rawaudioparse: GStreamer Base Plugins 1.0 Plugins Reference Manual

## rawaudioparse rawaudioparse |

## Properties

GValueArray * | channel-positions | Read / Write
GstRawAudioParseFormat | format | Read / Write
gboolean | interleaved | Read / Write
gint | num-channels | Read / Write
GstAudioFormat | pcm-format | Read / Write
gint | sample-rate | Read / Write

## Types and Values

struct | GstRawAudioParse

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GstObject
                ╰── GstElement
                    ╰── GstBaseParse
                        ╰── GstRawBaseParse
                            ╰── GstRawAudioParse

## Description

This element parses incoming data as raw audio samples and timestamps it. It also handles seek queries in said raw audio data, and ensures that output buffers contain an integer number of samples, even if the input buffers don't. For example, with sample format S16LE and 2 channels, an input buffer of 411 bytes contains 102.75 samples. rawaudioparse will then output 102 samples (= 408 bytes) and keep the remaining 3 bytes. These will then be prepended to the next input data.

The element implements the properties and sink caps configuration as specified in the GstRawBaseParse documentation. The properties configuration can be modified by using the sample-rate, num-channels, channel-positions, format, and pcm-format properties.

Currently, this parser supports raw data in a-law, mu-law, or linear PCM format.

To facilitate operation with the unalignedaudioparse element, rawaudioparse supports the "audio/x-unaligned-raw" media type. This is treated identically to "audio/x-raw", except that it is used by source elements which do not guarantee that the buffers they push out are timestamped and contain an integer amount of samples (see the 411 bytes example above). By using a different media type, it is guaranteed that unalignedaudioparse is autoplugged, making sure that the autoplugged chain does not push unparsed content downstream. The source caps' media type with linear PCM data is always "audio/x-raw", even if the sink caps use "audio/x-unaligned-raw".

The channel-positions property can be used to set explicit position information for each channel. If the array that is passed to this property does not match the number of channels indicated by num-channels, then said number of channels is updated to the array length. If channel-positions is NULL, then the default GStreamer positioning is used. This property is also useful for swapping left and right in a stereo signal for example.

#### Example pipelines

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    gst-launch-1.0 souphttpsrc http://my-dlna-server/track.l16 \
        rawaudioparse ! audioconvert ! audioresample ! autoaudiosink

Receive L16 data from a DLNA server, parse and timestamp it with rawaudioparse, and play it. use-sink-caps is set to true since souphttpsrc will set its source pad's caps to audio/x-unaligned-raw for the L16 stream.

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    gst-launch-1.0 filesrc location=audio.raw ! rawaudioparse use-sink-caps=false \
            format=pcm pcm-format=s16le sample-rate=48000 num-channels=2 \
            audioconvert ! audioresample ! autoaudiosink

Read raw data from a local file and parse it as PCM data with 48000 Hz sample rate, signed 16 bit integer samples, and 2 channels. use-sink-caps is set to false to ensure the property information is used and the parser does not expect audio/x-raw or audio/x-unaligned-raw caps.

## Synopsis

### Element Information

plugin | rawparse
author | Carlos Rafael Giani <dv@pseudoterminal.org>
class | Codec/Parser/Audio

### Element Pads

name | sink
direction | sink
presence | always
details | audio/x-unaligned-raw, format=(string){ S8, U8, S16LE, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string){ interleaved, non-interleaved }
| audio/x-raw, format=(string){ S8, U8, S16LE, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string){ interleaved, non-interleaved }
| audio/x-alaw, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]
| audio/x-mulaw, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]

name | src
direction | source
presence | always
details | audio/x-raw, format=(string){ S8, U8, S16LE, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE }, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string){ interleaved, non-interleaved }
| audio/x-alaw, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]
| audio/x-mulaw, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]

## Functions

## Types and Values

### struct GstRawAudioParse

    struct GstRawAudioParse;

## Property Details

### The `“channel-positions”` property

      “channel-positions”        GValueArray *

Channel positions used on the output.

Owner: GstRawAudioParse

Flags: Read / Write

### The `“format”` property

      “format”                   GstRawAudioParseFormat

Format of the raw audio stream.

Owner: GstRawAudioParse

Flags: Read / Write

Default value: PCM

### The `“interleaved”` property

      “interleaved”              gboolean

True if audio has interleaved layout.

Owner: GstRawAudioParse

Flags: Read / Write

Default value: TRUE

### The `“num-channels”` property

      “num-channels”             gint

Number of channels in raw stream.

Owner: GstRawAudioParse

Flags: Read / Write

Allowed values: >= 1

Default value: 2

### The `“pcm-format”` property

      “pcm-format”               GstAudioFormat

Format of audio samples in PCM stream (ignored if format property is not set to pcm).

Owner: GstRawAudioParse

Flags: Read / Write

Default value: GST_AUDIO_FORMAT_UNKNOWN

### The `“sample-rate”` property

      “sample-rate”              gint

Rate of audio samples in raw stream.

Owner: GstRawAudioParse

Flags: Read / Write

Allowed values: >= 1

Default value: 44100