Merge commit 'meins/next' into next
[paraslash.git] / vss.c
diff --git a/vss.c b/vss.c
index 0801eeb089b05bf3e0f47aad86d953f5ecc4dee0..21f4cb4de07706f53591b3e7161f8c22a570ff24 100644 (file)
--- a/vss.c
+++ b/vss.c
@@ -11,7 +11,9 @@
  * senders.
  */
 
+#include <regex.h>
 #include <dirent.h>
+#include <osl.h>
 
 #include "para.h"
 #include "error.h"
@@ -87,38 +89,76 @@ struct vss_task {
        const char *header_buf;
        /** Length of the audio file header. */
        size_t header_len;
+       /** Time between audio file headers are sent. */
+       struct timeval header_interval;
 };
 
+/**
+ * The list of currently connected fec clients.
+ *
+ * Senders may use \ref vss_add_fec_client() to add entries to the list.
+ */
 static struct list_head fec_client_list;
 
-struct fec_slice {
-       uint8_t num;
-       uint16_t bytes;
-};
-
+/**
+ * Data associated with one FEC group.
+ *
+ * A FEC group consists of a fixed number of slices and this number is given by
+ * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
+ * group contains a number of chunks of the current audio file.
+ *
+ * FEC slices directly correspond to the data packages sent by the paraslash
+ * senders that use FEC. Each slice is identified by its group number and its
+ * number within the group. All slices have the same size, but the last slice
+ * of the group may not be filled entirely.
+ */
 struct fec_group {
+       /** The number of the FEC group. */
        uint32_t num;
+       /** Number of bytes in this group. */
        uint32_t bytes;
+       /** The first chunk of the current audio file belonging to the group. */
        uint32_t first_chunk;
+       /** The number of chunks contained in this group. */
        uint32_t num_chunks;
-       struct timeval duration;
+       /** When the first chunk was sent. */
        struct timeval start;
+       /** 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;
 };
 
+/**
+ * Describes one connected FEC client.
+ */
 struct fec_client {
+       /** If negative, this client is temporarily disabled. */
+       int error;
+       /** Parameters requested by the client. */
        struct fec_client_parms *fcp;
+       /** Used by the core FEC code. */
        struct fec_parms *parms;
+       /** The position of this client in the fec client list. */
        struct list_head node;
+       /** When the first slice for this client was sent. */
        struct timeval stream_start;
+       /** The first chunk sent to this FEC client. */
        int first_stream_chunk;
+       /** Describes the current group. */
        struct fec_group group;
-       struct fec_slice slice;
+       /** The current slice. */
+       uint8_t current_slice_num;
+       /** The data to be FEC-encoded (point to a region within the mapped audio file). */
        const unsigned char **src_data;
+       /** Last time an audio  header was sent. */
+       struct timeval next_header_time;
+       /** Used for the last source pointer of an audio file. */
        unsigned char *extra_src_buf;
-       size_t extra_src_buf_size;
+       /** Extra slices needed to store largest chunk + header. */
+       int num_extra_slices;
+       /** Contains the FEC-encoded data. */
        unsigned char *enc_buf;
-       size_t enc_buf_size;
 };
 
 /**
@@ -135,92 +175,211 @@ struct timeval *vss_chunk_time(void)
        return &mmd->afd.afhi.chunk_tv;
 }
 
