avcodec/libdav1d: Use AVCodecInternal.in_pkt instead of stack packet

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/libdav1d.c

@@ -40,6 +40,9 @@
 typedef struct Libdav1dContext {
     AVClass *class;
     Dav1dContext *c;
+    /* This packet coincides with AVCodecInternal.in_pkt
+     * and is not owned by us. */
+    AVPacket *pkt;
     AVBufferPool *pool;
     int pool_size;
 
@@ -214,6 +217,8 @@ static av_cold int libdav1d_init(AVCodecContext *c)
 #endif
     int res;
 
+    dav1d->pkt = c->internal->in_pkt;
+
     av_log(c, AV_LOG_INFO, "libdav1d %s\n", dav1d_version());
 
     dav1d_default_settings(&s);
@@ -292,25 +297,26 @@ static int libdav1d_receive_frame(AVCodecContext *c, AVFrame *frame)
     int res;
 
     if (!data->sz) {
-        AVPacket pkt = { 0 };
+        AVPacket *const pkt = dav1d->pkt;
 
-        res = ff_decode_get_packet(c, &pkt);
+        res = ff_decode_get_packet(c, pkt);
         if (res < 0 && res != AVERROR_EOF)
             return res;
 
-        if (pkt.size) {
-            res = dav1d_data_wrap(data, pkt.data, pkt.size, libdav1d_data_free, pkt.buf);
+        if (pkt->size) {
+            res = dav1d_data_wrap(data, pkt->data, pkt->size,
+                                  libdav1d_data_free, pkt->buf);
             if (res < 0) {
-                av_packet_unref(&pkt);
+                av_packet_unref(pkt);
                 return res;
             }
 
-            data->m.timestamp = pkt.pts;
-            data->m.offset = pkt.pos;
-            data->m.duration = pkt.duration;
+            data->m.timestamp = pkt->pts;
+            data->m.offset    = pkt->pos;
+            data->m.duration  = pkt->duration;
 
-            pkt.buf = NULL;
-            av_packet_unref(&pkt);
+            pkt->buf = NULL;
+            av_packet_unref(pkt);
 
             if (c->reordered_opaque != AV_NOPTS_VALUE) {
                 uint8_t *reordered_opaque = av_malloc(sizeof(c->reordered_opaque));
@@ -329,7 +335,7 @@ static int libdav1d_receive_frame(AVCodecContext *c, AVFrame *frame)
                 }
             }
         } else if (res >= 0) {
-            av_packet_unref(&pkt);
+            av_packet_unref(pkt);
             return AVERROR(EAGAIN);
         }
     }