fftools/ffmpeg_sched: allow encoders to send to multiple destinations

Will become useful in following commits.

fftools/ffmpeg_sched.c

@@ -104,7 +104,9 @@ typedef struct SchEnc {
     const AVClass      *class;
 
     SchedulerNode       src;
-    SchedulerNode       dst;
+    SchedulerNode      *dst;
+    uint8_t            *dst_finished;
+    unsigned         nb_dst;
 
     // [0] - index of the sync queue in Scheduler.sq_enc,
     // [1] - index of this encoder in the sq
@@ -134,7 +136,9 @@ typedef struct SchEnc {
     ThreadQueue        *queue;
     // tq_send() to queue returned EOF
     int                 in_finished;
-    int                 out_finished;
+
+    // temporary storage used by sch_enc_send()
+    AVPacket           *send_pkt;
 } SchEnc;
 
 typedef struct SchDemuxStream {
@@ -569,6 +573,11 @@ void sch_free(Scheduler **psch)
         SchEnc *enc = &sch->enc[i];
 
         tq_free(&enc->queue);
+
+        av_packet_free(&enc->send_pkt);
+
+        av_freep(&enc->dst);
+        av_freep(&enc->dst_finished);
     }
     av_freep(&sch->enc);
 
@@ -819,6 +828,10 @@ int sch_add_enc(Scheduler *sch, SchThreadFunc func, void *ctx,
 
     task_init(sch, &enc->task, SCH_NODE_TYPE_ENC, idx, func, ctx);
 
+    enc->send_pkt = av_packet_alloc();
+    if (!enc->send_pkt)
+        return AVERROR(ENOMEM);
+
     ret = queue_alloc(&enc->queue, 1, 0, QUEUE_FRAMES);
     if (ret < 0)
         return ret;
@@ -1048,9 +1061,14 @@ int sch_connect(Scheduler *sch, SchedulerNode src, SchedulerNode dst)
         enc = &sch->enc[src.idx];
         ms  = &sch->mux[dst.idx].streams[dst.idx_stream];
 
-        av_assert0(!enc->dst.type && !ms->src.type);
-        enc->dst = dst;
-        ms->src  = src;
+        av_assert0(!ms->src.type);
+
+        ret = GROW_ARRAY(enc->dst, enc->nb_dst);
+        if (ret < 0)
+            return ret;
+
+        enc->dst[enc->nb_dst - 1] = dst;
+        ms->src                   = src;
 
         break;
         }
@@ -1339,12 +1357,16 @@ int sch_start(Scheduler *sch)
                    "Encoder not connected to a source\n");
             return AVERROR(EINVAL);
         }
-        if (!enc->dst.type) {
+        if (!enc->nb_dst) {
             av_log(enc, AV_LOG_ERROR,
-                   "Encoder not connected to a sink\n");
+                   "Encoder not connected to any sink\n");
             return AVERROR(EINVAL);
         }
 
+        enc->dst_finished = av_calloc(enc->nb_dst, sizeof(*enc->dst_finished));
+        if (!enc->dst_finished)
+            return AVERROR(ENOMEM);
+
         ret = task_start(&enc->task);
         if (ret < 0)
             return ret;
@@ -1518,15 +1540,21 @@ static int send_to_enc_sq(Scheduler *sch, SchEnc *enc, AVFrame *frame)
     // TODO: consider a cleaner way of passing this information through
     //       the pipeline
     if (!frame) {
-        SchMux      *mux = &sch->mux[enc->dst.idx];
-        SchMuxStream *ms = &mux->streams[enc->dst.idx_stream];
+        for (unsigned i = 0; i < enc->nb_dst; i++) {
+            SchMux      *mux;
+            SchMuxStream *ms;
 
-        pthread_mutex_lock(&sch->schedule_lock);
 
-        ms->source_finished = 1;
-        schedule_update_locked(sch);
+            mux = &sch->mux[enc->dst[i].idx];
+            ms = &mux->streams[enc->dst[i].idx_stream];
 
-        pthread_mutex_unlock(&sch->schedule_lock);
+            pthread_mutex_lock(&sch->schedule_lock);
+
+            ms->source_finished = 1;
+            schedule_update_locked(sch);
+
+            pthread_mutex_unlock(&sch->schedule_lock);
+        }
     }
 
     pthread_mutex_lock(&sq->lock);
@@ -2080,20 +2108,64 @@ int sch_enc_receive(Scheduler *sch, unsigned enc_idx, AVFrame *frame)
     return ret;
 }
 
+static int enc_send_to_dst(Scheduler *sch, const SchedulerNode dst,
+                           uint8_t *dst_finished, AVPacket *pkt)
+{
+    int ret;
+
+    if (*dst_finished)
+        return AVERROR_EOF;
+
+    if (!pkt)
+        goto finish;
+
+    ret = send_to_mux(sch, &sch->mux[dst.idx], dst.idx_stream, pkt);
+    if (ret == AVERROR_EOF)
+        goto finish;
+
+    return ret;
+
+finish:
+    send_to_mux(sch, &sch->mux[dst.idx], dst.idx_stream, NULL);
+
+    *dst_finished = 1;
+
+    return AVERROR_EOF;
+}
+
 int sch_enc_send(Scheduler *sch, unsigned enc_idx, AVPacket *pkt)
 {
     SchEnc *enc;
     int ret;
+    unsigned nb_done = 0;
 
     av_assert0(enc_idx < sch->nb_enc);
     enc = &sch->enc[enc_idx];
 
-    if (enc->out_finished)
-        return pkt ? AVERROR_EOF : 0;
+    for (unsigned i = 0; i < enc->nb_dst; i++) {
+        uint8_t *finished = &enc->dst_finished[i];
+        AVPacket *to_send = pkt;
 
-    ret = send_to_mux(sch, &sch->mux[enc->dst.idx], enc->dst.idx_stream, pkt);
-    if (ret < 0)
-        enc->out_finished = 1;
+        // sending a packet consumes it, so make a temporary reference if needed
+        if (i < enc->nb_dst - 1) {
+            to_send = enc->send_pkt;
+
+            ret = av_packet_ref(to_send, pkt);
+            if (ret < 0)
+                return ret;
+        }
+
+        ret = enc_send_to_dst(sch, enc->dst[i], finished, to_send);
+        if (ret < 0) {
+            av_packet_unref(to_send);
+            if (ret == AVERROR_EOF) {
+                nb_done++;
+                ret = 0;
+                continue;
+            }
+            return ret;
+        }
+    }
 
     return ret;
 }
@@ -2101,10 +2173,17 @@ int sch_enc_send(Scheduler *sch, unsigned enc_idx, AVPacket *pkt)
 static int enc_done(Scheduler *sch, unsigned enc_idx)
 {
     SchEnc *enc = &sch->enc[enc_idx];
+    int ret = 0;
 
     tq_receive_finish(enc->queue, 0);
 
-    return send_to_mux(sch, &sch->mux[enc->dst.idx], enc->dst.idx_stream, NULL);
+    for (unsigned i = 0; i < enc->nb_dst; i++) {
+        int err = enc_send_to_dst(sch, enc->dst[i], &enc->dst_finished[i], NULL);
+        if (err < 0 && err != AVERROR_EOF)
+            ret = err_merge(ret, err);
+    }
+
+    return ret;
 }
 
 int sch_filter_receive(Scheduler *sch, unsigned fg_idx,