packed chroma

420W

4:2:0 Packed 16-bit (custom format) - Macroblock interleaved, 16 pixels of Y followed by 8 pixels of U (even lines) or V (odd lines)

P016

4:2:0 Semi-planar 16-bit - Luma then packed chroma

Video output process flow:

video_playback::pull_frames thread

  • Wait for vertical sync interrupt: video_playback::pull_frames

  • Pull a frame from the NDI FrameSync Instance: network_recv::get_video()

  • Copy video frame to reserved memory region visible by hardware: video_decode::add_frame()

  • Push copied frame onto NDI Decode queue: video_decode::add_frame()

  • Free video frame acquired from the NDI FrameSync Instance

video_decode::decode_frames thread

  • Wait for new frame to decode

  • Setup hardware to decode NDI frame into raw video data: video_decode::decode_frame()

  • Start hardware decoding: video_decode::post_frame()

  • Wait for interrupt

  • Queue the raw frame for display: video_playback::send_frame()

  • The frame will display after the next vertical sync

Software Applications

ndi_encode

This is an example application illustrating the use of the FPGA based NDI encoder with the Advanced NDI SDK. For full details and a theory of operation covering the entire system (software, hardware, and OS), refer to the top-level README file.

Usage

The ndi_encode program is simply launched from the command line, eg:

Note that this will launch the version installed in /usr/local/bin/. Alternatively, the program can be run from the build directory. Note that root permissions are required so it is necessary to use sudo:

Run Time Commands

Once running, the program will listen for commands on stdin. These commands are intended to modify the running behavior of the program and illustrate how to integrate with a separate utility monitoring the physical video input source (eg: an HDMI or SDI input) as a signal is acquired, locked, or lost. The commands which change the raw video parameters (resolution, frame rate, format, alpha) only apply when running in pattern generator mode.

  • start | stop

    Start or stop streaming video and audio. This would correspond with the acquisition (start) or loss (stop) of a stable signal.

  • 720 | 1080 | 4k

    Change the video resolution

  • 24 | 25 | 30 | 50 | 60

    Set the primary video frame rate

  • 1000 | 1001

    Set the secondary frame rate: 1000=exact (eg: 60.00), 1001=NTSC (eg: 59.94)

  • UYVY | YUYV | NV16 | UYVW | Y216 | P216 | 420 | NV12 | 420W | P016

    Set the raw video format

  • Alpha+ | Alpha-

    Enable / Disable alpha (4:2:2 modes only)

  • exit

    Quit the program

Command Line Options

Various command line switches are available to control the program's behavior:

General Options

  • Set default video resolution

    • -1 1080p60 (default)

    • -7 720p60

    • -4 4Kp60

  • Video options

    • -P Pattern generator

      Use the built-in pattern generator instead of live video input.

    • -v Increase verbosity

      Output more detailed information. This switch may be provided multiple times to further increase the debugging output. The available levels are:

      • Fatal

      • Error (default)

      • Warning

      • Information

      • Debugging

    • -q Decrease verbosity (quiet)

      Decrease the amount of output generated. This switch may be provided multiple times. See the discussion of -v (above) for details.

  • Audio Options

    • -h HDMI input

      Use embedded audio from the HDMI stream.

    • -l Line input

      Use analog audio input.

    • -p Pattern generator

      The audio input hardware includes a simple saw-tooth pattern generator that can be used as an input source for testing.

Debugging and Advanced Options

  • -X Disable video capture

    This disables the video capture thread. No video frames will be captured, compressed, or sent to the NDI stack. Only audio will be processed.

  • -x Disable audio capture

    This disables the video capture thread. No audio samples will be captured, compressed, or sent to the NDI stack. Only video will be processed.

  • -F Full resolution capture only

    This option disables the preview stream and only sends full resolution frames to the NDI stack.

  • -f fflush() after each log message

    This is useful if the application is crashing to insure log error messages actually reach the terminal.

  • -A Use ACP

  • -B Bypass ACP

    These options do nothing on the current Zynq development boards and only apply to Cyclone-V based platforms.

ndi_decode

This is an example application illustrating the use of the FPGA based NDI decoder with the Advanced NDI SDK. For full details and a theory of operation covering the entire system (software, hardware, and OS), refer to the top-level README file.

Usage

The ndi_decode program is simply launched from the command line, eg:

Note that this will launch the version installed in /usr/local/bin/. Alternatively, the program can be run from the build directory. Note that root permissions are required so it is necessary to use sudo:

sudo /path/to/workdir/ndi_receive

Command Line Options

Various command line switches are available to control the program's behavior:

General Options

  • -s <NDI Source>

    Specify NDI source to stream. If this setting is not provided, ndi_receive will attempt to connect to the first NDI source it finds on the network.

  • Set output video resolution

    • -1 1080p (default)

    • -7 720p

    • -4 4Kp

  • Set output video framerate

    • -6 60 Hz (default)

    • -5 50 Hz

  • Select output video

    • -k Output key (alpha) data if available instead of image data

  • Select SDRAM burst mode

    • -b Disable SDRAM burst mode (e.g., 1 macroblock to SDRAM per burst transfer). Default behavior is to burst 4 macroblocks to SDRAM per burst transfer.

  • -o <output format>

    Specifies the output video format, where output format is one of the enumerated video_format_t values in hardware.h in decimal. The default is packed 4:2:2 (e.g., UYVY).

Debugging and Advanced Options

  • -v Increase verbosity

    Output more detailed information. This switch may be provided multiple times to further increase the debugging output. The available levels are:

    • Fatal

    • Error (default)

    • Warning

    • Information

    • Debugging

  • -q Decrease verbosity (quiet)

    Decrease the amount of output generated. This switch may be provided multiple times. See the discussion of -v (above) for details.

  • -f fflush() after each log message

    This is useful if the application is crashing to insure log error messages actually reach the terminal.

  • -A Use ACP

  • -B Bypass ACP

    These options do nothing on the current Zynq development boards and only apply to Cyclone-V based platforms.

  • -c <capture file>

Allows for individual frames to be captured to the filesystem. This switch is intended for debugging purposes and assumes that the stride is equal to the length of a row of image data. The default is to capture frame number 25, but this can be modified using the -n argument to select a different value. No more than one frame can be captured at a time.

  • -n <frame capture number>

If capturing video frames, indicates the frame number to capture (defaults to 25). Requires the use of the -c option to capture frames.

NDI Utilities

This directory contains utilities helpful for debugging or initial testing of the FPGA hardware. For full details and a theory of operation covering the entire system (software, hardware, and OS), refer to the top-level README file.

ndi_reg Utility

This utility allows reading and writing of the NDI hardware registers. To read an NDI register, provide the register address on the command line:

To write an NDI register, provide the register address and write data on the command line:

For details on register settings, refer to the corresponding software and hardware files (detailed in the top-level README file). Refer to the following table for the base addresses of the various hardware functions:

Hardware
Base Address

NDI Encoder Core 0

0x000

NDI Encoder Core 1

0x040

NDI Encoder Core 2

0x080

NDI Encoder Core 3

0x0c0

NDI Decoder Core 0

0x100

NDI Decoder Core 1

0x140

NDI Decoder Core 2

0x180

NDI Decoder Core 3

0x1c0

Video Input

0x200

Preview Input

0x210

Audio Input

0x220

Video Tracking

0x230

Video Output

0x280

Audio Output

0x290

Version (Date)

0x3fe

Version (Revision)

0x3ff

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