/* Copyright (C) 2002 Paul Davis Copyright (C) 2003 Jack O'Quin This program 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. This program 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 this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef __jack_transport_h__ #define __jack_transport_h__ #ifdef __cplusplus extern "C" { #endif #include #include /** * Transport states. */ typedef enum { /* the order matters for binary compatibility */ JackTransportStopped = 0, /**< Transport halted */ JackTransportRolling = 1, /**< Transport playing */ JackTransportLooping = 2, /**< For OLD_TRANSPORT, now ignored */ JackTransportStarting = 3 /**< Waiting for sync ready */ } jack_transport_state_t; typedef uint64_t jack_unique_t; /**< Unique ID (opaque) */ /** * Optional struct jack_position_t fields. */ typedef enum { JackPositionBBT = 0x10, /**< Bar, Beat, Tick */ JackPositionTimecode = 0x20, /**< External timecode */ JackBBTFrameOffset = 0x40, /**< Frame offset of BBT information */ JackAudioVideoRatio = 0x80, /**< audio frames per video frame */ JackVideoFrameOffset = 0x100, /**< frame offset of first video frame */ JackTickDouble = 0x200, /**< double-resolution tick */ } jack_position_bits_t; /** all valid position bits */ #define JACK_POSITION_MASK (JackPositionBBT|JackPositionTimecode|JackBBTFrameOffset|JackAudioVideoRatio|JackVideoFrameOffset) #define EXTENDED_TIME_INFO /** transport tick_double member is available for use */ #define JACK_TICK_DOUBLE /** * Struct for transport position information. */ typedef struct { /*@{*/ /** @name Server-set fields * these cannot be set from clients; the server sets them */ jack_unique_t unique_1; /**< unique ID */ jack_time_t usecs; /**< microsecond timestamp that is guaranteed to be monotonic, but not neccessarily linear. The absolute value is implementation-dependent (i.e. it could be wall-clock, time since jack started, uptime, etc). */ jack_nframes_t frame_rate; /**< current frame rate, in frames per second */ /*}@*/ /*@{*/ /** @name Mandatory fields */ jack_nframes_t frame; /**< frame number, always present/required. This is the frame number on the transport timeline, which is not the same as what @ref jack_frame_time returns. */ jack_position_bits_t valid; /**< which other fields are valid, as a bitmask constructed from values in \ref jack_position_bits_t */ /*}@*/ /*@{*/ /** @name JackPositionBBT fields * Bar:Beat.Tick-related information. * * Applications that support * JackPositionBBT are encouraged to also fill the JackBBTFrameOffset */ int32_t bar; /**< current bar Should be >0: the first bar is bar '1'. */ int32_t beat; /**< current beat-within-bar Should be >0 and <=beats_per_bar: the first beat is beat '1'. */ int32_t tick; /**< current tick-within-beat Should be >= 0 and < ticks_per_beat: the first tick is tick '0'. */ double bar_start_tick; /**< number of ticks that have elapsed between frame 0 and the first beat of the current measure. */ float beats_per_bar; /**< time signature "numerator" */ float beat_type; /**< time signature "denominator" */ double ticks_per_beat; /**< number of ticks within a beat. Usually a moderately large integer with many denominators, such as 1920.0 */ double beats_per_minute; /**< BPM, quantized to block size. This means when the tempo is not constant within this block, the BPM value should adapted to compensate for this. This is different from most fields in this struct, which specify the value at the beginning of the block rather than an average.*/ /*}@*/ /*@{*/ /** @name JackPositionTimecode fields * EXPERIMENTAL: could change */ double frame_time; /**< current time in seconds */ double next_time; /**< next sequential frame_time (unless repositioned) */ /*}@*/ /*@{*/ /* JackBBTFrameOffset fields */ jack_nframes_t bbt_offset; /**< frame offset for the BBT fields (the given bar, beat, and tick values actually refer to a time frame_offset frames before the start of the cycle), should be assumed to be 0 if JackBBTFrameOffset is not set. If JackBBTFrameOffset is set and this value is zero, the BBT time refers to the first frame of this cycle. If the value is positive, the BBT time refers to a frame that many frames before the start of the cycle. */ /*}@*/ /*@{*/ /* JACK video positional data * EXPERIMENTAL: could change */ float