Helix DNA Producer 10.0 Audience File Reference |
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This document describes Helix DNA Producer audience files. An audience file is an XML formatted text file that holds settings used by the codecs to compress media for a particular target bit rate. The audience file is composed of XML elements organized in a hierarchal tree structure as shown below:
The above hierarchy represents all the major sections in a audience file or the audiences section of a job file. Each of the sections are documented below.
XML documents are composed of elements and attributes. Elements may contain a simple value or other elements. Elements that contain simple values are referred to as properties. An example of a property is <enableTwoPass>true</enableTwoPass>. Elements that contain other elements are referred to as sections. Examples of a section is the streams section above which includes 4 subsections.
Audience files may be read, created or modified through Helix DNA Producer applications or SDK as well as any text or XML document editor. Information on how to edit Helix DNA Producer XML settings files is available in the Editing XML Files Reference. The remainder of this document provides information on the properties in the outline above.
Helix DNA Producer Audience files are given a special file extension. The file extension for a server file is ".rpad" which stands for RealNetworks Producer Audience File.
Audience Section |
[ job > audience ] |
An XML file can contain one and only one root element. The root element
of the audience file is 'audience'. The audience element contains one
attribute, (xmlns), two properties (avgBitrate and maxBitrate) and one
sub-section (streams). The outline below shows the structure of the
audience element and its immediate children.
The attributes and properties of the audience element are described below. The streams section is described in the following section.
The audience tag contains three attributes:
These attributes are described below.
xmlns | [ job > audience ] |
XML Namespace Attribute. The xmlns attribute stands for XML Namespace. This setting is used to store the type and version of an XML file for purposes of validation.
Default:
http://ns.real.com/tools/audience.2.0
Values:
Helix DNA Producer 10 audience files are given a version of 2.0. If a newer
version is encountered, the Helix DNA Producer SDK or command line
application will refuse to open the audience.
Example:
<audience xmlns="http://ns.real.com/tools/audience.2.0">
xmlns:xsi | [ job > audience ] |
XML Schema Instance Namespace Attribute. The xsi:schemaLocation attribute provided information on where to locate the XML Schema file used to validate the server file. The value of the xsi:schemaLocation is a space separated list of namespace/URI pairs.
Default:
http://www.w3.org/2001/XMLSchema-instance
Values:
A string containing the XML Schema Instance namespace. The XML Schema Instance namespace
provides functionality for handling XML schema validation. The definitions of xsi:type and
xsi:schemaLocation used in Heilx Produer settings files are provided by this namespace. More information on the
xmlns:xsi namespace and the definitions it provides can be found in the document, Extending
and Validating Helix DNA Producer Settings Files with XML Schemas.
Example:
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation | [ job > audience ] |
XML Schema Location Attribute. The xsi:schemaLocation attribute provided information on where to locate the XML Schema file used to validate the server file. The value of the xsi:schemaLocation is a space separated list of namespace/URI pairs.
Default:
http://ns.real.com/tools/server.2.0 http://ns.real.com/tools/server.2.0.xsd
Values:
A string containing the namespace on the left (http://ns.real.com/tools/server.2.0) and the
location of the XML Schema file in the form of a URI. The default is
http://ns.real.com/tools/server.2.0.xsd which works for most XML Schema validators as long as
there is network connectivity to the Internet. The URI can also be any valid filename
including path.
More information on the xsi:schemaLocation attribute can be found in the document, Validating Helix DNA Producer Settings Files with XML Schemas.
Example:
xsi:schemaLocation="http://ns.real.com/tools/server.2.0 server.2.0.xsd" (relative
path)
xsi:schemaLocation="http://ns.real.com/tools/server.2.0 C:\server.2.0.xsd" (absolute
path)
The audience tag contains two properties:
These properties are described below.
maxBitrate | [ job > audience ] |
This setting limits total bit rate for the audience from going above the specified value in bps (bits per second). Only applies to encodingType of encodingType is vbrBitrate or vbrQuality.
Default:
No Default
Values:
Any positive integer of
1-999999
Type:
uint
Example:
<maxBitrate type="uint">350000</maxBitrate>
avgBitrate | [ job > audience ] |
Bit rate in bps (bits per second) of the entire audience. Ignored if encodingType property is set to vbrQuality.
