X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=vss.c;h=c6e4053321c950e8ae03c352382610515de561cb;hp=aae601d14153d6973a8a86f8f8a93e69cd6c8bbd;hb=70f527312e613fd89be88177dc2a44ad24b2d27c;hpb=7cb521f3eeb7fda02344c523989d5903251e673e

diff --git a/vss.c b/vss.c
index aae601d1..c6e40533 100644
--- a/vss.c
+++ b/vss.c
@@ -121,6 +121,8 @@ struct fec_group {
 	uint32_t num_chunks;
 	/** When the first chunk was sent. */
 	struct timeval start;
+	/** The duration of the full group. */
+	struct timeval duration;
 	/** The group duration divided by the number of slices. */
 	struct timeval slice_duration;
 	/** Group contains the audio file header that occupies that many slices. */
@@ -232,15 +234,16 @@ static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *resul
 	return 1;
 }
 
-static void set_slice_duration(struct fec_client *fc, struct fec_group *g)
+/* set group start and group duration */
+static void set_group_timing(struct fec_client *fc, struct fec_group *g)
 {
-	struct timeval group_duration, *chunk_tv = vss_chunk_time();
+	struct timeval *chunk_tv = vss_chunk_time();
 
-	tv_scale(g->num_chunks, chunk_tv, &group_duration);
+	tv_scale(g->num_chunks, chunk_tv, &g->duration);
 	tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
-		&group_duration, &g->slice_duration);
+		&g->duration, &g->slice_duration);
 	PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
-		tv2ms(&group_duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
+		tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
 }
 
 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
@@ -248,46 +251,51 @@ static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
 	int ret, i, k, data_slices;
 	size_t len;
 	const char *buf, *start_buf;
-	struct timeval tmp, *chunk_tv = vss_chunk_time();
 	struct fec_group *g = &fc->group;
 	unsigned slice_bytes = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
 	uint32_t max_data_size;
 
-	assert(chunk_tv);
-	k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
 	if (fc->first_stream_chunk < 0) {
-		uint32_t largest = afh_get_largest_chunk_size(&mmd->afd.afhi)
-			+ vsst->header_len;
-		uint8_t needed, want;
+		uint8_t hs, ds; /* needed header/data slices */
+		uint8_t rs = fc->fcp->slices_per_group
+			- fc->fcp->data_slices_per_group; /* redundant slices */
+		int n;
 
-		ret = num_slices(largest, fc, &needed);
+		ret = num_slices(vsst->header_len, fc, &hs);
+		if (ret < 0)
+			return ret;
+		ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
+			fc, &ds);
+		if (ret < 0)
+			return ret;
+		k = (int)hs + ds;
+		if (k > 255)
+			return -E_BAD_CT;
+		if (k < fc->fcp->data_slices_per_group)
+			k = fc->fcp->data_slices_per_group;
+		n = k + rs;
+		fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
+		PARA_NOTICE_LOG("fec parms %d:%d:%d (%d extra slices)\n",
+			slice_bytes, k, n, fc->num_extra_slices);
+		fec_free(fc->parms);
+		fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
+		ret = fec_new(k, n, &fc->parms);
 		if (ret < 0)
 			return ret;
-		if (needed > fc->fcp->data_slices_per_group)
-			PARA_WARNING_LOG("fec parms insufficient for this audio file\n");
-		want = PARA_MAX(needed, fc->fcp->data_slices_per_group);
-		if (want != k) {
-			fec_free(fc->parms);
-			fc->src_data = para_realloc(fc->src_data, want * sizeof(char *));
-			ret = fec_new(want, want + fc->fcp->slices_per_group
-				- fc->fcp->data_slices_per_group, &fc->parms);
-			if (ret < 0)
-				return ret;
-			k = want;
-			fc->num_extra_slices = 0;
-			if (k > fc->fcp->data_slices_per_group) {
-				fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
-				PARA_NOTICE_LOG("using %d extra slices\n",
-					fc->num_extra_slices);
-			}
-		}
 		fc->stream_start = *now;
 		fc->first_stream_chunk = mmd->current_chunk;
 		g->first_chunk = mmd->current_chunk;
 		g->num = 0;
+		g->start = *now;
 	} else {
-		/* use duration of the previous group for the timing of this group */
-		set_slice_duration(fc, g);
+		/*
+		 * Start and duration of this group depend only on the previous
+		 * group. Compute the new group start as g->start += g->duration.
+		 */
+		struct timeval tmp = g->start;
+		tv_add(&tmp, &g->duration, &g->start);
+		k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
+		set_group_timing(fc, g);
 		g->first_chunk += g->num_chunks;
 		g->num++;
 	}
@@ -315,7 +323,7 @@ static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
 	assert(g->num_chunks);
 	fc->current_slice_num = 0;
 	if (g->num == 0)
-		set_slice_duration(fc, g);
+		set_group_timing(fc, g);
 
 	/* setup header slices */
 	buf = vsst->header_buf;
@@ -353,14 +361,6 @@ static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
 		g->first_chunk + g->num_chunks - 1,
 		g->num_header_slices, data_slices
 	);
-	/* set group start */
-	if (g->num != 0 && vsst->header_len != 0 && fc->first_stream_chunk == 0)
-		/* chunk #0 is the audio file header */
-		tv_scale(g->first_chunk - 1, chunk_tv, &tmp);
-	else
-		tv_scale(g->first_chunk - fc->first_stream_chunk,
-			chunk_tv, &tmp);
-	tv_add(&fc->stream_start, &tmp, &g->start);
 	return 1;
 }