/* * 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); /** * 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. */ 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. */ 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. */ void avdevice_capabilities_free(AVDeviceCapabilitiesQuery **caps, AVFormatContext *s); /** * 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 */