diff options
Diffstat (limited to 'libmpv2/libmpv2-sys/include/stream_cb.h')
| -rw-r--r-- | libmpv2/libmpv2-sys/include/stream_cb.h | 392 |
1 files changed, 200 insertions, 192 deletions
diff --git a/libmpv2/libmpv2-sys/include/stream_cb.h b/libmpv2/libmpv2-sys/include/stream_cb.h index 4257b40..86e8496 100644 --- a/libmpv2/libmpv2-sys/include/stream_cb.h +++ b/libmpv2/libmpv2-sys/include/stream_cb.h @@ -17,154 +17,159 @@ #include "client.h" #ifdef __cplusplus -extern "C" { +extern "C" +{ #endif -/** - * Warning: this API is not stable yet. - * - * Overview - * -------- - * - * This API can be used to make mpv read from a stream with a custom - * implementation. This interface is inspired by funopen on BSD and - * fopencookie on linux. The stream is backed by user-defined callbacks - * which can implement customized open, read, seek, size and close behaviors. - * - * Usage - * ----- - * - * Register your stream callbacks with the mpv_stream_cb_add_ro() function. You - * have to provide a mpv_stream_cb_open_ro_fn callback to it (open_fn argument). - * - * Once registered, you can `loadfile myprotocol://myfile`. Your open_fn will be - * invoked with the URI and you must fill out the provided mpv_stream_cb_info - * struct. This includes your stream callbacks (like read_fn), and an opaque - * cookie, which will be passed as the first argument to all the remaining - * stream callbacks. - * - * Note that your custom callbacks must not invoke libmpv APIs as that would - * cause a deadlock. (Unless you call a different mpv_handle than the one the - * callback was registered for, and the mpv_handles refer to different mpv - * instances.) - * - * Stream lifetime - * --------------- - * - * A stream remains valid until its close callback has been called. It's up to - * libmpv to call the close callback, and the libmpv user cannot close it - * directly with the stream_cb API. - * - * For example, if you consider your custom stream to become suddenly invalid - * (maybe because the underlying stream died), libmpv will continue using your - * stream. All you can do is returning errors from each callback, until libmpv - * gives up and closes it. - * - * Protocol registration and lifetime - * ---------------------------------- - * - * Protocols remain registered until the mpv instance is terminated. This means - * in particular that it can outlive the mpv_handle that was used to register - * it, but once mpv_terminate_destroy() is called, your registered callbacks - * will not be called again. - * - * Protocol unregistration is finished after the mpv core has been destroyed - * (e.g. after mpv_terminate_destroy() has returned). - * - * If you do not call mpv_terminate_destroy() yourself (e.g. plugin-style code), - * you will have to deal with the registration or even streams outliving your - * code. Here are some possible ways to do this: - * - call mpv_terminate_destroy(), which destroys the core, and will make sure - * all streams are closed once this function returns - * - you refcount all resources your stream "cookies" reference, so that it - * doesn't matter if streams live longer than expected - * - create "cancellation" semantics: after your protocol has been unregistered, - * notify all your streams that are still opened, and make them drop all - * referenced resources - then return errors from the stream callbacks as - * long as the stream is still opened - * - */ - -/** - * Read callback used to implement a custom stream. The semantics of the - * callback match read(2) in blocking mode. Short reads are allowed (you can - * return less bytes than requested, and libmpv will retry reading the rest - * with another call). If no data can be immediately read, the callback must - * block until there is new data. A return of 0 will be interpreted as final - * EOF, although libmpv might retry the read, or seek to a different position. - * - * @param cookie opaque cookie identifying the stream, - * returned from mpv_stream_cb_open_fn - * @param buf buffer to read data into - * @param size of the buffer - * @return number of bytes read into the buffer - * @return 0 on EOF - * @return -1 on error - */ -typedef int64_t (*mpv_stream_cb_read_fn)(void *cookie, char *buf, uint64_t nbytes); - -/** - * Seek callback used to implement a custom stream. - * - * Note that mpv will issue a seek to position 0 immediately after opening. This - * is used to test whether the stream is seekable (since seekability might - * depend on the URI contents, not just the protocol). Return - * MPV_ERROR_UNSUPPORTED if seeking is not implemented for this stream. This - * seek also serves to establish the fact that streams start at position 0. - * - * This callback can be NULL, in which it behaves as if always returning - * MPV_ERROR_UNSUPPORTED. - * - * @param cookie opaque cookie identifying the stream, - * returned from mpv_stream_cb_open_fn - * @param offset target absolute stream position - * @return the resulting offset of the stream - * MPV_ERROR_UNSUPPORTED or MPV_ERROR_GENERIC if the seek failed - */ -typedef int64_t (*mpv_stream_cb_seek_fn)(void *cookie, int64_t offset); - -/** - * Size callback used to implement a custom stream. - * - * Return MPV_ERROR_UNSUPPORTED if no size is known. - * - * This callback can be NULL, in which it behaves as if always returning - * MPV_ERROR_UNSUPPORTED. - * - * @param cookie opaque cookie identifying the stream, - * returned from mpv_stream_cb_open_fn - * @return the total size in bytes of the stream - */ -typedef int64_t (*mpv_stream_cb_size_fn)(void *cookie); - -/** - * Close callback used to implement a custom stream. - * - * @param cookie opaque cookie identifying the stream, - * returned from mpv_stream_cb_open_fn - */ -typedef void (*mpv_stream_cb_close_fn)(void *cookie); - -/** - * Cancel callback used to implement a custom stream. - * - * This callback is used to interrupt any current or future read and seek - * operations. It will be called from a separate thread than the demux - * thread, and should not block. - * - * This callback can be NULL. - * - * Available since API 1.106. - * - * @param cookie opaque cookie identifying the stream, - * returned from mpv_stream_cb_open_fn - */ -typedef void (*mpv_stream_cb_cancel_fn)(void *cookie); - -/** - * See mpv_stream_cb_open_ro_fn callback. - */ -typedef struct mpv_stream_cb_info { + /** + * Warning: this API is not stable yet. + * + * Overview + * -------- + * + * This API can be used to make mpv read from a stream with a custom + * implementation. This interface is inspired by funopen on BSD and + * fopencookie on linux. The stream is backed by user-defined callbacks + * which can implement customized open, read, seek, size and close behaviors. + * + * Usage + * ----- + * + * Register your stream callbacks with the mpv_stream_cb_add_ro() function. + * You have to provide a mpv_stream_cb_open_ro_fn callback to it (open_fn + * argument). + * + * Once registered, you can `loadfile myprotocol://myfile`. Your open_fn will + * be invoked with the URI and you must fill out the provided + * mpv_stream_cb_info struct. This includes your stream callbacks (like + * read_fn), and an opaque cookie, which will be passed as the first argument + * to all the remaining stream callbacks. + * + * Note that your custom callbacks must not invoke libmpv APIs as that would + * cause a deadlock. (Unless you call a different mpv_handle than the one the + * callback was registered for, and the mpv_handles refer to different mpv + * instances.) + * + * Stream lifetime + * --------------- + * + * A stream remains valid until its close callback has been called. It's up + * to libmpv to call the close callback, and the libmpv user cannot close it + * directly with the stream_cb API. + * + * For example, if you consider your custom stream to become suddenly invalid + * (maybe because the underlying stream died), libmpv will continue using + * your stream. All you can do is returning errors from each callback, until + * libmpv gives up and closes it. + * + * Protocol registration and lifetime + * ---------------------------------- + * + * Protocols remain registered until the mpv instance is terminated. This + * means in particular that it can outlive the mpv_handle that was used to + * register it, but