vss: Initialize all bytes of the FEC header.
[paraslash.git] / vss.c
diff --git a/vss.c b/vss.c
index a8984a4..21ac374 100644 (file)
--- a/vss.c
+++ b/vss.c
@@ -1,5 +1,5 @@
 /*
 /*
- * Copyright (C) 1997-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 1997-2011 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -26,8 +26,8 @@
 #include "net.h"
 #include "server.cmdline.h"
 #include "list.h"
 #include "net.h"
 #include "server.cmdline.h"
 #include "list.h"
-#include "vss.h"
 #include "send.h"
 #include "send.h"
+#include "vss.h"
 #include "ipc.h"
 #include "fd.h"
 #include "sched.h"
 #include "ipc.h"
 #include "fd.h"
 #include "sched.h"
@@ -123,18 +123,30 @@ struct fec_group {
        uint32_t num_chunks;
        /** When the first chunk was sent. */
        struct timeval start;
        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. */
        uint8_t num_header_slices;
        /** The group duration divided by the number of slices. */
        struct timeval slice_duration;
        /** Group contains the audio file header that occupies that many slices. */
        uint8_t num_header_slices;
+       /** Number of bytes per slice for this group. */
+       uint16_t slice_bytes;
+};
+
+enum fec_client_state {
+       FEC_STATE_NONE = 0,     /**< not initialized and not enabled */
+       FEC_STATE_DISABLED,     /**< temporarily disabled */
+       FEC_STATE_READY_TO_RUN  /**< initialized and enabled */
 };
 
 /**
  * Describes one connected FEC client.
  */
 struct fec_client {
 };
 
 /**
  * Describes one connected FEC client.
  */
 struct fec_client {
-       /** If negative, this client is temporarily disabled. */
-       int error;
+       /** Current state of the client */
+       enum fec_client_state state;
+       /** The connected sender client (transport layer). */
+       struct sender_client *sc;
        /** Parameters requested by the client. */
        struct fec_client_parms *fcp;
        /** Used by the core FEC code. */
        /** Parameters requested by the client. */
        struct fec_client_parms *fcp;
        /** Used by the core FEC code. */
@@ -159,6 +171,8 @@ struct fec_client {
        int num_extra_slices;
        /** Contains the FEC-encoded data. */
        unsigned char *enc_buf;
        int num_extra_slices;
        /** Contains the FEC-encoded data. */
        unsigned char *enc_buf;
+       /** Maximal packet size. */
+       int mps;
 };
 
 /**
 };
 
 /**
@@ -197,180 +211,359 @@ static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
        write_u32(buf + 14, g->bytes);
 
        write_u8(buf + 18, fc->current_slice_num);
        write_u32(buf + 14, g->bytes);
 
        write_u8(buf + 18, fc->current_slice_num);
-       write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
+       write_u8(buf + 19, 0); /* unused */
+       write_u16(buf + 20, g->slice_bytes);
        write_u8(buf + 22, g->first_chunk? 0 : 1);
        write_u8(buf + 23, vsst->header_len? 1 : 0);
        write_u8(buf + 22, g->first_chunk? 0 : 1);
        write_u8(buf + 23, vsst->header_len? 1 : 0);
-       memset(buf + 24, 0, 7);
+       memset(buf + 24, 0, 8);
 }
 
 }
 
-static int need_audio_header(struct fec_client *fc, struct vss_task *vsst)
+static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
 {
        if (!mmd->current_chunk) {
                tv_add(now, &vsst->header_interval, &fc->next_header_time);
 {
        if (!mmd->current_chunk) {
                tv_add(now, &vsst->header_interval, &fc->next_header_time);
-               return 0;
+               return false;
        }
        if (!vsst->header_buf)
        }
        if (!vsst->header_buf)
-               return 0;
-       if (!vsst->header_len)
-               return 0;
-       if (fc->group.num && tv_diff(&fc->next_header_time, now, NULL) > 0)
-               return 0;
+               return false;
+       if (vsst->header_len == 0)
+               return false;
+       if (fc->group.num > 0) {
+               if (!fc->fcp->need_periodic_header)
+                       return false;
+               if (tv_diff(&fc->next_header_time, now, NULL) > 0)
+                       return false;
+       }
        tv_add(now, &vsst->header_interval, &fc->next_header_time);
        tv_add(now, &vsst->header_interval, &fc->next_header_time);
-       return 1;
+       return true;
 }
 
