interplayvideo: Handle changed video dimensions on the fly

Signed-off-by: Martin Storsjö <martin@martin.st>

libavcodec/interplayvideo.c

@@ -1019,9 +1019,6 @@ static av_cold int ipvideo_decode_init(AVCodecContext *avctx)
 
     dsputil_init(&s->dsp, avctx);
 
-    /* decoding map contains 4 bits of information per 8x8 block */
-    s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
-
     s->current_frame.data[0] = s->last_frame.data[0] =
     s->second_last_frame.data[0] = NULL;
 
@@ -1036,6 +1033,9 @@ static int ipvideo_decode_frame(AVCodecContext *avctx,
     int buf_size = avpkt->size;
     IpvideoContext *s = avctx->priv_data;
 
+    /* decoding map contains 4 bits of information per 8x8 block */
+    s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
+
     /* compressed buffer needs to be large enough to at least hold an entire
      * decoding map */
     if (buf_size < s->decoding_map_size)
@@ -1096,6 +1096,6 @@ AVCodec ff_interplay_video_decoder = {
     .init           = ipvideo_decode_init,
     .close          = ipvideo_decode_end,
     .decode         = ipvideo_decode_frame,
-    .capabilities   = CODEC_CAP_DR1,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
     .long_name = NULL_IF_CONFIG_SMALL("Interplay MVE video"),
 };