* compile PNG only when ZLIB is available

Originally committed as revision 1609 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/allformats.c

@@ -75,7 +75,9 @@ void av_register_all(void)
     av_register_image_format(&ppm_image_format);
     av_register_image_format(&pgmyuv_image_format);
     av_register_image_format(&yuv_image_format);
+#ifdef CONFIG_ZLIB
     av_register_image_format(&png_image_format);
+#endif
     av_register_image_format(&jpeg_image_format);
     av_register_image_format(&gif_image_format);
 

libavformat/avformat.h

@@ -253,7 +253,9 @@ extern AVImageFormat pgm_image_format;
 extern AVImageFormat ppm_image_format;
 extern AVImageFormat pgmyuv_image_format;
 extern AVImageFormat yuv_image_format;
+#ifdef CONFIG_ZLIB
 extern AVImageFormat png_image_format;
+#endif
 extern AVImageFormat jpeg_image_format;
 extern AVImageFormat gif_image_format;
 

libavformat/png.c

@@ -18,6 +18,7 @@
  */
 #include "avformat.h"
 
+#ifdef CONFIG_ZLIB
 #include <zlib.h>
 
 //#define DEBUG
@@ -563,3 +564,4 @@ AVImageFormat png_image_format = {
     (1 << PIX_FMT_RGB24) | (1 << PIX_FMT_GRAY8) | (1 << PIX_FMT_MONOBLACK) | (1 << PIX_FMT_PAL8),
     png_write,
 };
+#endif