avcodec/noise_bsf: move the reference in the bsf internal buffer

There's no need to allocate a new packet for it.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/noise_bsf.c

@@ -35,45 +35,38 @@ typedef struct NoiseContext {
     unsigned int state;
 } NoiseContext;
 
-static int noise(AVBSFContext *ctx, AVPacket *out)
+static int noise(AVBSFContext *ctx, AVPacket *pkt)
 {
     NoiseContext *s = ctx->priv_data;
-    AVPacket *in;
     int amount = s->amount > 0 ? s->amount : (s->state % 10001 + 1);
     int i, ret = 0;
 
     if (amount <= 0)
         return AVERROR(EINVAL);
 
-    ret = ff_bsf_get_packet(ctx, &in);
+    ret = ff_bsf_get_packet_ref(ctx, pkt);
     if (ret < 0)
         return ret;
 
     if (s->dropamount > 0 && s->state % s->dropamount == 0) {
         s->state++;
-        av_packet_free(&in);
+        av_packet_unref(pkt);
         return AVERROR(EAGAIN);
     }
 
-    ret = av_new_packet(out, in->size);
+    ret = av_packet_make_writable(pkt);
     if (ret < 0)
         goto fail;
 
-    ret = av_packet_copy_props(out, in);
-    if (ret < 0)
-        goto fail;
-
-    memcpy(out->data, in->data, in->size);
-
-    for (i = 0; i < out->size; i++) {
-        s->state += out->data[i] + 1;
+    for (i = 0; i < pkt->size; i++) {
+        s->state += pkt->data[i] + 1;
         if (s->state % amount == 0)
-            out->data[i] = s->state;
+            pkt->data[i] = s->state;
     }
 fail:
     if (ret < 0)
-        av_packet_unref(out);
-    av_packet_free(&in);
+        av_packet_unref(pkt);
+
     return ret;
 }