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ffmpeg/libavdevice/avdevice.h

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/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVDEVICE_AVDEVICE_H
#define AVDEVICE_AVDEVICE_H
#include "version.h"
/**
* @file
* @ingroup lavd
* Main libavdevice API header
*/
/**
* @defgroup lavd libavdevice
* Special devices muxing/demuxing library.
*
* Libavdevice is a complementary library to @ref libavf "libavformat". It
* provides various "special" platform-specific muxers and demuxers, e.g. for
* grabbing devices, audio capture and playback etc. As a consequence, the
* (de)muxers in libavdevice are of the AVFMT_NOFILE type (they use their own
* I/O functions). The filename passed to avformat_open_input() often does not
* refer to an actually existing file, but has some special device-specific
* meaning - e.g. for xcbgrab it is the display name.
*
* To use libavdevice, simply call avdevice_register_all() to register all
* compiled muxers and demuxers. They all use standard libavformat API.
*
* @{
*/
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
#include "libavformat/avformat.h"
/**
* Return the LIBAVDEVICE_VERSION_INT constant.
*/
unsigned avdevice_version(void);
/**
* Return the libavdevice build-time configuration.
*/
const char *avdevice_configuration(void);
/**
* Return the libavdevice license.
*/
const char *avdevice_license(void);
/**
* Initialize libavdevice and register all the input and output devices.
*/
void avdevice_register_all(void);
/**
* 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.
*/
AVInputFormat *av_input_audio_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.
*/
AVInputFormat *av_input_video_device_next(AVInputFormat *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.
*/
AVOutputFormat *av_output_audio_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.
*/
AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
typedef struct AVDeviceRect {
int x; /**< x coordinate of top left corner */
int y; /**< y coordinate of top left corner */
int width; /**< width */
int height; /**< height */
} AVDeviceRect;
/**
* Message types used by avdevice_app_to_dev_control_message().
*/
enum AVAppToDevMessageType {
/**
* Dummy message.
*/
AV_APP_TO_DEV_NONE = MKBETAG('N','O','N','E'),
/**
* 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_SIZE = MKBETAG('G','E','O','M'),
/**
* 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_WINDOW_REPAINT = MKBETAG('R','E','P','A'),
/**
* 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_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'),
/**
* 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_SET_VOLUME = MKBETAG('S', 'V', 'O', 'L'),
/**
* 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_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'),
/**
* 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_VOLUME = MKBETAG('G', 'V', 'O', 'L'),
AV_APP_TO_DEV_GET_MUTE = MKBETAG('G', 'M', 'U', 'T'),
};
/**
* Message types used by avdevice_dev_to_app_control_message().
*/
enum AVDevToAppMessageType {
/**
* Dummy message.
*/
AV_DEV_TO_APP_NONE = MKBETAG('N','O','N','E'),
/**
* 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_CREATE_WINDOW_BUFFER = MKBETAG('B','C','R','E'),
/**
* 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_PREPARE_WINDOW_BUFFER = MKBETAG('B','P','R','E'),
/**
* 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_DISPLAY_WINDOW_BUFFER = MKBETAG('B','D','I','S'),
/**
* 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_DESTROY_WINDOW_BUFFER = MKBETAG('B','D','E','S'),
/**
* Buffer fullness status messages.
*
* Device signals buffer overflow/underflow.
*
* data: NULL.
*/
AV_DEV_TO_APP_BUFFER_OVERFLOW = MKBETAG('B','O','F','L'),
AV_DEV_TO_APP_BUFFER_UNDERFLOW = MKBETAG('B','U','F','L'),
/**
* 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_READABLE = MKBETAG('B','R','D',' '),
AV_DEV_TO_APP_BUFFER_WRITABLE = MKBETAG('B','W','R',' '),
/**
* 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_MUTE_STATE_CHANGED = MKBETAG('C','M','U','T'),
/**
* Volume level change message.
*
* Device informs that volume level has changed.
*
* data: double: new volume with range of 0.0 - 1.0.
*/
AV_DEV_TO_APP_VOLUME_LEVEL_CHANGED = MKBETAG('C','V','O','L'),
};
/**
* Send control message from application to device.
*
* @param s device context.
* @param type message type.
* @param data message data. Exact type depends on message type.
* @param data_size size of message data.
* @return >= 0 on success, negative on error.
* AVERROR(ENOSYS) when device doesn't implement handler of the message.
*/
int avdevice_app_to_dev_control_message(struct AVFormatContext *s,
enum AVAppToDevMessageType type,
void *data, size_t data_size);
/**
* Send control message from device to application.
*
* @param s device context.
* @param type message type.
* @param data message data. Can be NULL.
* @param data_size size of message data.
* @return >= 0 on success, negative on error.
* AVERROR(ENOSYS) when application doesn't implement handler of the message.
*/
int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
enum AVDevToAppMessageType type,
void *data, size_t data_size);
#if FF_API_DEVICE_CAPABILITIES
/**
* Following API allows user to probe device capabilities (supported codecs,
* pixel formats, sample formats, resolutions, channel counts, etc).
* It is build on top op AVOption API.
* Queried capabilities make it possible to set up converters of video or audio
* parameters that fit to the device.
*
* List of capabilities that can be queried:
* - Capabilities valid for both audio and video devices:
* - codec: supported audio/video codecs.
* type: AV_OPT_TYPE_INT (AVCodecID value)
* - Capabilities valid for audio devices:
* - sample_format: supported sample formats.
