Group PJMEDIA_VID_CODEC

group PJMEDIA_VID_CODEC

Defines

PJMEDIA_VID_CODEC_MAX_DEC_FMT_CNT
PJMEDIA_VID_CODEC_MAX_FPS_CNT
PJMEDIA_VID_CODEC_MGR_MAX_CODECS

Declare maximum codecs

Typedefs

typedef struct pjmedia_vid_codec_mgr pjmedia_vid_codec_mgr

Opaque declaration for codec manager.

Enums

enum pjmedia_vid_packing

This enumeration specifies the packetization property of video encoding process. The value is bitmask, and smaller value will have higher priority to be used.

Values:

PJMEDIA_VID_PACKING_UNKNOWN

This specifies that the packetization is unknown, or if nothing is supported.

PJMEDIA_VID_PACKING_PACKETS = 1

This specifies that the result of video encoding process will be segmented into packets, which is suitable for RTP transmission. The maximum size of the packets is set in enc_mtu field of pjmedia_vid_codec_param.

PJMEDIA_VID_PACKING_WHOLE = 2

This specifies that video encoding function will produce a whole or full frame from the source frame. This is normally used for encoding video for offline storage such as to an AVI file. The maximum size of the packets is set in enc_mtu field of pjmedia_vid_codec_param.

enum pjmedia_vid_frm_bit_info

Enumeration of video frame info flag for the bit_info field in the pjmedia_frame.

Values:

PJMEDIA_VID_FRM_KEYFRAME = 1

The video frame is keyframe.

Functions

pjmedia_vid_codec_param *pjmedia_vid_codec_param_clone(pj_pool_t *pool, const pjmedia_vid_codec_param *src)

Duplicate video codec parameter.

Return

Duplicated codec parameter.

Parameters
  • pool: The pool.

  • src: The video codec parameter to be duplicated.

pj_status_t pjmedia_vid_codec_mgr_create(pj_pool_t *pool, pjmedia_vid_codec_mgr **mgr)

Initialize codec manager. If there is no the default video codec manager, this function will automatically set the default video codec manager to the new codec manager instance. Normally this function is called by pjmedia endpoint’s initialization code.

Return

PJ_SUCCESS on success.

Parameters
  • pool: The pool instance.

  • mgr: The pointer to the new codec manager instance.

pj_status_t pjmedia_vid_codec_mgr_destroy(pjmedia_vid_codec_mgr *mgr)

Destroy codec manager. Normally this function is called by pjmedia endpoint’s deinitialization code.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: Codec manager instance. If NULL, it is the default codec manager instance will be destroyed.

pjmedia_vid_codec_mgr *pjmedia_vid_codec_mgr_instance(void)

Get the default codec manager instance.

Return

The default codec manager instance or NULL if none.

void pjmedia_vid_codec_mgr_set_instance(pjmedia_vid_codec_mgr *mgr)

Set the default codec manager instance.

Parameters
  • mgr: The codec manager instance.

pj_status_t pjmedia_vid_codec_mgr_register_factory(pjmedia_vid_codec_mgr *mgr, pjmedia_vid_codec_factory *factory)

Register codec factory to codec manager. This will also register all supported codecs in the factory to the codec manager.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • factory: The codec factory to be registered.

pj_status_t pjmedia_vid_codec_mgr_unregister_factory(pjmedia_vid_codec_mgr *mgr, pjmedia_vid_codec_factory *factory)

Unregister codec factory from the codec manager. This will also remove all the codecs registered by the codec factory from the codec manager’s list of supported codecs.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • factory: The codec factory to be unregistered.

pj_status_t pjmedia_vid_codec_mgr_enum_codecs(pjmedia_vid_codec_mgr *mgr, unsigned *count, pjmedia_vid_codec_info info[], unsigned *prio)

Enumerate all supported codecs that have been registered to the codec manager by codec factories.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • count: On input, specifies the number of elements in the array. On output, the value will be set to the number of elements that have been initialized by this function.

  • info: The codec info array, which contents will be initialized upon return.

  • prio: Optional pointer to receive array of codec priorities.

pj_status_t pjmedia_vid_codec_mgr_get_codec_info(pjmedia_vid_codec_mgr *mgr, unsigned pt, const pjmedia_vid_codec_info **info)

Get codec info for the specified payload type. The payload type must be static or locally defined in pjmedia_video_pt.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • pt: The payload type/number.

  • info: Pointer to receive codec info.

pj_status_t pjmedia_vid_codec_mgr_get_codec_info2(pjmedia_vid_codec_mgr *mgr, pjmedia_format_id fmt_id, const pjmedia_vid_codec_info **info)

Get codec info for the specified format ID.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • fmt_id: Format ID. See pjmedia_format_id

  • info: Pointer to receive codec info.

char *pjmedia_vid_codec_info_to_id(const pjmedia_vid_codec_info *info, char *id, unsigned max_len)

Convert codec info struct into a unique codec identifier. A codec identifier looks something like “H263/34”, where “H263” is the codec name and “34” is the (default) payload type.

