avcodec/libx265: Allow user-supplied buffers

Here the packet size is known before allocating the packet,
so that supporting user-supplied buffers is trivial.

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/libx265.c

@@ -32,6 +32,7 @@
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avcodec.h"
+#include "encode.h"
 #include "internal.h"
 #include "packet_internal.h"
 
@@ -531,7 +532,7 @@ static int libx265_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     for (i = 0; i < nnal; i++)
         payload += nal[i].sizeBytes;
 
-    ret = ff_alloc_packet2(avctx, pkt, payload, payload);
+    ret = ff_get_encode_buffer(avctx, pkt, payload, 0);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Error getting output packet.\n");
         return ret;
@@ -687,6 +688,9 @@ AVCodec ff_libx265_encoder = {
     .long_name        = NULL_IF_CONFIG_SMALL("libx265 H.265 / HEVC"),
     .type             = AVMEDIA_TYPE_VIDEO,
     .id               = AV_CODEC_ID_HEVC,
+    .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY |
+                        AV_CODEC_CAP_OTHER_THREADS |
+                        AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
     .init             = libx265_encode_init,
     .init_static_data = libx265_encode_init_csp,
     .encode2          = libx265_encode_frame,
@@ -694,8 +698,6 @@ AVCodec ff_libx265_encoder = {
     .priv_data_size   = sizeof(libx265Context),
     .priv_class       = &class,
     .defaults         = x265_defaults,
-    .capabilities     = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_OTHER_THREADS |
-                        AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
     .caps_internal    = FF_CODEC_CAP_AUTO_THREADS,
     .wrapper_name     = "libx265",
 };