bethsoftvideo: fix palette reading.

Return the correct number of consumed bytes and set *data_size = 0.
Returned size is 1 too small, leading to that 1 byte being read as the next
frame, which results in an extra blank frame at the beginning of the stream.

1 files changed, 8 insertions, 2 deletions

diff --git a/libavcodec/bethsoftvideo.c b/libavcodec/bethsoftvideo.c
index fa0457cc66..743e387cbe 100644
--- a/libavcodec/bethsoftvideo.c
+++ b/libavcodec/bethsoftvideo.c
@@ -59,7 +59,7 @@ static int set_palette(BethsoftvidContext *ctx)
         palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
     }
     ctx->frame.palette_has_changed = 1;
-    return 256*3;
+    return 0;
 }
 
 static int bethsoftvid_decode_frame(AVCodecContext *avctx,
@@ -86,7 +86,13 @@ static int bethsoftvid_decode_frame(AVCodecContext *avctx,
 
     switch(block_type = bytestream2_get_byte(&vid->g)){
         case PALETTE_BLOCK: {
-            return set_palette(vid);
+            int ret;
+            *data_size = 0;
+            if ((ret = set_palette(vid)) < 0) {
+                av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
+                return ret;
+            }
+            return bytestream2_tell(&vid->g);
         }
         case VIDEO_YOFF_P_FRAME:
             yoffset = bytestream2_get_le16(&vid->g);