Return

The null terminated codec info string, or NULL if the buffer is not long enough.

Parameters
  • info: The codec info

  • id: Buffer to put the codec info string.

  • max_len: The length of the buffer.

pj_status_t pjmedia_vid_codec_mgr_find_codecs_by_id(pjmedia_vid_codec_mgr *mgr, const pj_str_t *codec_id, unsigned *count, const pjmedia_vid_codec_info *p_info[], unsigned prio[])

Find codecs by the unique codec identifier. This function will find all codecs that match the codec identifier prefix. For example, if “H26” is specified, then it will find “H263”, “H264”, and so on, up to the maximum count specified in the argument.

Return

PJ_SUCCESS if at least one codec info is found.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • codec_id: The full codec ID or codec ID prefix. If an empty string is given, it will match all codecs.

  • count: Maximum number of codecs to find. On return, it contains the actual number of codecs found.

  • p_info: Array of pointer to codec info to be filled. This argument may be NULL, which in this case, only codec count will be returned.

  • prio: Optional array of codec priorities.

pj_status_t pjmedia_vid_codec_mgr_set_codec_priority(pjmedia_vid_codec_mgr *mgr, const pj_str_t *codec_id, pj_uint8_t prio)

Set codec priority. The codec priority determines the order of the codec in the SDP created by the endpoint. If more than one codecs are found with the same codec_id prefix, then the function sets the priorities of all those codecs.

Return

PJ_SUCCESS if at least one codec info is found.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • codec_id: The full codec ID or codec ID prefix. If an empty string is given, it will match all codecs.

  • prio: Priority to be set. The priority can have any value between 1 to 255. When the priority is set to zero, the codec will be disabled.

pj_status_t pjmedia_vid_codec_mgr_get_default_param(pjmedia_vid_codec_mgr *mgr, const pjmedia_vid_codec_info *info, pjmedia_vid_codec_param *param)

Get default codec param for the specified codec info.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • info: The codec info, which default parameter’s is being queried.

  • param: On return, will be filled with the default codec parameter.

pj_status_t pjmedia_vid_codec_mgr_set_default_param(pjmedia_vid_codec_mgr *mgr, const pjmedia_vid_codec_info *info, const pjmedia_vid_codec_param *param)

Set default codec param for the specified codec info.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • pool: The pool instance.

  • info: The codec info, which default parameter’s is being updated.

  • param: The new default codec parameter. Set to NULL to reset codec parameter to library default settings.

pj_status_t pjmedia_vid_codec_mgr_alloc_codec(pjmedia_vid_codec_mgr *mgr, const pjmedia_vid_codec_info *info, pjmedia_vid_codec **p_codec)

Request the codec manager to allocate one instance of codec with the specified codec info. The codec will enumerate all codec factories until it finds factory that is able to create the specified codec.

Return

PJ_SUCCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • info: The information about the codec to be created.

  • p_codec: Pointer to receive the codec instance.

pj_status_t pjmedia_vid_codec_mgr_dealloc_codec(pjmedia_vid_codec_mgr *mgr, pjmedia_vid_codec *codec)

Deallocate the specified codec instance. The codec manager will return the instance of the codec back to its factory.

Return

PJ_SUCESS on success.

Parameters
  • mgr: The codec manager instance. If NULL, the default codec manager instance will be used.

  • codec: The codec instance.

pj_status_t pjmedia_vid_codec_init(pjmedia_vid_codec *codec, pj_pool_t *pool)

Initialize codec using the specified attribute.

Return

PJ_SUCCESS on success.

Parameters
  • codec: The codec instance.

  • pool: Pool to use when the codec needs to allocate some memory.

pj_status_t pjmedia_vid_codec_open(pjmedia_vid_codec *codec, pjmedia_vid_codec_param *param)

Open the codec and initialize with the specified parameter. Upon successful initialization, the codec may modify the parameter and fills in the unspecified values (such as size or frame rate of the encoder format, as it may need to be negotiated with remote preferences via SDP fmtp).

Return

PJ_SUCCESS on success.

Parameters
  • codec: The codec instance.

  • param: Codec initialization parameter.

pj_status_t pjmedia_vid_codec_close(pjmedia_vid_codec *codec)

Close and shutdown codec, releasing all resources allocated by this codec, if any.

Return

PJ_SUCCESS on success.

Parameters
  • codec: The codec instance.

pj_status_t pjmedia_vid_codec_modify(pjmedia_vid_codec *codec, const pjmedia_vid_codec_param *param)

Modify the codec parameter after the codec is open. Note that not all codec parameters can be modified during run-time. When the parameter cannot be changed, this function will return non-PJ_SUCCESS, and the original parameters will not be changed.

Return

PJ_SUCCESS on success.