once mpv_terminate_destroy() is called, your registered + * callbacks will not be called again. + * + * Protocol unregistration is finished after the mpv core has been destroyed + * (e.g. after mpv_terminate_destroy() has returned). + * + * If you do not call mpv_terminate_destroy() yourself (e.g. plugin-style + * code), you will have to deal with the registration or even streams + * outliving your code. Here are some possible ways to do this: + * - call mpv_terminate_destroy(), which destroys the core, and will make + * sure all streams are closed once this function returns + * - you refcount all resources your stream "cookies" reference, so that it + * doesn't matter if streams live longer than expected + * - create "cancellation" semantics: after your protocol has been + * unregistered, notify all your streams that are still opened, and make them + * drop all referenced resources - then return errors from the stream + * callbacks as long as the stream is still opened + * + */ + + /** + * Read callback used to implement a custom stream. The semantics of the + * callback match read(2) in blocking mode. Short reads are allowed (you can + * return less bytes than requested, and libmpv will retry reading the rest + * with another call). If no data can be immediately read, the callback must + * block until there is new data. A return of 0 will be interpreted as final + * EOF, although libmpv might retry the read, or seek to a different + * position. + * + * @param cookie opaque cookie identifying the stream, + * returned from mpv_stream_cb_open_fn + * @param buf buffer to read data into + * @param size of the buffer + * @return number of bytes read into the buffer + * @return 0 on EOF + * @return -1 on error + */ + typedef int64_t (*mpv_stream_cb_read_fn) (void *cookie, char *buf, + uint64_t nbytes); + + /** + * Seek callback used to implement a custom stream. + * + * Note that mpv will issue a seek to position 0 immediately after opening. + * This is used to test whether the stream is seekable (since seekability + * might depend on the URI contents, not just the protocol). Return + * MPV_ERROR_UNSUPPORTED if seeking is not implemented for this stream. This + * seek also serves to establish the fact that streams start at position 0. + * + * This callback can be NULL, in which it behaves as if always returning + * MPV_ERROR_UNSUPPORTED. + * + * @param cookie opaque cookie identifying the stream, + * returned from mpv_stream_cb_open_fn + * @param offset target absolute stream position + * @return the resulting offset of the stream + * MPV_ERROR_UNSUPPORTED or MPV_ERROR_GENERIC if the seek failed + */ + typedef int64_t (*mpv_stream_cb_seek_fn) (void *cookie, int64_t offset); + + /** + * Size callback used to implement a custom stream. + * + * Return MPV_ERROR_UNSUPPORTED if no size is known. + * + * This callback can be NULL, in which it behaves as if always returning + * MPV_ERROR_UNSUPPORTED. + * + * @param cookie opaque cookie identifying the stream, + * returned from mpv_stream_cb_open_fn + * @return the total size in bytes of the stream + */ + typedef int64_t (*mpv_stream_cb_size_fn) (void *cookie); + + /** + * Close callback used to implement a custom stream. + * + * @param cookie opaque cookie identifying the stream, + * returned from mpv_stream_cb_open_fn + */ + typedef void (*mpv_stream_cb_close_fn) (void *cookie); + + /** + * Cancel callback used to implement a custom stream. + * + * This callback is used to interrupt any current or future read and seek + * operations. It will be called from a separate thread than the demux + * thread, and should not block. + * + * This callback can be NULL. + * + * Available since API 1.106. + * + * @param cookie opaque cookie identifying the stream, + * returned from mpv_stream_cb_open_fn + */ + typedef void (*mpv_stream_cb_cancel_fn) (void *cookie); + + /** + * See mpv_stream_cb_open_ro_fn callback. + */ + typedef struct mpv_stream_cb_info + { /** * Opaque user-provided value, which will be passed to the other callbacks. * The close callback will be called to release the cookie. It is not @@ -185,55 +190,58 @@ typedef struct