Audio Configuration
Picolo U4 H.264 PCI-104 supports the following audio configurations:
- 8-bit μ-law companded audio at 8 kHz (G.711)
- 8-bit A-law companded audio at 8 kHz (G.711)
- 16-bit linear PCM audio at 8 kHz
- 16-bit linear PCM audio at 16 kHz
- 16-bit linear PCM audio at 22.05 kHz
- 16-bit linear PCM audio at 44.1 kHz
- 16-bit linear PCM audio at 48 kHz
The default audio configuration is 6-bit linear PCM 8 kHz.
Child elements of AudioEncoder root element
XML elements |
Attributes |
Content |
Number of occurrences |
Description |
Verbose/VB |
Immediate |
EMPTY |
0/1 |
Syntax that the driver uses to generate this XML file. By default, the driver uses the verbose syntax. |
Active/ACT |
Immediate |
EMPTY |
0/1 |
Controls the audio encoder operation. |
Volume/V |
Immediate |
PCDATA |
0/1 |
Controls the volume. Value range: [25..275]. Default value: 100. |
FormatG711ALAW/G711A |
|
EMPTY |
0/1 |
Selects the audio format. The default format is G.711 A. |
BufferSizeAuto/BSA |
|
EMPTY |
0/1 |
The buffer size is automatically determined by the driver. Its capacity corresponds to 160 milliseconds regardless the sampling rate. This is the default setting. |
BufferSize/BS |
|
PCDATA |
0/1 |
Size, expressed in bytes, of one encoded audio buffer. Default value: 0.(*) |
BufferCount/BC |
|
PCDATA |
0/1 |
Number of encoded audio buffers. Default value: 3. |
BufferOffset/BO |
|
PCDATA |
0/1 |
Address offset of the first data. Default value: 0. |
(*) The buffer is filled with at most 160 millisecond of data regardless the sampling rate.
Child elements of FormatLPCM16 element
XML elements |
Attributes |
Content |
Number of occurrences |
Description |
SamplingRate8KHz/K8 |
|
EMPTY |
0/1 |
Audio sampling rate. (*) The default sampling rate is 8 kHz. |
(*) Each audio source can be configured individually. However, the following restriction applies: The audio sampling frequencies of all the audio sources of a board must belong to one frequency groups. There are two groups:
- The '48 kHz group' contains the following frequencies: 8, 16, and 48 kHz.
- The '44.1 kHz group' contains the following frequencies: 22.05, and 44.1 kHz.
XML File Example
<root>/audio/source*/config.xml Read operation Verbose mode
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE AudioEncoder SYSTEM "config.dtd">
<AudioEncoder version="1.0">
<Verbose Immediate="true"/>
<Idle Immediate="true"/>
<Volume Immediate="true">100</Volume>
<FormatLPCM16><SamplingRate8KHz/></FormatLPCM16>
<BufferSizeAuto/>
<BufferCount>3</BufferCount>
<BufferOffset>0</BufferOffset>
</AudioEncoder>