Default:
No Default
Values:
Any positive integer of 1-999999
Type:
uint
Example:
<avgBitrate type="uint">28000</avgBitrate>
Streams Section |
[ job > audience ] |
An audience holds a set of streams for a particular target bit rate. The audience defines a combination of audio, video, event and image map streams. Depending on the type of input and the media profile settings, different streams in the audience will be used. For example, if an input is audio-only, only the audio stream section is used and the video stream section is ignored.
The streams section groups one or more stream sections. Below is an outline of the streams section.
One or more stream sections may occur within a streams section. A stream may be audio, video, events or image maps as described in the Stream section of this document. At least one stream must exist in order to perform encoding with this audience.
Stream Section |
[ job > audience > streams ] |
A stream section contains settings for a single stream. A stream can be one of several types depending on the value of the xsi:type attribute. The xsi:type attribute is a special XML entity that allows a single parent tag name to contain different sets of properties and subsections. The value of xsi:type identifies which set of properties and subsections may be contained within the parent tag.
A stream can contain any value of xsi:type as long as there is a plug-in defined to handle that stream type. If XML Schema validation is being performed, there must also be a type defined matching the value of xsi:type as described in Validating and Extending Helix DNA Producer Settings Files with XML Schemas. Following is a list of known destination types.
Each of these four stream types are described below following the definition of the xsi:type attribute.
XML Schema Instance Type Attribute xsi:type | [ job > audience > streams > stream ] |
The xsi:type attribute stands for XML Schema Instance. This setting is used to identify the type of stream that is defined within the section. Each instance of a stream section may be one of several types and each type may contain a different group of properties and subsections. There are four known stream types but new types can be defined as documented in Validating and Extending Helix DNA Producer Settings Files with XML Schemas.
Default:
No Default
Values:
The list of values below for xsi:type are known. Other types can be added.
Example:
xsi:type="audioStream"
xsi:type="acmeAnimationStream"
Audio Stream Section |
[ job > audience > streams > stream ] |
The stream section of xsi:type audioStream defines settings used by the audio codec. It contains three properties and one subsection. The outline below shows the structure for the audio stream section.
The streamContext section contains properties to allow the application to select only one audio stream among several choices. See Stream Context Subsection below for details.
pluginName | [ job > audience > streams > stream (audioStream) ] |
Audio Codec Plug-in Name. A string that defines the name of the plug-in to load. The pluginName property is used to identify the formal plug-in name advertised by a given Helix DNA Producer plug-in. A plug-in name can be any string as long as it matches the string advertised by the intended plug-in but should comply with the recommended syntax for plug-in names as described in the Plug-in Names section.
Default:
rn-audiocodec-realaudio
Values:
rn-audiocodec-realaudio, rn-audiocodec-lossless, rn-audiocodec-vorbis or a
valid plug-in name.
Type:
string
Example:
<pluginName type="string">rn-audiocodec-realaudio</pluginName>
codecName | [ job > audience > streams > stream (audioStream) ] |
Audio Codec Name. The fourcc audio codec name to be used. This is a required property.
Default:
No Default
Values:
sipr, cook, ralf, raac or the 4CC for other 3rd party codecs. See Audio Codec Tables
below for a list of available audio codec names.
Type:
string
Example:
<codecName type="string">cook</codecName>
codecFlavor | [ job > audience > streams > stream (audioStream) ] |
The audio codec flavor number to use. This is a required property.
Default:
No Default
Values:
Any valid codec flavor number. See Audio Codec Tables
below for a list of available audio codec flavors.
Type:
uint
Example:
<codecFlavor type="uint">12</codecFlavor>
encodingComplexity | [ job > audience > streams > stream (audioStream) ] |
A measure of how hard the codec will work to achieve the desired result. The specific result varies according to the codec. For some codecs, like RealVideo, the result is quality. For other codecs, like RealAudio Lossless codec, the result is file size.
For the RealAudio Lossless codec, the value of encodingComplexity affects the resulting file size and how long it takes to encode. An encodingComplexity of low will take the least amount of time and result in the largest file size. An encodingComplexity of high will take the most amount of time and result in the smallest file size.
For file to file encoding, encoding complexity has an impact on how long it takes to encode. For live capture or broadcast, encoding complexity affects the amount of CPU consumed by the encoder. Unlike video, the encoding complexity is not automatically adjusted to match system resources. in live capture or broadcast encoding situations.
