lavfi: support hwdec filters for --lavfi-complex

Not so important by itself, but important for when we replace the vf
libavfilter wrapper with the common implementation. (Which will
hopefully happen, but not too soon.)

player/lavfi.c

@@ -40,6 +40,7 @@
 #include "video/mp_image.h"
 #include "audio/fmt-conversion.h"
 #include "video/fmt-conversion.h"
+#include "video/hwdec.h"
 
 #include "lavfi.h"
 
@@ -52,6 +53,8 @@ struct lavfi {
     struct mp_log *log;
     char *graph_string;
 
+    struct mp_hwdec_devices *hwdec_devs;
+
     AVFilterGraph *graph;
     // Set to true once all inputs have been initialized, and the graph is
     // linked.
@@ -423,6 +426,7 @@ static bool init_pads(struct lavfi *c)
                 params->height = pad->in_fmt_v->h;
                 params->sample_aspect_ratio.num = pad->in_fmt_v->params.p_w;
                 params->sample_aspect_ratio.den = pad->in_fmt_v->params.p_h;
+                params->hw_frames_ctx = pad->in_fmt_v->hwctx;
                 filter_name = "buffer";
             } else {
                 assert(0);
@@ -471,6 +475,11 @@ static void dump_graph(struct lavfi *c)
 #endif
 }
 
+void lavfi_set_hwdec_devs(struct lavfi *c, struct mp_hwdec_devices *hwdevs)
+{
+    c->hwdec_devs = hwdevs;
+}
+
 // Initialize the graph if all inputs have formats set. If it's already
 // initialized, or can't be initialized yet, do nothing.
 static void init_graph(struct lavfi *c)
@@ -478,6 +487,15 @@ static void init_graph(struct lavfi *c)
     assert(!c->initialized);
 
     if (init_pads(c)) {
+        if (c->hwdec_devs) {
+            struct mp_hwdec_ctx *hwdec = hwdec_devices_get_first(c->hwdec_devs);
+            for (int n = 0; n < c->graph->nb_filters; n++) {
+                AVFilterContext *filter = c->graph->filters[n];
+                if (hwdec && hwdec->av_device_ref)
+                    filter->hw_device_ctx = av_buffer_ref(hwdec->av_device_ref);
+            }
+        }
+
         // And here the actual libavfilter initialization happens.
         if (avfilter_graph_config(c->graph, NULL) < 0) {
             MP_FATAL(c, "failed to configure the filter graph\n");

player/lavfi.h

@@ -22,6 +22,7 @@ bool lavfi_get_connected(struct lavfi_pad *pad);
 bool lavfi_process(struct lavfi *c);
 bool lavfi_has_failed(struct lavfi *c);
 void lavfi_seek_reset(struct lavfi *c);
+void lavfi_set_hwdec_devs(struct lavfi *c, struct mp_hwdec_devices *hwdevs);
 int lavfi_request_frame_a(struct lavfi_pad *pad, struct mp_audio **out_aframe);
 int lavfi_request_frame_v(struct lavfi_pad *pad, struct mp_image **out_vframe);
 bool lavfi_needs_input(struct lavfi_pad *pad);

player/video.c

@@ -496,6 +496,9 @@ int reinit_video_chain_src(struct MPContext *mpctx, struct lavfi_pad *src)
 
     vo_c->hwdec_devs = vo_c->vo->hwdec_devs;
 
+    if (mpctx->lavfi)
+        lavfi_set_hwdec_devs(mpctx->lavfi, vo_c->hwdec_devs);
+
     vo_c->filter_src = src;
     if (!vo_c->filter_src) {
         vo_c->track = track;