libavfilter/avfilter.c:319: error: Uninitialized Value
  The value read from src[_] was never initialized.

libavfilter/avfilter.c:319:17: 
317.                 ff_get_plane_bytewidth(link->format, link->cur_buf->w, i);
318. 
319.             if(!src[i]) continue;
                     ^
320. 
321.             for(j = 0; j < h >> (i==0 ? 0 : vsub); j ++) {

void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
{
    uint8_t *src[4], *dst[4];
    int i, j, vsub;
    void (*draw_slice)(AVFilterLink *, int, int, int);
    FF_DPRINTF_START(NULL, draw_slice); ff_dprintf_link(NULL, link, 0); dprintf(NULL, " y:%d h:%d dir:%d\n", y, h, slice_dir);
    if(link->src_buf) {
        vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
        for(i = 0; i < 4; i ++) {
            if(link->src_buf->data[i]) {
                src[i] = link->src_buf-> data[i] +
                    (y >> (i==0 ? 0 : vsub)) * link->src_buf-> linesize[i];
                dst[i] = link->cur_buf->data[i] +
                    (y >> (i==0 ? 0 : vsub)) * link->cur_buf->linesize[i];
            } else
                src[i] = dst[i] = NULL;
        }
        for(i = 0; i < 4; i ++) {
            int planew =
                ff_get_plane_bytewidth(link->format, link->cur_buf->w, i);
            if(!src[i]) continue;
            for(j = 0; j < h >> (i==0 ? 0 : vsub); j ++) {
                memcpy(dst[i], src[i], planew);
                src[i] += link->src_buf ->linesize[i];
                dst[i] += link->cur_buf->linesize[i];
            }
        }
    }
    if(!(draw_slice = link_dpad(link).draw_slice))
        draw_slice = avfilter_default_draw_slice;
    draw_slice(link, y, h, slice_dir);
}
['void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)\n{\n    uint8_t *src[4], *dst[4];\n    int i, j, vsub;\n    void (*draw_slice)(AVFilterLink *, int, int, int);\n    FF_DPRINTF_START(NULL, draw_slice); ff_dprintf_link(NULL, link, 0); dprintf(NULL, " y:%d h:%d dir:%d\\n", y, h, slice_dir);\n    if(link->src_buf) {\n        vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;\n        for(i = 0; i < 4; i ++) {\n            if(link->src_buf->data[i]) {\n                src[i] = link->src_buf-> data[i] +\n                    (y >> (i==0 ? 0 : vsub)) * link->src_buf-> linesize[i];\n                dst[i] = link->cur_buf->data[i] +\n                    (y >> (i==0 ? 0 : vsub)) * link->cur_buf->linesize[i];\n            } else\n                src[i] = dst[i] = NULL;\n        }\n        for(i = 0; i < 4; i ++) {\n            int planew =\n                ff_get_plane_bytewidth(link->format, link->cur_buf->w, i);\n            if(!src[i]) continue;\n            for(j = 0; j < h >> (i==0 ? 0 : vsub); j ++) {\n                memcpy(dst[i], src[i], planew);\n                src[i] += link->src_buf ->linesize[i];\n                dst[i] += link->cur_buf->linesize[i];\n            }\n        }\n    }\n    if(!(draw_slice = link_dpad(link).draw_slice))\n        draw_slice = avfilter_default_draw_slice;\n    draw_slice(link, y, h, slice_dir);\n}']