X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=fecdec_filter.c;h=6b6716a115c18c26429d12d49f38a40981314574;hb=eb51951a61a641ef0c403c3c6df560f29b8c5468;hp=721fc09443011c7bfcc53e2f655f171e9cef3d8c;hpb=625c5cd993d07a63061a0788f174e12fa1c221e0;p=paraslash.git

diff --git a/fecdec_filter.c b/fecdec_filter.c
index 721fc094..6b6716a1 100644
--- a/fecdec_filter.c
+++ b/fecdec_filter.c
@@ -4,7 +4,7 @@
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
-/** \file fecdev_filter.c A filter fec-decodes an audio stream. */
+/** \file fecdec_filter.c A filter fec-decodes an audio stream. */
 
 #include <dirent.h>
 #include "para.h"
@@ -18,56 +18,77 @@
 #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;
 };
 
-struct fec_group {
+/**
+ * The status of one partially received FEC group.
+ */
+struct fecdec_group {
+	/** The header read from the last slice. */
 	struct fec_header h;
+	/** How many slices received so far. */
 	int num_received_slices;
+	/** The size of the \a idx and the \a data arrays below. */
 	int num_slices;
+	/** Array of indices of the received slices. */
 	int *idx;
+	/** Content of the received slices. */
 	unsigned char **data;
 };
 
+/**
+ * Data private to the fecdec filter.
+ */
 struct private_fecdec_data {
+	/** Used by the fec core code. */
 	struct fec_parms *fec;
-	struct fec_group groups[NUM_FEC_GROUPS];
+	/** Keeps track of what was received so far. */
+	struct fecdec_group groups[NUM_FEC_GROUPS];
 };
 
-#define FOR_EACH_FEC_GROUP(g, d) for (g = (d)->groups; \
+/** Iterate over all fecdec groups. */
+#define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
 	(g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
 
-#define UNUSED_GROUP_NUM 0xffffffff
-
-static int group_complete(struct fec_group *fg)
+static int group_complete(struct fecdec_group *fg)
 {
-	if (fg->h.group_num == UNUSED_GROUP_NUM)
-		return 0;
-	//PARA_INFO_LOG("received slices: %u, slices per group: %u\n", fg->num_received_slices, fg->h.data_slices_per_group);
 	return fg->num_received_slices >= fg->h.data_slices_per_group;
 }
 
-static int group_empty(struct fec_group *fg)
+static int group_empty(struct fecdec_group *fg)
 {
 	return fg->num_received_slices == 0;
 }
 
-static void clear_group(struct fec_group *fg)
+static void clear_group(struct fecdec_group *fg)
 {
 	int i;
 
@@ -85,39 +106,39 @@ static void clear_group(struct fec_group *fg)
 	fg->num_slices = 0;
 	memset(&fg->h, 0, sizeof(struct fec_header));
 	fg->num_received_slices = 0;
-	fg->h.group_num = UNUSED_GROUP_NUM;
 }
 
 static int find_group(struct fec_header *h,
-		struct private_fecdec_data *pfd, struct fec_group **result)
+		struct private_fecdec_data *pfd, struct fecdec_group **result)
 {
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 
-	FOR_EACH_FEC_GROUP(fg, pfd) {
+	FOR_EACH_FECDEC_GROUP(fg, pfd) {
 		if (fg->h.group_num != h->group_num)
 			continue;
+		/* FIXME: Add some more sanity checks here */
 		*result = fg;
 		return 1;
 	}
 	return 0;
 }
 
-static struct fec_group *find_unused_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
 {
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 
-	FOR_EACH_FEC_GROUP(fg, pfd) {
+	FOR_EACH_FECDEC_GROUP(fg, pfd) {
 		if (fg->num_received_slices == 0)
 			return fg;
 	}
 	return NULL;
 }
 
-static struct fec_group *try_to_free_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
 {
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 
-	FOR_EACH_FEC_GROUP(fg, pfd) {
+	FOR_EACH_FECDEC_GROUP(fg, pfd) {
 		if (!group_complete(fg))
 			continue;
 		clear_group(fg);
@@ -126,11 +147,11 @@ static struct fec_group *try_to_free_group(struct private_fecdec_data *pfd)
 	return NULL;
 }
 
-static struct fec_group *free_oldest_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
 {
-	struct fec_group *fg, *oldest = NULL;
+	struct fecdec_group *fg, *oldest = NULL;
 
-	FOR_EACH_FEC_GROUP(fg, pfd) {
+	FOR_EACH_FECDEC_GROUP(fg, pfd) {
 		if (!oldest || oldest->h.group_num > fg->h.group_num)
 			oldest = fg;
 	}
@@ -139,9 +160,9 @@ static struct fec_group *free_oldest_group(struct private_fecdec_data *pfd)
 }
 
 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
-		struct fec_group **result)
+		struct fecdec_group **result)
 {
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 	int ret = find_group(h, pfd, &fg);
 
 	if (ret < 0)
@@ -163,7 +184,7 @@ success:
 	return 1;
 }
 
-static int add_slice(char *buf, struct fec_group *fg)
+static int add_slice(char *buf, struct fecdec_group *fg)
 {
 	int r, slice_num;
 
@@ -184,7 +205,7 @@ static int add_slice(char *buf, struct fec_group *fg)
 	return 1;
 }
 
-static int decode_group(struct fec_group *fg, struct filter_node *fn)
+static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
 {
 	int i, ret, sb = fg->h.slice_bytes;
 	size_t written = 0;
@@ -243,7 +264,7 @@ static int read_fec_header(char *buf, size_t len, struct fec_header *h)
 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
 		struct filter_node *fn)
 {
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 	int ret;
 	struct private_fecdec_data *pfd = fn->private_data;
 
@@ -284,7 +305,7 @@ static int fecdec(char *buf, size_t len, struct filter_node *fn)
 	ret = read_fec_header(buf, len, &h);
 	if (ret <= 0)
 		return ret;
-	if (h.slice_bytes > INPUT_BUFFER_SIZE)
+	if (h.slice_bytes > fn->bufsize)
 		return -E_BAD_SLICE_SIZE;
 	if (h.slice_num > h.slices_per_group)
 		return -E_BAD_SLICE_NUM;
@@ -299,9 +320,9 @@ static int fecdec(char *buf, size_t len, struct filter_node *fn)
 static void fecdec_close(struct filter_node *fn)
 {
 	struct private_fecdec_data *pfd = fn->private_data;
-	struct fec_group *fg;
+	struct fecdec_group *fg;
 
-	FOR_EACH_FEC_GROUP(fg, pfd)
+	FOR_EACH_FECDEC_GROUP(fg, pfd)
 		clear_group(fg);
 	free(fn->buf);
 	fn->buf = NULL;