int ff_framesync_request_frame(FFFrameSync *fs, AVFilterLink *outlink) { AVFilterContext *ctx = outlink->src; int input, ret; if ((ret = ff_framesync_process_frame(fs, 0)) < 0) return ret; if (ret > 0) return 0; if (fs->eof) return AVERROR_EOF; input = fs->in_request; ret = ff_request_frame(ctx->inputs[input]); if (ret == AVERROR_EOF) { if ((ret = ff_framesync_add_frame(fs, input, NULL)) < 0) return ret; if ((ret = ff_framesync_process_frame(fs, 0)) < 0) return ret; ret = 0; } return ret; }