[vlc-commits] libvlc: add libvlc_media_new_callbacks() for custom input media
Rémi Denis-Courmont
git at videolan.org
Mon Mar 30 22:05:08 CEST 2015
vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Mon Mar 30 22:39:47 2015 +0300| [b67f295520b479d0ead21d11fb8c9aea74902f77] | committer: Rémi Denis-Courmont
libvlc: add libvlc_media_new_callbacks() for custom input media
(fixes #8562)
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=b67f295520b479d0ead21d11fb8c9aea74902f77
---
include/vlc/libvlc_media.h | 91 ++++++++++++++++++++++++++++++++++++++++++++
lib/libvlc.sym | 1 +
lib/media.c | 20 ++++++++++
3 files changed, 112 insertions(+)
diff --git a/include/vlc/libvlc_media.h b/include/vlc/libvlc_media.h
index 18cb500..9b16526 100644
--- a/include/vlc/libvlc_media.h
+++ b/include/vlc/libvlc_media.h
@@ -270,6 +270,64 @@ typedef enum libvlc_media_parse_flag_t
} libvlc_media_parse_flag_t;
/**
+ * Callback prototype to open a custom bitstream input media.
+ *
+ * The same media item can be opened multiple times. Each time, this callback
+ * is invoked. It should allocate and initialize any instance-specific
+ * resources, then store them in *datap. The instance resources can be freed
+ * in the @ref libvlc_close_cb callback.
+ *
+ * \param opaque private pointer as passed to libvlc_media_new_callbacks()
+ * \param datap storage space for a private data pointer [OUT]
+ * \param sizep byte length of the bitstream or 0 if unknown [OUT]
+ *
+ * \note For convenience, *datap is initially NULL and *sizep is initially 0.
+ *
+ * \return 0 on success, non-zero on error. In case of failure, the other
+ * callbacks will not be invoked and any value stored in *datap and *sizep is
+ * discarded.
+ */
+typedef int (*libvlc_media_open_cb)(void *opaque, void **datap,
+ uint64_t *sizep);
+
+/**
+ * Callback prototype to read data from a custom bitstream input media.
+ *
+ * \param opaque private pointer as set by the @ref libvlc_media_open_cb
+ * callback
+ * \param buf start address of the buffer to read data into
+ * \param len bytes length of the buffer
+ *
+ * \return strictly positive number of bytes read, 0 on end-of-stream,
+ * or -1 on non-recoverable error
+ *
+ * \note If no data is immediately available, then the callback should sleep.
+ * \warning The application is responsible for avoiding deadlock situations.
+ * In particular, the callback should return an error if playback is stopped;
+ * if it does not return, then libvlc_media_player_stop() will never return.
+ */
+typedef ssize_t (*libvlc_media_read_cb)(void *opaque, unsigned char *buf,
+ size_t len);
+
+/**
+ * Callback prototype to seek a custom bitstream input media.
+ *
+ * \param opaque private pointer as set by the @ref libvlc_media_open_cb
+ * callback
+ * \param offset absolute byte offset to seek to
+ * \return 0 on success, -1 on error.
+ */
+typedef int (*libvlc_media_seek_cb)(void *opaque, uint64_t offset);
+
+/**
+ * Callback prototype to close a custom bitstream input media.
+ *
+ * \param opaque private pointer as set by the @ref libvlc_media_open_cb
+ * callback
+ */
+typedef void (*libvlc_media_close_cb)(void *opaque);
+
+/**
* Create a media with a certain given media resource location,
* for instance a valid URL.
*
@@ -329,6 +387,39 @@ LIBVLC_API libvlc_media_t *libvlc_media_new_fd(
libvlc_instance_t *p_instance,
int fd );
+/**
+ * Create a media with custom callbacks to read the data from.
+ *
+ * \param instance LibVLC instance
+ * \param open_cb callback to open the custom bitstream input media
+ * \param read_cb callback to read data (must not be NULL)
+ * \param seek_cb callback to seek, or NULL if seeking is not supported
+ * \param close_cb callback to close the media, or NULL if unnecessary
+ * \param opaque data pointer for the open callback
+ *
+ * \return the newly created media or NULL on error
+ *
+ * \note If open_cb is NULL, the opaque pointer will be passed to read_cb,
+ * seek_cb and close_cb, and the stream size will be treated as unknown.
+ *
+ * \note The callbacks may be called asynchronously (from another thread).
+ * A single stream instance need not be reentrant. However the open_cb needs to
+ * be reentrant if the media is used by multiple player instances.
+ *
+ * \warning The callbacks may be used until all or any player instances
+ * that were supplied the media item are stopped.
+ *
+ * \see libvlc_media_release
+ *
+ * \version LibVLC 3.0.0 and later.
+ */
+LIBVLC_API libvlc_media_t *libvlc_media_new_callbacks(
+ libvlc_instance_t *instance,
+ libvlc_media_open_cb open_cb,
+ libvlc_media_read_cb read_cb,
+ libvlc_media_seek_cb seek_cb,
+ libvlc_media_close_cb close_cb,
+ void *opaque );
/**
* Create a media as an empty node with a given name.
diff --git a/lib/libvlc.sym b/lib/libvlc.sym
index 1e241e7..c0c206f 100644
--- a/lib/libvlc.sym
+++ b/lib/libvlc.sym
@@ -131,6 +131,7 @@ libvlc_media_list_remove_index
libvlc_media_list_retain
libvlc_media_list_set_media
libvlc_media_list_unlock
+libvlc_media_new_callbacks
libvlc_media_new_fd
libvlc_media_new_location
libvlc_media_new_path
diff --git a/lib/media.c b/lib/media.c
index 1d01c11..f5886ad 100644
--- a/lib/media.c
+++ b/lib/media.c
@@ -426,6 +426,26 @@ libvlc_media_t *libvlc_media_new_fd( libvlc_instance_t *p_instance, int fd )
return libvlc_media_new_location( p_instance, mrl );
}
+libvlc_media_t *libvlc_media_new_callbacks(libvlc_instance_t *p_instance,
+ libvlc_media_open_cb open_cb,
+ libvlc_media_read_cb read_cb,
+ libvlc_media_seek_cb seek_cb,
+ libvlc_media_close_cb close_cb,
+ void *opaque)
+{
+ libvlc_media_t *m = libvlc_media_new_location(p_instance, "imem://");
+ if (unlikely(m == NULL))
+ return NULL;
+
+ assert(read_cb != NULL);
+ input_item_AddOpaque(m->p_input_item, "imem-data", opaque);
+ input_item_AddOpaque(m->p_input_item, "imem-open", open_cb);
+ input_item_AddOpaque(m->p_input_item, "imem-read", read_cb);
+ input_item_AddOpaque(m->p_input_item, "imem-seek", seek_cb);
+ input_item_AddOpaque(m->p_input_item, "imem-close", close_cb);
+ return m;
+}
+
/**************************************************************************
* Create a new media descriptor object
**************************************************************************/
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