 }
 
-static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *result)
+static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
 {
 {
-       unsigned long m = fc->fcp->max_slice_bytes - FEC_HEADER_SIZE;
-       unsigned rv, redundant_slices = fc->fcp->slices_per_group
-               - fc->fcp->data_slices_per_group;
+       if (fc->group.num > 0)
+               return true;
+       if (!vsst->header_buf)
+               return true;
+       if (vsst->header_len == 0)
+               return true;
+       if (fc->fcp->need_periodic_header)
+               return true;
+       return false;
+}
 
 
-       if (!m)
-               return -E_BAD_CT;
-       rv = (bytes + m - 1) / m;
-       if (rv + redundant_slices > 255)
+static int num_slices(long unsigned bytes, int max_payload, int rs)
+{
+       int ret;
+
+       assert(max_payload > 0);
+       assert(rs > 0);
+       ret = DIV_ROUND_UP(bytes, max_payload);
+       if (ret + rs > 255)
                return -E_BAD_CT;
                return -E_BAD_CT;
-       *result = rv;
-       return 1;
+       return ret;
 }
 
 }
 
-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 vss_task *vsst)
 {
 {
-       struct timeval group_duration, *chunk_tv = vss_chunk_time();
+       struct fec_group *g = &fc->group;
+       struct timeval *chunk_tv = vss_chunk_time();
 
 
-       tv_scale(g->num_chunks, chunk_tv, &group_duration);
+       if (!need_data_slices(fc, vsst))
+               ms2tv(200, &g->duration);
+       else
+               tv_scale(g->num_chunks, chunk_tv, &g->duration);
        tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
        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",
        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)
+static int initialize_fec_client(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);
-       if (fc->first_stream_chunk < 0) {
-               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;
+       int k, n, ret;
+       int hs, ds, rs; /* header/data/redundant slices */
+       struct fec_client_parms *fcp = fc->fcp;
 
