dxa: make code independent of sizeof(AVFrame)

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/dxa.c

@@ -39,7 +39,7 @@
  * Decoder context
  */
 typedef struct DxaDecContext {
-    AVFrame prev;
+    AVFrame *prev;
 
     int dsize;
     uint8_t *decomp_buf;
@@ -229,7 +229,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac
 
     outptr = frame->data[0];
     srcptr = c->decomp_buf;
-    tmpptr = c->prev.data[0];
+    tmpptr = c->prev->data[0];
     stride = frame->linesize[0];
 
     if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
@@ -250,8 +250,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac
     case -1:
         frame->key_frame = 0;
         frame->pict_type = AV_PICTURE_TYPE_P;
-        if(c->prev.data[0])
-            memcpy(frame->data[0], c->prev.data[0], frame->linesize[0] * avctx->height);
+        if (c->prev->data[0])
+            memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);
         else{ // Should happen only when first frame is 'NULL'
             memset(frame->data[0], 0, frame->linesize[0] * avctx->height);
             frame->key_frame = 1;
@@ -279,19 +279,19 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPac
     case 13:
         frame->key_frame = 0;
         frame->pict_type = AV_PICTURE_TYPE_P;
-        if (!c->prev.data[0]) {
+        if (!c->prev->data[0]) {
             av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
             return AVERROR_INVALIDDATA;
         }
-        decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, c->prev.data[0]);
+        decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, c->prev->data[0]);
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
         return AVERROR_INVALIDDATA;
     }
 
-    av_frame_unref(&c->prev);
-    if ((ret = av_frame_ref(&c->prev, frame)) < 0)
+    av_frame_unref(c->prev);
+    if ((ret = av_frame_ref(c->prev, frame)) < 0)
         return ret;
 
     *got_frame = 1;
@@ -306,11 +306,14 @@ static av_cold int decode_init(AVCodecContext *avctx)
 
     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 
-    avcodec_get_frame_defaults(&c->prev);
+    c->prev = av_frame_alloc();
+    if (!c->prev)
+        return AVERROR(ENOMEM);
 
     c->dsize = avctx->width * avctx->height * 2;
     c->decomp_buf = av_malloc(c->dsize);
     if (!c->decomp_buf) {
+        av_frame_free(&c->prev);
         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
         return AVERROR(ENOMEM);
     }
@@ -323,7 +326,7 @@ static av_cold int decode_end(AVCodecContext *avctx)
     DxaDecContext * const c = avctx->priv_data;
 
     av_freep(&c->decomp_buf);
-    av_frame_unref(&c->prev);
+    av_frame_free(&c->prev);
 
     return 0;
 }