-static void setup_fec_group(struct fec_client *fc, struct vss_task *vsst)
-{
-       uint32_t num_bytes = 0, chunk_num, max_group_size, last_payload_size;
-       int i, k = fc->fcp->data_slices_per_group;
-       const unsigned char *start_buf = NULL;
-       struct timeval tmp, *chunk_tv = vss_chunk_time();
-
-       assert(chunk_tv);
-       max_group_size = (fc->fcp->max_slice_bytes - FEC_HEADER_SIZE) * k;
-       chunk_num = fc->group.first_chunk;
-       for (;;) {
-               const unsigned char *buf;
-               size_t len;
-
-               if (chunk_num >= mmd->afd.afhi.chunks_total)
-                       break;
-               afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, (const char **)&buf, &len);
-               if (!start_buf)
-                       start_buf = buf;
-               if (num_bytes + len > max_group_size)
-                       break;
-               chunk_num++;
-               num_bytes += len;
-       }
-       assert(start_buf);
-       fc->group.num_chunks = chunk_num - fc->group.first_chunk;
-       fc->group.num++;
-       fc->group.bytes = num_bytes;
-       fc->slice.num = 0;
-       fc->slice.bytes = ROUND_UP(num_bytes, k) / k;
-
-       /* The last slice will not be fully used */
-       last_payload_size = num_bytes % fc->slice.bytes;
-       if (!last_payload_size)
-               last_payload_size = fc->slice.bytes;
-
-       tv_scale(fc->group.num_chunks, chunk_tv, &fc->group.duration);
-       tv_scale(fc->group.first_chunk - fc->first_stream_chunk, chunk_tv,
-               &tmp);
-       tv_add(&fc->stream_start, &tmp, &fc->group.start);
-       tv_divide(fc->fcp->slices_per_group, &fc->group.duration,
-               &fc->group.slice_duration);
-
-       for (i = 0; i < k; i++)
-               fc->src_data[i] = start_buf + i * fc->slice.bytes;
-
-       if ((char *)start_buf + k * fc->slice.bytes > vsst->map + mmd->size) {
-               /* can not use last slice as it goes beyond the map */
-               if (fc->extra_src_buf_size < fc->slice.bytes)
-                       fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->slice.bytes);
-               memcpy(fc->extra_src_buf, start_buf + (k - 1) * fc->slice.bytes,
-                       last_payload_size);
-               memset(fc->extra_src_buf + last_payload_size, 0,
-                       fc->slice.bytes - last_payload_size);
-               fc->src_data[k - 1] = fc->extra_src_buf;
-       }
-
-}
-
 /**
  * Write a fec header to a buffer.
  *
  * \param buf The buffer to write to.
  * \param h The fec header to write.
  */
-static void write_fec_header(struct fec_client *fc)
+static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
 {
        char *buf = (char *)fc->enc_buf;
+       struct fec_group *g = &fc->group;
+       struct fec_client_parms *p = fc->fcp;
 
        write_u32(buf, FEC_MAGIC);
 
-       write_u8(buf + 4, fc->fcp->slices_per_group);
-       write_u8(buf + 5, fc->fcp->data_slices_per_group);
-       write_u32(buf + 6, (uint32_t)0); /* audio header len */
+       write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
+       write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
+       write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
+
+       write_u32(buf + 10, g->num);
+       write_u32(buf + 14, g->bytes);
 
-       write_u32(buf + 10, fc->group.num);
-       write_u32(buf + 14, fc->group.bytes);
+       write_u8(buf + 18, fc->current_slice_num);
+       write_u16(buf + 20, p->max_slice_bytes - FEC_HEADER_SIZE);
+       write_u8(buf + 22, g->first_chunk? 0 : 1);
+       write_u8(buf + 23, vsst->header_len? 1 : 0);
+       memset(buf + 24, 0, 7);
+}
 
-       write_u8(buf + 18, fc->slice.num);
-       write_u16(buf + 20, fc->slice.bytes);
-       memset(buf + 22, 0, 11);
+static int 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);
+               return 0;
+       }
+       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;
+       tv_add(now, &vsst->header_interval, &fc->next_header_time);
+       return 1;
+}
+
+static int num_slices(long unsigned bytes, struct fec_client *fc, uint8_t *result)
+{
+       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 (!m)
+               return -E_BAD_CT;
+       rv = (bytes + m - 1) / m;
+       if (rv + redundant_slices > 255)
+               return -E_BAD_CT;
+       *result = rv;
+       return 1;
+}
+
+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;
+
+               ret = num_slices(largest, fc, &needed);
+               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;
+       } else {
+               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);
+       fc->current_slice_num = 0;
+
+       /* 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;
+       }
+
+       /* setup data slices */
+       buf = start_buf;
+       for (i = g->num_header_slices; i < k; i++) {
+               if (buf + 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.
+                        */
+                       break;
+               fc->src_data[i] = (const unsigned char *)buf;
+               buf += slice_bytes;
+       }
+       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;
+       }
+
+       /* setup group timing */
+       tv_scale(g->first_chunk - fc->first_stream_chunk, chunk_tv, &tmp);
+       tv_add(&fc->stream_start, &tmp, &g->start);
+       if (g->num) /* quick hack to avoid buffer underruns */
+               g->start.tv_sec--;
+       tv_scale(g->num_chunks, chunk_tv, &tmp); /* group duration */
+       tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
+               &tmp, &g->slice_duration);
+
+       PARA_DEBUG_LOG("FEC group %d: %d chunks (%d - %d), %d header slices, %d data slices\n",
+               g->num, g->num_chunks, g->first_chunk,
+               g->first_chunk + g->num_chunks - 1,
+               g->num_header_slices, data_slices
+       );
+       PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
+               tv2ms(&tmp), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
+       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
+                       == fc->fcp->slices_per_group + fc->num_extra_slices) {
+               int ret = setup_next_fec_group(fc, vsst);
+               if (ret == 0)
+                       return 0;
+               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;
+               }
+       }
+       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);
+       return 1;
 }
 
