X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fecdec_filter.c;h=5f37f1a81f9199f6080b6669cd455d706a96af06;hp=721fc09443011c7bfcc53e2f655f171e9cef3d8c;hb=44c5fe64eebb185ecc7a406c3db26721834dbea4;hpb=625c5cd993d07a63061a0788f174e12fa1c221e0

diff --git a/fecdec_filter.c b/fecdec_filter.c
index 721fc094..5f37f1a8 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"
@@ -18,63 +18,85 @@
 #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 */
-#define FECDEC_OUTBUF_SIZE 81920
+/** Size of the output buffer of the fecdec filter. */
+#define FECDEC_OUTBUF_SIZE (1024 * 1024) /* FIXME: This has to depend on the fec params */
 
+/** 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;
+	/** Non-zero if this group is the beginning of the stream. */
+	uint8_t bos;
+	/** Non-zero if this stream embedds audio headers into fec groups. */
+	uint8_t header_stream;
 };
 
-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];
+	int have_header;
 };
 
-#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;
 
-	if (!group_complete(fg) && !group_empty(fg))
-		PARA_WARNING_LOG("Clearing incomplete group %d "
-			"(contains %d slices)\n", fg->h.group_num,
-			fg->num_received_slices);
 	for (i = 0; i < fg->num_slices; i++) {
 		free(fg->data[i]);
 		fg->data[i] = NULL;
@@ -85,39 +107,47 @@ 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;
+		if (fg->num_received_slices == 0)
+			goto success;
+		if (fg->h.slices_per_group != h->slices_per_group)
+			return -E_BAD_FEC_HEADER;
+		if (fg->h.data_slices_per_group != h->data_slices_per_group)
+			return -E_BAD_FEC_HEADER;
+		if (fg->h.group_bytes != h->group_bytes)
+			return -E_BAD_FEC_HEADER;
+success:
 		*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);
@@ -126,22 +156,27 @@ 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;
 	}
+	if (!group_complete(oldest) && !group_empty(oldest))
+		PARA_WARNING_LOG("Clearing incomplete group %d "
+			"(contains %d slices)\n", oldest->h.group_num,
+			oldest->num_received_slices);
 	clear_group(oldest);
 	return oldest;
 }
 
+/* returns 1 if the group was found, 0 if not, negative on errors */
 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)
@@ -151,24 +186,33 @@ static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
 	/* group not found */
 	fg = find_unused_group(pfd);
 	if (fg)
-		goto update_header;
+		goto success;
 	fg = try_to_free_group(pfd);
 	if (fg)
-		goto update_header;
+		goto success;
 	fg = free_oldest_group(pfd);
-update_header:
-	fg->h = *h;
+	ret = 0;
 success:
+	fg->h = *h;
 	*result = fg;
-	return 1;
+	return ret;
 }
 
-static int add_slice(char *buf, struct fec_group *fg)
+/*
+ * returns 1 if slice was added, zero otherwise (because the group was already
+ * complete). In any case the number of received slices is being increased by
+ * one.
+ */
+static int add_slice(char *buf, struct fecdec_group *fg)
 {
 	int r, slice_num;
 
-	if (group_complete(fg))
+	if (group_complete(fg)) {
+		PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
+			fg->h.slice_num);
+		fg->num_received_slices++;
 		return 0;
+	}
 	slice_num = fg->h.slice_num;
 	if (fg->num_slices == 0) {
 		fg->num_slices = fg->h.slices_per_group;
@@ -184,19 +228,58 @@ static int add_slice(char *buf, struct fec_group *fg)
 	return 1;
 }
 
-static int decode_group(struct fec_group *fg, struct filter_node *fn)
+enum fec_group_usability {
+	FEC_GROUP_UNUSABLE,
+	FEC_GROUP_USABLE,
+	FEC_GROUP_USABLE_SKIP_HEADER,
+};
+
+static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
+		struct private_fecdec_data *pfd)
+{
+	struct fec_header *h = &fg->h;
+
+	if (!h->header_stream)
+		return FEC_GROUP_USABLE;
+	if (pfd->have_header) {
+		if (h->audio_header_size)
+			return FEC_GROUP_USABLE_SKIP_HEADER;
+		return FEC_GROUP_USABLE;
+	}
+	if (fg->h.bos)
+		return FEC_GROUP_USABLE;
+	if (fg->h.audio_header_size)
+		return FEC_GROUP_USABLE;
+	return FEC_GROUP_UNUSABLE;
+}
+
+static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
 {
 	int i, ret, sb = fg->h.slice_bytes;
 	size_t written = 0;
 	struct private_fecdec_data *pfd = fn->private_data;
+	enum fec_group_usability u = group_is_usable(fg, pfd);
 
+	if (u == FEC_GROUP_UNUSABLE) {
+		PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
+		return 0;
+	}
+	PARA_DEBUG_LOG("decoding group %d %d slices\n", fg->h.group_num,
+		fg->h.data_slices_per_group);
 	ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
 	if (ret < 0)
 		return ret;
+	pfd->have_header = 1;
+	i = 0;
+	if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
+		i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
+			/ fg->h.slice_bytes;
+		PARA_DEBUG_LOG("skipping %d header slices\n", i);
+	}
 	PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
 		fg->h.group_num, fg->h.group_bytes,
 		fg->h.data_slices_per_group * sb);
-	for (i = 0; i < fg->h.data_slices_per_group; i++) {
+	for (; i < fg->h.data_slices_per_group; i++) {
 		size_t n = sb;
 		if (n + written > fg->h.group_bytes)
 			n = fg->h.group_bytes - written;
@@ -233,17 +316,20 @@ static int read_fec_header(char *buf, size_t len, struct fec_header *h)
 
 	h->slice_num = read_u8(buf + 18);
 	h->slice_bytes = read_u16(buf + 20);
-	if (!h->group_bytes && & h->slice_bytes)
+	h->bos = read_u8(buf + 22);
+	h->header_stream = read_u8(buf + 23);
+	if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
 		return -E_FECDEC_EOF;
 //	PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
 //		h->group_num, h->slice_num, h->slices_per_group);
 	return 1;
 }
 
+/* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
 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;
 
@@ -252,15 +338,8 @@ static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
 	ret = get_group(h, pfd, &fg);
 	if (ret < 0)
 		return ret;
-	if (group_complete(fg)) {
-		PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
-			h->slice_num);
+	if (!add_slice(buf, fg))
 		return 1;
-	}
-	fg->h = *h;
-	ret = add_slice(buf, fg);
-	if (ret < 0)
-		return ret;
 	if (group_complete(fg)) {
 		if (!pfd->fec) {
 			int k = h->data_slices_per_group, n = h->slices_per_group;
@@ -276,7 +355,7 @@ static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
 	return 1;
 }
 
-static int fecdec(char *buf, size_t len, struct filter_node *fn)
+static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
 {
 	int ret;
 	struct fec_header h;
@@ -284,7 +363,7 @@ 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 || h.slice_bytes > fn->bufsize)
 		return -E_BAD_SLICE_SIZE;
 	if (h.slice_num > h.slices_per_group)
 		return -E_BAD_SLICE_NUM;
@@ -299,12 +378,13 @@ 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;
+	fec_free(pfd->fec);
 	free(fn->private_data);
 	fn->private_data = NULL;
 }