vc-1: Optimise parser (with special attention to ARM)

[ffmpeg] / libavcodec / exif.c

diff --git a/libavcodec/exif.c b/libavcodec/exif.c
index 984adafd10e6de311c3812993c75724eaea73ce1..a980da2a7bed4370a9de0249ef461b27ec73f5ac 100644 (file)
--- a/libavcodec/exif.c
+++ b/libavcodec/exif.c
@@ -48,9 +48,11 @@ static int exif_add_metadata(AVCodecContext *avctx, int count, int type,
 {
     switch(type) {
     case TIFF_DOUBLE   : return ff_tadd_doubles_metadata(count, name, sep, gb, le, metadata);
-    case TIFF_SHORT    : return ff_tadd_shorts_metadata(count, name, sep, gb, le, metadata);
+    case TIFF_SSHORT   : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 1, metadata);
+    case TIFF_SHORT    : return ff_tadd_shorts_metadata(count, name, sep, gb, le, 0, metadata);
+    case TIFF_SBYTE    : return ff_tadd_bytes_metadata(count, name, sep, gb, le, 1, metadata);
     case TIFF_BYTE     :
-    case TIFF_UNDEFINED: return ff_tadd_bytes_metadata(count, name, sep, gb, le, metadata);
+    case TIFF_UNDEFINED: return ff_tadd_bytes_metadata(count, name, sep, gb, le, 0, metadata);
     case TIFF_STRING   : return ff_tadd_string_metadata(count, name, gb, le, metadata);
     case TIFF_SRATIONAL:
     case TIFF_RATIONAL : return ff_tadd_rational_metadata(count, name, sep, gb, le, metadata);
@@ -76,6 +78,11 @@ static int exif_decode_tag(AVCodecContext *avctx, GetByteContext *gbytes, int le
 
     ff_tread_tag(gbytes, le, &id, &type, &count, &cur_pos);
 
+    if (!bytestream2_tell(gbytes)) {
+        bytestream2_seek(gbytes, cur_pos, SEEK_SET);
+        return 0;
+    }
+
     // read count values and add it metadata
     // store metadata or proceed with next IFD
     ret = ff_tis_ifd(id);