 /**
  * Return a buffer that marks the end of the stream.
  *
+ * \param buf Result pointer.
  * \return The length of the eof buffer.
  *
  * This is used for (multicast) udp streaming where closing the socket on the
@@ -228,37 +387,11 @@ static void write_fec_header(struct fec_client *fc)
  */
 size_t vss_get_fec_eof_packet(const char **buf)
 {
-       static const char fec_eof_packet[FEC_HEADER_SIZE] =
-       "\xec\x0d\xcc\xfe\0\0\0\0"
-       "\0\0\0\0\0\0\0\0"
-       "\0\0\0\0\0\0\0\0"
-       "\0\0\0\0\0\0\0\0";
+       static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
        *buf = fec_eof_packet;
        return FEC_HEADER_SIZE;
 }
 
-static void compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
-{
-       if (fc->first_stream_chunk < 0) {
-               fc->stream_start = *now;
-               fc->first_stream_chunk = mmd->current_chunk;
-               fc->group.first_chunk = mmd->current_chunk;
-               fc->group.num = 0;
-               setup_fec_group(fc, vsst);
-       } else if (fc->slice.num == fc->fcp->slices_per_group) {
-               fc->group.first_chunk += fc->group.num_chunks;
-               setup_fec_group(fc, vsst);
-
-       }
-       if (fc->enc_buf_size < fc->slice.bytes + FEC_HEADER_SIZE) {
-               fc->enc_buf_size = fc->slice.bytes + FEC_HEADER_SIZE;
-               fc->enc_buf = para_realloc(fc->enc_buf, fc->enc_buf_size);
-       }
-       write_fec_header(fc);
-       fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
-               fc->slice.num, fc->slice.bytes);
-}
-
 /**
  * Add one entry to the list of active fec clients.
  *
@@ -282,6 +415,10 @@ int vss_add_fec_client(struct fec_client_parms *fcp, struct fec_client **result)
                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);
        *result = fc;
        return 1;
@@ -295,7 +432,7 @@ err:
 /**
  * Remove one entry from the list of active fec clients.
  *
- * \param result The client to be removed.
+ * \param fc The client to be removed.
  */
 void vss_del_fec_client(struct fec_client *fc)
 {
@@ -321,7 +458,7 @@ static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
 
        if (fc->first_stream_chunk < 0)
                return 1;
-       tv_scale(fc->slice.num, &fc->group.slice_duration, &tmp);
+       tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
        tv_add(&tmp, &fc->group.start, &next);
        ret = tv_diff(&next, now, diff);
        return ret < 0? 1 : 0;
@@ -334,21 +471,38 @@ static void compute_slice_timeout(struct timeval *timeout)
        assert(vss_playing());
        list_for_each_entry(fc, &fec_client_list, node) {
                struct timeval diff;
-               int ret = next_slice_is_due(fc, &diff);
 
-               // PARA_NOTICE_LOG("diff: %lu, ret: %d\n", tv2ms(&diff), ret);
-               if (ret) {
+               if (fc->error < 0)
+                       continue;
+               if (next_slice_is_due(fc, &diff)) {
                        timeout->tv_sec = 0;
                        timeout->tv_usec = 0;
-                       goto out;
+                       return;
                }
                /* timeout = min(timeout, diff) */
                if (tv_diff(&diff, timeout, NULL) < 0)
                        *timeout = diff;
        }
+}
+
+static void set_eof_barrier(struct vss_task *vsst)
+{
+       struct fec_client *fc;
+       struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
+
+       if (!chunk_tv)
+               goto out;
+       list_for_each_entry(fc, &fec_client_list, node) {
+               struct timeval group_duration;
+
+               if (fc->error < 0)
+                       continue;
+               tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
+               if (tv_diff(&timeout, &group_duration, NULL) < 0)
+                       timeout = group_duration;
+       }
 out:
-       return;
-       PARA_NOTICE_LOG("slice timeout: %lu:%lu\n", (long unsigned)timeout->tv_sec, (long unsigned)timeout->tv_usec);
+       tv_add(now, &timeout, &vsst->eof_barrier);
 }
 
