mjpegdec: use the AVFrame API properly.

libavcodec/mjpegdec.c

@@ -84,8 +84,12 @@ av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)
 {
     MJpegDecodeContext *s = avctx->priv_data;
 
-    if (!s->picture_ptr)
-        s->picture_ptr = &s->picture;
+    if (!s->picture_ptr) {
+        s->picture = av_frame_alloc();
+        if (!s->picture)
+            return AVERROR(ENOMEM);
+        s->picture_ptr = s->picture;
+    }
 
     s->avctx = avctx;
     ff_hpeldsp_init(&s->hdsp, avctx->flags);
@@ -1651,7 +1655,10 @@ av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)
     MJpegDecodeContext *s = avctx->priv_data;
     int i, j;
 
-    if (s->picture_ptr)
+    if (s->picture) {
+        av_frame_free(&s->picture);
+        s->picture_ptr = NULL;
+    } else if (s->picture_ptr)
         av_frame_unref(s->picture_ptr);
 
     av_free(s->buffer);

libavcodec/mjpegdec.h

@@ -84,7 +84,7 @@ typedef struct MJpegDecodeContext {
     int h_max, v_max; /* maximum h and v counts */
     int quant_index[4];   /* quant table index for each component */
     int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
-    AVFrame picture; /* picture structure */
+    AVFrame *picture; /* picture structure */
     AVFrame *picture_ptr; /* pointer to picture structure */
     int got_picture;                                ///< we found a SOF and picture is valid, too.
     int linesize[MAX_COMPONENTS];                   ///< linesize << interlaced