Default:
high
Values:
low, medium or high (value of low takes less encoding time but results in
significantly lower quality)
Type:
string
Example:
<encodingComplexity type="string">high</encodingComplexity>
encodingType | [ job > audience > streams > stream (audioStream) ] |
VBR encoding types provide higher quality but are not as well suited to low bit rate streaming situations and can cause network congestion due to spikes in bit rate when streaming. Use CBR for low bandwidth dial-up streaming, VBR constrained types for streaming at higher bit rates where network capacity is available, VBR unconstrained types for download. The quality versus bitrate types allow the output to be targeted towards a specified level of quality or a specified file size.
For lossless audio codec, only the vbrUnconstrainedQuality is allowed. Omitting this property when using lossless audio results in the default value of vbrUnconstrainedQuality being used.
Default:
cbr
Values:
cbr, vbrBitrate, vbrQuality, vbrUnconstrainedQuality, or vbrUnconstrainedBitrate
Type:
string
Example:
<encodingType type="string">vbrUnconstrainedBitrate</encodingType>
presentationType | [ job > audience > streams > stream (audioStream) > streamContext ] |
Describes the type of presentation (if it is audio only or audio and video). This setting allows different audio streams, one that uses a higher bit rate for audio-only presentations and one that uses a lower bit rate for audio-video presentations, to be assigned in an audience. The setting is used at runtime to determine what audio codec to use.
Default:
audio-video
Values:
audio-video, audio-only
Type:
string
Example:
<presentationType type="string">audio-video</presentationType>
audioMode | [ job > audience > streams > stream (audioStream) > streamContext ] |
Describes the type of audio content. Certain codecs are tuned to encode voice frequency responses and others are turned to encode music. This setting allows different codecs to be assigned in an audience for each type of input. The setting is used at runtime to determine, based on user selection of audio mode, what audio stream to apply.
Default:
music
Values:
music, voice
Type:
string
Example:
<audioMode type="string">music</audioMode>
Selecting Audio Codecs |
[ job > audience > streams > stream (audioStream) ] |
An audience is defined with up to 4 audio streams that define the audio codec to use under different conditions. The conditions that affect which audio stream is used are:
It is not required that an audience have 4 audio streams defined. If only one audio stream section is included in an audience file, the stream context section, that defines the audio mode and presentation type, may be omitted.
When selecting audio codecs for each stream, the overall bit rate is not exceeded. Thus, for audio streams with presentationType=audio-only, the bit rate of the audio codec should be less than the avgBitrate defined in the audience. For audio streams with presentationType=audio-video, the bit rate of the audio codec should be low enough to allow for sufficient bandwidth for the video stream.
For example, for an audience with an avgBitrate of 34 kbps the following choices should be made for each of the 4 audio streams:
Presentation Type | Audio Mode | Audio Codec Choice |
audio-only | voice | For audio-only, we choose an audio codec that uses as much of the available total bit rate as possible. For voice, we choose the highest bit rate below 34 kbps from the Voice Audio Codecs table (name=cook, flavor=7). |
audio-only | music | For music, the audio-only codec would be selected from the Music Audio Codecs table below, again, picking the largest bit rate for the available bit rate. This would be any of the 32 kbps codecs from the Music Audio Codecs table. In this case we'll choose the 32 Kbps Music High Response (name=cook flavor=16). |
audio-video | voice | For audio-video some bandwidth must be reserved for video so the audio codec bit rate should be low enough to allow for video bandwidth. Typically a good choice is to allocate about 20% of the total bit rate to audio or about 6-7 kbps. For voice, the 6.5 Kbps Voice (name=sipr flavor=0) is a good choice. |
audio-video | music | Likewise, for music, an audio codec is selected that is 20% of the total bit rate. For music, the 6 kbps music codec with a codec name of cook and a flavor of 8 is selected from the Music Audio Codecs table. |
Audio Codec Tables |
[ job > audience > streams > stream (audioStream) ] |
The following is a list of all codecs the corresponding codec name and flavor. The codec name and flavor are used to identify a specific codec in a job file. Codecs are grouped into tables according to the type of application such as voice or music.
Sample rates required as input for each codec is also provided. If possible, audio input should be the same sample rate as required by the desired output codec. In the case of SureStream encoding, the input sample rate should be equal or greater than the largest sample rate of all codecs in included in the output.
Player compatibility is provided in the last column. This information documents the minimum player that is needed in order to play back this data type. Players earlier than the indicated version will require an auto-update to play the content.
