Encoding parameters
Video
Video encoding
| Parameter | Description |
|---|---|
| Rate control | Define how the bitrate is managed for this service, either constant bit rate (CBR) or constant video quality (CVQ). |
| Target bit rate | Bandwidth used to encode the video stream Possible values: From 100 to 40000 (MPEG2), 50000 (H.264), 120000 (HEVC) |
| Resolution | Define the frame size of the video stream (width x height). Maximum resolution depends on codec. Possible values: Depends on codec. |
| Coding mode | Frames will be encoded either in progressive or interlace mode. Interlace mode is commonly used for set top boxes and is adapted to SD or 1080i (HDTV) resolutions. |
| Frame rate | Select the possible output frame rates. The actual output frame rate depends on input frame rate. |
| Codec | Different codecs (MPEG2, H.264, HEVC) can be used to encode the content. Select a codec and its profile for each video stream. |
| Quality preset | Different tradeoffs between video quality and density. CVQ rate control is optimized for High quality and Fast presets. |
| Stream conditioning | SCTE35 streams considered to condition the video. IDR frames are inserted based on SCTE35 cue points to prepare the stream for downstream adinsertion and replacement scenario |
| Subtitle burn-in | Select a subtitle stream to burnin if required, otherwise leave None. A subtitle must be configured in the Input stream configuration to be available for selection. |
Codec settings
| Parameter | Description |
|---|---|
| Buffer duration | Define the size of the video buffer. The video buffer is the standard MPEG4 VBV (Video Buffering Verifier). The instantaneous bitrate smoother (transmission buffer) ensures that the instantaneous bitrate never exceeds the target bitrate. |
| B-frames | Modes: Auto: Allows the encoder to choose the number of Bframes depending on the source. OFF: Disable Bframes. Select 2 or 3 to set a fixed number of Bframes (not applicable for MPEG2). |
| Entropy coding | Entropy coding can be defined as CABAC (Contextbased adaptive variablelength coding) or CAVLC (Contextbased adaptive binary arithmetic coding). |
| Frame/field coding mode | The mode depends on the selected Codec. Options include: Frame only when each image is considered progressive. Frame with MBAFF when each image is encoded as progressive with a interlaced/progressive choice at the macroblock level. PAFF when each image is encoded as either progressive or interlaced. PAFF with MBAFF so the recommended setting automatically detects the best encoding option for each frame. Field only when each image is considered interlaced. SAFF when each GOP is either encoded progressive or interlaced (HEVC only). |
| Dynamic range mode | Follow input leaves input format unchanged. Otherwise, the color space is converted if necessary: tone mapping (HDR to SDR) or inverse tone mapping (SDR to HDR). |
GOP settings
| Parameter | Description |
|---|---|
| GOP duration | Time between two key frames. Key frames are used to sync with the stream to start decoding it properly. Possible values: From 500 to 10000 for all codecs |
| GOP policy | Values: (1) Open: reference frames can be picked across the GOPs. (2) Closed: all the reference frames must be in the same GOP. Impact depends on player capabilities.² |
| GOP duration mode | Fixed: IDR frames are strictly generated every GOP duration. Adaptive: I/IDR frames are inserted when needed, depending on the video stream sequence. Maximum time elapsed between two I/IDR frames is set using the GOP duration parameter. |
| I-frame insertion | Fixed closed GOP, with interval Iframe insertion mode sets the maximum interval between IDR and IFrames inside a GOP. |
Aspect ratio
| Parameter | Description |
|---|---|
| Insert AFD | If present at the input, AFD (Active Format Description) information will be added in the output stream |
| Downscaling | Method applied to the video when downscaled from HD 16:9 to SD 4:3. The Anamorphic type dynamically adapts the pixel aspect ratio (width x height) per frame. Letterbox inserts black stripes to fit the target ratio. |
| Top | The percentage of the image to crop from the top. |
| Bottom | The percentage of the image to crop from the bottom. |
| Left | The percentage of the image to crop from the left. |
| Right | The percentage of the image to crop from the right. |
| Output aspect ratio | Select an Output aspect ratio. |
| Zoom | Zooming reduces the size of the black stripes that are inserted when using the Letterbox downscaling method. Setting Zoom to 100% removes the black stripes but the image will be cropped. |
Stream metadata settings
| Parameter | Description |
|---|---|
| Insert closed captions | If selected then closed captions present in the input will be added in the output stream. |
| Insert VUI timing info | Insert VUI (video usability information) timing info in the video. This is usually used by players such as settoboxes to get the video framerate |
| Insert HRD signaling | HRD signaling is used for compliance testing. |
Logo insertion
| Parameter | Description |
|---|---|
| Image URL | Url of the logo image. |
| Placement | Corner where the image will be placed. |
| Horizontal gap | Horizontal adjustment of the logo. Percentage of the video width |
| Vertical gap | Vertical adjustment of the logo. Percentage of the video height. |
| Size | Size of the logo. |
Audio
MPEG-1 Layer II audio encoding parameters
Parameters display in relation to the Channel mode and Codec.
