Use the frame delay calculated by dav1id

common/decode.c

@@ -137,10 +137,7 @@ int open_decoder
                                          * For instance, when stream is encoded as AC-3,
                                          * AVCodecContext.codec_id might have been set to AV_CODEC_ID_EAC3
                                          * while AVCodec.id is set to AV_CODEC_ID_AC3. */
-    if( !strcmp( codec->name, "libdav1d" )
-     && (ret = av_opt_set_int( c->priv_data, "framethreads", 1, 0 )) < 0 )
-        goto fail;
-    else if( !strcmp( codec->name, "vp9" )
+    if( !strcmp( codec->name, "vp9" )
           && thread_count != 1
           && av_cpu_count() > 1 )
         c->thread_count = 2;
@@ -174,6 +171,8 @@ int open_decoder
     if( is_qsv_decoder( c->codec ) )
         if( (ret = do_qsv_decoder_workaround( c )) < 0 )
             goto fail;
+    if (!strcmp(codec->name, "libdav1d"))
+        c->thread_count = c->delay;
     *ctx = c;
     return ret;
 fail:

common/decode.h

@@ -25,7 +25,10 @@ static inline uint32_t get_decoder_delay
     AVCodecContext *ctx
 )
 {
-    return ctx->has_b_frames + ((ctx->active_thread_type & FF_THREAD_FRAME) ? ctx->thread_count - 1 : 0);
+    if (!strcmp(ctx->codec->name, "libdav1d"))
+        return ctx->delay;
+    else
+        return ctx->has_b_frames + ((ctx->active_thread_type & FF_THREAD_FRAME) ? ctx->thread_count - 1 : 0);
 }
 
 const AVCodec *find_decoder