Voice Audio Codecs
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
5 Kbps Voice - RealAudio | sipr | 2 | 8 kHz | RealPlayer 5 |
6.5 Kbps Voice - RealAudio | sipr | 0 | 8 kHz | RealPlayer 4 |
8.5 Kbps Voice - RealAudio | sipr | 1 | 8 kHz | RealPlayer 4 |
16 Kbps Voice - RealAudio | sipr | 3 | 16 kHz | RealPlayer 5 |
32 Kbps Voice - RealAudio | cook | 7 | 22.05 kHz | RealPlayer G2 |
64 Kbps Voice - RealAudio | cook | 14 | 44.1 kHz | RealPlayer G2 |
Music Audio Codecs
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
6 Kbps Music - RealAudio | cook | 8 | 8 kHz | RealPlayer G2 |
8 Kbps Music - RealAudio | cook | 0 | 8 kHz | RealPlayer G2 |
11 Kbps Music - RealAudio | cook | 1 | 11.025 kHz | RealPlayer G2 |
16 Kbps Music - RealAudio | cook | 2 | 22.05 kHz | RealPlayer G2 |
20 Kbps Music - RealAudio | cook | 3 | 22.05 kHz | RealPlayer G2 |
20 Kbps Music High Response - RealAudio | cook | 15 | 44.1 kHz | RealPlayer G2 |
32 Kbps Music - RealAudio | cook | 4 | 44.1 kHz | RealPlayer G2 |
32 Kbps Music High Response - RealAudio | cook | 16 | 44.1 kHz | RealPlayer G2 |
44 Kbps Music - RealAudio | cook | 5 | 44.1 kHz | RealPlayer G2 |
64 Kbps Music - RealAudio | cook | 6 | 44.1 kHz | RealPlayer G2 |
Stereo Music Audio Codecs
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
12 Kbps Stereo Music - RealAudio | cook | 26 | 11.025 kHz | RealPlayer 8 |
16 Kbps Stereo Music - RealAudio | cook | 17 | 22.05 kHz | RealPlayer 8 |
20 Kbps Stereo Music | cook | 9 | 11.025 kHz | RealPlayer G2 |
20 Kbps Stereo Music - RealAudio | cook | 18 | 22.05 kHz | RealPlayer 8 |
20 Kbps Stereo Music High Response - RealAudio | cook | 19 | 22.05 kHz | RealPlayer 8 |
32 Kbps Stereo Music | cook | 10 | 22.05 kHz | RealPlayer G2 |
32 Kbps Stereo Music - RealAudio | cook | 20 | 22.05 kHz | RealPlayer 8 |
32 Kbps Stereo Music High Response - RealAudio | cook | 21 | 44.1 kHz | RealPlayer 8 |
44 Kbps Stereo Music | cook | 11 | 22.05 kHz | RealPlayer G2 |
44 Kbps Stereo Music - RealAudio | cook | 22 | 44.1 kHz | RealPlayer 8 |
44 Kbps Stereo Music High Response - RealAudio | cook | 23 | 44.1 kHz | RealPlayer 8 |
64 Kbps Stereo Music | cook | 12 | 44.1 kHz | RealPlayer G2 |
64 Kbps Stereo Music - RealAudio | cook | 24 | 44.1 kHz | RealPlayer 8 |
128 Kbps Stereo Music - RealAudio 10 | raac | 0 | 44.1 kHz | RealPlayer 8 |
64 Kbps Stereo Music - RealAudio 10 | raac | 0 | 44.1 kHz | RealOne Player |
96 Kbps Stereo Music | cook | 13 | 44.1 kHz | RealPlayer G2 |
96 Kbps Stereo Music - RealAudio | cook | 25 | 44.1 kHz | RealPlayer 8 |
96 Kbps Stereo Music - RealAudio 10 | raac | 1 | 44.1 kHz | RealOne Player |
128 Kbps Stereo Music - RealAudio 10 | raac | 2 | 44.1 kHz | RealOne Player |
160 Kbps Stereo Music - RealAudio 10 | raac | 3 | 44.1 kHz | RealOne Player |
192 Kbps Stereo Music - RealAudio 10 | raac | 4 | 44.1 kHz | RealOne Player |
256 Kbps Stereo Music - RealAudio 10 | raac | 5 | 44.1 kHz | RealOne Player |
320 Kbps Stereo Music - RealAudio 10 | raac | 6 | 44.1 kHz | RealOne Player |
Stereo Surround Audio Codecs
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