 
-               ret = num_slices(vsst->header_len, fc, &hs);
+       /* set mps */
+       if (fcp->init_fec) {
+               /*
+                * Set the maximum slice size to the Maximum Packet Size if the
+                * transport protocol allows to determine this value. The user
+                * can specify a slice size up to this value.
+                */
+               ret = fcp->init_fec(fc->sc);
                if (ret < 0)
                        return ret;
                if (ret < 0)
                        return ret;
-               ret = num_slices(afh_get_largest_chunk_size(&mmd->afd.afhi),
-                       fc, &ds);
+               fc->mps = ret;
+       } else
+               fc->mps = generic_max_transport_msg_size(fc->sc->fd);
+       if (fc->mps <= FEC_HEADER_SIZE)
+               return -ERRNO_TO_PARA_ERROR(EINVAL);
+
+       rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
+       ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
+       if (ret < 0)
+               return ret;
+       hs = ret;
+       ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
+       if (ret < 0)
+               return ret;
+       ds = ret;
+       if (fc->fcp->need_periodic_header)
+               k = hs + ds;
+       else
+               k = PARA_MAX(hs, ds);
+       if (k < fc->fcp->data_slices_per_group)
+               k = fc->fcp->data_slices_per_group;
+       fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
+       n = k + rs;
+       fec_free(fc->parms);
+       ret = fec_new(k, n, &fc->parms);
+       if (ret < 0)
+               return ret;
+       PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
+               fc->mps, k, n, fc->num_extra_slices);
+       fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
+       fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
+       fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
+
+       fc->state = FEC_STATE_READY_TO_RUN;
+       fc->next_header_time.tv_sec = 0;
+       fc->stream_start = *now;
+       fc->first_stream_chunk = mmd->current_chunk;
+       return 1;
+}
+
+static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
+               int max_bytes)
+{
+       int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
+
+       g->num_chunks = 0;
+       g->bytes = 0;
+       /*
+        * Include chunks into the group until the group duration is at least
+        * 150ms.  For ogg and wma, a single chunk's duration (ogg page/wma
+        * super frame) is already larger than 150ms, so a FEC group consists
+        * of exactly one chunk for these audio formats.
+        */
+       for (i = 0;; i++) {
+               const char *buf;
+               size_t len;
+               int chunk_num = g->first_chunk + i;
+
+               if (g->bytes > 0 && i >= max_chunks) /* duration limit */
+                       break;
+               if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
+                       break;
+               afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
+               if (g->bytes + len > max_bytes)
+                       break;
+               /* Include this chunk */
+               g->bytes += len;
+               g->num_chunks++;
+       }
+       assert(g->num_chunks);
+}
+
+/*
+ * Compute the slice size of the next group.
+ *
+ * The FEC parameters n and k are fixed but the slice size varies per
+ * FEC group.  We'd like to choose slices as small as possible to avoid
+ * unnecessary FEC calculations but large enough to guarantee that the
+ * k data slices suffice to encode the header (if needed) and the data
+ * chunk(s).
+ *
+ * Once we know the payload of the next group, we define the number s
+ * of bytes per slice for this group by
+ *
+ *     s = ceil(payload / k)
+ *
+ * However, for header streams, computing s is more complicated since no
+ * overlapping of header and data slices is possible. Hence we have k >=
+ * 2 and s must satisfy
+ *
+ * (*) ceil(h / s) + ceil(d / s) <= k
+ *
+ * where h and d are payload of the header and the data chunk(s)
+ * respectively. In general there is no value for s such that (*)
+ * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
+ *
+ * We use the following approach for computing a suitable value for s:
+ *
+ * Let
+ *     k1 := ceil(k * min(h, d) / (h + d)),
+ *     k2 := k - k1.
+ *
+ * Note that k >= 2 implies k1 > 0 and k2 > 0, so
+ *
+ *     s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
+ *
+ * is well-defined. Inequality (*) holds for this value of s since k1
+ * slices suffice to store min(h, d) while k2 slices suffice to store
+ * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
+ * second by k2.
+ *
+ * For the above example we obtain
+ *
+ *     k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
+ *     s = max(4000 / 5, 5000 / 5) = 1000,
+ *
+ * which is optimal since a slice size of 999 bytes would already require
+ * 11 slices.
+ */
+static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
+{
+       struct fec_group *g = &fc->group;
+       int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
+       int n = fc->fcp->slices_per_group + fc->num_extra_slices;
