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Main libavdevice API header. More...

#include "version.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavformat/avformat.h"

Go to the source code of this file.

Data Structures

struct  AVDeviceRect
 
struct  AVDeviceCapabilitiesQuery
 Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc). More...
 
struct  AVDeviceInfo
 Structure describes basic parameters of the device. More...
 
struct  AVDeviceInfoList
 List of devices. More...
 

Enumerations

enum  AVAppToDevMessageType {
  AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'), AV_APP_TO_DEV_WINDOW_SIZE = MKBETAG('G','E','O','M'), AV_APP_TO_DEV_WINDOW_REPAINT = MKBETAG('R','E','P','A'), AV_APP_TO_DEV_PAUSE = MKBETAG('P', 'A', 'U', ' '),
  AV_APP_TO_DEV_PLAY = MKBETAG('P', 'L', 'A', 'Y'), AV_APP_TO_DEV_TOGGLE_PAUSE = MKBETAG('P', 'A', 'U', 'T'), AV_APP_TO_DEV_SET_VOLUME = MKBETAG('S', 'V', 'O', 'L'), AV_APP_TO_DEV_MUTE = MKBETAG(' ', 'M', 'U', 'T'),
  AV_APP_TO_DEV_UNMUTE = MKBETAG('U', 'M', 'U', 'T'), AV_APP_TO_DEV_TOGGLE_MUTE = MKBETAG('T', 'M', 'U', 'T'), AV_APP_TO_DEV_GET_VOLUME = MKBETAG('G', 'V', 'O', 'L'), AV_APP_TO_DEV_GET_MUTE = MKBETAG('G', 'M', 'U', 'T')
}
 Message types used by avdevice_app_to_dev_control_message(). More...
 
enum  AVDevToAppMessageType {
  AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'), AV_DEV_TO_APP_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'), AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'), AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'),
  AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S'), AV_DEV_TO_APP_BUFFER_OVERFLOW = MKBETAG('B','O','F','L'), AV_DEV_TO_APP_BUFFER_UNDERFLOW = MKBETAG('B','U','F','L'), AV_DEV_TO_APP_BUFFER_READABLE = MKBETAG('B','R','D',' '),
  AV_DEV_TO_APP_BUFFER_WRITABLE = MKBETAG('B','W','R',' '), AV_DEV_TO_APP_MUTE_STATE_CHANGED = MKBETAG('C','M','U','T'), AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED = MKBETAG('C','V','O','L')
}
 Message types used by avdevice_dev_to_app_control_message(). More...
 

Functions

unsigned avdevice_version (void)
 Return the LIBAVDEVICE_VERSION_INT constant.
 
const char * avdevice_configuration (void)
 Return the libavdevice build-time configuration.
 
const char * avdevice_license (void)
 Return the libavdevice license.
 
void avdevice_register_all (void)
 Initialize libavdevice and register all the input and output devices.
 
AVInputFormatav_input_audio_device_next (AVInputFormat *d)
 Audio input devices iterator.
 
AVInputFormatav_input_video_device_next (AVInputFormat *d)
 Video input devices iterator.
 
AVOutputFormatav_output_audio_device_next (AVOutputFormat *d)
 Audio output devices iterator.
 
AVOutputFormatav_output_video_device_next (AVOutputFormat *d)
 Video output devices iterator.
 
int avdevice_app_to_dev_control_message (struct AVFormatContext *s, enum AVAppToDevMessageType type, void *data, size_t data_size)
 Send control message from application to device.
 
int avdevice_dev_to_app_control_message (struct AVFormatContext *s, enum AVDevToAppMessageType type, void *data, size_t data_size)
 Send control message from device to application.
 
int avdevice_capabilities_create (AVDeviceCapabilitiesQuery **caps, AVFormatContext *s, AVDictionary **device_options)
 Initialize capabilities probing API based on AVOption API.
 
void avdevice_capabilities_free (AVDeviceCapabilitiesQuery **caps, AVFormatContext *s)
 Free resources created by avdevice_capabilities_create()
 
int avdevice_list_devices (struct AVFormatContext *s, AVDeviceInfoList **device_list)
 List devices.
 
void avdevice_free_list_devices (AVDeviceInfoList **device_list)
 Convenient function to free result of avdevice_list_devices().
 

Variables

const AVOption av_device_capabilities []
 AVOption table used by devices to implement device capabilities API.
 

Detailed Description

Main libavdevice API header.

