X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fecdec_filter.c;h=8cb17ad642098e81621e2be6f6c0643ac6de4038;hp=5c01a0395e79139a0bbd09633f127b06321d5268;hb=58151b60c9782a52aac5d39ace7e69c3635ee260;hpb=2b3cc3af64d5574473c2f1ea9c32d7589abbb811

diff --git a/fecdec_filter.c b/fecdec_filter.c
index 5c01a039..8cb17ad6 100644
--- a/fecdec_filter.c
+++ b/fecdec_filter.c
@@ -4,7 +4,7 @@
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
 
-/** \file fecdec_filter.c A filter fec-decodes an audio stream. */
+/** \file fecdec_filter.c A filter that fec-decodes an audio stream. */
 
 #include <dirent.h>
 #include "para.h"
@@ -27,8 +27,10 @@
  */
 #define NUM_FEC_GROUPS 3
 
-/** Size of the output buffer of the fecdec filter. */
-#define FECDEC_OUTBUF_SIZE (128 * 1024)
+/** Default size of the output buffer of the fecdec filter. */
+#define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
+/** Maximal size of the output buffer of the fecdec filter. */
+#define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
 
 /** Data read from the header of a slice. */
 struct fec_header {
@@ -46,6 +48,10 @@ struct fec_header {
 	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;
 };
 
 /**
@@ -72,11 +78,15 @@ struct private_fecdec_data {
 	struct fec_parms *fec;
 	/** Keeps track of what was received so far. */
 	struct fecdec_group groups[NUM_FEC_GROUPS];
+	/** Whether an audio file header was already received. */
+	int have_header;
+	/** Points to the first received group. */
+	struct fecdec_group *first_complete_group;
 };
 
 /** Iterate over all fecdec groups. */
 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
-	(g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
+	(g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
 
 static int group_complete(struct fecdec_group *fg)
 {
@@ -98,7 +108,9 @@ static void clear_group(struct fecdec_group *fg)
 		fg->idx[i] = -1;
 	}
 	free(fg->data);
+	fg->data = NULL;
 	free(fg->idx);
+	fg->idx = NULL;
 	fg->num_slices = 0;
 	memset(&fg->h, 0, sizeof(struct fec_header));
 	fg->num_received_slices = 0;
@@ -112,10 +124,15 @@ static int find_group(struct fec_header *h,
 	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)
-			continue;
+			return -E_BAD_FEC_HEADER;
 		if (fg->h.data_slices_per_group != h->data_slices_per_group)
-			continue;
+			return -E_BAD_FEC_HEADER;
+		if (fg->h.group_bytes != h->group_bytes)
+			return -E_BAD_FEC_HEADER;
+success:
 		*result = fg;
 		return 1;
 	}
@@ -140,6 +157,12 @@ static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
 	FOR_EACH_FECDEC_GROUP(fg, pfd) {
 		if (!group_complete(fg))
 			continue;
+		/*
+		 * Don't clear the first complete group if it has not yet been
+		 * decoded.
+		 */
+		if (fg == pfd->first_complete_group)
+			continue;
 		clear_group(fg);
 		return fg;
 	}
@@ -156,12 +179,15 @@ static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
 	}
 	if (!group_complete(oldest) && !group_empty(oldest))
 		PARA_WARNING_LOG("Clearing incomplete group %d "
-			"(contains %d slices)\n", fg->h.group_num,
-			fg->num_received_slices);
+			"(contains %d slices)\n", oldest->h.group_num,
+			oldest->num_received_slices);
+	if (oldest == pfd->first_complete_group)
+		pfd->first_complete_group = NULL;
 	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 fecdec_group **result)
 {
@@ -180,51 +206,122 @@ static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
 	if (fg)
 		goto success;
 	fg = free_oldest_group(pfd);
+	ret = 0;
 success:
 	fg->h = *h;
 	*result = fg;
-	return 1;
+	return ret;
 }
 
+/*
+ * 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 %d complete, ignoring slice %d\n",
+			fg->h.group_num, 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;
-		fg->idx = malloc(fg->num_slices * sizeof(int));
-		fg->data = malloc(fg->num_slices * sizeof(unsigned char *));
+		fg->idx = para_malloc(fg->num_slices * sizeof(int));
+		fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
 		memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
 	}
 	r = fg->num_received_slices;
 	fg->idx[r] = slice_num;
-	fg->data[r] = malloc(fg->h.slice_bytes);
+	fg->data[r] = para_malloc(fg->h.slice_bytes);
 	memcpy(fg->data[r], buf, fg->h.slice_bytes);
 	fg->num_received_slices++;
 	return 1;
 }
 