mpv_stream_cb_info { mpv_stream_cb_size_fn size_fn; mpv_stream_cb_close_fn close_fn; mpv_stream_cb_cancel_fn cancel_fn; /* since API 1.106 */ -} mpv_stream_cb_info; - -/** - * Open callback used to implement a custom read-only (ro) stream. The user - * must set the callback fields in the passed info struct. The cookie field - * also can be set to store state associated to the stream instance. - * - * Note that the info struct is valid only for the duration of this callback. - * You can't change the callbacks or the pointer to the cookie at a later point. - * - * Each stream instance created by the open callback can have different - * callbacks. - * - * The close_fn callback will terminate the stream instance. The pointers to - * your callbacks and cookie will be discarded, and the callbacks will not be - * called again. - * - * @param user_data opaque user data provided via mpv_stream_cb_add() - * @param uri name of the stream to be opened (with protocol prefix) - * @param info fields which the user should fill - * @return 0 on success, MPV_ERROR_LOADING_FAILED if the URI cannot be opened. - */ -typedef int (*mpv_stream_cb_open_ro_fn)(void *user_data, char *uri, - mpv_stream_cb_info *info); - -/** - * Add a custom stream protocol. This will register a protocol handler under - * the given protocol prefix, and invoke the given callbacks if an URI with the - * matching protocol prefix is opened. - * - * The "ro" is for read-only - only read-only streams can be registered with - * this function. - * - * The callback remains registered until the mpv core is registered. - * - * If a custom stream with the same name is already registered, then the - * MPV_ERROR_INVALID_PARAMETER error is returned. - * - * @param protocol protocol prefix, for example "foo" for "foo://" URIs - * @param user_data opaque pointer passed into the mpv_stream_cb_open_fn - * callback. - * @return error code - */ -MPV_EXPORT int mpv_stream_cb_add_ro(mpv_handle *ctx, const char *protocol, void *user_data, - mpv_stream_cb_open_ro_fn open_fn); + } mpv_stream_cb_info; + + /** + * Open callback used to implement a custom read-only (ro) stream. The user + * must set the callback fields in the passed info struct. The cookie field + * also can be set to store state associated to the stream instance. + * + * Note that the info struct is valid only for the duration of this callback. + * You can't change the callbacks or the pointer to the cookie at a later + * point. + * + * Each stream instance created by the open callback can have different + * callbacks. + * + * The close_fn callback will terminate the stream instance. The pointers to + * your callbacks and cookie will be discarded, and the callbacks will not be + * called again. + * + * @param user_data opaque user data provided via mpv_stream_cb_add() + * @param uri name of the stream to be opened (with protocol prefix) + * @param info fields which the user should fill + * @return 0 on success, MPV_ERROR_LOADING_FAILED if the URI cannot be + * opened. + */ + typedef int (*mpv_stream_cb_open_ro_fn) (void *user_data, char *uri, + mpv_stream_cb_info *info); + + /** + * Add a custom stream protocol. This will register a protocol handler under + * the given protocol prefix, and invoke the given callbacks if an URI with + * the matching protocol prefix is opened. + * + * The "ro" is for read-only - only read-only streams can be registered with + * this function. + * + * The callback remains registered until the mpv core is registered. + * + * If a custom stream with the same name is already registered, then the + * MPV_ERROR_INVALID_PARAMETER error is returned. + * + * @param protocol protocol prefix, for example "foo" for "foo://" URIs + * @param user_data opaque pointer passed into the mpv_stream_cb_open_fn + * callback. + * @return error code + */ + MPV_EXPORT int mpv_stream_cb_add_ro (mpv_handle *ctx, const char *protocol, + void *user_data, + mpv_stream_cb_open_ro_fn open_fn); #ifdef MPV_CPLUGIN_DYNAMIC_SYM -MPV_DEFINE_SYM_PTR(mpv_stream_cb_add_ro) + MPV_DEFINE_SYM_PTR (mpv_stream_cb_add_ro) #define mpv_stream_cb_add_ro pfn_mpv_stream_cb_add_ro #endif |