Definition in file avdevice.h.

Enumeration Type Documentation

Message types used by avdevice_app_to_dev_control_message().

Enumerator:
AV_APP_TO_DEV_NONE 

Dummy message.

AV_APP_TO_DEV_WINDOW_SIZE 

Window size change message.

Message is sent to the device every time the application changes the size of the window device renders to. Message should also be sent right after window is created.

data: AVDeviceRect: new window size.

AV_APP_TO_DEV_WINDOW_REPAINT 

Repaint request message.

Message is sent to the device when window has to be repainted.

data: AVDeviceRect: area required to be repainted. NULL: whole area is required to be repainted.

AV_APP_TO_DEV_PAUSE 

Request pause/play.

Application requests pause/unpause playback. Mostly usable with devices that have internal buffer. By default devices are not paused.

data: NULL

AV_APP_TO_DEV_PLAY 
AV_APP_TO_DEV_TOGGLE_PAUSE 
AV_APP_TO_DEV_SET_VOLUME 

Volume control message.

Set volume level. It may be device-dependent if volume is changed per stream or system wide. Per stream volume change is expected when possible.

data: double: new volume with range of 0.0 - 1.0.

AV_APP_TO_DEV_MUTE 

Mute control messages.

Change mute state. It may be device-dependent if mute status is changed per stream or system wide. Per stream mute status change is expected when possible.

data: NULL.

AV_APP_TO_DEV_UNMUTE 
AV_APP_TO_DEV_TOGGLE_MUTE 
AV_APP_TO_DEV_GET_VOLUME 

Get volume/mute messages.

Force the device to send AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED or AV_DEV_TO_APP_MUTE_STATE_CHANGED command respectively.

data: NULL.

AV_APP_TO_DEV_GET_MUTE 

Definition at line 118 of file avdevice.h.

Message types used by avdevice_dev_to_app_control_message().

Enumerator:
AV_DEV_TO_APP_NONE 

Dummy message.

AV_DEV_TO_APP_CREATE_WINDOW_BUFFER 

Create window buffer message.

Device requests to create a window buffer. Exact meaning is device- and application-dependent. Message is sent before rendering first frame and all one-shot initializations should be done here. Application is allowed to ignore preferred window buffer size.

Note
: Application is obligated to inform about window buffer size with AV_APP_TO_DEV_WINDOW_SIZE message.

data: AVDeviceRect: preferred size of the window buffer. NULL: no preferred size of the window buffer.

AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER 

Prepare window buffer message.

Device requests to prepare a window buffer for rendering. Exact meaning is device- and application-dependent. Message is sent before rendering of each frame.

data: NULL.

AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER 

Display window buffer message.

Device requests to display a window buffer. Message is sent when new frame is ready to be displayed. Usually buffers need to be swapped in handler of this message.

data: NULL.

AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER 

Destroy window buffer message.

Device requests to destroy a window buffer. Message is sent when device is about to be destroyed and window buffer is not required anymore.

data: NULL.

AV_DEV_TO_APP_BUFFER_OVERFLOW 

Buffer fullness status messages.

Device signals buffer overflow/underflow.

data: NULL.

AV_DEV_TO_APP_BUFFER_UNDERFLOW 
AV_DEV_TO_APP_BUFFER_READABLE 

Buffer readable/writable.

Device informs that buffer is readable/writable. When possible, device informs how many bytes can be read/write.

Warning
Device may not inform when number of bytes than can be read/write changes.

data: int64_t: amount of bytes available to read/write. NULL: amount of bytes available to read/write is not known.

AV_DEV_TO_APP_BUFFER_WRITABLE 
AV_DEV_TO_APP_MUTE_STATE_CHANGED 

Mute state change message.

Device informs that mute state has changed.

data: int: 0 for not muted state, non-zero for muted state.

AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED 

Volume level change message.

Device informs that volume level has changed.

data: double: new volume with range of 0.0 - 1.0.

Definition at line 197 of file avdevice.h.

Function Documentation

unsigned avdevice_version ( void  )

Return the LIBAVDEVICE_VERSION_INT constant.

Definition at line 63 of file avdevice.c.

const char* avdevice_configuration ( void  )

Return the libavdevice build-time configuration.

Definition at line 69 of file avdevice.c.

const char* avdevice_license ( void  )

Return the libavdevice license.

Definition at line 74 of file avdevice.c.

void avdevice_register_all ( void  )

Initialize libavdevice and register all the input and output devices.