 /**
@@ -462,12 +616,11 @@ static struct timeval *vss_compute_timeout(struct vss_task *vsst)
 static void vss_eof(struct vss_task *vsst)
 {
 
-       mmd->stream_start = *now;
        if (!vsst->map)
                return;
        if (mmd->new_vss_status_flags & VSS_NOMORE)
                mmd->new_vss_status_flags = VSS_NEXT;
-       tv_add(&mmd->afd.afhi.eof_tv, now, &vsst->eof_barrier);
+       set_eof_barrier(vsst);
        para_munmap(vsst->map, mmd->size);
        vsst->map = NULL;
        mmd->chunks_sent = 0;
@@ -477,10 +630,6 @@ static void vss_eof(struct vss_task *vsst)
        mmd->afd.afhi.chunk_tv.tv_usec = 0;
        free(mmd->afd.afhi.chunk_table);
        mmd->afd.afhi.chunk_table = NULL;
-       free(mmd->afd.afhi.info_string);
-       mmd->afd.afhi.info_string = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_FILE_INFO],
-               status_item_list[SI_TAGINFO1], status_item_list[SI_TAGINFO2]);
-       make_empty_status_items(mmd->afd.verbose_ls_output);
        mmd->mtime = 0;
        mmd->size = 0;
        mmd->events++;
@@ -516,13 +665,8 @@ static int need_to_request_new_audio_file(struct vss_task *vsst)
        return 1;
 }
 
-
-
 /**
- * Compute the timeout for para_server's main select-loop.
- *
- * This function gets called from para_server to determine the timeout value
- * for its main select loop.
+ * Compute the timeout for the main select-loop of the scheduler.
  *
  * \param s Pointer to the server scheduler.
  * \param t Pointer to the vss task structure.
@@ -546,18 +690,22 @@ 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();
-               list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
+               list_for_each_entry_safe(fc, tmp, &fec_client_list, node) {
                        fc->first_stream_chunk = -1;
+                       fc->error = 0;
+               }
+               mmd->stream_start.tv_sec = 0;
+               mmd->stream_start.tv_usec = 0;
        }
        if (vss_next())
                vss_eof(vsst);
        else if (vss_paused()) {
                if (mmd->chunks_sent)
-                       tv_add(&mmd->afd.afhi.eof_tv, now, &vsst->eof_barrier);
+                       set_eof_barrier(vsst);
                mmd->chunks_sent = 0;
        } else if (vss_repos()) {
                tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
-               tv_add(&mmd->afd.afhi.eof_tv, now, &vsst->eof_barrier);
+               set_eof_barrier(vsst);
                mmd->chunks_sent = 0;
                mmd->current_chunk = mmd->repos_request;
                mmd->new_vss_status_flags &= ~VSS_REPOS;
@@ -604,9 +752,9 @@ static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
        for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
                if (cmsg->cmsg_level != SOL_SOCKET
                        || cmsg->cmsg_type != SCM_RIGHTS)
-               continue;
+                       continue;
                if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
-               continue;
+                       continue;
                *fd = *(int *)CMSG_DATA(cmsg);
        }
        return 1;
@@ -619,7 +767,6 @@ static void recv_afs_result(struct vss_task *vsst)
        struct stat statbuf;
 
        vsst->afsss = AFS_SOCKET_READY;
-       mmd->afd.afhi.chunk_table = NULL;
        ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
        if (ret < 0)
                goto err;
@@ -676,7 +823,7 @@ err:
  */
 static void vss_send(struct vss_task *vsst)
 {
-       int i;
+       int i, sent_something = 0;
        struct timeval due;
        struct fec_client *fc, *tmp_fc;
 
