diff options
Diffstat (limited to 'stream.h')
| -rw-r--r-- | stream.h | 75 |
1 files changed, 75 insertions, 0 deletions
@@ -25,6 +25,12 @@ struct uvc_device; struct uvc_function_config; struct v4l2_device; +/* + * struct uvc_stream - Representation of a UVC stream + * @cap: V4L2 capture device + * @uvc: UVC V4L2 output device + * @events: struct events containing event information + */ struct uvc_stream { struct v4l2_device *cap; @@ -33,14 +39,83 @@ struct uvc_stream struct events *events; }; +/* + * uvc_stream_new - Create a new UVC stream + * @uvc_device: Filename of UVC device node + * @cap_device: Filename of V4L2 capture device node + * + * Create a new UVC stream with V4L2 @uvc_device as the output and @cap_device + * as input. + * + * Streams allocated with this function can be deleted with uvc_stream_delete(). + * + * On success, returns a pointer to newly allocated and populated struct uvc_stream. + * On failure, returns NULL. + */ struct uvc_stream *uvc_stream_new(const char *uvc_device, const char *cap_device); + +/* + * uvc_stream_init_uvc - Initialize a UVC stream + * @stream: the UVC stream + * @fc: UVC function configuration + * + * Before it can be used, a UVC stream has to be initialized by calling this + * function with a UVC function configuration @fc. The function configuration + * contains all the parameters of the UVC function that will be handled by the + * UVC stream. It can be parsed from the UVC function ConfigFS directory using + * configfs_parse_uvc_function(). + */ void uvc_stream_init_uvc(struct uvc_stream *stream, struct uvc_function_config *fc); + +/* + * uvc_stream_set_event_handler - Set an event handler for a stream + * @stream: the UVC stream + * @events: the event handler + * + * This function sets the event handler that the stream can use to be notified + * of file descriptor events. Event notifiers can be registered by this + * function, the caller must ensure that the event handler is immediately + * usable. If the event loop is already running, all initialization steps + * required to handle events must be fully performed before calling this + * function. + */ void uvc_stream_set_event_handler(struct uvc_stream *stream, struct events *events); + +/* + * uvc_stream_delete - Delete a UVC stream + * @stream: the UVC stream + * + * This functions deletes the @stream created with uvc_stream_new(). Upon return + * the stream object may be freed, the @stream pointer thus becomes invalid and + * the stream must not be touched anymore. + * + * Every stream allocated with uvc_stream_new() must be deleted when not needed + * anymore. + */ void uvc_stream_delete(struct uvc_stream *stream); + +/* + * uvc_stream_set_format - Set the active video format for the stream + * @stream: the UVC stream + * + * This function is called from the UVC protocol handler to configure the video + * format for the @stream. It must not be called directly by applications. + * + * Returns 0 on success, or a negative error code on failure. + */ int uvc_stream_set_format(struct uvc_stream *stream); + +/* + * uvc_stream_enable - Turn on/off video streaming for the UVC stream + * @stream: the UVC stream + * @enable: 0 to stop the stream, 1 to start it + * + * This function is called from the UVC protocol handler to start video transfer + * for the @stream. It must not be called directly by applications. + */ void uvc_stream_enable(struct uvc_stream *stream, int enable); #endif /* __STREAM_H__ */ |