avfilter/lavfutils: Avoid initializing packet

av_read_frame() can handle uninitialized packets.

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavfilter/lavfutils.c

@@ -35,8 +35,6 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     AVPacket pkt;
     AVDictionary *opt=NULL;
 
-    av_init_packet(&pkt);
-
     iformat = av_find_input_format("image2pipe");
     if ((ret = avformat_open_input(&format_ctx, filename, iformat, NULL)) < 0) {
         av_log(log_ctx, AV_LOG_ERROR,
@@ -89,6 +87,7 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     }
 
     ret = avcodec_decode_video2(codec_ctx, frame, &frame_decoded, &pkt);
+    av_packet_unref(&pkt);
     if (ret < 0 || !frame_decoded) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to decode image from file\n");
         if (ret >= 0)
@@ -107,7 +106,6 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, *pix_fmt, *w, *h);
 
 end:
-    av_packet_unref(&pkt);
     avcodec_free_context(&codec_ctx);
     avformat_close_input(&format_ctx);
     av_frame_free(&frame);