Add some more FEC source code documentation.

diff --git a/fecdec_filter.c b/fecdec_filter.c
index a17ddf7cf6fff85192d6b49cc0c56b286fe45610..6bb827c83fde8f9bf12a393324af909d9205037f 100644 (file)
--- a/fecdec_filter.c
+++ b/fecdec_filter.c
@@ -18,21 +18,35 @@
 #include "fec.h"
 #include "fd.h"
 
+/**
+ * How many FEC groups to store in memory.
+ *
+ * Packet reordering requires to keep more than one FEC group in memory because
+ * slices belonging to the next FEC group may arrive before the current FEC group
+ * is complete.
+ */
 #define NUM_FEC_GROUPS 3
+
 #define INPUT_BUFFER_SIZE 16384
 
-/** size of the output buffer */
+/** Size of the output buffer of the fecdec filter. */
 #define FECDEC_OUTBUF_SIZE 81920
 
+/** Data read from the header of a slice. */
 struct fec_header {
+       /** Total number of slices in this group. */
        uint8_t slices_per_group;
+       /** Number of slices needed to start decoding. */
        uint8_t data_slices_per_group;
+       /** Size of the ogg vorbis header (zero for mp3, aac). */
        uint32_t audio_header_size;
-
+       /** Number of the FEC group this slice belongs to. */
        uint32_t group_num;
+       /** Size of the data in this FEC group. */
        uint32_t group_bytes;
-
+       /** Number of this slice in the group. */
        uint8_t slice_num;
+       /** Used data bytes of this slice. */
        uint16_t slice_bytes;
 };
 

diff --git a/vss.c b/vss.c
index eef3a6320e2a7ed9e4ee8757bb0edde6ab1e8918..f1f9616768d21fdc2b682dabd5c8872b54eee2aa 100644 (file)
--- a/vss.c
+++ b/vss.c
@@ -89,35 +89,79 @@ struct vss_task {
        size_t header_len;
 };
 
+/**
+ * The list of currently connected fec clients.
+ *
+ * Senders may use \ref vss_add_fec_client() to add entries to the list.
+ */
 static struct list_head fec_client_list;
 
+/**
+ * Describes one slice of a FEC group.
+ *
+ * FEC slices directly correspond to the data packages sent by the paraslash
+ * senders that use FEC. Each slice is identified by its group number and its
+ * number within the group. All slices have the same size, but the last slice
+ * of the group may not be filled entirely.
+ */
 struct fec_slice {
+       /** The slice number within the FEC group. */
        uint8_t num;
+       /** The number of used bytes in this slice. */
        uint16_t bytes;
 };
 
+/**
+ * Data associated with one FEC group.
+ *
+ * A FEC group consists of a fixed number of slices and this number is given by
+ * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
+ * group contains a number of chunks of the current audio file.
+ */
 struct fec_group {
+       /** The number of the FEC group. */
        uint32_t num;
+       /** Number of bytes in this group. */
        uint32_t bytes;
+       /** The first chunk of the current audio file belonging to the group. */
        uint32_t first_chunk;
+       /** The number of chunks contained in this group. */
        uint32_t num_chunks;
+       /** The time needed to play all chunks of the group. */
        struct timeval duration;
+       /** When the first chunk was sent. */
        struct timeval start;
+       /** \a The group duration divided by \a slices_per_group. */
        struct timeval slice_duration;
 };
 
+/**
+ * Describes one connected FEC client.
+ */
 struct fec_client {
+       /** Parameters requested by the client. */
        struct fec_client_parms *fcp;
+       /** Used by the core FEC code. */
        struct fec_parms *parms;
+       /** The position of this client in \a \ref fec_client_list. */
        struct list_head node;
+       /** When the first slice for this client was sent. */
        struct timeval stream_start;
+       /** The first chunk sent to this FEC client. */
        int first_stream_chunk;
+       /** Describes the current group. */
        struct fec_group group;
+       /** Describes the current slice. */
        struct fec_slice slice;
+       /** The data to be FEC-encoded (point to a region within the mapped audio file). */
        const unsigned char **src_data;
+       /** Used for the last source pointer of the last group. */
        unsigned char *extra_src_buf;
+       /** The size of the buffer for the extra source pointer. */
        size_t extra_src_buf_size;
+       /** Contains FEC-encoded data. */
        unsigned char *enc_buf;
+       /** Size of \a enc_buf. */
        size_t enc_buf_size;
 };
 

diff --git a/vss.h b/vss.h
index efabdf36915425e913176f57098f501f235c642a..abe7a5702e286b2d6998c29f1c4ae6976d721adc 100644 (file)
--- a/vss.h
+++ b/vss.h
@@ -38,11 +38,17 @@ const char *supported_audio_formats(void);
  */
 struct fec_client;
 
+/** FEC parameters requested by FEC clients. */
 struct fec_client_parms {
+       /** Number of data slices plus redundant slices. */
        uint8_t slices_per_group;
+       /** Number of slices minus number of redundant slices. */
        uint8_t data_slices_per_group;
+       /** Maximal number of bytes per slice. */
        uint16_t max_slice_bytes;
+       /** Called by vss.c when the next slice should be sent. */
        int (*send)(char *buf, size_t num_bytes, void *private_data);
+       /** Passed verbatim to \a send(). */
        void *private_data;
 };