ff_png_zalloc      67 libavcodec/png.h void *ff_png_zalloc(void *opaque, unsigned int items, unsigned int size);
ff_png_zalloc     403 libavcodec/pngdec.c     s->zstream.zalloc = ff_png_zalloc;
ff_png_zalloc     281 libavcodec/pngenc.c     s->zstream.zalloc = ff_png_zalloc;