--- CV/CV.xs	2017/12/23 05:27:04	1.53
+++ CV/CV.xs	2018/07/30 22:55:46	1.57
@@ -22,6 +22,7 @@
 #include <assert.h>
 
 #if WEBP
+#include <webp/demux.h>
 #include <webp/decode.h>
 #endif
 
@@ -202,6 +203,7 @@
 }
 
 /////////////////////////////////////////////////////////////////////////////
+// memory source for libjpeg
 
 static void cv_ms_init (j_decompress_ptr cinfo)
 {
@@ -213,20 +215,26 @@
 
 static boolean cv_ms_fill (j_decompress_ptr cinfo)
 {
-  ERREXIT (cinfo, JERR_INPUT_EMPTY);
+  // unexpected EOF, warn and generate fake EOI marker
+
+  WARNMS (cinfo, JWRN_JPEG_EOF);
+
+  struct jpeg_source_mgr *src = (struct jpeg_source_mgr *)cinfo->src;
+
+  static const JOCTET eoi[] = { 0xFF, JPEG_EOI };
+
+  src->next_input_byte = eoi;
+  src->bytes_in_buffer = sizeof (eoi);
 
   return TRUE;
 }
 
 static void cv_ms_skip (j_decompress_ptr cinfo, long num_bytes)
 {
-  if (num_bytes > 0)
-    {
-      struct jpeg_source_mgr *src = (struct jpeg_source_mgr *)cinfo->src;
+  struct jpeg_source_mgr *src = (struct jpeg_source_mgr *)cinfo->src;
 
-      src->next_input_byte += num_bytes;
-      src->bytes_in_buffer -= num_bytes;
-    }
+  src->next_input_byte += num_bytes;
+  src->bytes_in_buffer -= num_bytes;
 }
 
 static void cv_jpeg_mem_src (j_decompress_ptr cinfo, void *buf, size_t buflen)
@@ -255,6 +263,7 @@
 
 PROTOTYPES: ENABLE
 
+# calculate the common prefix length of two strings
 # missing function in perl. really :)
 int
 common_prefix_length (a, b)
@@ -405,25 +414,34 @@
 	CODE:
 {
 #if WEBP
-        guchar *data;
 	STRLEN data_size;
         int alpha;
-	WebPDecoderConfig config;
+        WebPData data;
+        WebPDemuxer *demux;
+        WebPIterator iter;
+        WebPDecoderConfig config;
         int inw, inh;
 
-        data = SvPVbyte (image_data, data_size);
+        data.bytes = (uint8_t *)SvPVbyte (image_data, data_size);
+        data.size = data_size;
 
         perlinterp_release ();
 
         RETVAL = 0;
 
-	if (!WebPInitDecoderConfig (&config))
-          goto err;
+	if (!(demux = WebPDemux (&data)))
+          goto err_demux;
+
+        if (!WebPDemuxGetFrame (demux, 1, &iter))
+          goto err_iter;
+
+        if (!WebPInitDecoderConfig (&config))
+          goto err_iter;
 
         config.options.use_threads = 1;
 
-        if (WebPGetFeatures (data, data_size, &config.input) != VP8_STATUS_OK)
-          goto err;
+        if (WebPGetFeatures (iter.fragment.bytes, iter.fragment.size, &config.input) != VP8_STATUS_OK)
+          goto err_iter;
 
         inw = config.input.width;
         inh = config.input.height;
@@ -448,11 +466,11 @@
             ih = inh;
           }
 
-        alpha = config.input.has_alpha;
+        alpha = !!config.input.has_alpha;
 
-	RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, !!alpha, 8, iw, ih);
+	RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, alpha, 8, iw, ih);
         if (!RETVAL)
-          goto err;
+          goto err_iter;
 
         config.output.colorspace = alpha ? MODE_RGBA : MODE_RGB;
         config.output.u.RGBA.rgba   = gdk_pixbuf_get_pixels      (RETVAL);
@@ -460,14 +478,18 @@
         config.output.u.RGBA.size   = gdk_pixbuf_get_byte_length (RETVAL);
         config.output.is_external_memory = 1;
 
-        if (WebPDecode (data, data_size, &config) != VP8_STATUS_OK)
+        if (WebPDecode (iter.fragment.bytes, iter.fragment.size, &config) != VP8_STATUS_OK)
           {
             g_object_unref (RETVAL);
             RETVAL = 0;
-            goto err;
+            goto err_iter;
           }
 
-	err:
+	err_iter:
+        WebPDemuxReleaseIterator (&iter);
+	err_demux:
+        WebPDemuxDelete (demux);
+
         perlinterp_acquire ();
 #else
 	croak ("load_webp: webp not enabled at compile time");
@@ -507,6 +529,9 @@
             XSRETURN_UNDEF;
           }
 
+        if (!data_len)
+          longjmp (jerr.setjmp_buffer, 4);
+
         jpeg_create_decompress (&cinfo);
         cv_jpeg_mem_src (&cinfo, data, data_len);