44 kbps Surround Audio - RealAudio | cook | 29 | 22.05 kHz | RealPlayer 8 |
64 kbps Surround Audio - RealAudio | cook | 27 | 44.1 kHz | RealPlayer 8 |
96 kbps Surround Audio - RealAudio | cook | 28 | 44.1 kHz | RealPlayer 8 |
128 Kbps Stereo Surround - RealAudio 10 | raac | 7 | 44.1 kHz | RealPlayer 8 |
160 Kbps Stereo Surround - RealAudio 10 | raac | 8 | 44.1 kHz | RealPlayer 8 |
192 Kbps Stereo Surround - RealAudio 10 | raac | 9 | 44.1 kHz | RealPlayer 8 |
256 Kbps Stereo Surround - RealAudio 10 | raac | 10 | 44.1 kHz | RealPlayer 8 |
320 Kbps Stereo Surround - RealAudio 10 | raac | 11 | 44.1 kHz | RealPlayer 8 |
5.1 Multichannel Audio Codecs
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
96 Kbps 5.1 Multichannel - RealAudio 10 | cook | 30 | 22.05 kHz | RealPlayer 8 |
132 Kbps 5.1 Multichannel - RealAudio 10 | cook | 31 | 44.1 kHz | RealPlayer 8 |
184 Kbps 5.1 Multichannel - RealAudio 10 | cook | 32 | 44.1 kHz | RealPlayer 8 |
268 Kbps 5.1 Multichannel - RealAudio 10 | cook | 33 | 44.1 kHz | RealPlayer 8 |
RealAuido Lossless Codec
Codec Bit Rate Label | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
RealAudio Lossless Audio | ralf | 0 | 44.1 kHz | RealONE Player |
RealAuido Multi-channel Codec
Codec Bit Rate Label | Channels | Codec Name | Codec Flavor | Sample Rate | Player Compatibility |
96 Kbps Multi-channel | 6 | cook | 30 | 44.1 kHz | RealONE Player |
128 Kbps Multi-channel | 6 | cook | 31 | 44.1 kHz | RealONE Player |
180 Kbps Multi-channel | 6 | cook | 32 | 44.1 kHz | RealONE Player |
264 Kbps Multi-channel | 6 | cook | 33 | 44.1 kHz | RealONE Player |
Vorbis Audio Codecs*
Number of Channels | Sample Rate | Codec Name | Flavor | Player Compatibility |
1 (mono) | 8 kHz | vorbis | 0 | Vorbis |
1 (mono) | 22.05 kHz | vorbis | 1 | Vorbis |
1 (mono) | 44.1 kHz | vorbis | 2 | Vorbis |
1 (mono) | 48 kHz | vorbis | 3 | Vorbis |
2 (stereo) | 8 kHz | vorbis | 4 | Vorbis |
2 (stereo) | 22.05 kHz | vorbis | 5 | Vorbis |
2 (stereo) | 44.1 kHz | vorbis | 6 | Vorbis |
2 (stereo) | 48 kHz | vorbis | 7 | Vorbis |
* Vorbis audio codes are variable bit rate (VBR). Thus, the bit rate
is not defined as part of the codec flavor as is done with other CBR codecs.
* Vorbis audio codec support not shipped with the Retail encoder from
RealNetworks
Video Stream Section |
[ job > audience > streams > stream ] |
The stream section of xsi:type videoStream defines settings used by the video codec. It contains eight properties. The outline below shows the structure of the video stream section.
Note: Video bit rate is not specified. Instead, it is computed from avgBitrate and maxBitrate for the whole audience minus the audio bit rate.
pluginName | [ job > audience > streams > stream (videoStream) ] |
Video Stream Plug-in Name. The name of the video codec plug-in that is to be used.
Default:
rn-videocodec-realvideo
Values:
rn-videocodec-realvideo or a
valid plug-in name.
Type:
string
Example:
<pluginName type="string">rn-videocodec-realvideo</pluginName>
codecName | [ job > audience > streams > stream (videoStream) ] |
Video Codec Name. These refer to "RealVideo 8", "RealVideo 9" and "RealVideo 10" respectively.