+       int ret, k1, k2, h, d, min, max, sum;
+       int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
+       int max_group_bytes;
+
+       if (!need_audio_header(fc, vsst)) {
+               max_group_bytes = k * max_slice_bytes;
+               g->num_header_slices = 0;
+               compute_group_size(vsst, g, max_group_bytes);
+               g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
+               if (g->slice_bytes == 0)
+                       g->slice_bytes = 1;
+               return 1;
+       }
+       if (!need_data_slices(fc, vsst)) {
+               g->bytes = 0;
+               g->num_chunks = 0;
+               g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
+               g->num_header_slices = k;
+               return 1;
+       }
+       h = vsst->header_len;
+       max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
+               * max_slice_bytes;
+       compute_group_size(vsst, g, max_group_bytes);
+       d = g->bytes;
+       if (d == 0) {
+               g->slice_bytes = DIV_ROUND_UP(h, k);
+               ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
                if (ret < 0)
                        return ret;
                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);
+               g->num_header_slices = ret;
+               return 1;
+       }
+       min = PARA_MIN(h, d);
+       max = PARA_MAX(h, d);
+       sum = h + d;
+       k1 = DIV_ROUND_UP(k * min, sum);
+       k2 = k - k1;
+       assert(k1 > 0);
+       assert(k2 > 0);
+
+       g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
+       /*
+        * This value of s := g->slice_bytes satisfies inequality (*) above,
+        * but it might be larger than max_slice_bytes. However, we know that
+        * max_slice_bytes are sufficient to store header and data, so:
+        */
+       g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
+
+       ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
+       if (ret < 0)
+               return ret;
+       g->num_header_slices = ret;
+       return 1;
+}
+
+static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
+{
+       int ret, i, k, n, data_slices;
+       size_t len;
+       const char *buf;
+       struct fec_group *g = &fc->group;
+
+       if (fc->state == FEC_STATE_NONE) {
+               ret = initialize_fec_client(fc, vsst);
                if (ret < 0)
                        return ret;
                if (ret < 0)
                        return ret;
-               fc->stream_start = *now;
-               fc->first_stream_chunk = mmd->current_chunk;
                g->first_chunk = mmd->current_chunk;
                g->num = 0;
                g->first_chunk = mmd->current_chunk;
                g->num = 0;
+               g->start = *now;
        } else {
        } else {
-               k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
-               /* use duration of the previous group for the timing of this group */
-               set_slice_duration(fc, g);
+               struct timeval tmp;
+               if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
+                       return 0;
+               /*
+                * Start and duration of this group depend only on the previous
+                * group. Compute the new group start as g->start += g->duration.
+                */
+               tmp = g->start;
+               tv_add(&tmp, &g->duration, &g->start);
+               set_group_timing(fc, vsst);
                g->first_chunk += g->num_chunks;
                g->num++;
        }
                g->first_chunk += g->num_chunks;
                g->num++;
        }
-       if (g->first_chunk >= mmd->afd.afhi.chunks_total)
-               return 0;
-       if (need_audio_header(fc, vsst)) {
-               ret = num_slices(vsst->header_len, fc, &g->num_header_slices);
-               if (ret < 0)
-                       return ret;
-       } else
-               g->num_header_slices = 0;
-       afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &start_buf,
-               &len);
-       data_slices = k - g->num_header_slices;
-       assert(data_slices);
-       max_data_size = slice_bytes * data_slices;
-       g->bytes = 0;
-       for (i = g->first_chunk; i < mmd->afd.afhi.chunks_total; i++) {
-               afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
-               if (g->bytes + len > max_data_size)
-                       break;
-               g->bytes += len;
-       }
-       g->num_chunks = i - g->first_chunk;
-       assert(g->num_chunks);
+       k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
+       n = fc->fcp->slices_per_group + fc->num_extra_slices;
+
+       compute_slice_size(fc, vsst);
+       assert(g->slice_bytes > 0);
+       ret = num_slices(g->bytes, g->slice_bytes, n - k);
+       if (ret < 0)
+               return ret;
+       data_slices = ret;
+       assert(g->num_header_slices + data_slices <= k);
        fc->current_slice_num = 0;
        if (g->num == 0)
        fc->current_slice_num = 0;
        if (g->num == 0)
-               set_slice_duration(fc, g);
+               set_group_timing(fc, vsst);
 