audio_frames_per_video_frame; /**< number of audio frames per video frame. Should be assumed zero if JackAudioVideoRatio is not set. If JackAudioVideoRatio is set and the value is zero, no video data exists within the JACK graph */ jack_nframes_t video_offset; /**< audio frame at which the first video frame in this cycle occurs. Should be assumed to be 0 if JackVideoFrameOffset is not set. If JackVideoFrameOffset is set, but the value is zero, there is no video frame within this cycle. */ /*}@*/ /*@{*/ /** @name JACK Extra transport fields */ double tick_double; /**< current tick-within-beat in double resolution. Should be assumed zero if JackTickDouble is not set. Since older versions of JACK do not expose this variable, the macro JACK_TICK_DOUBLE is provided, which can be used as build-time detection. */ /*}@*/ /*@{*/ /** @name Other fields */ /* For binary compatibility, new fields should be allocated from * this padding area with new valid bits controlling access, so * the existing structure size and offsets are preserved. */ int32_t padding[5]; /*}@*/ /* When (unique_1 == unique_2) the contents are consistent. */ jack_unique_t unique_2; /**< unique ID */ } POST_PACKED_STRUCTURE jack_position_t; /** * @defgroup TransportControl Transport and Timebase control * @{ */ /** * Called by the timebase master to release itself from that * responsibility. * * If the timebase master releases the timebase or leaves the JACK * graph for any reason, the JACK engine takes over at the start of * the next process cycle. The transport state does not change. If * rolling, it continues to play, with frame numbers as the only * available position information. * * @see jack_set_timebase_callback * * @param client the JACK client structure. * * @return 0 on success, otherwise a non-zero error code. */ int jack_release_timebase (jack_client_t *client) JACK_OPTIONAL_WEAK_EXPORT; /** * Prototype for the @a sync_callback defined by @ref slowsyncclients * "slow-sync clients". When the client is active, this callback is * invoked just before process() in the same thread. This occurs once * after registration, then subsequently whenever some client requests * a new position, or the transport enters the ::JackTransportStarting * state. This realtime function must not wait. * * The transport @a state will be: * * - ::JackTransportStopped when a new position is requested; * - ::JackTransportStarting when the transport is waiting to start; * - ::JackTransportRolling when the timeout has expired, and the * position is now a moving target. * * @param state current transport state. * @param pos new transport position. * @param arg the argument supplied by jack_set_sync_callback(). * * @return TRUE (non-zero) when ready to roll. */ typedef int (*JackSyncCallback)(jack_transport_state_t state, jack_position_t *pos, void *arg); /** * Register (or unregister) as a @ref slowsyncclients "slow-sync client", that cannot * respond immediately to transport position changes. * * The @a sync_callback will be invoked at the first available * opportunity after its registration is complete. If the client is * currently active this will be the following process cycle, * otherwise it will be the first cycle after calling jack_activate(). * After that, it runs according to the ::JackSyncCallback rules. * Clients that don't set a @a sync_callback are assumed to be ready * immediately any time the transport wants to start. * * @param client the JACK client structure. * @param sync_callback is a realtime function that returns TRUE when * the client is ready. Setting @a sync_callback to NULL declares that * this client no longer requires slow-sync processing. * @param arg an argument for the @a sync_callback function. * * @return 0 on success, otherwise a non-zero error code. */ int jack_set_sync_callback (jack_client_t *client, JackSyncCallback sync_callback, void *arg) JACK_OPTIONAL_WEAK_EXPORT; /** * Set the timeout value for @ref slowsyncclients "slow-sync clients". * * This timeout prevents unresponsive slow-sync clients from * completely halting the transport mechanism. The default is two * seconds. When the timeout expires, the transport starts rolling, * even if some slow-sync clients are still unready. The @a * sync_callbacks of these clients continue being invoked, giving them * a chance to catch