## gstrtppayloads gstrtppayloads — Helper methods for dealing with RTP payloads |

## Synopsis

    #include <gst/rtp/gstrtppayload.h>

    enum                GstRTPPayload;
    #define             GST_RTP_PAYLOAD_IS_DYNAMIC          (pt)
    struct              GstRTPPayloadInfo;
    const GstRTPPayloadInfo * gst_rtp_payload_info_for_name (const gchar *media,
                                                             const gchar *encoding_name);
    const GstRTPPayloadInfo * gst_rtp_payload_info_for_pt   (guint8 payload_type);

## Description

The GstRTPPayloads helper functions makes it easy to deal with static and dynamic payloads. Its main purpose is to retrieve properties such as the default clock-rate and get session bandwidth information.

Last reviewed on 2007-10-01 (0.10.15)

## Details

### enum GstRTPPayload

    typedef enum {
      /* Audio: */
      GST_RTP_PAYLOAD_PCMU = 0,
      GST_RTP_PAYLOAD_1016 = 1, /* RFC 3551 says reserved */
      GST_RTP_PAYLOAD_G721 = 2, /* RFC 3551 says reserved */
      GST_RTP_PAYLOAD_GSM = 3,
      GST_RTP_PAYLOAD_G723 = 4,
      GST_RTP_PAYLOAD_DVI4_8000 = 5,
      GST_RTP_PAYLOAD_DVI4_16000 = 6,
      GST_RTP_PAYLOAD_LPC = 7,
      GST_RTP_PAYLOAD_PCMA = 8,
      GST_RTP_PAYLOAD_G722 = 9,
      GST_RTP_PAYLOAD_L16_STEREO = 10,
      GST_RTP_PAYLOAD_L16_MONO = 11,
      GST_RTP_PAYLOAD_QCELP = 12,
      GST_RTP_PAYLOAD_CN = 13,
      GST_RTP_PAYLOAD_MPA = 14,
      GST_RTP_PAYLOAD_G728 = 15,
      GST_RTP_PAYLOAD_DVI4_11025 = 16,
      GST_RTP_PAYLOAD_DVI4_22050 = 17,
      GST_RTP_PAYLOAD_G729 = 18,

      /* Video: */

      GST_RTP_PAYLOAD_CELLB = 25,
      GST_RTP_PAYLOAD_JPEG = 26,
      GST_RTP_PAYLOAD_NV = 28,
      GST_RTP_PAYLOAD_H261 = 31,
      GST_RTP_PAYLOAD_MPV = 32,
      GST_RTP_PAYLOAD_MP2T = 33,
      GST_RTP_PAYLOAD_H263 = 34,

      /* BOTH */
    } GstRTPPayload;

Standard predefined fixed payload types.

The official list is at: http://www.iana.org/assignments/rtp-parameters

Audio: reserved: 19 unassigned: 20-23,

Video: unassigned: 24, 27, 29, 30, 35-71, 77-95 Reserved for RTCP conflict avoidance: 72-76

`GST_RTP_PAYLOAD_PCMU` | ITU-T G.711. mu-law audio (RFC 3551)
`GST_RTP_PAYLOAD_1016` | RFC 3551 says reserved
`GST_RTP_PAYLOAD_G721` | RFC 3551 says reserved
`GST_RTP_PAYLOAD_GSM` | GSM audio
`GST_RTP_PAYLOAD_G723` | ITU G.723.1 audio
`GST_RTP_PAYLOAD_DVI4_8000` | IMA ADPCM wave type (RFC 3551)
`GST_RTP_PAYLOAD_DVI4_16000` | IMA ADPCM wave type (RFC 3551)
`GST_RTP_PAYLOAD_LPC` | experimental linear predictive encoding
`GST_RTP_PAYLOAD_PCMA` | ITU-T G.711 A-law audio (RFC 3551)
`GST_RTP_PAYLOAD_G722` | ITU-T G.722 (RFC 3551)
`GST_RTP_PAYLOAD_L16_STEREO` | stereo PCM
`GST_RTP_PAYLOAD_L16_MONO` | mono PCM
`GST_RTP_PAYLOAD_QCELP` | EIA & TIA standard IS-733
`GST_RTP_PAYLOAD_CN` | Comfort Noise (RFC 3389)
`GST_RTP_PAYLOAD_MPA` | Audio MPEG 1-3.
`GST_RTP_PAYLOAD_G728` | ITU-T G.728 Speech coder (RFC 3551)
`GST_RTP_PAYLOAD_DVI4_11025` | IMA ADPCM wave type (RFC 3551)
`GST_RTP_PAYLOAD_DVI4_22050` | IMA ADPCM wave type (RFC 3551)
`GST_RTP_PAYLOAD_G729` | ITU-T G.729 Speech coder (RFC 3551)
`GST_RTP_PAYLOAD_CELLB` | See RFC 2029
`GST_RTP_PAYLOAD_JPEG` | ISO Standards 10918-1 and 10918-2 (RFC 2435)
`GST_RTP_PAYLOAD_NV` | nv encoding by Ron Frederick
`GST_RTP_PAYLOAD_H261` | ITU-T Recommendation H.261 (RFC 2032)
`GST_RTP_PAYLOAD_MPV` | Video MPEG 1 & 2 (RFC 2250)
`GST_RTP_PAYLOAD_MP2T` | MPEG-2 transport stream (RFC 2250)
`GST_RTP_PAYLOAD_H263` | Video H263 (RFC 2190)

### GST_RTP_PAYLOAD_IS_DYNAMIC()

    #define GST_RTP_PAYLOAD_IS_DYNAMIC(pt) ((pt) >= 96 && (pt) <= 127)

Check if `pt` is a dynamic payload type.

`pt` : | a payload type

### struct GstRTPPayloadInfo

    struct GstRTPPayloadInfo {
      guint8       payload_type;
      const gchar *media;
      const gchar *encoding_name;
      guint        clock_rate;
      const gchar *encoding_parameters;
      guint        bitrate;
    };

Structure holding default payload type information.

guint8 `payload_type`; | payload type, -1 means dynamic
const gchar *`media`; | the media type(s), usually "audio", "video", "application", "text", "message".
const gchar *`encoding_name`; | the encoding name of `pt`
guint `clock_rate`; | default clock rate, 0 = unknown/variable
const gchar *`encoding_parameters`; | encoding parameters. For audio this is the number of channels. NULL = not applicable.
guint `bitrate`; | the bitrate of the media. 0 = unknown/variable.

### gst_rtp_payload_info_for_name ()

    const GstRTPPayloadInfo * gst_rtp_payload_info_for_name (const gchar *media,
                                                             const gchar *encoding_name);

Get the GstRTPPayloadInfo for `media` and `encoding_name`. This function is mostly used to get the default clock-rate and bandwidth for dynamic payload types specified with `media` and `encoding` name.

The search for `encoding_name` will be performed in a case insensitve way.

`media` : | the media to find
`encoding_name` : | the encoding name to find
Returns : | a GstRTPPayloadInfo or NULL when no info could be found.

### gst_rtp_payload_info_for_pt ()

    const GstRTPPayloadInfo * gst_rtp_payload_info_for_pt   (guint8 payload_type);

Get the GstRTPPayloadInfo for `payload_type`. This function is mostly used to get the default clock-rate and bandwidth for static payload types specified with `payload_type`.

`payload_type` : | the payload_type to find
Returns : | a GstRTPPayloadInfo or NULL when no info could be found.

## See Also

gstrtpbuffer