@@ -687,22 +834,39 @@ static void vss_send(struct vss_task *vsst)
        if (chk_barrier("data send", &vsst->data_send_barrier,
                        &due, 1) < 0)
                return;
+       list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
+               if (fc->error < 0)
+                       continue;
+               if (!next_slice_is_due(fc, NULL))
+                       continue;
+               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++;
+               sent_something = 1;
+       }
        if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
-               mmd->new_vss_status_flags |= VSS_NEXT;
+               if (!sent_something)
+                       mmd->new_vss_status_flags |= VSS_NEXT;
                return;
        }
-       if (!mmd->chunks_sent) {
-               struct timeval tmp;
-               mmd->stream_start = *now;
-               tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
-               mmd->offset = tv2ms(&tmp);
-               mmd->events++;
-       }
        compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
                &mmd->stream_start, &due);
        if (tv_diff(&due, now, NULL) <= 0) {
                const char *buf;
                size_t len;
+
+               if (!mmd->chunks_sent) {
+                       struct timeval tmp;
+                       mmd->stream_start = *now;
+                       tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
+                       mmd->offset = tv2ms(&tmp);
+                       mmd->events++;
+               }
                /*
                 * We call the send function also in case of empty chunks as
                 * they might have still some data queued which can be sent in
@@ -716,21 +880,9 @@ static void vss_send(struct vss_task *vsst)
                        senders[i].send(mmd->current_chunk, mmd->chunks_sent,
                                buf, len, vsst->header_buf, vsst->header_len);
                }
+               mmd->chunks_sent++;
+               mmd->current_chunk++;
        }
-       list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
-               if (!next_slice_is_due(fc, NULL))
-                       continue;
-               compute_next_fec_slice(fc, vsst);
-               PARA_DEBUG_LOG("sending %d:%d (%zu bytes)\n", fc->group.num,
-                       fc->slice.num, fc->slice.bytes);
-               fc->fcp->send((char *)fc->enc_buf,
-                       fc->slice.bytes + FEC_HEADER_SIZE,
-                       fc->fcp->private_data);
-               fc->slice.num++;
-       }
-       mmd->new_vss_status_flags |= VSS_PLAYING;
-       mmd->chunks_sent++;
-       mmd->current_chunk++;
 }
 
 static void vss_post_select(struct sched *s, struct task *t)
@@ -738,6 +890,7 @@ static void vss_post_select(struct sched *s, struct task *t)
        int ret, i;
        struct vss_task *vsst = container_of(t, struct vss_task, task);
 
+
        if (mmd->sender_cmd_data.cmd_num >= 0) {
                int num = mmd->sender_cmd_data.cmd_num,
                        sender_num = mmd->sender_cmd_data.sender_num;
@@ -752,7 +905,10 @@ static void vss_post_select(struct sched *s, struct task *t)
        } 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");
-               vsst->afsss = AFS_SOCKET_AFD_PENDING;
+               if (ret < 0)
+                       PARA_CRIT_LOG("%s\n", para_strerror(-ret));
+               else
+                       vsst->afsss = AFS_SOCKET_AFD_PENDING;
        }
        for (i = 0; senders[i].name; i++) {
                if (!senders[i].post_select)
@@ -782,12 +938,13 @@ void init_vss_task(int afs_socket)
                        conf.announce_time_arg : 300,
                autoplay_delay = conf.autoplay_delay_arg > 0?
                        conf.autoplay_delay_arg : 0;
-
+       vsst->header_interval.tv_sec = 5; /* should this be configurable? */
        vsst->afs_socket = afs_socket;
        vsst->task.pre_select = vss_pre_select;
        vsst->task.post_select = vss_post_select;
        ms2tv(announce_time, &vsst->announce_tv);
        PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
+       INIT_LIST_HEAD(&fec_client_list);
        for (i = 0; senders[i].name; i++) {
                PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
                senders[i].init(&senders[i]);
@@ -795,7 +952,6 @@ void init_vss_task(int afs_socket)
        free(hn);
        free(home);
        mmd->sender_cmd_data.cmd_num = -1;
-       make_empty_status_items(mmd->afd.verbose_ls_output);
        if (conf.autoplay_given) {
                struct timeval tmp;
                mmd->vss_status_flags |= VSS_PLAYING;
@@ -805,6 +961,5 @@ void init_vss_task(int afs_socket)
                tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
                        &vsst->data_send_barrier);
        }
-       INIT_LIST_HEAD(&fec_client_list);
        register_task(&vsst->task);
 }