/* * This file is part of MPlayer. * * MPlayer is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * MPlayer 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 General Public License for more details. * * You should have received a copy of the GNU General Public License along * with MPlayer; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef MP_AO_INTERNAL_H_ #define MP_AO_INTERNAL_H_ #include <stdbool.h> #include "audio/chmap.h" #include "audio/chmap_sel.h" // Minimum buffer size in seconds. #define MIN_BUFFER 0.2 // If ao_get_delay() reaches this value after ao_play() was called with the // AOPLAY_FINAL_CHUNK flag set, the playback core expects that the audio has // all been played. #define AO_EOF_DELAY 0.05 /* global data used by ao.c and ao drivers */ struct ao { int samplerate; struct mp_chmap channels; int format; // one of AF_FORMAT_... int bps; // bytes per second (per plane) int sstride; // size of a sample on each plane // (format_size*num_channels/num_planes) int num_planes; bool probing; // if true, don't fail loudly on init bool untimed; // don't assume realtime playback bool no_persistent_volume; // the AO does the equivalent of af_volume bool per_application_mixer; // like above, but volume persists (per app) int device_buffer; // device buffer in samples (guessed by // common init code if not set by driver) const struct ao_driver *api; // entrypoints to the wrapper (push.c/pull.c) const struct ao_driver *driver; void *priv; struct encode_lavc_context *encode_lavc_ctx; struct input_ctx *input_ctx; struct mp_log *log; // Using e.g. "[ao/coreaudio]" as prefix int buffer; void *api_priv; }; extern const struct ao_driver ao_api_push; extern const struct ao_driver ao_api_pull; /* Note: * * In general, there are two types of audio drivers: * a) push based (the user queues data that should be played) * b) pull callback based (the audio API calls a callback to get audio) * * The ao.c code can handle both. It basically implements two audio paths * and provides a uniform API for them. If ao_driver->play is NULL, it assumes * that the driver uses a callback based audio API, otherwise push based. * * Requirements: * a) Most functions (except ->control) must be provided. ->play is called to * queue audio. ao.c creates a thread to regularly refill audio device * buffers with ->play, but all driver functions are always called under * an exclusive lock. * Mandatory: * init * uninit * reset * get_space * play * get_delay * pause * resume * Optional: * control * drain * b) ->play must be NULL. The driver can start the audio API in init(). The * audio API in turn will start a thread and call a callback provided by the * driver. That callback calls ao_read_data() to get audio data. Most * functions are optional and will be emulated if missing (e.g. pausing * is emulated as silence). ->get_delay and ->get_space are never called. * Mandatory: * init * uninit * resume (starts the audio callback) * Also, the following optional callbacks can be provided: * reset (stops the audio callback, resume() restarts it) * control */ struct ao_driver { // If true, use with encoding only. bool encode; // Name used for --ao. const char *name; // Description shown with --ao=help. const char *description; // Init the device using ao->format/ao->channels/ao->samplerate. If the // device doesn't accept these parameters, you can attempt to negotiate // fallback parameters, and set the ao format fields accordingly. int (*init)(struct ao *ao); // Optional. See ao_control() etc. in ao.c int (*control)(struct ao *ao, enum aocontrol cmd, void *arg); void (*uninit)(struct ao *ao); void (*reset)(struct ao*ao); int (*get_space)(struct ao *ao); int (*play)(struct ao *ao, void **data, int samples, int flags); float (*get_delay)(struct ao *ao); void (*pause)(struct ao *ao); void (*resume)(struct ao *ao); void (*drain)(struct ao *ao); // For option parsing (see vo.h) int priv_size; const void *priv_defaults; const struct m_option *options; }; // These functions can be called by AOs. int ao_play_silence(struct ao *ao, int samples); void ao_need_data(struct ao *ao); void ao_wait_drain(struct ao *ao); int ao_read_data(struct ao *ao, void **data, int samples, int64_t out_time_us); bool ao_chmap_sel_adjust(struct ao *ao, const struct mp_chmap_sel *s, struct mp_chmap *map); bool ao_chmap_sel_get_def(struct ao *ao, const struct mp_chmap_sel *s, struct mp_chmap *map, int num); #endif