add version getters for decoder and encoder

WebPGetDecoderVersion() and WebPGetEncoderVersion()
will not return 0.1.2 encoded as 0x000102

dwebp and cwebp also have a new "-version" flag

Change-Id: I4fb4b5a8fc4e53681a386ff4b74fffb639fa237a

src/dec/vp8.c

@@ -16,6 +16,12 @@
 extern "C" {
 #endif
 
+//-----------------------------------------------------------------------------
+
+int WebPGetDecoderVersion() {
+  return (DEC_MAJ_VERSION << 16) | (DEC_MIN_VERSION << 8) | DEC_REV_VERSION;
+}
+
 //-----------------------------------------------------------------------------
 // VP8Decoder
 

src/dec/vp8i.h

@@ -22,6 +22,11 @@ extern "C" {
 //-----------------------------------------------------------------------------
 // Various defines and enums
 
+// version numbers
+#define DEC_MAJ_VERSION 0
+#define DEC_MIN_VERSION 1
+#define DEC_REV_VERSION 2
+
 #define ONLY_KEYFRAME_CODE      // to remove any code related to P-Frames
 
 // intra prediction modes

src/enc/vp8enci.h

@@ -23,6 +23,11 @@ extern "C" {
 //-----------------------------------------------------------------------------
 // Various defines and enums
 
+// version numbers
+#define ENC_MAJ_VERSION 0
+#define ENC_MIN_VERSION 1
+#define ENC_REV_VERSION 2
+
 // intra prediction modes
 enum { B_DC_PRED = 0,   // 4x4 modes
        B_TM_PRED = 1,

src/enc/webpenc.c

@@ -27,6 +27,12 @@ extern "C" {
 
 #define MAX_DIMENSION 16384   // maximum width/height allowed by the spec
 
+//-----------------------------------------------------------------------------
+
+int WebPGetEncoderVersion() {
+  return (ENC_MAJ_VERSION << 16) | (ENC_MIN_VERSION << 8) | ENC_REV_VERSION;
+}
+
 //-----------------------------------------------------------------------------
 // WebPPicture
 //-----------------------------------------------------------------------------

src/webp/decode.h

@@ -18,6 +18,10 @@
 extern "C" {
 #endif
 
+// Return the decoder's version number, packed in hexadecimal using 8bits for
+// each of major/minor/revision. E.g: v2.5.7 is 0x020507.
+int WebPGetDecoderVersion();
+
 // Retrieve basic header information: width, height.
 // This function will also validate the header and return 0 in
 // case of formatting error.

src/webp/encode.h

@@ -22,6 +22,10 @@ extern "C" {
 
 #define WEBP_ENCODER_ABI_VERSION 0x0001
 
+// Return the encoder's version number, packed in hexadecimal using 8bits for
+// each of major/minor/revision. E.g: v2.5.7 is 0x020507.
+int WebPGetEncoderVersion();
+
 //-----------------------------------------------------------------------------
 // One-stop-shop call! No questions asked: