Zixi Broadcaster offers live transcoding, enabling users to create multiple bitrate streams from a single input stream.
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- Video Decoding – MPEG2, H.264/AVC , H.265/HEVC
- Video Encoding – MPEG2, H.264/AVC , H.265/HEVC
Audio Decoding – AAC, MPEG-1 Audio Layer I / II / III, MPEG-2 Audio Layer I / II / III, AC-3 (Dolby Digital)
Info For AC-3, which can contain up to six discrete channels of sound, the transcoder only supports the left and right channels and will ignore the other channels.
- Audio Encoding – AAC, AAC- LC,
- HE (High Efficiency) and AAC- HEv1, Opus
- HEv2; Pass through (no encoding) – any audio codec (MPEG1/2 / AAC / AC-3, E-AC-3 (Dolby Digital Plus).
The transcoder comes with pre-set common video profiles:
1080i60 / 1080i59.94, 1080p30 / 1080p25, 720p60, 720p50 / 720p30, 576i60 / 576p25, 480i60 / 480p29.97
In order to transcode an input stream from the Inputs screen you must first configure the transcoding profiles in the Transcoder screen. For more information, see see Broadcaster Transcodersection section.
To Transcode an Input Stream:
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- In the Zixi Broadcaster Inputs page, click the desired incoming input stream that you want to transcode.
- Click the button on the right end of the selected row and then then Transcode. The The Transcode <input stream name> window window with the settings of the selected input stream is displayed.
- Enter the unique
- unique Stream I.D. , which will correspond to
- for the new transcoded input that will be added
- stream. Under
- Under Stream Parameters , select
- , in the Video profile and Audio profile fields, do one of the following options in Video Profile:
- Keep original stream – the stream will not be modified.
- Remove stream – the output will not include the video channel (audio only).
- Custom profile – select one of the custom profiles that have been configured in the transcoder.
- Under Stream Parameters, select one of the following options in Audio Profile:
- Keep original stream – the stream will not be modified.
- Remove stream – the output will not include the audio channel (video only).
- Custom profile – select one of the custom profiles that have been configured in the transcoder.
- If you have installed a GPU hardware accelerator on your transcoder you can select the Use hardware acceleration checkbox to enable acceleration.
- If you want to ensure all PIDs (which is used to distinguish between packets containing different types of information) are passed on through the transcoder, select the Pass all PIDs checkbox. To learn more about PIDs, see Packet Identifiers (PID).
- In the Smoothing buffer field, enter the buffering time in milliseconds. The buffering helps smoothen the stream, however it will delay its transfer by the duration that is specified in this field. Default: 1500 ms.
- Select the relevant additional parameters as described below.
- Click OK. The transcoded input stream is created and appears in an embedded window labeled Transcoded sources under the original input stream from which it was created.
Parameters Table
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- Select the desired Video Profile and/or Audio Profile that you have configured.
- Select Keep original stream - if you have not configured a video or audio profile or do not want it transcoded or you want to set specific transcoding parameters for the specific stream. In this case, the video or audio input will not be transcoded.
- Select Remove stream – you can use the transcoder to remove the video or audio track from the stream.
- Fill in additional fields (see table below for additional parameters).
- Click OK.
The transcoded input stream is created and appears in an embedded window labeled Transcoded sources under the original input stream from which it was created.
- ParameterDescription
Advanced Options Video Profile
Select an existing profile, select Keep original stream if you do not wish to transcode the video stream, or select Remove stream if you want to remove the video track.
Audio Profile
Select an existing profile, select Keep original stream if you do not wish to transcode the audio stream, or select Remove stream if you want to remove the audio track.
Transport Stream Bitrate (Kbps)
Specify the bitrate of the MPEG transport stream (TS).
This parameter is optional. If you do not specify a TS Bitrate, the transport stream will be variable bitrate (VBR) with no additional null packets added. If you specify a bitrate, the transport stream will be constant bitrate (CBR) where null packets are added as necessary to achieve the specified bitrate.
CBR transport streams are typically required when sending a stream to a satellite head-end or to a professional integrated receiver-decoder (IRD). The overhead of MPEG TS is about 7%. To determine the bitrate setting, sum the max video bitrate and audio bitrate from the encoding profile and then add the other PIDs (if choosing to pass all PIDs) and add 7%. If the bitrate needed for the transport stream exceeds the value specified, the Broadcaster will give a “bitrate too low” error message.
VBR transport streams are typically used for HLS, DASH, RTMP, and other similar live streaming workflows.
Use Hardware Acceleration (if available) Select this checkbox to use hardware acceleration component (e.g. NVIDIA or Intel) if it has been installed. Pass all PIDs
Select this checkbox to pass-through all non-transcoded PIDs.
Smoothing Buffer (ms) Specify how much of the transcoded stream (in milliseconds) to store before transmitting it back to the server in order to prevent bursts.
If the Transport stream bitrate [kbps] field is empty, the smoothing buffer is disabled.
If the Transport stream bitrate [kbps] field is NOT empty, it is recommended to enter around 200ms, which should be enough to prevent bursts.Enable time shift Maximum delay [hh:mm:ss]
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Specify the
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time
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of the delayed transmission of this
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stream. Maximum: 24 hours. Transmit as multicast
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Selecting this checkbox enables the transmission of this stream’s outputs as multicast. A Zixi
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receiver that will pull the stream will receive it in multicast
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. By default Zixi Broadcaster is configured to allow transparent fallback to unicast if it is out of the LAN
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. Requires enabling Multicast Pull in the Settings.
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This setting requires enabling Multicast Pool (Settings > Multicast Pool).
Multicast Only Selecting this checkbox will force the transmission of this stream only in multicast. Enable Encryption
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Select this checkbox to encrypt the Input stream. For more information, see Encrypting an Input Stream in Zixi Broadcaster
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Encryption type (for Encryption enabled) Specify the type of Encryption (AES 128/192/256). Encryption key (for
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encryption enabled) Click Generate to generate an encryption key. The generated encryption key must be sent to the end-user to decipher the received encoded stream. Recording parameters
Select this checkbox to customize the recording parameters.
Destination Type
Select the radio button for the desired storage type and then fill in the relevant parameters.
· Record to disk – the recording is saved on the local disk.
· Record to S3 – the file is saved to your AWS S3 Bucket.
Record to Disk Parameters
File Name Template
Specify the file name pattern that Zixi will use to generate when saving the recorded content. A separate file will be generated for each recording up to the time specified in the Max recorded file duration parameter (see above). After this duration a new file will be generated.
The file name pattern can include any string and up to five variables listed below. Only the %T=HH.MM.SS creation time is mandatory. You can change the order of these variables and add text as long as you maintain the legitimate structure of the file in Linux and Windows:
· %S=stream id - optional.
· %Y=year - optional
· %M=month - optional
· %D=day - optional
· %T=HH.MM.SS creation time - mandatory
For example, the following pattern %Y_recording%T.ts will generate the following file name 2017_recording15:32:35.ts.
Max recorded file duration [hours]
Specify the maximum time allotted for recording a video stream. Default: 2 hours
Keep recorded files for [hours]
Specify the maximum time for storing the recording. Default: 0 hours
Custom Path
Optionally specify a storage location for the recorded files that is relative to the root folder. This location bypasses the location specified as the root folder in the
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Settings > General screen.
Record to S3 Parameters
File Name Template
Specify the file name pattern that Zixi will use to generate when saving the recorded content. A separate file will be generated for each recording up to the time specified in the
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Max recorded file duration
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parameter (see above). After this duration a new file will be generated.
The file name pattern can include any string and up to five variables listed below. Only the
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%T=HH.MM.SS creation time
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is mandatory. You can change the order of these variables and add text as long as you maintain the legitimate structure of the file in Linux and Windows:
· %S=stream id - optional.
· %Y=year - optional
· %M=month - optional
· %D=day - optional
· %T=HH.MM.SS creation time - mandatory
For example, the following pattern
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%Y_recording%T.ts
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will generate the following file name 2017_recording15:32:35.ts.
Max recorded file duration [hours]
Specify the maximum time allotted for recording a video stream. Default: 2 hours
URL
Specify the URL of the S3 bucket.
Ignore TLS certificate errors
TLS certificate for S3 bucket might be detected as faulty if bucket name contains dot[s]. When this option is selected, Zixi Broadcaster will ignore the TLS certificate errors and transmit the stream to its destination.
Access Key
The access key that is used for accessing the S3 bucket.
Secret Key
The secret key that is used for accessing the S3 bucket.