        /* setup header slices */
        buf = vsst->header_buf;
        for (i = 0; i < g->num_header_slices; i++) {
                fc->src_data[i] = (const unsigned char *)buf;
 
        /* setup header slices */
        buf = vsst->header_buf;
        for (i = 0; i < g->num_header_slices; i++) {
                fc->src_data[i] = (const unsigned char *)buf;
-               buf += slice_bytes;
+               buf += g->slice_bytes;
        }
 
        /* setup data slices */
        }
 
        /* setup data slices */
-       buf = start_buf;
-       for (i = g->num_header_slices; i < k; i++) {
-               if (buf + slice_bytes > vsst->map + mmd->size)
+       afh_get_chunk(g->first_chunk, &mmd->afd.afhi, vsst->map, &buf, &len);
+       for (; i < g->num_header_slices + data_slices; i++) {
+               if (buf + g->slice_bytes > vsst->map + mmd->size) {
                        /*
                         * Can not use the memory mapped audio file for this
                         * slice as it goes beyond the map. This slice will not
                         * be fully used.
                         */
                        /*
                         * Can not use the memory mapped audio file for this
                         * slice as it goes beyond the map. This slice will not
                         * be fully used.
                         */
+                       uint32_t payload_size = vsst->map + mmd->size - buf;
+                       memcpy(fc->extra_src_buf, buf, payload_size);
+                       if (payload_size < g->slice_bytes)
+                               memset(fc->extra_src_buf + payload_size, 0,
+                                       g->slice_bytes - payload_size);
+                       fc->src_data[i] = fc->extra_src_buf;
+                       i++;
                        break;
                        break;
+               }
                fc->src_data[i] = (const unsigned char *)buf;
                fc->src_data[i] = (const unsigned char *)buf;
-               buf += slice_bytes;
+               buf += g->slice_bytes;
        }
        if (i < k) {
        }
        if (i < k) {
-               uint32_t payload_size = vsst->map + mmd->size - buf;
-               memcpy(fc->extra_src_buf, buf, payload_size);
-               fc->src_data[i] = fc->extra_src_buf;
-               i++;
                /* use arbitrary data for all remaining slices */
                buf = vsst->map;
                for (; i < k; i++)
                        fc->src_data[i] = (const unsigned char *)buf;
        }
                /* use arbitrary data for all remaining slices */
                buf = vsst->map;
                for (; i < k; i++)
                        fc->src_data[i] = (const unsigned char *)buf;
        }
-       PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), "
-               "%d header slices, %d data slices\n",
+       PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d bytes\n",
                g->num, g->num_chunks, g->first_chunk,
                g->num, g->num_chunks, g->first_chunk,
-               g->first_chunk + g->num_chunks - 1,
-               g->num_header_slices, data_slices
+               g->first_chunk + g->num_chunks - 1, g->bytes
+       );
+       PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
+               g->slice_bytes, 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;
 }
 
 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
 {
        return 1;
 }
 
 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
 {
-       assert(fc->error >= 0);
-       if (fc->first_stream_chunk < 0 || fc->current_slice_num
+       if (fc->state == FEC_STATE_NONE || fc->current_slice_num
                        == fc->fcp->slices_per_group + fc->num_extra_slices) {
                int ret = setup_next_fec_group(fc, vsst);
                if (ret == 0)
                        == fc->fcp->slices_per_group + fc->num_extra_slices) {
                int ret = setup_next_fec_group(fc, vsst);
                if (ret == 0)
@@ -378,14 +571,13 @@ static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
                if (ret < 0) {
                        PARA_ERROR_LOG("%s\n", para_strerror(-ret));
                        PARA_ERROR_LOG("FEC client temporarily disabled\n");
                if (ret < 0) {
                        PARA_ERROR_LOG("%s\n", para_strerror(-ret));
                        PARA_ERROR_LOG("FEC client temporarily disabled\n");
-                       fc->error = ret;
-                       return fc->error;
+                       fc->state = FEC_STATE_DISABLED;
+                       return ret;
                }
        }
        write_fec_header(fc, vsst);
        fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
                }
        }
        write_fec_header(fc, vsst);
        fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
-               fc->current_slice_num,
-               fc->fcp->max_slice_bytes - FEC_HEADER_SIZE);
+               fc->current_slice_num, fc->group.slice_bytes);
        return 1;
 }
 
        return 1;
 }
 
@@ -408,38 +600,20 @@ size_t vss_get_fec_eof_packet(const char **buf)
 /**
  * Add one entry to the list of active fec clients.
  *
 /**
  * Add one entry to the list of active fec clients.
  *
- * \param fcp Describes the fec parameters to be used for this client.
- * \param result An opaque pointer that must be used by remove the client later.
+ * \param sc  Generic sender_client data of the transport layer.
+ * \param fcp FEC parameters as supplied by the transport layer.
  *
  *
- * \return Standard.
+ * \return Newly allocated fec_client struct.
  */
  */
-int vss_add_fec_client(struct fec_client_parms *fcp, struct fec_client **result)
+struct fec_client *vss_add_fec_client(struct sender_client *sc,
+                                     struct fec_client_parms *fcp)
 {
 {
-       int ret;
-       struct fec_client *fc;
+       struct fec_client *fc = para_calloc(sizeof(*fc));
 