| Parameter | Description |
|---|---|
| Input | Define the selected stream to encode. |
| Codec | Different codecs can be used to encode the content. Select a codec for each audio stream. |
| Channel mode | Number of audio channels in the encoded audio track. |
| Bit rate | Bandwidth used to encode the audio stream. |
| Sampling rate | Number of audio samples per second defined in Hz. |
Dolby Digital parameters (stereo channel mode)
Parameters display in relation to the Channel mode and Codec.
| Parameter | Description |
|---|---|
| Input | Define the selected stream to encode. |
| Codec | Different codecs can be used to encode the content. Select a codec for each audio stream. |
| Channel mode | Number of audio channels in the encoded audio track. |
| Bit rate | Bandwidth used to encode the audio stream. |
| Sampling rate | Number of audio samples per second defined in Hz. |
Basic parameters
| Parameter | Description |
|---|---|
| Dialog normalization | Metadata parameter that controls playback gain. |
| Dolby Surround mode | Decoders can use this flag to automatically switch on Pro Logic decoding. |
Advanced parameters
| Parameter | Description |
|---|---|
| DRC Line Mode Profile | The Dynamic Range Control restricts the signal's absolute peak level for a decoder using the line mode. |
| DRC RF Mode Profile | The Dynamic Range Control restricts the signal's absolute peak level for decoder using the RF mode. |
| DC highpass filter | A DCblocking 3Hz highpass filter applied on the main Dolby channel. Used to remove DC offsets in the program audio. Only switch off in exceptional circumstances. |
Dolby Digital parameters (follow input channel mode)
Parameters display in relation to the Channel mode and Codec.
| Parameter | Description |
|---|---|
| Input | Define the selected stream to encode. |
| Codec | Different codecs can be used to encode the content. Select a codec for each audio stream. |
| Channel mode | Number of audio channels in the encoded audio track. |
| Bit rate | Bandwidth used to encode the audio stream. |
| Sampling rate | Number of audio samples per second defined in Hz. |
Basic parameters
| Parameter | Description |
|---|---|
| LFE Lowpass Filter | This parameter determines whether a 120 Hz eighthorder lowpass filter is applied to the LFE channel input of a Dolby Digital encoder prior to encoding. |
| Dialog normalization | Metadata parameter that controls playback gain. |
| Dolby Surround EX mode | Amplifier or receiver with Dolby Digital Surround EX decoding that can use this parameter as a flag to automatically switch the decoding On or Off. |
| LFE enable | The status of the LFE Channel parameter indicates whether an LFE Channel is present within the bitstream. |
Advanced parameters
| Parameter | Description |
|---|---|
| DRC Line Mode Profile | The Dynamic Range Control restricts the signal's absolute peak level for a decoder using the line mode. |
| DRC RF Mode Profile | The Dynamic Range Control restricts the signal's absolute peak level for decoder using the RF mode. |
| 90 Degree Phase Shift | This parameter causes the Dolby Digital encoder to apply a 90degree phase shift to the Surround channels. |
| 3 dB Attenuation | Attenuates the Surrounds channels by 3 dB before encoding. |
| Lo/Ro Center Mix Level | Level shift applied to the Center channel when added to the left and right outputs as a result of downmixing to an Lo/Ro output. |
| Lo/Ro Surround Mix Level | Level shift applied to the Surround channels when downmixing to an Lo/Ro output |
| Lt/Rt Center Mix Level | Level shift applied to the Center channel when added to the left and right outputs as a result of downmixing to an Lt/Rt output |
| Lt/Rt Surround Mix Level | Level shift applied to the Surround channels when downmixing to an Lt/Rt output |
| Stereo Downmix Preference | This parameter allows to select the preferred downmix method for decoders that has stereo outputs. |
Subtitle
Subtitle encoding parameters may vary in relation to the subtitle Type selected in input parameters.
| Parameter | Description |
|---|---|
| Input | Define the selected stream to encode. |
| Codec | Different codecs or formats can be used to produce subtitling. Select a codec for each subtitle stream |
| Adjust display height | Enabling this option ensures that the subtitles display correctly after resizing. DVB Subtitle or SCTE27 subtitles are sometimes out of the picture after a resize is performed. |
Metadata
| Parameter | Description |
|---|---|
| Input | Define the selected stream to encode |