mss2: make code independent of sizeof(AVFrame)

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

libavcodec/mss2.c

@@ -34,7 +34,7 @@
 typedef struct MSS2Context {
     VC1Context     v;
     int            split_position;
-    AVFrame        last_pic;
+    AVFrame       *last_pic;
     MSS12Context   c;
     MSS2DSPContext dsp;
     SliceContext   sc[2];
@@ -523,8 +523,8 @@ static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
         return AVERROR_INVALIDDATA;
 
     avctx->pix_fmt = is_555 ? AV_PIX_FMT_RGB555 : AV_PIX_FMT_RGB24;
-    if (ctx->last_pic.format != avctx->pix_fmt)
-        av_frame_unref(&ctx->last_pic);
+    if (ctx->last_pic->format != avctx->pix_fmt)
+        av_frame_unref(ctx->last_pic);
 
     if (has_wmv9) {
         bytestream2_init(&gB, buf, buf_size + ARITH2_PADDING);
@@ -601,18 +601,18 @@ static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
         if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
             return ret;
 
-        if (ctx->last_pic.data[0]) {
-            av_assert0(frame->linesize[0] == ctx->last_pic.linesize[0]);
-            c->last_rgb_pic = ctx->last_pic.data[0] +
-                              ctx->last_pic.linesize[0] * (avctx->height - 1);
+        if (ctx->last_pic->data[0]) {
+            av_assert0(frame->linesize[0] == ctx->last_pic->linesize[0]);
+            c->last_rgb_pic = ctx->last_pic->data[0] +
+                              ctx->last_pic->linesize[0] * (avctx->height - 1);
         } else {
             av_log(avctx, AV_LOG_ERROR, "Missing keyframe\n");
             return AVERROR_INVALIDDATA;
         }
     } else {
-        if ((ret = ff_reget_buffer(avctx, &ctx->last_pic)) < 0)
+        if ((ret = ff_reget_buffer(avctx, ctx->last_pic)) < 0)
             return ret;
-        if ((ret = av_frame_ref(frame, &ctx->last_pic)) < 0)
+        if ((ret = av_frame_ref(frame, ctx->last_pic)) < 0)
             return ret;
 
         c->last_rgb_pic = NULL;
@@ -726,8 +726,8 @@ static int mss2_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
         av_log(avctx, AV_LOG_WARNING, "buffer not fully consumed\n");
 
     if (c->mvX < 0 || c->mvY < 0) {
-        av_frame_unref(&ctx->last_pic);
-        ret = av_frame_ref(&ctx->last_pic, frame);
+        av_frame_unref(ctx->last_pic);
+        ret = av_frame_ref(ctx->last_pic, frame);
         if (ret < 0)
             return ret;
     }
@@ -802,7 +802,7 @@ static av_cold int mss2_decode_end(AVCodecContext *avctx)
 {
     MSS2Context *const ctx = avctx->priv_data;
 
-    av_frame_unref(&ctx->last_pic);
+    av_frame_free(&ctx->last_pic);
 
     ff_mss12_decode_end(&ctx->c);
     av_freep(&ctx->c.pal_pic);
@@ -820,10 +820,11 @@ static av_cold int mss2_decode_init(AVCodecContext *avctx)
     c->avctx = avctx;
     if (ret = ff_mss12_decode_init(c, 1, &ctx->sc[0], &ctx->sc[1]))
         return ret;
+    ctx->last_pic   = av_frame_alloc();
     c->pal_stride   = c->mask_stride;
     c->pal_pic      = av_mallocz(c->pal_stride * avctx->height);
     c->last_pal_pic = av_mallocz(c->pal_stride * avctx->height);
-    if (!c->pal_pic || !c->last_pal_pic) {
+    if (!c->pal_pic || !c->last_pal_pic || !ctx->last_pic) {
         mss2_decode_end(avctx);
         return AVERROR(ENOMEM);
     }