 
-       if (fcp->max_slice_bytes < FEC_HEADER_SIZE + fcp->data_slices_per_group)
-               return -ERRNO_TO_PARA_ERROR(EINVAL);
-       fc = para_calloc(sizeof(*fc));
+       fc->sc  = sc;
        fc->fcp = fcp;
        fc->fcp = fcp;
-       ret = fec_new(fcp->data_slices_per_group, fcp->slices_per_group,
-               &fc->parms);
-       if (ret < 0)
-               goto err;
-       fc->first_stream_chunk = -1; /* stream not yet started */
-       fc->src_data = para_malloc(fc->fcp->slices_per_group * sizeof(char *));
-       fc->enc_buf = para_calloc(fc->fcp->max_slice_bytes);
-       fc->num_extra_slices = 0;
-       fc->extra_src_buf = para_calloc(fc->fcp->max_slice_bytes);
-       fc->next_header_time.tv_sec = 0;
        para_list_add(&fc->node, &fec_client_list);
        para_list_add(&fc->node, &fec_client_list);
-       *result = fc;
-       return 1;
-err:
-       fec_free(fc->parms);
-       free(fc);
-       *result = NULL;
-       return ret;
+       return fc;
 }
 
 /**
 }
 
 /**
@@ -469,7 +643,7 @@ static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
        struct timeval tmp, next;
        int ret;
 
        struct timeval tmp, next;
        int ret;
 
-       if (fc->first_stream_chunk < 0)
+       if (fc->state == FEC_STATE_NONE)
                return 1;
        tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
        tv_add(&tmp, &fc->group.start, &next);
                return 1;
        tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
        tv_add(&tmp, &fc->group.start, &next);
@@ -481,11 +655,10 @@ static void compute_slice_timeout(struct timeval *timeout)
 {
        struct fec_client *fc;
 
 {
        struct fec_client *fc;
 
-       assert(vss_playing());
        list_for_each_entry(fc, &fec_client_list, node) {
                struct timeval diff;
 
        list_for_each_entry(fc, &fec_client_list, node) {
                struct timeval diff;
 
-               if (fc->error < 0)
+               if (fc->state != FEC_STATE_READY_TO_RUN)
                        continue;
                if (next_slice_is_due(fc, &diff)) {
                        timeout->tv_sec = 0;
                        continue;
                if (next_slice_is_due(fc, &diff)) {
                        timeout->tv_sec = 0;
@@ -508,7 +681,7 @@ static void set_eof_barrier(struct vss_task *vsst)
        list_for_each_entry(fc, &fec_client_list, node) {
                struct timeval group_duration;
 
        list_for_each_entry(fc, &fec_client_list, node) {
                struct timeval group_duration;
 
-               if (fc->error < 0)
+               if (fc->state != FEC_STATE_READY_TO_RUN)
                        continue;
                tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
                if (tv_diff(&timeout, &group_duration, NULL) < 0)
                        continue;
                tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
                if (tv_diff(&timeout, &group_duration, NULL) < 0)
@@ -637,7 +810,7 @@ static void vss_eof(struct vss_task *vsst)
        para_munmap(vsst->map, mmd->size);
        vsst->map = NULL;
        mmd->chunks_sent = 0;
        para_munmap(vsst->map, mmd->size);
        vsst->map = NULL;
        mmd->chunks_sent = 0;
-       mmd->offset = 0;
+       //mmd->offset = 0;
        mmd->afd.afhi.seconds_total = 0;
        mmd->afd.afhi.chunk_tv.tv_sec = 0;
        mmd->afd.afhi.chunk_tv.tv_usec = 0;
        mmd->afd.afhi.seconds_total = 0;
        mmd->afd.afhi.chunk_tv.tv_sec = 0;
        mmd->afd.afhi.chunk_tv.tv_usec = 0;
@@ -648,18 +821,6 @@ static void vss_eof(struct vss_task *vsst)
        mmd->events++;
 }
 