up. * * @see jack_set_sync_callback * * @param client the JACK client structure. * @param timeout is delay (in microseconds) before the timeout expires. * * @return 0 on success, otherwise a non-zero error code. */ int jack_set_sync_timeout (jack_client_t *client, jack_time_t timeout) JACK_OPTIONAL_WEAK_EXPORT; /** * Prototype for the @a timebase_callback used to provide extended * position information. Its output affects all of the following * process cycle. This realtime function must not wait. * * This function is called immediately after process() in the same * thread whenever the transport is rolling, or when any client has * requested a new position in the previous cycle. The first cycle * after jack_set_timebase_callback() is also treated as a new * position, or the first cycle after jack_activate() if the client * had been inactive. * * The timebase master may not use its @a pos argument to set @a * pos->frame. To change position, use jack_transport_reposition() or * jack_transport_locate(). These functions are realtime-safe, the @a * timebase_callback can call them directly. * * @param state current transport state. * @param nframes number of frames in current period. * @param pos address of the position structure for the next cycle; @a * pos->frame will be its frame number. If @a new_pos is FALSE, this * structure contains extended position information from the current * cycle. If TRUE, it contains whatever was set by the requester. * The @a timebase_callback's task is to update the extended * information here. * @param new_pos TRUE (non-zero) for a newly requested @a pos, or for * the first cycle after the @a timebase_callback is defined. * @param arg the argument supplied by jack_set_timebase_callback(). */ typedef void (*JackTimebaseCallback)(jack_transport_state_t state, jack_nframes_t nframes, jack_position_t *pos, int new_pos, void *arg); /** * Register as timebase master for the JACK subsystem. * * The timebase master registers a callback that updates extended * position information such as beats or timecode whenever necessary. * Without this extended information, there is no need for this * function. * * There is never more than one master at a time. When a new client * takes over, the former @a timebase_callback is no longer called. * Taking over the timebase may be done conditionally, so it fails if * there was a master already. * * The method may be called whether the client has been activated or not. * * @param client the JACK client structure. * @param conditional non-zero for a conditional request. * @param timebase_callback is a realtime function that returns * position information. * @param arg an argument for the @a timebase_callback function. * * @return * - 0 on success; * - EBUSY if a conditional request fails because there was already a * timebase master; * - other non-zero error code. */ int jack_set_timebase_callback (jack_client_t *client, int conditional, JackTimebaseCallback timebase_callback, void *arg) JACK_OPTIONAL_WEAK_EXPORT; /** * Reposition the transport to a new frame number. * * May be called at any time by any client. The new position takes * effect in two process cycles. If there are @ref slowsyncclients * "slow-sync clients" and the transport is already rolling, it will * enter the ::JackTransportStarting state and begin invoking their @a * sync_callbacks until ready. This function is realtime-safe. * * @see jack_transport_reposition, jack_set_sync_callback * * @param client the JACK client structure. * @param frame frame number of new transport position. * * @return 0 if valid request, non-zero otherwise. */ int jack_transport_locate (jack_client_t *client, jack_nframes_t frame) JACK_OPTIONAL_WEAK_EXPORT; /** * Query the current transport state and position. * * This function is realtime-safe, and can be called from any thread. * If called from the process thread, @a pos corresponds to the first * frame of the current cycle and the state returned is valid for the * entire cycle. * * @param client the JACK client structure. * @param pos pointer to structure for returning current transport * position; @a pos->valid will show which fields contain valid data. * If @a pos is NULL, do not return position information. * * @return Current transport state. */ jack_transport_state_t jack_transport_query (const jack_client_t *client, jack_position_t *pos) JACK_OPTIONAL_WEAK_EXPORT; /** * Return an estimate of the current transport frame, * including any time elapsed since the last transport * positional update. * * @param client the JACK client structure */ jack_nframes_t jack_get_current_transport_frame (const jack_client_t *client) JACK_OPTIONAL_WEAK_EXPORT; /** * Request a new transport position. * * May be called at any time by any client. The new position takes * effect in two process cycles. If there are @ref slowsyncclients * "slow-sync clients" and the transport is already rolling, it will * enter the ::JackTransportStarting state and begin invoking their @a * sync_callbacks until ready. This function is realtime-safe. * * @see jack_transport_locate, jack_set_sync_callback * * @param client the JACK client structure. * @param pos requested new transport position. Fill pos->valid to specify * which fields should be taken into account. If you mark a set of fields * as valid, you are expected to fill them all. * * @return 0 if valid request, EINVAL if position structure rejected. */ int jack_transport_reposition (jack_client_t *client, const jack_position_t *pos) JACK_OPTIONAL_WEAK_EXPORT; /** * Start the JACK transport rolling. * * Any client can make this request at any time. It takes effect no * sooner than the next process cycle, perhaps later if there are * @ref slowsyncclients "slow-sync clients". This function is realtime-safe. * * @see jack_set_sync_callback * * @param client the JACK client structure. */ void jack_transport_start (jack_client_t *client) JACK_OPTIONAL_WEAK_EXPORT; /** * Stop the JACK transport. * * Any client can make this request at any time. It takes effect on * the next process cycle. This function is realtime-safe. * * @param client the JACK client structure. */ void jack_transport_stop (jack_client_t *client) JACK_OPTIONAL_WEAK_EXPORT; /*@}*/ /********************************************************************* * The following interfaces are DEPRECATED. They are only provided * for compatibility with the earlier JACK transport implementation. *********************************************************************/ /** * Optional struct jack_transport_info_t fields. * * @see jack_position_bits_t. */ typedef enum { JackTransportState = 0x1, /**< Transport state */ JackTransportPosition = 0x2, /**< Frame number */ JackTransportLoop = 0x4, /**< Loop boundaries (ignored) */ JackTransportSMPTE = 0x8, /**< SMPTE (ignored) */ JackTransportBBT = 0x10 /**< Bar, Beat, Tick */ } jack_transport_bits_t; /** * Deprecated struct for transport position information. * * @deprecated This is for compatibility with the earlier transport * interface. Use the jack_position_t struct, instead. */ typedef struct { /* these two cannot be set from clients: the server sets them */ jack_nframes_t frame_rate; /**< current frame rate (per second) */ jack_time_t usecs; /**< monotonic, free-rolling */ jack_transport_bits_t valid; /**< which fields are legal to read */ jack_transport_state_t transport_state; jack_nframes_t frame; jack_nframes_t loop_start; jack_nframes_t loop_end; long smpte_offset; /**< SMPTE offset (from frame 0) */ float smpte_frame_rate; /**< 29.97, 30, 24 etc. */ int bar; int beat; int tick; double bar_start_tick; float beats_per_bar; float beat_type; double ticks_per_beat; double beats_per_minute; } jack_transport_info_t; /** * Gets the current transport info structure (deprecated). * * @param client the JACK client structure. * @param tinfo current transport info structure. The "valid" field * describes which fields contain valid data. * * @deprecated This is for compatibility with the earlier transport * interface. Use jack_transport_query(), instead. * * @pre Must be called from the process thread. */ void jack_get_transport_info (jack_client_t *client, jack_transport_info_t *tinfo) JACK_OPTIONAL_WEAK_DEPRECATED_EXPORT; /** * Set the transport info structure (deprecated). * * @deprecated This function still exists for compatibility with the * earlier transport interface, but it does nothing. Instead, define * a ::JackTimebaseCallback. */ void jack_set_transport_info (jack_client_t *client, jack_transport_info_t *tinfo) JACK_OPTIONAL_WEAK_DEPRECATED_EXPORT; #ifdef __cplusplus } #endif #endif /* __jack_transport_h__ */