Default:
rv10
Values:
rv8, rv9 or rv10
Type:
string
Example:
<codecName type="string">rv8</codecName>
encodingType | [ job > audience > streams > stream (videoStream) ] |
VBR encoding types provide higher quality but are not as well suited to low bit rate streaming situations and can cause network congestion due to spikes in bit rate when streaming. Use CBR for low bandwidth dial-up streaming, VBR constrained types for streaming at higher bit rates where network capacity is available, VBR unconstrained types for download. The quality versus bitrate types allow the output to be targeted towards a specified level of quality or a specified file size.
Default:
cbr
Values:
cbr, vbrBitrate, vbrQuality, vbrUnconstrainedQuality, or vbrUnconstrainedBitrate
Type:
string
Example:
<encodingType type="string">cbr</encodingType>
encodingComplexity | [ job > audience > streams > stream (videoStream) ] |
A measure of how hard the codec will work to achieve the desired result. The specific result varies according to the codec. For some codecs, like RealVideo, the result is quality. For other codecs, like RealAudio Lossless codec, the result is file size.
For the RealVideo codec, the value of encodingComplexity affects the resulting quality and how long it takes to encode. An encodingComplexity of low will take the least amount of time and result in the lowest quality. An encodingComplexity of high will take the most amount of time and result in the best quality.
For file to file encoding, encoding complexity has an impact on how long it takes to encode. For live capture or broadcast, encoding complexity affects the amount of CPU consumed by the encoder. If the system has insufficient CPU, Producer will automatically adjust the encoding complexity down and print warnings when it does so.
Default:
high
Values:
low, medium and high
Type:
string
Example:
<encodingComplexity type="string">high</encodingComplexity>
quality | [ job > audience > streams > stream (videoStream) ] |
Target Video Picture Quality. Target quality at which the codec will attempt to encode the file at. Ideal for files intended for download. Acceptable for live streams only under conditions where network allows for large spikes in bit rate (maxBitrate may be applied to limit impact on network). Quality is a measure of how well the original picture quality is reproduced in the output video image. A quality value of 0 represents a low quality reproduction and a quality value of 100 represents a near perfect reproduction. The encoding may or may not achieve the target quality objective depending on the frame size and target video frame rate. Applies only if encodingType is quality.
Default:
No Default
Values:
Any positive integer value from 1-100
Type:
uint
Example:
<quality type="uint">90</quality>
maxStartupLatency | [ job > audience > streams > stream (videoStream) ] |
Maximum Player Startup Latency. The maximum time in seconds the clip will pre-buffer before playing begins. The larger the value, the longer the user will wait but the better the quality. For download, this can be set to the maximum value with no penalty in start up time. Large values of pre-roll will allow the codec the freedom to spend more bits during high action scenes and hence increase the quality during difficult segments of the content. Specifically the codec can borrow bits from slow scenes of video and spend them in high action scenes where it needs more bits to achieve the desired quality.
Default:
4
Values:
Any number value between 4-25.0
Type:
double
Example:
<maxStartupLatency type="double">4.0</maxStartupLatency>
maxFrameRate | [ job > audience > streams > stream (videoStream) ] |
Maximum Target Frame Rate. The maximum frame rate that the codec will attempt to reach. While the codec will attempt to reach this frame rate and maintain it, the resulting frame rate may be lower than requested if the bit rate is not high enough to achieve a baseline level of quality. The higher the bit rate, the more likely it is the codec will be able to achieve the frame rate specified.
Default:
30
Values:
Any positive number from 0-60.000
Type:
double
Example:
<maxFrameRate type="double">15.0</maxFrameRate>
maxKeyFrameInterval | [ job > audience > streams > stream (videoStream) ] |
The maximum amount of time in seconds between when keyframes are inserted into a RealMedia file. Key frames encode the entire image in one frame. Between key frames are delta frames that encode only the region of the image that has changed since the last delta frame. Because delta frames do not repaint the entire image, a lost packet does result in a defect in a small region of the video that may not get corrected until the next key frame. Key frames are useful to recover from cumulative errors in the video resulting from packet loss. The RealVideo codec typically inserts a key frame when it detects as scene change but will also insert a key frame as needed to ensure that the maxKeyFrameInterval value is not exceeded. Use this setting to force more key frames than will normally be inserted into a media file. This will give the media file more resilience to packet loss.
Default:
10
Values:
Any positive number from 0-60.000
Type:
double
Example:
<maxKeyFrameInterval type="double">10</maxKeyFrameInterval>
enableLossProtection | [ job > audience > streams > stream (videoStream) ] |
Use this enableLossProtection option when you want to protect against packet loss between the server and the player.