        mmd->events++;
 }
 
-/**
- * Get the list of all supported audio formats.
- *
- * \return Aa space separated list of all supported audio formats
- * It is not allocated at runtime, i.e. there is no need to free
- * the returned string in the caller.
- */
-const char *supported_audio_formats(void)
-{
-       return SUPPORTED_AUDIO_FORMATS;
-}
-
 static int need_to_request_new_audio_file(struct vss_task *vsst)
 {
        struct timeval diff;
 static int need_to_request_new_audio_file(struct vss_task *vsst)
 {
        struct timeval diff;
@@ -678,6 +839,13 @@ static int need_to_request_new_audio_file(struct vss_task *vsst)
        return 1;
 }
 
        return 1;
 }
 
+static void set_mmd_offset(void)
+{
+       struct timeval offset;
+       tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
+       mmd->offset = tv2ms(&offset);
+}
+
 /**
  * Compute the timeout for the main select-loop of the scheduler.
  *
 /**
  * Compute the timeout for the main select-loop of the scheduler.
  *
@@ -695,7 +863,7 @@ static int need_to_request_new_audio_file(struct vss_task *vsst)
 static void vss_pre_select(struct sched *s, struct task *t)
 {
        int i;
 static void vss_pre_select(struct sched *s, struct task *t)
 {
        int i;
-       struct timeval *tv, diff;
+       struct timeval *tv;
        struct vss_task *vsst = container_of(t, struct vss_task, task);
 
        if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
        struct vss_task *vsst = container_of(t, struct vss_task, task);
 
        if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
@@ -703,10 +871,8 @@ static void vss_pre_select(struct sched *s, struct task *t)
                for (i = 0; senders[i].name; i++)
                        if (senders[i].shutdown_clients)
                                senders[i].shutdown_clients();
                for (i = 0; senders[i].name; i++)
                        if (senders[i].shutdown_clients)
                                senders[i].shutdown_clients();
-               list_for_each_entry_safe(fc, tmp, &fec_client_list, node) {
-                       fc->first_stream_chunk = -1;
-                       fc->error = 0;
-               }
+               list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
+                       fc->state = FEC_STATE_NONE;
                mmd->stream_start.tv_sec = 0;
                mmd->stream_start.tv_usec = 0;
        }
                mmd->stream_start.tv_sec = 0;
                mmd->stream_start.tv_usec = 0;
        }
@@ -722,6 +888,7 @@ static void vss_pre_select(struct sched *s, struct task *t)
                mmd->chunks_sent = 0;
                mmd->current_chunk = mmd->repos_request;
                mmd->new_vss_status_flags &= ~VSS_REPOS;
                mmd->chunks_sent = 0;
                mmd->current_chunk = mmd->repos_request;
                mmd->new_vss_status_flags &= ~VSS_REPOS;
+               set_mmd_offset();
        }
        if (need_to_request_new_audio_file(vsst)) {
                PARA_DEBUG_LOG("ready and playing, but no audio file\n");
        }
        if (need_to_request_new_audio_file(vsst)) {
                PARA_DEBUG_LOG("ready and playing, but no audio file\n");
@@ -735,8 +902,8 @@ static void vss_pre_select(struct sched *s, struct task *t)
                senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
        }
        tv = vss_compute_timeout(vsst);
                senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
        }
        tv = vss_compute_timeout(vsst);
-       if (tv && tv_diff(tv, &s->timeout, &diff) < 0)
-               s->timeout = *tv;
+       if (tv)
+               sched_request_timeout(tv, s);
 }
 
 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
 }
 
 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
@@ -773,16 +940,20 @@ static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
        return 1;
 }
 
        return 1;
 }
 
-static void recv_afs_result(struct vss_task *vsst)
+static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
 {
        int ret, passed_fd, shmid;
        uint32_t afs_code = 0, afs_data = 0;
        struct stat statbuf;
 
