avfilter/lavfutils: remove usage of AVStream->codec

Signed-off-by: James Almer <jamrial@gmail.com>

libavfilter/lavfutils.c

@@ -29,6 +29,7 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
     AVFormatContext *format_ctx = NULL;
     AVCodec *codec;
     AVCodecContext *codec_ctx;
+    AVCodecParameters *par;
     AVFrame *frame;
     int frame_decoded, ret = 0;
     AVPacket pkt;
@@ -50,14 +51,27 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
         return ret;
     }
 
-    codec_ctx = format_ctx->streams[0]->codec;
-    codec = avcodec_find_decoder(codec_ctx->codec_id);
+    par = format_ctx->streams[0]->codecpar;
+    codec = avcodec_find_decoder(par->codec_id);
     if (!codec) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to find codec\n");
         ret = AVERROR(EINVAL);
         goto end;
     }
 
+    codec_ctx = avcodec_alloc_context3(codec);
+    if (!codec_ctx) {
+        av_log(log_ctx, AV_LOG_ERROR, "Failed to alloc video decoder context\n");
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    ret = avcodec_parameters_to_context(codec_ctx, par);
+    if (ret < 0) {
+        av_log(log_ctx, AV_LOG_ERROR, "Failed to copy codec parameters to decoder context\n");
+        goto end;
+    }
+
     av_dict_set(&opt, "thread_type", "slice", 0);
     if ((ret = avcodec_open2(codec_ctx, codec, &opt)) < 0) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to open codec\n");
@@ -96,7 +110,7 @@ int ff_load_image(uint8_t *data[4], int linesize[4],
 
 end:
     av_packet_unref(&pkt);
-    avcodec_close(codec_ctx);
+    avcodec_free_context(&codec_ctx);
     avformat_close_input(&format_ctx);
     av_frame_free(&frame);
     av_dict_free(&opt);