* type: AV_OPT_TYPE_INT (AVSampleFormat value)
* - sample_rate: supported sample rates.
* type: AV_OPT_TYPE_INT
* - channels: supported number of channels.
* type: AV_OPT_TYPE_INT
* - channel_layout: supported channel layouts.
* type: AV_OPT_TYPE_INT64
* - Capabilities valid for video devices:
* - pixel_format: supported pixel formats.
* type: AV_OPT_TYPE_INT (AVPixelFormat value)
* - window_size: supported window sizes (describes size of the window size presented to the user).
* type: AV_OPT_TYPE_IMAGE_SIZE
* - frame_size: supported frame sizes (describes size of provided video frames).
* type: AV_OPT_TYPE_IMAGE_SIZE
* - fps: supported fps values
* type: AV_OPT_TYPE_RATIONAL
*
* Value of the capability may be set by user using av_opt_set() function
* and AVDeviceCapabilitiesQuery object. Following queries will
* limit results to the values matching already set capabilities.
* For example, setting a codec may impact number of formats or fps values
* returned during next query. Setting invalid value may limit results to zero.
*
* Example of the usage basing on opengl output device:
*
* @code
* AVFormatContext *oc = NULL;
* AVDeviceCapabilitiesQuery *caps = NULL;
* AVOptionRanges *ranges;
* int ret;
*
* if ((ret = avformat_alloc_output_context2(&oc, NULL, "opengl", NULL)) < 0)
* goto fail;
* if (avdevice_capabilities_create(&caps, oc, NULL) < 0)
* goto fail;
*
* //query codecs
* if (av_opt_query_ranges(&ranges, caps, "codec", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
* goto fail;
* //pick codec here and set it
* av_opt_set(caps, "codec", AV_CODEC_ID_RAWVIDEO, 0);
*
* //query format
* if (av_opt_query_ranges(&ranges, caps, "pixel_format", AV_OPT_MULTI_COMPONENT_RANGE)) < 0)
* goto fail;
* //pick format here and set it
* av_opt_set(caps, "pixel_format", AV_PIX_FMT_YUV420P, 0);
*
* //query and set more capabilities
*
* fail:
* //clean up code
* avdevice_capabilities_free(&query, oc);
* avformat_free_context(oc);
* @endcode
*/
/**
* Structure describes device capabilities.
*
* It is used by devices in conjunction with av_device_capabilities AVOption table
* to implement capabilities probing API based on AVOption API. Should not be used directly.
*/
typedef struct AVDeviceCapabilitiesQuery {
const AVClass *av_class;
AVFormatContext *device_context;
enum AVCodecID codec;
enum AVSampleFormat sample_format;
enum AVPixelFormat pixel_format;
int sample_rate;
int channels;
int64_t channel_layout;
int window_width;
int window_height;
int frame_width;
int frame_height;
AVRational fps;
} AVDeviceCapabilitiesQuery;
/**
* AVOption table used by devices to implement device capabilities API. Should not be used by a user.
*/
attribute_deprecated
extern const AVOption av_device_capabilities[];
/**
* Initialize capabilities probing API based on AVOption API.
*
* avdevice_capabilities_free() must be called when query capabilities API is
* not used anymore.
*
* @param[out] caps Device capabilities data. Pointer to a NULL pointer must be passed.
* @param s Context of the device.
* @param device_options An 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.
*
* @return >= 0 on success, negative otherwise.
*/
attribute_deprecated
int avdevice_capabilities_create(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s,
AVDictionary **device_options);
/**
* Free resources created by avdevice_capabilities_create()
*
* @param caps Device capabilities data to be freed.
* @param s Context of the device.
*/
attribute_deprecated
void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s);
#endif
/**
* Structure describes basic parameters of the device.
*/
typedef struct AVDeviceInfo {
char *device_name; /**< device name, format depends on device */
char *device_description; /**< human friendly name */
} AVDeviceInfo;
/**
* List of devices.
*/
typedef struct AVDeviceInfoList {
AVDeviceInfo **devices; /**< list of autodetected devices */
int nb_devices; /**< number of autodetected devices */
int default_device; /**< index of default device or -1 if no default */
} AVDeviceInfoList;
/**
* 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.
*
* @param s device context.
* @param[out] device_list list of autodetected devices.
* @return count of autodetected devices, negative on error.
*/
int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list);
/**
* Convenient function to free result of avdevice_list_devices().
*
* @param devices device list to be freed.
*/
void avdevice_free_list_devices(AVDeviceInfoList **device_list);
/**
* List devices.
*
* Returns available device names and their parameters.
* These are convinient wrappers for avdevice_list_devices().
* Device context is allocated and deallocated internally.
*
* @param device device format. May be NULL if device name is set.
* @param device_name device name. May be NULL if device format is set.
* @param device_options An AVDictionary filled with device-private options. 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.
* @param[out] device_list list of autodetected devices
* @return count of autodetected devices, negative on error.
* @note device argument takes precedence over device_name when both are set.
*/
int avdevice_list_input_sources(struct AVInputFormat *device, const char *device_name,
AVDictionary *device_options, AVDeviceInfoList **device_list);
int avdevice_list_output_sinks(struct AVOutputFormat *device, const char *device_name,
AVDictionary *device_options, AVDeviceInfoList **device_list);
/**
* @}
*/
#endif /* AVDEVICE_AVDEVICE_H */
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