Parameters
  • codec: The codec instance.

  • param: The new codec parameter.

pj_status_t pjmedia_vid_codec_get_param(pjmedia_vid_codec *codec, pjmedia_vid_codec_param *param)

Get the codec parameter after the codec is opened.

Return

PJ_SUCCESS on success.

Parameters
  • codec: The codec instance.

  • param: The codec parameter.

pj_status_t pjmedia_vid_codec_encode_begin(pjmedia_vid_codec *codec, const pjmedia_vid_encode_opt *opt, const pjmedia_frame *input, unsigned out_size, pjmedia_frame *output, pj_bool_t *has_more)

Encode the specified input frame. The input MUST contain only one picture with the appropriate format as specified when opening the codec. Depending on the packing or packetization set in the packing param, the process may produce multiple encoded packets or payloads to represent the picture. This is true for example for PJMEDIA_VID_PACKING_PACKETS packing. In this case, the has_more field will be set to PJ_TRUE, and application should call pjmedia_vid_codec_encode_more() to get the remaining results from the codec.

Return

PJ_SUCCESS on success;

Parameters
  • codec: The codec instance.

  • opt: Optional encoding options.

  • input: The input frame.

  • out_size: The length of buffer in the output frame. This should be at least the same as the configured encoding MTU of the codec.

  • output: The output frame.

  • has_more: PJ_TRUE if more payloads are available; application should then call pjmedia_vid_codec_encode_more() to retrieve the remaining results.

pj_status_t pjmedia_vid_codec_encode_more(pjmedia_vid_codec *codec, unsigned out_size, pjmedia_frame *output, pj_bool_t *has_more)

Retrieve more encoded packets/payloads from the codec. Application should call this function repeatedly until has_more flag is set to PJ_FALSE.

Return

PJ_SUCCESS on success;

Parameters
  • codec: The codec instance.

  • out_size: The length of buffer in the output frame. This should be at least the same as as the configured encoding MTU of the codec.

  • output: The output frame.

  • has_more: PJ_TRUE if more payloads are available, which in this case application should call encode_more() to retrieve them.

pj_status_t pjmedia_vid_codec_decode(pjmedia_vid_codec *codec, pj_size_t pkt_count, pjmedia_frame packets[], unsigned out_size, pjmedia_frame *output)

Decode the input packets into one picture. If the packing is set to PJMEDIA_VID_PACKING_PACKETS when opening the codec, the codec is set to decode multiple encoded packets into one picture. These encoded packets are typically retrieved from the jitter buffer. If the packing is set to PJMEDIA_VID_PACKING_WHOLE, then this decode function can only accept one frame as the input.

Note that the decoded picture format may different to the configured setting (i.e. the format specified in the pjmedia_vid_codec_param when opening the codec), in this case the PJMEDIA_EVENT_FMT_CHANGED event will be emitted by the codec to notify the event. The codec parameter will also be updated, and application can query the format by using pjmedia_vid_codec_get_param().

Return

PJ_SUCCESS on success;

Parameters
  • codec: The codec instance.

  • pkt_count: Number of packets in the input.

  • packets: Array of input packets, each containing an encoded frame.

  • out_size: The length of buffer in the output frame.

  • output: The output frame.

pj_status_t pjmedia_vid_codec_recover(pjmedia_vid_codec *codec, unsigned out_size, pjmedia_frame *output)

Recover a missing frame.

Return

PJ_SUCCESS on success;

Parameters
  • codec: The codec instance.

  • out_size: The length of buffer in the output frame.

  • output: The output frame where generated signal will be placed.

struct pjmedia_vid_encode_opt
#include <vid_codec.h>

Encoding option.

struct pjmedia_vid_codec_info
#include <vid_codec.h>

Identification used to search for codec factory that supports specific codec specification.

struct pjmedia_vid_codec_param
#include <vid_codec.h>

Detailed codec attributes used in configuring a codec and in querying the capability of codec factories. Default attributes of any codecs could be queried using pjmedia_vid_codec_mgr_get_default_param() and modified using pjmedia_vid_codec_mgr_set_default_param().

Please note that codec parameter also contains SDP specific setting, dec_fmtp and enc_fmtp, which may need to be set appropriately based on the effective setting. See each codec documentation for more detail.

struct pjmedia_vid_codec_op
#include <vid_codec.h>

This structure describes codec operations. Each codec MUST implement all of these functions.

struct pjmedia_vid_codec
#include <vid_codec.h>

This structure describes a video codec instance. Codec implementers should use pjmedia_vid_codec_init() to initialize this structure with default values.

Forward declaration for video codec.

struct pjmedia_vid_codec_factory_op
#include <vid_codec.h>

This structure describes operations that must be supported by codec factories.

struct pjmedia_vid_codec_factory
#include <vid_codec.h>

Codec factory describes a module that is able to create codec with specific capabilities. These capabilities can be queried by codec manager to create instances of codec.