 {
        int ret, passed_fd, shmid;
        uint32_t afs_code = 0, afs_data = 0;
        struct stat statbuf;
 
-       vsst->afsss = AFS_SOCKET_READY;
+       if (!FD_ISSET(vsst->afs_socket, rfds))
+               return;
        ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
        ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
+       if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
+               return;
        if (ret < 0)
                goto err;
        if (ret < 0)
                goto err;
+       vsst->afsss = AFS_SOCKET_READY;
        PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
                afs_data);
        ret = -E_NOFD;
        PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
                afs_data);
        ret = -E_NOFD;
@@ -848,7 +1019,7 @@ static void vss_send(struct vss_task *vsst)
                        &due, 1) < 0)
                return;
        list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
                        &due, 1) < 0)
                return;
        list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
-               if (fc->error < 0)
+               if (fc->state == FEC_STATE_DISABLED)
                        continue;
                if (!next_slice_is_due(fc, NULL)) {
                        fec_active = 1;
                        continue;
                if (!next_slice_is_due(fc, NULL)) {
                        fec_active = 1;
@@ -857,10 +1028,9 @@ static void vss_send(struct vss_task *vsst)
                if (compute_next_fec_slice(fc, vsst) <= 0)
                        continue;
                PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
                if (compute_next_fec_slice(fc, vsst) <= 0)
                        continue;
                PARA_DEBUG_LOG("sending %d:%d (%u bytes)\n", fc->group.num,
-                       fc->current_slice_num, fc->fcp->max_slice_bytes);
-               fc->fcp->send((char *)fc->enc_buf,
-                       fc->fcp->max_slice_bytes,
-                       fc->fcp->private_data);
+                       fc->current_slice_num, fc->group.slice_bytes);
+               fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
+                       fc->group.slice_bytes + FEC_HEADER_SIZE);
                fc->current_slice_num++;
                fec_active = 1;
        }
                fc->current_slice_num++;
                fec_active = 1;
        }
@@ -876,11 +1046,9 @@ static void vss_send(struct vss_task *vsst)
                size_t len;
 
                if (!mmd->chunks_sent) {
                size_t len;
 
                if (!mmd->chunks_sent) {
-                       struct timeval tmp;
                        mmd->stream_start = *now;
                        mmd->stream_start = *now;
-                       tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
-                       mmd->offset = tv2ms(&tmp);
                        mmd->events++;
                        mmd->events++;
+                       set_mmd_offset();
                }
                /*
                 * We call the send function also in case of empty chunks as
                }
                /*
                 * We call the send function also in case of empty chunks as
@@ -910,14 +1078,17 @@ static void vss_post_select(struct sched *s, struct task *t)
                int num = mmd->sender_cmd_data.cmd_num,
                        sender_num = mmd->sender_cmd_data.sender_num;
 
                int num = mmd->sender_cmd_data.cmd_num,
                        sender_num = mmd->sender_cmd_data.sender_num;
 
-               if (senders[sender_num].client_cmds[num])
-                       senders[sender_num].client_cmds[num](&mmd->sender_cmd_data);
+               if (senders[sender_num].client_cmds[num]) {
+                       ret = senders[sender_num].client_cmds[num]
+                               (&mmd->sender_cmd_data);
+                       if (ret < 0)
+                               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+               }
                mmd->sender_cmd_data.cmd_num = -1;
        }
                mmd->sender_cmd_data.cmd_num = -1;
        }
-       if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE) {
-               if (FD_ISSET(vsst->afs_socket, &s->rfds))
-                       recv_afs_result(vsst);
-       } else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
+       if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
+               recv_afs_result(vsst, &s->rfds);
+       else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
                PARA_NOTICE_LOG("requesting new fd from afs\n");
                ret = send_buffer(vsst->afs_socket, "new");
                if (ret < 0)
                PARA_NOTICE_LOG("requesting new fd from afs\n");
                ret = send_buffer(vsst->afs_socket, "new");
                if (ret < 0)