Video Encoder Settings

• BNC-1

Check this checkbox to enable Input Image Filtering for the input interface. This parameter filters the video input and removes noise in order to optimize the compression of the image and to enhance the overall quality of the coded video stream.

Tip

Input Image filtering is useful with sources that are monochrome, noisy and difficult to encode because the content is detailed. Enabling this parameter filters the image in order to reduce the amount of noise, resulting in better quality video after the encoding since less noise is being compressed into the stream.

This is the input signal auto-detected from the video source. It includes the number of pixels per line, whether the video is interlaced or progressively scanned (indicated by i or p), and the number of frames per second.

Note

If the signal cannot be detected (or is outside the supported range), the Input Format will be Unknown.

(10-bit Chroma Subsampling must be selected) Select to configure the encoder to detect the inbound High Dynamic Range (HDR) transfer function signaling and forward that information within the encoded stream.

• Off (SDR/BT.709)
• Automatic: the encoder detects HDR transfer function from the source
• HDR-HLG: HDR content is based on the Hybrid Log Gamma (HLG, BT.2100) transfer function
• HDR-PQ: HDR content is based on the Perceptual Quantizer (PQ, SMPTE ST 2084/BT.2100) transfer function

(Rate Control must be CBR) Select whether to allow the encoder to skip part of the image in order to respect the bitrate limit.

This parameter is used to create streams that are CBR-compliant according to the MPEG-2 TS specification. One aspect of this functionality is to have the video encoder control the total number of bits generated across a GOP sequence so that all the NALs in each GOP have roughly the same amount of bits and to avoid overflowing the coded picture buffer (CPBuf). One method of doing this is the limit the size of individual video NALs associated with a frame when the bit budget is being over-subscribed. In essence the video encoder will skip encoding part of the image in order to not oversubscribe the bit budget for the GOP sequence. 

Partial Image Skip is useful for ISR customers who have multiple streams being decoded by various decoders with limited network bandwidth resources. In order to ensure that all the streams stay within their bandwidth budgets, they use CBR implementations of video encoders to constrain their output streams to adhere to specified bandwidth limits.

Note

Intra-Refresh is not an option in these situations since they use multiple types of decoders and not all of them support decoding Intra-Refresh content.

Select the stream output resolution (i.e., the number of lines per frame and pixels per line to be encoded):

• Automatic: Encodes at the same resolution as the incoming video.
• Manually select the coded picture resolution from the list of available options (includes down-scaled resolutions). The options depend on the Input Format detected.

Note

Manually selecting a coded picture resolution will increase the video encoder latency by one (1) frame period.

(Resolution cannot be set to Automatic and must be less than the Input Format) Select whether to scale or crop the input to the desired resolution:

• Scale: Changes the resolution of the encoded image from what is input to what is specified in Resolution parameter without discarding any portion of the image.
• Crop: Crops the input and encodes to a rectangle within the input image while discarding the rest of the input image. When Crop is enabled, the output resolution is the portion of the input that is encoded from the center. This may be done instead of down-scaling.

By default, input is scaled to the specified output resolution.

Select the coded picture frame rate per second:

• Automatic: Encodes at the same frame rate as the input
• 60..1

Note

The frame rate cannot exceed the input frame rate.

Select the video compression mode for the encoded video:

• I: I frames only (lowest delay; lowest quality)
• IP: I and P frames only
• IBP: I, B and P frames
• IBBP: I, BB (two B frames in sequence) and P frames
• IBBBP: I, BBB (three B frames in sequence) and P frames
• IBBBBP: I, BBBB (four B frames in sequence) and P frames (highest delay; highest quality)
  

Note

B frames require a Main Profile decoder. B frames provide more quality as the encoding is more efficient; thus more details can be rendered in the same bandwidth/bitrate.

Tip

When B frames are used, the GOP may be rounded up to make the sequence end with a P frame.

Check this checkbox to enable scene change detection. When enabled, this feature automatically detects significant scene changes in the source video and generates an I-Frame to reduce trailing artifacts. 

The scene change percentage (i.e. the percentage of the scene that changes in order for the encoder to detect it) is set to 50% by default, and can be altered using the slider. 

Check this checkbox to enable Intra-refresh video encoding support. 

Intra-refresh is a video encoding mode of operation in which no distinct IDR frame is sent in the video elementary stream. Instead, the macro-blocks that make up the IDR frame are sent gradually within a certain time so that the entire video reference frame is rebuilt (at the decoder) within the number of frames specified by the Intra Refresh Rate parameter. Intra-refresh minimizes latency, smooths the video bitrate, and minimizes GOP pulsing artifacts.

Tip

Intra-refresh requires that decoders that do not support random access points be started first.

Configures the encoder to use multiple slices per frame instead of the normal 1 slice per frame encoder configuration. Encoding latency is improved since encoded slices can be transmitted on the network without having to wait for the whole frame to be encoded. 1..11

Setting the number of slices to 2 or higher will automatically enable slice-based video capture and encoding, resulting in even lower end-to-end latency. Streams with multiple slices will remain compliant with H.264 and H.265 standards, and will still be compatible with standard receivers and decoders. 

Note

Latency improvements are only seen on decoders that do not buffer entire video frames before decoding and can actually decode and output slices.

Multiple slices cannot be used in conjunction with Partial Image Skip or Framing containing B-frames (IBP, .... IBBBBP).

(Optional) Check this checkbox to enable Closed Captioning on the output Stream.

Timecodes are used to mark video frames, mainly for editing purposes. This field either disables timecoding, or selects the source to “timecode” the encoded video frame. The following selections are available:

• None: No time code will be inserted in the video stream (saves bandwidth if not required).
• Video (SDI only): The timecode will be extracted from the incoming video signal.
• System: If no timecode is included in the video feed, the encoded timecode is based on the encoder’s system clock. In this case, it is a good idea to enable NTP (see Configuring Network Settings).

Specifies the aspect ratio of the video source and signals it into the MPEG stream:

• Automatic: Aspect ratio is derived from the incoming video source resolution.
• Manually force aspect ratio to either: 3:2, 4:3, 5:3, 5:4, 16:9, 16:10, or 17:9.
• WSS/AFD: Aspect ratio is extracted from the incoming video source based on WSS (Wide Screen Signaling) or AFD (Active Format Description) if detected.

Note

WSS is only supported with analog PAL video; AFD is only supported with SD-SDI video.