+int av_get_image_linesize(enum PixelFormat pix_fmt, int width, int plane)
+{
+ const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[pix_fmt];
+ int max_step [4]; /* max pixel step for each plane */
+ int max_step_comp[4]; /* the component for each plane which has the max pixel step */
+ int s, i;
+
+ if (desc->flags & PIX_FMT_BITSTREAM)
+ return (width * (desc->comp[0].step_minus1+1) + 7) >> 3;
+
+ memset(max_step , 0, sizeof(max_step ));
+ memset(max_step_comp, 0, sizeof(max_step_comp));
+ for (i = 0; i < 4; i++) {
+ const AVComponentDescriptor *comp = &(desc->comp[i]);
+ if ((comp->step_minus1+1) > max_step[comp->plane]) {
+ max_step [comp->plane] = comp->step_minus1+1;
+ max_step_comp[comp->plane] = i;
+ }
+ }
+
+ s = (max_step_comp[plane] == 1 || max_step_comp[plane] == 2) ? desc->log2_chroma_w : 0;
+ return max_step[plane] * (((width + (1 << s) - 1)) >> s);
+}
+