+enum fec_group_usability {
+	FEC_GROUP_UNUSABLE,
+	FEC_GROUP_USABLE,
+	FEC_GROUP_USABLE_SKIP_HEADER,
+	FEC_GROUP_USABLE_WITH_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_WITH_HEADER;
+	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;
+	size_t written, need;
 	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++) {
+	need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
+	if (need > fn->bufsize) {
+		fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
+		if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
+			return -E_FECDEC_OVERRUN;
+		PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
+		fn->buf = para_realloc(fn->buf, fn->bufsize);
+	}
+	if (u == FEC_GROUP_USABLE_WITH_HEADER) {
+		PARA_INFO_LOG("writing audio file header\n");
+		written = 0;
+		for (i = 0; i < fg->h.data_slices_per_group; i++) {
+			size_t n = sb;
+			if (written >= fg->h.audio_header_size)
+				break;
+			if (sb + written > fg->h.audio_header_size)
+				n = fg->h.audio_header_size - written;
+			memcpy(fn->buf + fn->loaded, fg->data[i], n);
+			fn->loaded += n;
+			written += n;
+		}
+	}
+	written = 0;
+	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;
-		if (fn->loaded + n > fn->bufsize)
-			return -E_FECDEC_OVERRUN;
 		memcpy(fn->buf + fn->loaded, fg->data[i], n);
 		fn->loaded += n;
 		written += n;
@@ -256,18 +353,21 @@ 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 fecdec_group *fg;
-	int ret;
+	int ret, k, n;
 	struct private_fecdec_data *pfd = fn->private_data;
 
 	if (h->slice_bytes > len) /* can not use the thing, try to read more */
@@ -275,30 +375,43 @@ 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)) /* group already complete */
+		return 1;
+	if (!group_complete(fg))
+		return 1;
+	/* this slice completed the group */
+	if (pfd->fec)
+		goto decode;
+	/* it's either the first or the second complete group */
+	if (!pfd->first_complete_group) { /* it's the first group */
+		enum fec_group_usability u = group_is_usable(fg, pfd);
+		assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
+		if (u == FEC_GROUP_UNUSABLE) /* forget it */
+			return 1;
+		pfd->first_complete_group = fg; /* remember it */
 		return 1;
 	}
-	ret = add_slice(buf, fg);
+	/* we have two complete groups, let's go */
+	k = h->data_slices_per_group;
+	n = h->slices_per_group;
+	PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
+	ret = fec_new(k, n, &pfd->fec);
+	if (ret < 0)
+		return ret;
+	/* decode and clear the first group */
+	ret = decode_group(pfd->first_complete_group, fn);
+	if (ret < 0)
+		return ret;
+	clear_group(pfd->first_complete_group);
+	pfd->first_complete_group = NULL;
+decode:
+	ret = decode_group(fg, fn);
 	if (ret < 0)
 		return ret;
-	if (group_complete(fg)) {
-		if (!pfd->fec) {
-			int k = h->data_slices_per_group, n = h->slices_per_group;
-			PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
-			ret = fec_new(k, n, &pfd->fec);
-			if (ret < 0)
-				return ret;
-		}
-		ret = decode_group(fg, fn);
-		if (ret < 0)
-			return ret;
-	}
 	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;
@@ -306,7 +419,7 @@ 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 > fn->bufsize)
+	if (!h.slice_bytes)
 		return -E_BAD_SLICE_SIZE;
 	if (h.slice_num > h.slices_per_group)
 		return -E_BAD_SLICE_NUM;
@@ -327,15 +440,18 @@ static void fecdec_close(struct filter_node *fn)
 		clear_group(fg);
 	free(fn->buf);
 	fn->buf = NULL;
+	fec_free(pfd->fec);
 	free(fn->private_data);
 	fn->private_data = NULL;
 }
 
 static void fecdec_open(struct filter_node *fn)
 {
-	fn->bufsize = FECDEC_OUTBUF_SIZE;
+	struct private_fecdec_data *pfd;
+	fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
 	fn->buf = para_malloc(fn->bufsize);
-	fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
+	pfd = para_calloc(sizeof(*pfd));
+	fn->private_data = pfd;
 	fn->loaded = 0;
 }