REQUIREMENTS update.

[paraslash.git] / write.h

diff --git a/write.h b/write.h
index 79531b508839ea06947873cab38e770be0daba0f..091f8c77181cbf3f1a014e31db2667b534aa5b0d 100644 (file)
--- a/write.h
+++ b/write.h
@@ -1,19 +1,7 @@
 /*
- * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
  *
- *     This program 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.
- *
- *     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 General Public License for more details.
- *
- *     You should have received a copy of the GNU General Public License
- *     along with this program; if not, write to the Free Software
- *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
 /** \file write.h writer-related structures */
@@ -22,7 +10,7 @@
 enum writer_enum {WRITER_ENUM};
 
 /**
- * decbribes one running instance of a writer
+ * Describes one running instance of a writer.
  */
 struct writer_node {
        /** points to the writer structure associated with this node */
@@ -60,27 +48,33 @@ struct writer {
         * more than once with different values of \a options.
         *
         */
-               void * (*parse_config)(char *options);
+               void * (*parse_config)(const char *options);
        /**
         *
         * open one instance of this writer
         *
         * This function should perform any work necessary to write the incoming
         * stream. If To this aim, it may allocate its private data structure and store
-        * a pointer to that structure via the given writer_node paramenter.
+        * a pointer to that structure via the given writer_node parameter.
         */
        int (*open)(struct writer_node *);
        /**
         *
         * write a chunk of audio data
         *
-        * This is called from the driving application whenever a data block of \a
-        * chunk_bytes is available. It must return the number of bytes consumed from
-        * \a data on success, and negative on errors.
-        *
+        * This is called from the writer node group task's pre_select(). It
+        * may use the sched pointer to add any file descriptors or to decrease
+        * the select timeout. It must return positive on success and negative
+        * on errors.
         */
-       int (*write)(char *data, size_t nbytes, struct writer_node *);
        int (*pre_select)(struct sched *s, struct writer_node *wn);
+       /**
+        * Called from the post_select function of the wng task. It must keep
+        * track of the number of bytes consumed from the wng's buffer via
+        * the wn->written variable (which may be modified by the wng handling
+        * functions). This function must return positive on success and
+        * negative on errors.
+        */
        int (*post_select)(struct sched *s, struct writer_node *wn);
        /**
         * close one instance of the writer
@@ -107,14 +101,20 @@ struct writer_node_group {
        struct writer_node *writer_nodes;
        /** the maximum of the chunk_bytes values of the writer nodes in this group */
        size_t max_chunk_bytes;
-       /** non-zero if end of file was encountered */
-       int *input_eof;
-       int eof;
+       /** Non-zero if an error or end of file was encountered by the feeding task. */
+       int *input_error;
+       /** current output buffer */
        char *buf;
+       /** number of bytes loaded in the output buffer */
+       size_t *loaded;
+       /** number of audio channels of the current stream */
        unsigned int *channels;
+       /** sample rate of the current stream */
        unsigned int *samplerate;
-       size_t *loaded;
+       /** the task associated to this group */
        struct task task;
+       /** Whether the group is open, i.e. wng_open() was called. */
+       int open;
 };
 
 /** loop over each writer node in a writer group */