Warning
This function is not thread safe.

Definition at line 40 of file alldevices.c.

Referenced by main().

AVInputFormat* av_input_audio_device_next ( AVInputFormat d)

Audio input devices iterator.

If d is NULL, returns the first registered input audio/video device, if d is non-NULL, returns the next registered input audio/video device after d or NULL if d is the last one.

Definition at line 102 of file avdevice.c.

AVInputFormat* av_input_video_device_next ( AVInputFormat d)

Video input devices iterator.

If d is NULL, returns the first registered input audio/video device, if d is non-NULL, returns the next registered input audio/video device after d or NULL if d is the last one.

Definition at line 108 of file avdevice.c.

AVOutputFormat* av_output_audio_device_next ( AVOutputFormat d)

Audio output devices iterator.

If d is NULL, returns the first registered output audio/video device, if d is non-NULL, returns the next registered output audio/video device after d or NULL if d is the last one.

Definition at line 114 of file avdevice.c.

AVOutputFormat* av_output_video_device_next ( AVOutputFormat d)

Video output devices iterator.

If d is NULL, returns the first registered output audio/video device, if d is non-NULL, returns the next registered output audio/video device after d or NULL if d is the last one.

Definition at line 120 of file avdevice.c.

int avdevice_app_to_dev_control_message ( struct AVFormatContext s,
enum AVAppToDevMessageType  type,
void data,
size_t  data_size 
)

Send control message from application to device.

Parameters
sdevice context.
typemessage type.
datamessage data. Exact type depends on message type.
data_sizesize of message data.
Returns
>= 0 on success, negative on error. AVERROR(ENOSYS) when device doesn't implement handler of the message.

Definition at line 126 of file avdevice.c.

int avdevice_dev_to_app_control_message ( struct AVFormatContext s,
enum AVDevToAppMessageType  type,
void data,
size_t  data_size 
)

Send control message from device to application.

Parameters
sdevice context.
typemessage type.
datamessage data. Can be NULL.
data_sizesize of message data.
Returns
>= 0 on success, negative on error. AVERROR(ENOSYS) when application doesn't implement handler of the message.

Definition at line 134 of file avdevice.c.

Referenced by opengl_create_window(), opengl_draw(), opengl_release_window(), opengl_resize(), opengl_write_header(), opengl_write_trailer(), pulse_audio_sink_input_cb(), pulse_overflow(), pulse_stream_writable(), pulse_underflow(), and pulse_write_packet().

int avdevice_capabilities_create ( AVDeviceCapabilitiesQuery **  caps,
AVFormatContext s,
AVDictionary **  device_options 
)

Initialize capabilities probing API based on AVOption API.

avdevice_capabilities_free() must be called when query capabilities API is not used anymore.

Parameters
[out]capsDevice capabilities data. Pointer to a NULL pointer must be passed.
sContext of the device.
device_optionsAn AVDictionary filled with device-private options. On return this parameter will be destroyed and replaced with a dict containing options that were not found. May be NULL. The same options must be passed later to avformat_write_header() for output devices or avformat_open_input() for input devices, or at any other place that affects device-private options.
Returns
>= 0 on success, negative otherwise.

Definition at line 142 of file avdevice.c.

void avdevice_capabilities_free ( AVDeviceCapabilitiesQuery **  caps,
AVFormatContext s 
)

Free resources created by avdevice_capabilities_create()

Parameters
capsDevice capabilities data to be freed.
sContext of the device.

Definition at line 171 of file avdevice.c.

int avdevice_list_devices ( struct AVFormatContext s,
AVDeviceInfoList **  device_list 
)

List devices.

Returns available device names and their parameters.

Note
: Some devices may accept system-dependent device names that cannot be autodetected. The list returned by this function cannot be assumed to be always completed.
Parameters
sdevice context.
[out]device_listlist of autodetected devices.
Returns
count of autodetected devices, negative on error.

Definition at line 186 of file avdevice.c.

void avdevice_free_list_devices ( AVDeviceInfoList **  device_list)

Convenient function to free result of avdevice_list_devices().

Parameters
devicesdevice list to be freed.

Definition at line 211 of file avdevice.c.

Referenced by avdevice_list_devices().

Variable Documentation

const AVOption av_device_capabilities[]

AVOption table used by devices to implement device capabilities API.

Should not be used by a user.

Definition at line 35 of file avdevice.c.