Default:
false
Values:
Any valid Boolean Value
Type:
bool
Example:
<enableLossProtection type="bool">false</enableLossProtection>
Because users primarily care about the total bit rate, the total bit rate is defined for all streams and the user is not required to enter a video bit rate. The video bit rate is then computed automatically based on the audio codec bit rate chosen at run time and any other streams defined in the audience. Using this scheme, the user can rely on the total bit rate always being the same while the video bit rate various according to which audio stream is used under given encoding conditions.
The following formulas are used to compute the video bit rate for given encoding session:
Average Video Bit Rate = avgBitrate - [ Audio Codec Bit Rate ]
Max VBR Video Bit Rate = vbrMaxBitrate - [ Audio Codec Bit Rate ]
Event and Image Map bit rate, if any, are also subtraced from the total bit rate. The audio codec is selected from the available audio streams at run time as discussed in Selecting Audio Codecs.
When encoding, only the streams that are needed based on the current settings of audioMode and presentationType are required (see Selecting Audio Codecs).
Note: Setting maxBitrate equal to avgBitrate is the same as constant
bit rate and forces the RealPlayer to assume a
constant bit rate audience.
When combining the audio and video streams from multiple audiences the following rules apply. These rules are only applied to the streams that are needed based on the current settings of audioMode and presentationType.
Event Stream Section |
[ job > audience > streams > stream ] |
The stream section of xsi:type eventStream defines settings for an event transform filter. It contains two properties. The outline below shows the structure of the event stream section.
pluginName | [ job > audience > streams > stream (eventStream) ] |
Event Stream Plug-in Name. The name of the event transform plug-in that is to be used. This is a way to uniquely identify event transform plug-in.
Default:
rn-transform-events
Values:
rn-transform-event or a
valid plug-in name.
Type:
string
Example:
<pluginName type="string">rn-event-tranform</pluginName>
avgBitrate | [ job > audience > streams > stream (eventStream) ] |
Bit rate for event stream in bps.
Default:
200
Values:
Any number value from 1-1000
Type:
double
Example:
<avgBitrate type="uint">200</avgBitrate>
Image Map Stream Section |
[ job > audience > streams > stream ] |
The stream section of xsi:type imageMap defines settings for an image map transform filter. It contains two properties. The outline below shows the structure of the image map stream section.
pluginName | [ job > audience > streams > stream (imageMapStream) ] |
Image Map Stream Plug-in Name. The name of the image map transform plug-in that is to be used. This is a way to uniquely identify image map transform plug-in.
Default:
rn-transform-imagemap
Values:
rn-transform-imagemap or a
valid plug-in name.
Type:
string
Example:
<pluginName type="string">rn-imagemap-tranform</pluginName>
avgBitrate | [ job > audience > streams > stream (imageMapStream) ] |
Bit rate for image map stream in bps.
Default:
400
Values:
Any number value from 1-1000
Type:
double
Example:
<avgBitrate type="uint">200</avgBitrate>
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Audience files are given a special file extension. The file extension for an audience file is ".rpad".
Audiences are located in the audiences directory. The audiences directory is defined in the preferences file (producer.pref). By default, the audiences directory is located in the main application directory.
A Schema is a document that describes the format of an XML document. It specifies almost everything about an XML document structure. The syntax of the document itself is defined by simple XML rules. Schemas are useful in identifying syntax and structure errors in an XML document. XML Schema Part 0 Primer <http://www.w3.org/TR/xmlschema-0/> from WC3's website is an excellent introduction to XML Schemas provided by the W3C. There are also many good books on the subject.
Schemas are defined by the WC3. More information about the XML Schemas can be found at http://www.w3.org/XML/Schema. At this site you will find a list of tools that support both XML document validation based on Schemas as well as tools that allow one to edit XML documents based on an XML Schema.
While Helix DNA Producer itself does not perform XML Schema validation, Helix DNA Producer ships with an XML 1.0 compliant XML Schema for the audience file. This Schema file can be used to validate audience files and ensure their accuracy before putting into production. There are even tools that allow editing of XML documents based on XML Schemas. Products like XML Spy can enable a audience file to be edited and provide interactive information on the structure of the file as you build it.
Information on how to edit XML files is available in the Editing XML Files Reference. The audience file XML Schema can be found in the samples directory in Helix DNA Producer application installation directory.
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